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Steps of specimen processing
inoculation, incubation, isolation, inspection, identification
Results are only as good as:
The specimen you collect.
Define inoculation.
Introducing tiny sample to proper growth medium.
What is a “culture”?
Any observable growth of sample on medium.
What main condition must be met to do inoculations?
sterile environment
What is incubation?
the proper time and other conditions and time to encourage microbe growth.
What is “isolation” in the context of microbiology?
growth of a single species of microbe.
What are the steps in isolation?
Separate one cell from group. Allow to grow. Obtain mass of cells (colony).
What are the methods used in isolation?
streak plate (great when you know you have a good sample), pour plate - loop dilution, spread plate (not sure how much you have, spread sample every.)
Discuss growth media.
Provides nutrients for microbes. Must meet nutritional needs of organism. Three classifications of media: physical states, chemical composition, functional type.
What are possible physical states of media?
Broth - liquid. Agar - solid (solidifies at 42 degrees C), semi-solid (1/2 agar content) - this shows mobility.
What are the types of chemical media?
Synthetic - exact formula. Complex (non-synthetic) - at least one ingredient not chemically definable and composition varies slightly from batch to batch.
Discuss media grouped by function.
General purpose media - grows broad spectrum microbes -- non-synthetic. Enriched media provides special growth factors for fastidious microbes.
Define selective media.
Inhibits growth of some organisms but not others.
Define differential media.
Grows several types of microbes but gives different colonial morphology - groups.
What are some misc media?
Reducing media. transport media (for specimens that don’t keep well - don’t support much growth, but preserves), fermentation media (can tell conditions by ph), assay media, enumeration media (enables you to count organisms).
(some organisms won’t grow on artificial media. How do they grow these?
On live cultures.
Most microbes grow best at what temperature.
20-40 C (room to body temperature)
What is a pure culture?
Only one species
What is a mixed culture?
Contains two or more separate species. (easily separated and identified)
What is a contaminated culture?
Unwanted microbes.
How do you identify species through inspection?
How they look (color, texture, growth patterns, etc)
How can you identify species scientifically?
Biochemical tests, DNA analysis
What’s the most important lab tool?
microscope
What are types of microscopes?
Bright-field or compound light - object appears dark, so good for using stained material. Dark-field - used if they don’t take up stain well or ones that are distorted by the stain.Phase-contrast and Interference m’scopes (light passes thru specimen for more refraction. Eye can tell the difference. Highlights subtle difference (best for viewing live objects. Differential interference contrast m’scope - gives a more detailed view (3D). Fluorescent (uses UV light and fluorescent dyes. Dyes can be tagged to antibodies to make a stain specific for an organism. Electron M’scope - Uses electron beam. Highest magnification possible. Used to view viruses and cellular organelles. Scanning 3D 100,000x or even a million!
Discuss fixed smears.
Spread thin suspension of cells on slide. allow to air dry. Fix by heat or chemical - heat fixation - kills cells, adheres to sides.
Steps to prepare specimens for viewing.
Wet mount (view living material, slide and coverslip). Hanging drop slide (uses depression slide and sealant. Keeps alive longer)
Discuss staining.
Apply dyes to cells for visualization. Negative stains (stain is a background and cells stand out as unstained. Nigrosin or India Ink. Shows cell morphology and presence of capsules. In positive stains, the cells are stained with plain background, simple stains (all cells one color) differential
What is a common differential stain?
Gram stain - apply one stain, wash with water, apply one stain, wash with alcohol. Usually purple/blue in gram positive. Gram negative cells. Acid-fast stain - double washing, again. Endospore stain.
What do “special stains” do?
They stain only certain structures.
What are the two categories of chemistry?
Inorganic (all elements, small molecules) and organic
Discuss Inorganic Chemistry.
small molecules, covalent or ionic bonds, carbon or hydrogen, NOT BOTH, water, acids, bases, salts
Discuss Organic Chemistry.
Carbon and hydrogen (hydrocarbons)- originally, they were thought to only come from living system. Large, complex molecules, contain covalent bonds only, (usually non-polar), most are macromolecules or polymers.
What are the macromolecules of life?
Carbohydrates, Lipids, Proteins, Nucleic acids
What is our primary fuel source?
Carbohydrates
What is the most effective fuel storage?
Lipids.
What is matter?
Takes up space and has mass.
What are the three forms of matter?
Solid, liquid, gas
What is an atom?
Smallest piece of something that's still that!
What are the three subatomic particles?
Positive protons, negative electric, neutral neutrons
Atomic number is:
Number of the protons.
Atomic mass is:
Protons + neutrons.
What is an element?
Substance composed of only one kind of atom.
What is a compound?
Two or more different kinds of atom in a fixed ration.
What is a molecule?
Two or more atoms held together by covalent bonds.
Which elements don't typically form bonds?
Noble gases - those with 2 + multiple of 8.
What is valence?
Number of electrons in outer shell.
Discuss chemical bonds.
Depends on valence (# of electrons in outer shell), determines activity of atom, atoms combine to fill outer shell, outer shell full with 8 electrons (except first level which holds 2).
Discuss covalent bonds.
Sharing electrons in an effort to fill outer shell. May share 1-3 electrons. Non polar covalent bonds have equal sharing. Polar covalent bond - sharing electrons unequally, causes each end to be charged slightly differently.
Discuss ionic bonds.
Sharing so strong, it rips one electron away, now it's charged.
What is a cation?
An atom that looses an electron and becomes positive.
What is an anion?
An atom that gains an electron, becoming negative.
What is an electrolyte?
A salt dissolved in water that can conduct electricity.
Discuss hydrogen bonds.
Are weak chemical attraction between polar molecules. Polar molecules that contain hydrogen. Oxygen and nitrogen bond to hydrogen.
Discuss electron transfer.
Oxidation/reduction - cellular work requires energy. Energy is stored in chemical bonds and then released through electron transfer (redox).
Leo Ger
Losing electrons is oxidation. Gaining electrons is reduction.
Chemical equations a similar to:
Math equations. Reactants --> Products
What is a synthesis reaction?
Building - requires energy.
What is a decomposition reaction?
Taking apart - releases energy.
What is an exchange reaction?
Switching ingredients around to make new compounds.
What is a reverse able reaction?
Most are. Compound can change, then change back.
What is a solution?
Uniformly dispersed molecules. Chemical connection.
What is a solute?
Dispersed substance.
What is a solvent?
Dissolving medium.
Hydrophilic vs. Hydrophobic
Water-loving vs. Water-fearing.
Discuss pH.
Hs to do with the hydrogen ion concentration. A way of measuring the acidity or baseness of a solution.
What do proteins do primarily?
Structural and functional
What do nucleic acids do?
They store and release instructions/information for what the organism will be.
Discuss carbohydrates.
Atoms are C,H,O - (1)C(1)H(2)O, monomers=monosaccharide, glycosidic bonds --> polysaccharides, Functions as structural support, cellulose, chitin, peptidoglycan, agar - The storage/energy are starch and glycogen
Discuss Woese-Fox Classification system.
They replaced Whittaker’s 5 kingdoms with a type of super kingdom - archaea, bacteria, eukaria
Discuss archaea.
Methane produces, halophiles, thromophiles
Discuss bacteria
Blue green bacteria, eubacteria, chlamydias, ricketesias
Viruses aren’t in classification system because
They’re not true life.
Discuss Lipids.
Atoms are C, H, O.... neutral fat (triglyceride), Glycerol + 3 fatty acids. Ester bonds, function - concentrated energy source.
Discuss viruses.
Not cells, can’t appropriately classify, have separate classification system.
What are some other lipid molecules?
Phospholipids, Cholesterol, prostaglandins
Discuss phospholipids.
Glycerol + 2 fatty acids + phosphate, major component of cell membrane.
Discuss Cholesterol (Steroids)
4 carbon rings - membrane stability.
What are prostaglandins?
local hormones
Discuss proteins.
Atoms are C,H,O, N (most contain some amount of sulfur). Monomers are amino acids. Peptide bonds. Polypeptide folded into a specific 3-D shape (only a protein when shaped).
What are the levels of protein structure?
Primary - amino acid sequence (covalent bonds). Secondary - Hydrogen bonds producing pleated sheet or alpha helix (hydrogen bonds, too). Tertiary - folding based on other covalent, hydrogen, and ionic bonds, all twisted and held in shape by multiple types of bonds. Quaternary - 2 or more different polypeptide chains formed together to make larger proteins.
Define denaturation.
altering of protein shape - totally changes or destroys function.
What are enzymes?
They catalyze reactions - must recognize specific substrate.
What are antibodies?
Immune guys.
Discuss nucleic acids.
Atoms are C,H,O,N, P. Monomer is nucleotide - pentose (5 carbon sugar), phosphate, Nitrogen containing base. Function - info - genetic info storage and retrieval.
What are the nitrogen containing bases in DNA?
Guanine, Cytosine, Thymine, Adenine
Who discovered Double Helix?
Watson & Crick
What rule is DNA/RNA replication based on?
A-T, C-G pairing.
What are the nitrogen containing bases in RNA?
Adenine-Uracil, Guanine-Cytosine.
What is ATP?
Adenosine Triphosphate - the only energy a cell can use. All fuel used make ATP molecule. Adenine + 2 more phosphates
How does micro differ from biology?
The study of tiny living things - small life forms. Most not visible.
"What percentage of life is ""micro""?"
Almost 90%
Discuss the scope of microbiology.
Bacteria, Viruses, Fungi, Protozoa, Algae, Helminths (worms)
What a other connected areas to micro?
Immunology, epidemiology, food micro (dairy/aquatic, etc), agricultural micro,
Define epidemiology.
Study of infection spread and control.
Discuss microbial interaction with humans.
It's ubiquitous, involved in nutrient and energy flow, (photosynthesis by microbes, decomposition), Genetic engineering, bioremediaton (naturally cleaning up our own messes), pathogens and normal flora.
Discuss the types of microorganisms.
Prokaryotic cells (simple, no nucleus or other membrane bound organelles), Eucaryotic cells (more complex, nucleated), viruses (sort of alive... Not cells, 2 molecules? Just particles of protein + nucleic acid).
What does micro usually measure in?
Micrometer 10 to -6 of a meter (bacteria). Nanometers are 10 to -9 (viruses)
Discuss microbes.
Many are free-living, going around, obtaining nutrients from environment. Some are parasites - where one species benefits off host, host is harmed. Some species can exist both ways just fine.
Define hypothesis.
An educated guess.
What is a theory?
Beyond a guess... A way if thinking of something with. A lot of scientific weight behind it.
Discuss deductive reasoning.
Form hypothesis, then test. Measure consequences of each variable. Have control groups (where you didn't change anything). Sort data, form conclusion.
In order for results to be valid they have to be:
Reproduceable!
If a theory is tested and seemingly proven over and over, you have a:
Law
What theories/things are Pasteur responsible for?
Theory of biogenies, Germ theory of disease, Germ theory of fermentation, Pasteurization. Immunology. Cleanliness in treating patients.
What is Semmelweis known for?
Hand washing.
What is Joeseph Lister?
Clean hands, sterile surgical tools, clean clothes. Asceptic surgery.
What was Koch known for?
Koch's Postulates. First to connect certain germs with certain diseases. Pure culture techniques.
What was Linnaeus known for?
Taxonomy - domain, Kingdom, phylum or division, class, order, family, genus, species. Dumb King Phillip came over for good spaghetti.
Scientific naming.
"Binomial nomenclature (two scientific names for each organism), (it avoids common names which may be misunderstood in various regions.) First part is the genus, second part is species. Always capitalize genus name. Second word is the ""Specific epithet"" and is not capitalized. Both words is always underlined or italicized."
Discuss Woese-Fox classification system.
They replaced Whittakerr's 5 kingdoms with a type of super kingdom - archaea, bactia, eukarua
Discuss archaea.
Methane producers, halophiles, thrrmophiles
Discuss bacteria
Blue green Bactria, eubacteria, chlamydias, ricketesias
Viruses aren't in classification systems because
They're not true life.
Discuss viruses.
Not cells, can't appropriately classify, have separate classification system.
What is matter?
Takes up space and has mass.
What are the three forms of matter?
Solid, liquid, gas
What is an atom?
Smallest piece of something that's still that!
What are the three subatomic particles?
Positive protons, negative electric, neutral neutrons
Atomic number is:
Number of the protons.
Atomic mass is:
Protons + neutrons.
What is an element?
Substance composed of only one kind of atom.
What is a compound?
Two or more different kinds of atom in a fixed ration.
What is a molecule?
Two or more atoms held together by covalent bonds.
Which elements don't typically form bonds?
Noble gases - those with 2 + multiple of 8.
What is valence?
Number of electrons in outer shell.
Discuss chemical bonds.
Depends on valence (# of electrons in outer shell), determines activity of atom, atoms combine to fill outer shell, outer shell full with 8 electrons (except first level which holds 2).
Discuss covalent bonds.
Sharing electrons in an effort to fill outer shell. May share 1-3 electrons. Non polar covalent bonds have equal sharing. Polar covalent bond - sharing electrons unequally, causes each end to be charged slightly differently.
Discuss ionic bonds.
Sharing so strong, it rips one electron away, now it's charged.
What is a cation?
An atom that looses an electron and becomes positive.
What is an anion?
An atom that gains an electron, becoming negative.
What is an electrolyte?
A salt dissolved in water that can conduct electricity.
Discuss hydrogen bonds.
Are weak chemical attraction between polar molecules. Polar molecules that contain hydrogen. Oxygen and nitrogen bond to hydrogen.
Discuss electron transfer.
Oxidation/reduction - cellular work requires energy. Energy is stored in chemical bonds and then released through electron transfer (redox).
Leo Ger
Losing electrons is oxidation. Gaining electrons is reduction.
Chemical equations a similar to:
Math equations. Reactants --> Products
What is a synthesis reaction?
Building - requires energy.
What is a decomposition reaction?
Taking apart - releases energy.
What is an exchange reaction?
Switching ingredients around to make new compounds.
What is a reverse able reaction?
Most are. Compound can change, then change back.
What is a solution?
Uniformly dispersed molecules. Chemical connection.
What is a solute?
Dispersed substance.
What is a solvent?
Dissolving medium.
Hydrophilic vs. Hydrophobic
Water-loving vs. Water-fearing.
Discuss pH.
Has to do with the hydrogen ion concentration. A way of measuring the acidity or baseness of a solution.
Method used to obtain isolated colonies is the:
Streak plate and pour plate.
know stains better
Define synthetic media.
Exact chemical composition.
Define non-synthetic media.
Natural - potential unknown ingredient.
List cellular characteristics that are common to prokaryotic and eukaryotic cells.
1. Cytoplasm 2. Cell membrane 3. DNA 4. Ribosomes
What do ribosomes do?
Synthesize protein.
What are two characteristics unique to eukaryotic cells?
Nucleus, organelles
List characteristics of life.
1. Growth and development 2. Reproduction and heredity 3. Metabolism (energy utilization) 4. Movement (response to stimuli) 5. Cell support, protection, storage - ordered structure 6. Transports materials in and out of cell 7.
Discuss the structures of the prokaryotic cell.
External - appendages (motility or attachment); glycocalyx (slime layer or capsule). Cell envelope - cell wall and membrane. Internal - cytoplasmic matrix, various internal structures. Flagella - function mobility (1. filament - single protein strand 2. inserted into curved hook or sheath 3. Held in place by basal body.)
What is the dif between a eukaryotic and a prokaryotic flagellum?
back & forth vs. 360 degrees.
What are the polar arrangements of flagella in prokaryotic cells?
Polar (attached at one or both ends) Montrichjous - (single flagellum) Lophotrichous - (tuft of flagella at one end) Amphitrichous - (flagella at both ends) Or peritrichous (which has flagella all over cell), or Atrichous - no flagella.
How do you detect flagella?
1. Electron microscope. 2. Flagellar stain (a type of differential stain) 3. Demonstrate motility (semisolid agar or hanging drop slide)
Define chemotaxis.
Movement in response to a detected chemical. (positive - moving toward or negative - moving away)
Where do you find periplasmic flagella?
Spirochetes.
Define periplasmic flagella.
Internal flagella - between outer sheath and cell wall; cell wrapped around filaments - twisting, flexing movement.
Define Pili and fimbriae.
Function in attachment to cells or surfaces, made of hollow tubes.
Discuss Pili.
just a few - connection to exchange genetic information - bacterial variation, but no new cell.
Discuss Fibriae.
Numerous - attachment. Need better definition.
Define cell envelope.
Complex layers external to cytoplasm - glycocalyx, cell wall, cell membrane.
Define glycocalyx.
Coating of macromolecules, protection and adherence. 1. Slime layer (loose, prevents dehydration). 2. Capsule (thicker and tightly bound to cell, sticky), contributes to pathogenicity.
Discuss cell wall.
Determines shape of cell, provides support, contains peptidoglycan. Exact cell wall composition can vary somewhat. Cell wall basis for some staining techniques.
Define peptidoglycan.
Structural sugar/protein that lends structure to cell wall.
Discuss gram positive cell wall.
Thick cell wall, Primary composition (peptidoglycan and techoic acids), Almost no periplasmic...
Discuss gram negative cell wall.
Thinner (less peptidoglycan) cell wall, larger periplasmic space, Outer membrane (contains lipopolysacchararides), soluble in nonpolar solvents. Acts as endotoxin. Often resistant to host defenses.
Discuss acid fast cell wall.
Have gram positive cell wall, mostly contain mycolic acid - wax, contributes to pathogenicity, difficult to stain (carbol fuschin best dye), Stain not removed by acid.
Give a couple examples of acid fast bacteria.
Mycobacteria, nocardia
What are the two domains that are Prokaryotes?
Archaea and Bacteria.
What is the cell wall main component in bacteria?
Glycoprotein
Bacteria domain contains the Eubacteria species.
Discuss the archaea types of bateria.
Vary in cell wall composition, lack peptidoglycan, composed of other polysaccharides or proteins, a few have NO cell well.
Discuss features of mycoplasmas.
They have no cell walls (sterols in cell membrane prevent lysis), Pleomorphic (showing extreme variations in shape).
Some bacteria loose cell walls.
L forms or L phase variants. Arises from mutation or treatment with enzymes or antibiotics.
What is a protoplast?
Gram positive cells that loose their peptidoglycan covering.
What is a spheroplast?
Gram negative cells that loose their peptidoglycan covering.
Discuss cell membrane.
Phospholipid bilayer with proteins in, on and through. Selectively permeable (transports nutrients in/wastes out. Mesosomes extend into cell to increase surface area. Site of almost all biochemical reactions, no membranous organelles.
List internal structures.
Cytoplasm, genetic material, Ribosomes, cytoskeleton,
What is cytoplasm (protoplasm)
Gelatinous solution, mostly water. SIte of biochemical reactions.
What is the genetic material in a prokaryote?
Single, circular strand of DNA (concentrated in nucleoid); plasmids (small, circular extrachromosomal DNA - outside genes that are carried on the outside that aren’t absolutely necessary for life).
What do granules or inclusions do?
Storage vesicles
What is the cytoskeleton?
network of protein polymers associated with cell wall - maintain shape. May influence cell wall formation.
Define pilus.
An elongate, hollow appendage used in transfers of DNA to other cells in cell adhesion.
Discuss endospores.
Survival structures, form under unfavorable conditions, germinate in favorable conditions (returns to vegetative cell), constant invaders of sterility, extremely resistant to destruction.
What are some examples of microbes with endospores?
Clostridium bacillus
Shapes of bacteria -
Vibrio (excessively curvy rods - spirillum are rigid, spirochete are flexible and have an axial filament.)
Bacterial cells are grouped by shape and ______.
Arrangement.
How do diplo bacteria arrange themselves?
pairs
How do staphylo bacteria arrange themselves?
clusters
How do strepto bacteria arrange themselves?
chains
How do tetrad bacteria arrange themselves?
packets of 4 cells
How do sarcina bacteria arrange themselves?
packets of 8-24 cells.
What is pleomorphism?
Vary in shape due to variations in cell wall structure.
What are palisades?
Fence-like arrangement. Cells fold together length-wise.
What are methods of bacterial identification?
Microscopic morphology, Macroscopic morphology (shape of colony), Physiological/biochemical characteristic, Chemical analysis, serological analysis, genetic and molecular analysis.
Classification of bacteria.
Difficult (few fossil records), no universally accepted method, oldest and best known is (Bergey’s manual of systematic bateriology) , phenetic system - first edition (based on cell wall composition, morphology, metabolism.
What is phylogentic classification?
second edition, based on recent genetic info. Changed from 2 domains and 4 phyla to 5 major subgroups and 25 phyla, each subgroup presented in a a separate volume.
What does volume 1 cover?
Domain archaea, most ancient members of domain bacteria, live in extreme conditions, cyanobacteria,
What does volume 2 cover?
Phylum proteobacteria, gram negative cell wall (escherichia, salmonella, heliocobacter), rickettsias (no cell walls), purple bacteria - protosynthetic.
What does volume 3 cover?
Phylum firmicutes, gram positive cell wall - low G & C content. Includes staphylococcus, streptococcus, clostridium, bacillus; Mycoplasmas (no cell wall).
What does volume 4 cover?
Phylum actinobacteria, gram positive cell wall, High G & C content (corynebacterium, mycobacterium, micrococcus), pleomorphic and branching cells.
What does volume 5 cover?
Nine phyla (may or may not be related), gram negative cell wall, anaerobic GNB, chlamydia, spirochetes (Borrelia, Treponema).
Discuss informal classification of bacteria of med. importance.
Use gram stain reaction - get GPC (gram positive coccus), GNC, GPB, GNB
What is a bacterial species?
Collection of cells sharing an overall similar pattern of traits.
Discuss subspecies or variants
Strains - differ from parent in structure or metaolism, types - differ in antigenic makeup, viral susceptibility, pathogenicity
What are some GPCs of medical importance?
Staphylococcus, streptococcus, enterococcus, enterococcus, peptococcus, peptostreptococcus
What are some GNCs of medical importance?
Neisseria, Branhamella, Moraxella, Acinetobacter, Veillonella
What are some GPBs of medical importance?
Bacillus, Clostridium (endospore formers), lactobacillus, listeria, erysipelothrix, propionibacteriu, corynebacterium, mycobacterium, nocardia (acid fast), actinomyces, strptomyces (branching cells)
What are some GNBs of medical importance?
Brucella, bordetella, francisella, pseudomonas, enterbacteriaceae (E. coli, etc), legionella, vibrio, campylobacter, haemophilus, ...
What are some Misc Bacteria of medical importance?
Spirochetes, ....
Discuss eukaryote - motility.
Cilia and flagella (used for motility, 9 + 2 arrangement - meaning no 360, but whip-like) flagella are longer, cilia are shorter.
Discuss eukaryotic glycocalyx.
Glycocalyx (polysaccharides, network of fibers, may be slime layer or capsule, protection adherence and signal recognition. Cell walls seen in algae (cellulose, pectin, minerals) and fungi (chitin)
Cytoplasmic membrane in eukaryotes.
Phospholipid bilayer with proteins in, on, and through; sterols found in eucaryoticcell membrane for stability, selectively permeable.
Discuss the internal structures within eukaryote.
Nucleus (separated from cytoplasm by nuclear membrane, Nucleolus-RNA synthesis, chromosomes are linear)
Discuss Endoplasmic Reticulum (ER).
Separates cytoplasm into “rooms,” site of enzyme attachment; sit of enzyme attachment (worktable); Smooth ER - site of lipid synthesis, rough ER - ribosomes attached, complex protein secretions (closely associated with Golgi apparatus.
What part of the cell produces lipids?
Smooth ER.
What part of the cell produces genetic material?
Rough ER
Discuss the Golgi Complex (Apparatus).
materials form Rough ER pass through Golgi vesicles for processing.
Eukaryotic flagella have ____ movement. Prokaryotic flagella have _______ movement.
whiplike - whiplike.
What is a cell vesicle?
A little package filled with needed things - goes where it needs and merges with appropriate membrane to deliver its contents.
Define lysosome.
Vesicles from Golgi containing digestive enzymes. They are for “breaking” or “eating” things.
Define dehydration synthesis.
Define hydrolysis.
Define apoptosis.
Programmed cell death. (all lysosomes programmed to empty at once)
Define vacuole.
Tupperware of the cell. Storing things until needed - food it will need later, waste products, pigments)
Define mitochondria.
Powerhouse of the cell. Site of glucose oxidation to form ATP - cellular respiration.
Define chloroplasts.
Site of photosynthesis. Take sun energy and build sugar for later use.
Mitochondrial DNA passes through ______.
Mother
Mitochondria and chloroplasts are associated with ______ and have their own ___.
energy, DNA.
What parts of plants have chloroplasts?
The green parts.
What two organelles are considered to possibly have one time lived as independent organisms?
mitochondria and chloroplasts.
What characteristics of the mitochondria and chloroplasts make them quite similar to individual organisms?
Have double membrane, contain circular DNA, Have 70S ribosomes, Capable of dividing independent of cell division
What cells have the highest number of mitochondria and chloroplasts and why?
Muscle & nerve - because they take the most energy.
Discuss the ribosome.
Non-membranous organelle; protein synthesis (large subunit 60S, small subunit 40S - combine together to make 80S?!?!) Ribosomes in cell are different from ribosomes within mitochondria.
Discuss cytoskeleton.
Microtubules and microfilaments, provide cell shape, allows for movement (in absense of flegella, etc), anchor organelles, transports organelles.
What are some common eukaryotic microbes?
fungi, protists (algae and protozoa), parasitic worms.
Discuss kingdom Eumycota.
Always fungus (sometimes a name will be similar if it has fungus-like symptoms), Yeast (round to oval cells), mushrooms, mildew, mold.
What is “myco”?
fungus or fungus-like.
Most fungi are multi or single celled?
multi
What fungi are single celled?
yeast
How do yeast reproduce?
asexually by “budding”
Define pseudohyphae.
Chain of yeast cells that result when buds remain attached. Clumping.
Define hyphae.
Thread-like cells that compose filamentous fungi (molds).
What is a mycelium?
The whole “body” of a fungus. form of body of mold, collection of hyphae.
What is the difference between septate and aseptate?
Septate has cross-walls, aseptate doesn’t (many connections, doors/openings throughout)
What is an absorptive decomposer?
Something (fungus) that grows on the food source and just absorbs all the food they need.
Define dimorphic.
Fungus that can exist as single cells or a form hyphae, depends on growth conditions.
Are fungus dimorphic or do they have only one form?
Both.
Define heterotrophic.
Cannot make their own food.
Why are fungi, etc. essential?
Because they breakdown dead things.
Define saprobes (saprophytic)
Feed off dead plants/animals
Where do fungi tend to live?
In nutritionally poor environments.
Define mycoses.
Fungal infections. (in animals, plants, humans - some are species specific - others are not).
How does fungal reproduction differ from other eukaryotes?
they are normally haploid, asexual reproduction (spores from mitosis), sexual reproduction - spores produced through fusion of two parental nuclei, Meiosis follows (haploid)
Define peritrichous flagella.
having flagella all around the cell.
Which type of cell has more peptidoglycan and less periplasmic space?
Gram positive cells
What are the phylum (divisions) of fungi?
Phylum I - zygomaycota, Phylum II - Ascomycota, Phylum III - Basidiomycota, Phylum IV - Chytridomycota, Phylum V - Deuteromycota.
Which phylum of mold produces only asexually?
Phylum V - Deuteromycota.
What are some common ascospores?
Histoplasma, Microsporum, Penicillium, Pneumo....
What are some basidiospores.
Most form mushrooms - Amanita, Claviceps purpurea, cryptococcus neoformans
Discuss Phylum IV (Chytridomycota).
Chytrids, primitive, don’t form hypae or yeast-like cells, prodcue flagellated spores and gametes, free-living in soil water, may plant and animal parasites (no parasites for humans).
What are identifying factors of fungi?
Grow on nutirtionally poor media (prevents bacterial growth), Macroscopic evaluation, microscopic evaluation, Characteristics (asexual spores, hyphal type, colony texture, physiology, genetic makeup, pigmentation)
What’s the difference between a primary and opportunistic infectious agents?
Primary will make anyone sick, Opportunistic makes you sick if over-exposed and under-immune protected.
What portion of crops are destroyed by fungus?
40%!
What are the beneficial characteristics of fungus?
Major decomposers of dead organic matter and mineral/nutrient recyclers. Mycorrhizae (symbiotic relationship with plant roots - increase water absorption), Source of antibiotics/vitamins/drugs, Used in food and beverage manufacturing.
What is the “junk drawer” of fungus?
Kingdom Protista.
Discuss algae.
A subkingdom under Protista. Photosynthetic, contain chlorophyll and other pigments, few are infectious, some produce toxins that cause illness if ingested or inhaled, “red tides”, plankton, diatoms.
Discuss protozoa.
A subkingdom under Protista. Heterotrophic, some parasitic, Classified based on motility (flagella, ...)
What is a protozoal cyst?
A mature but dormant stage of a protozoa’s life.
What is the active feeding stage of a protozoan?
Trophozoite. (Troph)
What are the classes of protozoa?
Mastigophora, Sarcidona, Ciliophora, Sporozoa,
Discuss mastigophora.
Flagellated, many species are parasitic - Pathogens: Trypanosoma, Leishmania are blood parasites. Giardia (intestinal, diarrhea), Trichomonas (vaginitis)
Discuss Sarcidona.
Pseudopods, few parasites (Entamoeba histolytica), Montezuma’s Revenge.
Discuss Ciliophora.
Ciliated, few parasites in this class, Balantidium coli - intestinal.
Discuss Sporozoa (Apicomplexa)
No organelle for motility, complex life cycles (sexual and asexual), Mostly parasitic. Plasmodium (Malaria), Toxoplasma, Cryptosporidium.
Discuss Trypanosoma cruzi.
South & Central America, Chagas Disease, Blood flagellate, Transmitted by blood-sucking reduviid bug, Soon leaves blood for smooth muscle and cardiac muscle.
What is the “bug” responsible for Montezuma’s Revenge?
Entamoeba histolytica
What kingdom are Helminths in?
Animalia
Discuss Parasitic Helminths.
Identified by microscopic examination of eggs, shape and size of worm, presence of special structures, mode of reproduction, kind of hosts,
What class are flukes in?
Class Trematoda.
What class is tapeworms in?
Class Cestoda.
What types of things are in Phylum Platyhelminthes?
Flatworms (tapeworms, flukes)
What types of things are in Phylum Aschelminthes?
Roundworms - nematodes.
What are types of morphology in helminths?
Cephalization (definite head region - with extra nerve activity there), Some have organs and organ systems, Reproductive systems are more “well developed,”
Discuss life cycles and reproduction of helminths.
Complex with multiple hosts, most reproduction is sexual, produces eggs in protective shells.
What is Enterobius vermicularis?
Pinworm or seat worm (roundworm), Intestinal infection, Oral/fecal transmission, Simple, uncomplicated infection, Very common infection in children.
Who was Bergey?
He developed the oldest and best known classification system used for bacteria.
Define Sarcina.
A bacterial cell arrangement in which the cells form packets of 8-64 cells.
Define basal body.
Prokaryotic structure that holds flagellum in place.
Define “trichous.”
root meaning “flagellum.”
Discuss characteristics of viruses.
They are “infectious particles” Obligate intracellular parasites. Protein coat with surrounds Nucleic acid - DNA or RNA. Acellular. Ultramicroscopic (20-450 nm)
Define “capsid.”
the capsomere - protein coat surrounding virus.
Discuss virus “envelope.”
Cell membrane with protein spikes. These spikes allow attachment to new host cell. This envelope is used as a cell wall, but stolen from previous host cell. Some viruses are naked - protein coat with nucleic acid.
Define virion.
Fully formed virus capable of infection.
What does a capsid/envelope do?
Responsible for infective properties of virus. Contain proteins for attachment. Protect viral nucleic acid when outside a host cell.
Prokaryotic cells’ genetic information is always stored by:
DNA.
Viral genetic information is stored as:
DNA, RNA (not both), single stranded, double stranded, linear, circular or fragmented.
Define polymerases.
Puts nucleotides together to build DNA/RNA. (or catalyze for such)
What is a retrovirus?
One that must have host-specific enzymes already packaged within to be functional. They make DNA from RNA.
Discuss classification and naming of viruses.
3 orders, 63 familles, 263 genera. Family names end in -viridae. Genus names end in -virus. ot widely accepted - genus or common names used.
Discuss order of viral multiplication.
1. adsorption, 2. penetration/uncoating, 3. replication, 4. assembly, 5. release
What is viral “adsorption”?
Recognition of host cell (attachment)
What is viral penetration/uncoating?
Entrance of virion into host cell.
What is viral replication?
Copy and manufacture of viral components.
What cells do viruses attack?
Only specific ones, depending on virus type.
How are naked viruses typically taken into the cell?
Endocytosis.
How are envelope viruses typically taken into the cell?
They become a part of the cell membrane and empty contents within cell.
What are the steps of replication and protein production?
DNA viruses - DNA migrates to nucleus, directs activities of replication. RNA remains in cytoplasms and directs activities of replication.; mature virus particles assembled from pool of parts; capsid shell forms; nucleic acid inserted; enveloped viruses insert protein. Rlease (naked viruses cell lyses and dies, enveloped viruses - virus particles “bud” from cell membrane exocytosis. Takes more and more cell membrane.)
What is positive sense RNA?
translates directly.
Define CPE.
Cytopathic Effect. - Virally incduced damage to host cell, visible through microscope; Cell Death; Latent state (persistent infections); oncogenticity - causes host cell to transform into a cancer cell.
Define bacteriophage.
Viruses that infect bacteria. Well-studied, complex viruses, some show lysogeny. Dormant state - phage DNA becomes inactive prophage; Host cell not lysed - may reactivate.
What are some bacteria that are made virulent by viruses?
corynebacterium diphtheriae, scarlet fever, bivrio cholerae, clostridium botulinum
Cultivation and identification of animals viruses.
Require living cells - animal inoculation, bird embryos, cell or tissue culture
What is a prion?
proteinaceous infectious particles; small, highly resistant particles; spongiform encephalopathies. (Mad cow disease or Cruetzfeld-Jakob Disease) A possible genetic factor.
Define “viroids.”
Tiny, naked strands of infectious RNA. Plants only. Can find with probe using labeled complementary RNA.
Discuss detection and treatment of viral diseases.
Direct rapid antibody tests or checking cells for CPE. Treatments - antibiotics work on prokaryotic cells. Antibiotics work on prokaryotic cells, antiviral drugs more toxic to host. Interferon - a natural antiviral. Vaccines.
What type of culture method is best for isolation?
Streak plate.
What type of culture method is best for counting?
Pour plate.
Define agar.
Solidifying agent (with necessary nutrients included) culture medium. Melts at 100 C, solidifies at 40 C.
How do you know if a broth culture is positive?
It will appear cloudy or “turbid”.
One colony alone is a pure ______.
Culture.
What are three visual characteristics used to identify colonies growing on bacteria?
Colonial form (shape of colonies), elevation (flat, convex, umbonate), and margin (smooth or not).
What is the formula to determine the quantity of cells in a liquid or mixed culture?
number of colonies x dilution = # of bacteria per ml
All algae have:
Chlorophyll
Pseudomonis is a gram ____ cell.
negative
Define nutrition.
A substance that provides nourishment essential for growth and the maintenance of life.
Define essential nutrient.
a nutrient required for normal body functioning that either cannot be synthesized by the body at all, or cannot be synthesized in amounts adequate for good health (e.g. niacin, choline), and thus must be obtained from a dietary source.
Define macronutrients.
needed in larger quantities
Define micronutrient.
needed in larger quantities
Define inorganic nutrient.
a substance or nutrient that does not carbon or hydrogen.
Define organic nutrient.
a substance or nutrient that contains carbon or hydrogen.
What portion of water is a microorganism?
80-90 percent
What is the most abundant component of cells (after water)?
hydrogen
What elements make up 96% of dry weight of a cell?
CHONPS carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur
How does a heterotroph get its carbon?
Organic carbon by eating/consuming other living things.
How does an autotroph get its carbon?
Accessing it from inorganic sources.
Where do we get our nitrogen?
Air and food
What can take nitrogen gas from air and convert it into forms used by other creatures?
Bacteria
Where do we get our oxygen?
Air
What do we use hydrogen for?
mostly as water
What are sources of sulfur?
hydrogen sulfide (H2S), sulfur, and thiosulfate (S2O32-).
What are growth factors.
Growth factors are organic compounds such as amino acids (def), purines (def), pyrimidines (def), and vitamins (def) that a cell must have for growth but cannot synthesize itself
What are the life requirements of prokaryotes?
Temperature, pH, Oxygen or not, solute concentration, nutritional requirements.
What is a fastidious organism?
require specialized environments due to complex nutritional requirements.
What are the 4 nutritional categories of organisms?
"1. Photoautotrophs 2. Photoheterotrophs 3. Chemoautotrophs or Lithotrophs (Lithoautotrophs) 4. Chemoheterotrophs or Heterotrophs
What is carbon source and energy source of chemoautotrophs?
Chemoautotrophs use inorganic energy sources, such as hydrogen sulfide, elemental sulfur, ferrous iron, molecular hydrogen, and ammonia.
Give examples of chemoautotrophs.
extremophiles, usually bacteria.
Give examples of photoheterotrophs.
plants
What is carbon source and energy source of chemoheterotrophs?
Mostly autotrophs.
Give examples of chemoheterotrophs.
People, animals - anyone that can’t make their own food.
Discuss metabolism of photoautotrophs.
able to harvest the carbon they need directly from light.
Discuss metabolism of chemoautotrophs.
Chemoautotrophs use inorganic energy sources, such as hydrogen sulfide, elemental sulfur, ferrous iron, molecular hydrogen, and ammonia.
Define saprobe.
An organism that derives its nourishment from nonliving or decaying organic matter.
Define parasite.
an organism that lives on or in an organism of another species, known as the host, from the body of which it obtains nutriment.
What is the difference between obligate parasite and facultative parasite.
An obligate parasite is a parasitic organism that cannot complete its life cycle without dependence on its host. A facultative parasite is an organism that may resort to parasitic activity, but does not absolutely rely on any host for completion of its life cycle.
Differentiate active and passive transport.
Passive relies on physical laws. Active transport require energy - forcing something against what naturally occurs.
List the three types of passive transport.
1. Diffusion, 2. Osmosis, 3. Facilitate diffusion.
List the three types of active transport.
1. pumps, group translocation, 3. endocytosis/exocytosis.
Define diffusion.
Movement of solute molecules from an area of higher concentration of solute to an area of lower solute concentration along a concentration gradient. Membrane must be permeable to solute.
Discuss Osmosis.
Diffusion of water molecules when membrane is not permeable to solute. (if solute can’t move, the solvent (H2O) will. Concentration gradient.
Define isotonic.
Two compared solutions have the same concentration of solvent to solute.
Define hypotonic solution.
Solution is less concentrated than cytoplasm. More water outside cell.
Define hypertonic solution.
Solution more concentrated than cytoplasm. Net movement of water out of cell.
What organisms “like” a hypotonic environment?
Plants and fungi.
What happens when you place a cell in a hypertonic solution?
Plasmolysis - the cell wall rips away and cell dies.
What environment do cells with no cell wall like?
Isotonic.
Define crenation.
Cells shrinking up from hypertonic.
What is typically the least stressful solution type?
isotonic.
What do fresh water critters have to enable them to live in the hypotonic solution of fresh water?
Contractile vacuole or cell wall (plants).
How do organisms live in the hypertonic solution of salty water?
They absorb salts to restrict water loss - Halophiles - require high salt environment.
Discuss facilitated diffusion.
solute molecules move along concentration gradient with help of carrier protein. Occurs fast. specific proteins allow specific molecules to pass through.
How does active transport differ from passive?
It requires energy input.
What are the types of active transport?
1. Pumps, group translocation, 3. endocytosis/exocytosis.
What is the point of a transport pump?
Solute molecules move against a concentration gradient. Moves from lower to higher concentration. Uses ATP to change shape of molecule.
Discuss group translocation.
Molecule brought into cell an changed into useable form at same time. May involve addition of other atoms/functional groups.
Discuss endo and exocytosis.
Non-transmembrane transport, bulk transport, vacuole forms around particle, endocytosis (taking in).
Define Phagocytosis.
Cell eating. Solids.
Define pinocytosis.
Cell drinking. Liquids.
Define exocytosis.
exiting from cell.
List various environmental factors that influence microbial growth.
Temperature, atmosphere (gas requirements), pH, Osmotic pressure, Each organism has an optimum and an acceptable range. Radiation, hydrostatic pressure.
What are the 3 cardinal temperatures?
minimum (lowest at which organism grows), Maximum (highest), Optimal (for most growth)
Define Psychrophile.
“cold lovers” - optimum temperature < 15 degrees C. Grow at 0 degrees C but not above 20 degrees C.
Define psychrotroph.
Grow in refrigerator but optimum > 20 C
Define Mesophile.
Optimum temperature is between 20 and 40 degrees C.
Define Thermophile.
Heat lovers - optimum temperature over 40 degrees C.
What are atmospheric requirements?
Atmospheric gases, temperature, pH, pressure,
Define obligate aerobe.
Requires oxygen for growth.
Define obligate anaerobe.
Dones not require oxygen, oxygen is toxic.
Define facultative anaerobe.
Can have O2 or none.
Diefine microaerobphile.
Requires less oxygen, prefers increased carbon dioxide, capnophiles.
Define aerotolerant.
Does not use oxygen but can survive in its presence.
Define Neutrophiles
pH 6-8
Define Acidophiles.
pH 0-4.5
Define Alkalophiles.
pH 7-10
What is a barophile?
An organism that can tolerate extremely high pressures.
Define symbiosis.
Two organisms living together.
What types of symbiosis are there?
Mutualism (both benefit, obligatory), Commensalism (one benefits, one neutral), Parasitism (one benefits, one harmed), Synergism (free-living - when they live together both benefit, but they don’t need each other), Antagonism (competition between organism, one secretes substances against the other.
What is a bacteriocins?
Toxic proteins secreted by Gram-bacteria.
What is a Biofilm?
Community of microbes. Able to communicate and act as a group - chemical signaling. Initial organisms secrete inducer molecules. More cells attach until “quorum” reached, Inducer molecules allow film to function as a unit. Breakdown of complex molecules by saprobes. Colonization of body by organisms, colonization of medical surfaces (big problem). May contain several species. Allows for genetic exchange.
Discuss bacterial growth.
Reproduction is by binary (transverse) fission. Generation time 30-60 minutes is average 5 minutes to several days. Doubles size first.
What are ways to measure microbial growth in a liquid broth?
Turbidity - can tell visually or with a spectrophotometer to see how much light passes through.
List some ways to measure microbial growth.
Turbidity, Direct cell counts (pour plates)
Define metabolism.
Totality of all chemical reactions - breaking down and building up.
Define catabolic reaction.
Degradation - breaking down. Utilizes energy in something.
Define anabolic reaction.
Synthesis - building things. Costs but creates value.
Anabolism requires _________.
Energy.
Define enzyme.
A catalytic protein. Speeds up reaction. Lowers activation energy.
List the types of enzymes.
Simple enzyme, conjugate enzyme, Holoenzyme = apoenzyme + cofactor.
Define coenzyme.
An organic coenzyme - something that can join with protein to make it an active enzyme.
Define inorganic.
Lacks carbon and hydrogen.
Coenzymes are usually provided by ________.
Vitamins.
Define exoenzyme.
secreted and act outside the cells.
Define endoenzyme.
Retained - acts inside cell.
Define constitutive enzymes.
Always present, constant amount.
Define regulated enzymes.
Produced only if substrate is present.
Discuss synthesis reaction.
Anabolism. Requires enzymes and energy to form bonds. Usually liberate water condensation.
Discuss degradation reaction.
Catabolism. Require enzymes to break bonds and liberate energy.
OIL RIG
Oxidation is lost. Reduction is gained.
What is the role of enzymes in disease?
Digest tissues, inactivate antibiotics
Discuss enzyme sensitivity.
Anything that affects protein structure. pH, Temperature,
How are enzymes controlled in Direct control?
Direct - enzyme already produced, control enzyme, competitive inhibition, Molecules with structure similar to substrate occupies active site on enzyme, Noncompetitive inhibition - Enzyme has two binding sites, active site and regulatory site, binding to regulatory site inactivates enzyme. Feedback inhibition (endproduct of pathway inhibits enzyme pathway)
How are enzymes controlled in indirect control?
Control enzyme synthesis - enzyme repression (endproduct of pathway stops gene expression), Enzyme induction (presence of substrate causes gene to be expressed).
Discuss energy formation and utilization.
Energy in cell in electrons involved in chemical bonds. Intact bonds represent potential energy, breaking bonds releases kinetic energy - endergonic reactions require (energy anabolism), exergonic reactions release energy (catabolism)
“Who” is oxidized and “who” is reduced?
Energy donor, energy acceptor.
Molecules that are rich in hydrogen are rich in _______.
energy.
Define dehydrogenation.
Moving hydrogen from one molecule to another.
What is the only source of living human cells can use to do work?
ATP
What do electron carrier molecules do?
They repeatedly release and accept electrons. Most carriers are coenzymes NAD+ and FAD, At the end of the chain is final electron acceptor, accepts electron and doesn’t release it.
How does ATP become ADP?
It phosphorylates.
What manages energy for every cell?
ATP
What is the primary energy molecule stored in cells?
Glucose.
What are different catabolic actions that can generate ATP?
Glucose primary energy molecule, aerobic respiration (phosphogluconate pathway), anaerobic respiration (fermentation).
What is the most efficient method for regenerating ATP?
Glycolysis, Krebs cycle, electron transport chain.
What is the path/order for glycolysis?
Gulcose-6-PO4 (phosphate) > 2 pyruvate + 2 ATP + 2NADH
What is substrate level phosphorylation?
When the phosphate is taken from glucose and added to ADP to make ATP.
What is the path/order for Krebs Cycle? Tricarboxylic Acid Cycle
Pyruvate > Acetyl CoA + CO2 + NADH -- Acetyl CoA > 3CO2 + ATP + FADH2 + 3NADH
What are the only things that continue to final electron transport chain?
NADH & FADH2`
Discuss the electron transport system.
Series of carrier molecules (each one in the line has a little stronger pull), cytochromes (molecule carrier), and Electron transport steps, and chemiosmosis.
What is the path/order for Electron transport system?
10 NADH + 2 FADH2 + O2 . 34 ATP + 6 H2O
What is the end waste product of the electron transport system?
H2O
Define Chemiosmosis?
Chemiosmosis is the movement of ions across a selectively permeable membrane, down their electrochemical gradient.
Discuss the phosphogluconate pathway.
“Hexose Monophosphate Shunt” Anaerobic utilization of glucose and other hexoses, also allows for use of pentoses, electron carrier NADP, Common pathway in the heterolactic fermentative bacteria.
What is the only anaerobic step of energy production?
Glycolysis.
Discuss anaerobic respiration.
Glycolysis; Kebs cycle (bypasses steps using O2); Electron transport system (uses different cytochromes); Final electron acceptor - oxygen (containing inorganic salt); Produces > 2ATP but < 34ATP
What organisms carry out anaerobic respiration?
Mostly bacteria.
Discuss fermentation.
Incomplete oxidation of glucose, oxygen is absent, pyruvate reduced (acid fermentation); Alcohol fermentation (pyruvate > acid > Alcohol); 2 ATP (glycolysis), final electron acceptor is organic molecule.
What is the path/order for acid fermentation?
Pyruvate + NADH > NAD + acid
What are the major catabolic pahtways?
Aerobic respiration (glucose, steps - glycolysis, Krebs cycle, ETS. O2, 36 ATPS); Anaerobic Repsiration (glucose, steps - glycolysis, Krebs cycle, ETS, Inorganic, 3-32 ATPS); Fermentation (Glucose, steps - glycolysis, fermenation, Organic, ATPS)
What is anabolism?
The building up (Biosynthesis).
What are things that a cell has to build?
Proteins, nucleic acids, lipids, carbohydrates.
Define gluconeogenesis.
Forming new glucose from non-carbohydrates.
Discuss carbohydrate synthesis.
Monosaccharides from nutriets, synthesize sugars from other things.
Discuss protein synthesis.
amino acids from nutrients. Synthesize amino acids. Protein synthesis major anabolic process.
Discuss nucleic acid synthesis.
The body can build DNA, etc. from things present in environment.
Define Genetics.
The study of heredity.
Define Genome.
Total of genetic material in cell.
Discuss chromosomes.
DNA and associated proteins, linear in eukaryotes- circular in prokaryotes.
Define gene.
Unit of heredity. Usually a coding for one characteristic.
Discuss gene types.
Structural genes code for proteins (building stuff), regulatory genes control gene expression, Some genes code for RNA.
Define genotype.
Complete genetic makeup. (2 copies in diploid, 1 copy in haploid)
Discuss DNA.
Deoxyribonucleic Acid. Polymer of nucleotides (double strand) - Pentose (deoxyribose), Phosphate, nitrogenous base (purines - adenine,guanine), (Pyrimidine bases - (thymine, cytosine). Specific base pairing.
What are the steps of DNA replication?
Initiation (at origin of replication, both strands separate and act as templates, primers are tiny RNA that bind), Elongation (DNA polymerase reads each n.t. on template and adds the complementary n.t. to new strand), Termination (RNA removed and fragments joined).
How big is RNA?
Just usually about 10 nucleotides long.
Define semiconservative model.
Each new DNA molecule consists of an original strand and a new one.
Discuss 3 prime and 5 prime.
The two ends of the replicating DNA. Polymerase can only read/add at the 3’ end.
Why is bacterial replication more random than eukaryotic replication?
It is quick and not picky. Many mistakes for much variation.
Discuss genes code for proteins.
Protein function based on shape of protein - tertiary dependent on secondary, secondary dependent on primary, primary structure dependent on amio acid sequence (encoded in genes).
What is the blueprint for genes?
DNA
What determines the characteristics of the cell?
The proteins.
What base differs in RNA?
Uracil replaces thymine.
Discuss RNA.
Polymer of nucleotides - single strand, Converts DNA - writes it into new material.
Discuss DNA triplet.
Genetic code is based on three base sequencing. In tandem, cannot overlap (while genes can overlap). They determine function.
Define codon.
Complementary bases to triplet, on mRNA.
Define anticodon.
the complementary to codon
What is the “start” codon?
AUG (methionine)
What are the “stop” codons?
UAA, UAG, UGA
Discuss the two steps protein synthesis.
Transcription (copying DNA to mRNA - mRNA synthesis.) Translation (converting nucleotide chain to amino acid chain - polypeptide synthesis.
Discuss steps of transcription.
Initiation (RNA polymerase binds to promoter on DNA, promoter sequence marks the start of a gene), Elongation (RNA polymerase reads n.t. sequence on template DNA and adds each complementarry n.t. to new mRNA strand.), Termination (RNA polymerase comes off when it reaches the Terminator on DNA, terminator tells it when to end).
Discuss steps of translation.
Initiation (mRNA attaches to ribosome, First tRNA bonds to start codon bringing bringing first amino acid, start codon AUG), Elongation (Ribosome reads each codon on mRNA, each complementary tRNA brings in te appropriate amino acid.), Termination (Ribosome comes off mRNA reaches a stop codon).
Discuss protein synthesis in eukaryotic cells.
DNA contains non-coding sequences, genes scttered across genome, primary mRNA transcript must be edited before leaving nucleus, remove introns (non-coding regions) and splice together (exons) coding)
Discuss protein synthesis in prokaryotic cells.
All DNA codes for protein - no introns, no editing necessary. Genes organized in groups - operons, not scattered.
Discuss Viral nucleic acid replication. (DNA)
dsDNA viruses, Viral DNA migrates to nucleus, Viral genes transcribed, Viral DNA replicates in nucleus.
Discuss viral nucleic acid replication. (RNA)
RNA viruses ss-postive sense, Replicate a negative sense template for viral RNA
Discuss viral nucleic acid replication. (retrovirus)
Works backwards, Contain RNA and reverse transcriptase (enzyme), Uses reverse transcriptase to synthasize DNA from RNA; DNA migrates to nucleus and acts like DNA virus.
Discuss the genetic regulation of enzymes.
Bacterial genes for a metabolic pathway all together on DNA (operons, related genes activated in unison), Inducible enzymes are produced when substrate is available.Repressible enzyme production halted by buildup of endproduct.
Define operon.
Functional group of related genes.
Discuss operon structure and regulation.
Regulator gene (produces regulator protein), Promoter-operator (site for RNA polymerase attachment for production of mRNA), Structural genes (produces enzymes of metabolic pathway).
Some ________ work by affecting protein synthesis.
antibiotics.
Why don’t antibiotics kill your own cells?
Ribosomes and enzymes differ in eukaryotic and prokaryotic cells.
What are some examples of antibiotics that affect protein synthesis?
Rifampin binds RNA polymerase, Erythromycin interferes with mRNA attachment to ribosome (can’t translate to protein).
Define mutation.
Permanent, heritable change in genetic information.
What are some characteristics of a mutation.
Some are spontaneous, some are induced (mutagens - physical or chemical agent that cause a change in DNA)
Define point mutation.
Substitution of one base in a base pair.
Define missense.
One codon affected, different amino acid (produces faulty protein) - or no effect. Possibly a different functional protein.
Define nonsense mutation.
When there is a STOP - codon - No functional protein is made.
Discuss frame shift mutation.
Deletion or addition of one or more base pairs.
What does UV damage need for repair?
photoactive repair (visible light).
What is excision repair?
When a damaged or wrong section of the DNA is cut out to repair.
Discuss Ames test.
Uses back mutation to determine mutagenicity. Salmonella typhimurium is unable to synthesize histidine.
Define back mutation.
Gene mutates back to normal in presence of mutagen.
Discuss eukaryotic genetic exchange.
Eukaryotic recombination (new genetic recombinants are the product of sexual reproduction, each unique, both parents donate).
Discuss prokaryotic genetic exchange.
Prokaryotic recombination - conjugation (cell to cell transfer of DNA), transformation (uptake of naked DNA), transduction (viral introduction of DNA - accidental), transposons (“jumping genes”).
Define plasmid.
extra circular piece of DNA.
Sequences of DNA that move within the chromosome are known as:
Transposons.
List some high-resistant microbes.
Bacterial endospores, prions.
List some moderate-resistant microbes.
protozoan cysts, fungal spores, naked viruses.
List some low-resistant microbes.
Vegetative bacterial & fungal cells, enveloped viruses, protozoan trophs
Define sterilization.
Devoid of life.
Define -cidal agents.
Agents that kill. “Germocide” kills pathogens.
Define -static agents.
Prevent new growth. “Bacteriostatic” prevents more bacteria from growing.
Define disinfection.
Removal of vegetative cells from inanimate objects.
Define antisepsis.
Removal of vegetative cells from tissues (or procedures that prevent their introduction).
Define sepsis.
Growth of microbes or presence of toxins in blood or tissues.
Define asepsis.
Any practice that prevents entry of infectious agents into sterile tissues.
Define sanitization.
Any cleansing technique that mechanically removes microbes to reduce the level of contaminants. Used in food industry.
Define degermination.
Decreasing level of microbes from skin (washing hands).
Define bioburden.
The number of organisms.
What issues affect microbe death rate.
Bioburden, kind of organisms (spores, cells), Environment (temperature and pH), concentration of chemical agent, mode action agent uses, Presence of other substances.
What are some practical questions to ask concerning microbial control.
How clean does it have to be? Is it reusable? What can I do to it and not harm it? Is the method I want to use suitable? Will the agent penetrate sufficiently? Safe? Cost? Labor effective?
List ways that an antimicrobial agent works.
Damage to cell wall (lysozyme and penicillin), Damage to cell membrane (surfactants), affect protein and nucleic acid synthesis (Chloramphenicol, radiation), Alter protein function (heat, alcohol, pH)
List some methods of physical microbe control.
Heat, cold, drying, radiation and filtration
Discuss heat in microbe control.
Most heat can coagulate proteins, Dry heat dehydrates.
What is thermal death time?
The shortest time necessary to kill a specific organism at a specific temperature. Generally higher temp = lower death time.
What is moist heat?
60-135 degrees C.
What is the most common method of cleaning medical equipment?
Autoclave - steam under pressure. Reaches about 121 C.
What is the temperature and pressure of an autoclave?
121 C and 15 psi.
Define Tydallization.
Non-pressurized steam.
Define intermittent sterilization.
Expose to steam (vegetative), then cool and incubate to allow spores to germinate. Expose to steam again. Repeat for 3 days. Used on certain media like egg and sera.
Discuss water sterilization.
Boil. 100 C for 30 minutes. Kills all but endospores. Recommended method for disinfecting unsafe drinking water.
Discuss dry heat.
160 C to several thousand degrees. Incineration is fast, effective, destructive.
Discuss hot air decontamiation.
150-180 C, 12 min-4 ours. Used for items that do not sterilize well with moist heat. (glassware, metallic, instruments, powder/oils, not for plastics, cotton, paper). Time required can be a problem.
Discuss decontamination by cold and drying.
Effects are erratic and uncertain. Cold kills some, but used as a preservation technique. Drying - some organisms are killed, used as preservation technique.
Define lyophilization.
Freeze-drying, preservation.
Discuss radiation as decontamination.
Ionizing radiation. Electrons break DNA. Food, prepackaged plastic, vaccines, drugs. (can penetrate)... UV (nonionizing radiation) - short term DNA damage. Cannot penetrate - only for surfaces.
How do you sterilize things that can’t be heated?
Filtration.
What is HEPA?
An air filter.
What determines removal in filtration?
The pore size.
What are are some chemical purification methods?
disinfectants, sterilants,
How do you know what chemical to use for disinfection?
Enough to kill “bugs” without hurting you. Rapid action in low concentrations, soluble in water or alcohol, broad-spectrum and non-toxic, penetrates surface with persistence, resists inactivation, non-corrosive non-staining, sanitizes, deodorizes, cheap, available.
What can a “high level” disinfectant?
Kills endospores, sterilant if used correctly.
What can an “intermediate level” disinfectant?
kills fungal spores, resistant bacteria viruses, used for mucous membrane contact.
What can a “low level” disinfectant?
kills vegetative cells
List factors that affect germicidal activity of chemicals
Concentration....
List chemical groups that are used as cleaning agents.
halogens, phenolics, chlorhexidine, alcohols, detergents, hydrogen peroxide, heavy metals, aldehydes, gases, dyes, acids and alkalis.
How do halogens work as cleaning agents?
They tend to denature proteins (chlorine as a sinitizer), iodine (skin antisepic), Iodophors (iodine and PVA (polyvinyl alcohol), time release effect), Betadine, Povidone, Isodine)
How do Phenolics work as cleaning agents?
Damages cell membrane, protein, Penol (carbolic acid - poisonous), Bisphenols - Hexachlorophene (skin antiseptic -time release effect - Amphyl, pHisoHex, Triclosan.
How do Chlorhexidine work as cleaning agents?
Surfactant, denatures protein, Chlorine + 2 phenolic rings, Hibiclens, Hibitane, Skin atiseptic - time release effect, Milk, low toxicity, rapid action, used in obstetrics and neonatal.
How do Alcohols work as cleaning agents?
Dissolves membranes, Ethyl and isopropyl most common, good against vegetative cells. Evaporation time diminishes contact time, damp dust in surgery
How does Hydrogen Peroxide work as a cleaning agent?
Highly reactive - damaging to cells, somewhat unstable, inactivated by catalase, 35% mixed with 35% peracetic acid, powerful sterilans, endoscopes, - Ozone (O3) - sterilize air.
How do detergents work as cleaning agents?
Damages cell membranes, cationic (most effective, quarternary ammounium compounds, Zephiran (quates) - sanitizes) Anionic (limited microbicidal activity - soaps - mechanical removal of microbes.
How do heavy metals work as cleaning agents?
(Hg, Ag, Au, Cu, As, Zn,) Denature proteins, toxic, allergens, inactivated by inorganic substances; Mercury compounds, Thimersol (preservative), Mercurochrome, merthiolate, Silver nitrate used in eyes of newborns and on mouth ulcers.
How do aldehydes work as cleaning agents?
Denature proteins, Glutaraldehyde (Cidex - used in surgerty to disinfect endoscopes, fiber optics, dental), Formaldehyde (used to disinfect some surgical instruments and dialysis machines. TOXIC
How do Gases work as cleaning agents?
Affect DNA, Ethylene oxide (ETO) - Alkayting agent - carcinogenic, Used in chemiclave (gas autoclave), Chlorine dioxide - treats drinking water, wastewater, food processing equipment, medical waste - Decontaminant for Anthrax in 2001. Prophylene oxide is less toxic and breaks down. Better than ETO for foods (nuts, powders, starches, spices)
How do Dyes work as cleaning agents?
Aniline dyes - Crystal violet, Malachite green. Used in solutions for skin infections, also used for animal medicines.
How do Acids and alkalis work as cleaning agents?
Denature proteins, caustic, corrosive, hazardous, Acids are primarily used as food preservatives. Ammonium hydroxide used in detergents.
What is a Chemotherapeutic Drug?
Chemical used in treatment, relief, or prophylaxis (prevention).
Define antimicrobial chemotherapy.
Chemotherapy used to control infection.
Define antibiotics.
Substances produced by microbes (bacillus, Streptomyces, Penicillium.
Define synthetic drug.
Totally chemical - lab produced.
Define semisynthetic drug.
Chemically altered antibiotics.
Define narrow spectrum.
Limited in scope - effective against one or few organisms.
Define Broad spectrum.
Wide range of antimicrobial activity.
List the goals of any antimicrobial.
Disrupt cellular process or structures of microbe resulting in deaht. Inhibiting replication of microbe.
Define Selective toxicity.
Kill or inhibit growth of microbe without damaging host tissues.
What do medium spectrum antibiotics effect?
Gram + or Gram _, but not all of them.
What do broad-spectrum antibiotics effect?
Most Gram + and Gram - cells, Rikcettsias and mycoplasms.
In what ways do antibiotics work?
Affect bacterial cell wall mostly by inhibiting peptidoglycan synthesis. Disrupt cell membrane function, affect nucleic acid synthesis. Block translation, Block metabolic pathways,
Discuss drugs that inhibit cell wall synthesis.
Most contain beta-lactam rings (1. Penicillins, 2. Cephalosporins, 3. Misc beta-lactam drugs, 4. Misc non-betat-lactam-drugs.
Discuss Penicillians.
Penicillium - most end in -cillin, Contain beta lactam ring in structure (PenG, PenV=GPC, meningitis, Treponema, Ampicillin, carbenicillin, amoxicillin - broad spectrum -GNB, Methicillan, nafcillin, cloxacillin - pencillin resistant organisms.
Discuss Cephalosporins.
Cephalosporium, Usually have cef, ceph, kef in name, contain beta lactam ring, many poorly absorbed across intestines, Parenteral - injected. Tend to be broad spectrum (Keflex),
Discuss other Beta Lactams
Imipenem - broad spectrum, low toxicity, effective at low doses, Aztreonam - penicillin allergies.
Discuss non beta-lactam cell wall inhibitors.
Vancomycin, narrow spectrum, used to treat Streptococcus and methcillin resistant resistant Staph (MRSA), Very toxic, difficult to administer.
Discuss Bacitracin.
Bacillus. Toxic - topical only, narrow spectrum, CPC, Component of Neosporin.
Discuss synthetic drugs.
Isoniazid (INH) and Ethambutol, Interferes with mycolic acid synthesis, acid fast organisms.
List some antibiotics that damage cell membranes.
Polymyxin (Bacillus), Narrow spectrum, detergent activity, toxic to kidneys (PolyE (Colistin) - toxic used to treat Pseudomonas - PolyB - in Neosporin.
Discuss drugs that act on DNA or RNA.
Flouroquinolones Bind DNA enzymes, inhibit replication, broad spectrum, very potent, readily absorbed across intestines. Norfloxacin, Zythrofloxin.
Discuss Refampin.
BLocks RNA polymerase, Prevents transcription, Cannot pass through cell envelope so limited in treating G(-), TB and leprosy, prophylactic fro Neisseria meningitidis.
List some drugs that interfere with protein synthesis.
Aminoglycosides, tetracyclines, Chloramphenical, Macrolides
Discuss Aminoglycosides.
Broad spectrum, bind to ribosomal subunits, used to treat aerobic GNB, Streptomycin (oldest - toxic), Gentamicin, Amikacin, Tobramycin - Newer (less toxic) Tend to be neprhotoxic and ototoxic.
Discuss Tetracyclines.
Broad spectrum, Binds to ribosomes - Aureomycin, Teramycin, Tetracycline, Mincycline and Doxycyclines used for STSDs, RMSF and chronic infections - Side effects, GI disruption, teeth staining, abnormal fetal bone development.
Discuss Chloramphenical
Streptomyces, potent, broad spectrum, nitrobenzene structure, blocks peptide bond formation, extremely toxic, damages bone marrow - aplastic anemia, use limited to life-threatening situations.
Define Macrolides.
Discuss Clindamycin (Lincomycin)
Broad spectrum, adverse GI side effects, limited to treatment of large bowel infections.
Discuss drugs that block metabolic pathways.
Most are synthetic, most derived from plants or analine dyes, most replaced by antibiotics, blocks folic acid synthesis...
List some newer classes of antibiotics.
Fosfomycin (UTI’s caused by enterics), Synercid (treats staphs, enterococcus, and resistant streps.) Daptomycin, Oxazolidinone Class (Prevent ribosome/mRNA interaction - Zyvox - MRSA, VRE) Drs urge NOT to use these.
Discuss anti-fungal drugs.
Eukaryotic - drugs most toxic to us! Most act on cell membranes (Amphotericin B, Griseofulvin, Azoles, Flucytosine, Echinocandins)
What are some anti-parasitic drugs?
Quinine, Chloroquine, primaquine - treat malaria, caused by Plasmodium; Metronidazole (Flagyl) are non-blood protozoan infections, amoebicide, treats intestinal infections and hepatic disease.
Discuss Anti-helminth drugs.
Larger, greater similiarities to humans, most drugs inhibit metabolism at all stages of life cycle (Mebendazole, thiabendazole (Roundworms); Pyrantel, piperazine (roundworms); Niclosamide, Praziquantel, Ivermectin (Tapeworms and flukes)
Discuss anti-viral medicines.
Vaccines are best but not always possible. Very limited spectrum, drugs target steps in replicative cycle. Usually prevents host penetration, Block replication/transcription/translation of viral genome; prevent viral maturation. Cannot destroy existing viruses. Base analogs - mimic nucleotides - stop replication/transcription when incorporated.
Discuss Drug Resistance.
Adaptive response in which microbes begin to tolerate an amount of drug that would ordinarily be inhibitory - may arise randomly by gene mutation, acquired from other bacteria via conjugation, transduction or transformation. Resistance (R) factors - plasmids are an easy way to pass resistance.
List some specific types of anti-virals.
REVERSE transcriptase inhibitors for retroviruses. AZT. Protease Inhibitors (Indinavir) Blocks final virus assembly, inhibit uncoating preventing viral entry;
What type of bacteria has a tendency to pass from - to +
Bacillus.
What are some mechanics of resistance?
Enzyme inactivation of drug, loss of permeability of drug or increase elimination, alter drug receptor sites, modify the affected metabolic pathway.
_________ are groups that are extremely drug resistant.
Biofilms.
Why is a biofilm so drug resistant?
Thick extracellular matrix blocks drug penetration; Combined effort of organisms (coordinating drug pumps, sharing resistance genes; Low metabolism of cells protective.
Define prebiotics.
Nutrients that encourage growth of beneficial organisms.
Define Probiotics.
Enhance or replace normal flora (yogurt)
Define Lantibiotic.
Bacterial peptides that inhibit bacterial growth.
Discuss drug/host interactions.
Toxicity - mostly liver and kidneys, Allergy, (penicillans, sulfanomides), Disruption of normal flora (superinfections),
Discuss the method of selecting an antimicrobial agent.
Identify the microbe, Identify susceptibility to drug, Medical condition of patient (patient history, age, pregnancy, other drugs)
What is the Kirby-Bauer Test?
Disc diffusion susceptibility test - provides information on organism’s susceptibility.
What is a tube dilution test?
Different dilutions of drugs, introduce the same amount of culture. You’re looking for the lowest effective dose. MIC
What is MIC?
Minimum inhibitory Concentration. Smallest effective dose.
Why might a drug fail?
Inability of drug to diffuse in body, resistant cells in culture, mixed infection,
Define therapeutic index.
Ratio of toxic dose of drug to therapeutic dose of drug (MIC).
Discuss Innate Immunity.
Innate, nonspecific and specific components that provide immunity, multiple components working together. 1st line of defense (skin, mucous membranes, lysozymes), 2nd Line of defense - non-specific internal, inflammation, 3rd Line of defense - specific immunity, antibodies.
Discuss the first layer of immune defense.
Body surface - cornified and keratinized skin, Cilia and hairs (nose), mucous, Flushing effects (sweat, urine, tears), coughing, sneezing; Chemical defenses (Lysosomes in tears and saliva hydrolyzes bacterial cell walls); Dermicidin - peptide secreted from skin breaks down bacterial membranes; chemical compositions of fluids, pH)
First line defenses are ______ and ____________.
Innate and non-specific.
List the components of the first line of defense.
Sebaceous glands, tears (lysosomes), Mucus, ear wax, saliva (lysosomes), sweat, cilia, stomach acid, intestinal enzymes, defecation, urination.
Define Immunology.
The study of all bacterial, chemical and physical events surrounding the immune phenomenon. Encompasses 2nd and 3rd line of defense - recognition/destruction.
How does your body usually tell self from non-self.
Pathogen-associated molecular patterns (PAMPs), (Peptidoglycan, lipopolysaccharide, dsRNA - things that aren’t in eukaryotic cells). Pattern-recognition receptors (PRRs) - found on our cells, able to recognize PAMPS.
What are compartments of immune system?
Reticuloendothelial system (RES) - network of connective tissue fibers connecting cells/tissues; extracellular fluid; bloodstream; lymphatic system;
What are parts of the circulatory system?
circulatory system (heart,vessels); Lymphatic system (lymph nodes, vessels); WHOLE BLOOD (plasma - water, proteins, globulins, albumin, clotting factors (fibrinogen), hormones, nutrients, ions, gases, wastes (urea) - BLOOD CELLS (produced from stem cells in bone marrow) erythrocytes (RBCs), Leukocytes (WBCs)
List types of leukocytes.
Granulocytes - noticeable granules and lobed nuclei, include neutrophils (phagocytes)/eosinophils(inflammation - destroy large eukaryotic pathogens)/ basophils (inflammation - mast cells - similar to basophils but are nonmotile - directly release histamine). Agranulocytes - non0visible granules; non-lobed nuclei - Monocytes - macrophages (dendritic cells trap pathogens), Lymphocytes - specific immunity (T-cells - cell mediated immunity and B-cells produce immunity).
List functions of the lymphatic system.
Return extracellular fluid to bloodstream, “drain-off” for inflammatory response, Surveillance and protection from pathogens.
Discuss lymphatic fluid.
plasma-like. similar to blood but NO RBCs.
What is the “pump” of the circulatory system?
The large muscles.
LIst the organs of the lymphatic system.
Primary - site of origin of lymphocytes - Bone marrow (B cells), Thymus (T cells); Secondary - lymph nodes - clusters of bean shaped organs that filter lymph and provide niches for immune reactions; Spleen - filters blood to remove pathogens and worn out RBCs; Miscellaneous, tonsils, GALT,
Discuss second line of immune defense.
Involves physical and chemical defenses. Relies on recognition of invaders - but still non-specific. TLRs (Toll-like receptors) Identify the enemy as an enemy and begin various processes.
List some non-specific internal defenses.
Inflammation, fever, phagocytose, interferon, Complement.
List signs of inflammation.
Rubor (redness), Calor (warmth), Tumor (swelling), Dolor (pain) - maybe loss of function.
List functions of the inflammation response.
Mobilize and attract immune components to site of injury/infection, Initiate repair of damaged tissues and remove harmful substances, Destroy microbes and prevent further invasion.
Discuss states of inflammatory response.
1. Vascular changes (cytokines and chemical mediators)
Discuss chemotactic chemokines
attract WBCs and platelets to area - chemotaxis - migration of cells due to chemical stimulus; diapedesis - WBC warping, changing shape to change function.
What does exudate do?
It’s the result of edema, dilutes toxins, fibrin traps microbes, neutrophils begin phagocytosis
Define pyogenic.
Pus-forming.
Major events of inflammation.
injury/immediate reactions, vascular reactions, edema/pus formation, resolution/scar formation.
Define fever.
Abnormal elevation of body temperature.
Where is the body’s thermostat?
Hypothalamus
Define pyrogen.
circulating molecules that reset the hypothalamus’ “thermostat.”
What is an exogenous pyrogen?
From outside the body - causes a fever.
What is an endogenous pyrogen?
From inside the body - released by monocytes, neutrophils, etc.
List benefits of fever.
Inhibits multiplication of some organisms. Impedes nutrition of some bacteria by limiting iron availability, increases host metabolism and stimulates immune reactions (increase hematopoiesis and phagocytosis.)
Discuss phagocytosis.
Function of neutrophils and macrophages (monocytes). Mechanism is chemotaxis - chemokines, PAMPs, Ingestion (pseudopodia form phagosome - Digestion (phagosome fuses with lysosome) - ospsonization - pathogens are altered by molecules that enhance phaygocytosis.
Discuss Interferons.
Discuss the third line of immune defense.
Immunocompetence - ability of body to react to foreign substances (antigens); T and B cells go through selective process specializing them to interact with antigens.
Discuss characteristics of specific immunity
1st time exposed, body goes through regular process, second time it’s much faster - “memory”
Discuss active immunity.
Natural - exposure, have the disease. Artificial - immunizations.
Discuss passive immunity.
Someone else’s antibodies - natural from mother. Injected with antibodies from another source. Short lived.
Discuss the concept of self vs. non-self.
Major Histocompatibility Complex (MHC) - also called Human leukocyte antigen. Series of glycoproteins on all cells (-RBCs). Class I MHC - protein markers found on all nucleated cells, combinations are unique on each individual, identifies “self.” Class II MHC - immune regulatory receptors found only on macrophages and dendritic and B cells, APCs - antigen presenting cells, present antigens to T cell during immune response.
Discuss Immune response system.
Lymphocytes involved in specific immunity - begin development in bone marrow. B cells complete development in bone marrow - receptors bind free antigens. T cell complete development in Thymus - receptors bind processed antigens on infected cells and APCs
Define self-tolerance.
When your immune system recognizes self, but not too strongly.
Define immunocompetence.
Must recognize foreign markers and react.
What acts to stimulate the immune system.
antigens.
Discuss cell-mediated immunity.
Function of the T cells. Cell-to-cell combat.
Discuss humoral (anti-body mediated) immunity.
Function of B cells. Chemical warfare.
What is the APC and it’s role?
Antigen presenting Cell, Antigen (foreign cell) ingested by a macrophage, macrophage processes antigen and inserts it on cell surface on MHC II (APC), APC contacts and binds to proper CD4 receptor on T-helper cell. Cytokines produced - interleukins (APC - interleukin1, Th cell - interleukin 2)
Discuss B-Cell responses.
Large, complex antigen may directly stimulate B cell - most antigens aren’t complex, response is weak. Usual route of stimulation is interleukins from CD4 cells (T-helper cells), B cell processes and present antigen on MHC II, APC stimulates CD4 cell.
What two types of cells do B cells develop into?
Memory B cells, Plasma cells (secrete antibodies, proteins that inactivate antigens)
Discuss cytokines.
Stimulate production of more CD4 cells (T-helper 1 & 2 cells), Stimulate production of CD8 (cytooxic T cells (Tc cells), Stimulate production of CD4 and CD8 - memory cells.
Discuss Cytotoxic T cells.
Triggers apoptosis of target cell by secreting perforins (proteins that punch holes in target cell membrane) and secretion of Granzymes (digest proteins causing target cell to lose selective permeability and trigger apoptosis.
What might be targeted by T-cytotoxic cells (CD8)?
Tumor, Cells with intracellular parasites (rickettsia, mycobacteria, viruses, chlamydia.), Fungi, Protozoa,
Define apoptosis.
Cell suicide.
Define anamnestic response.
Secondary response - just a memory of the antigen.
What is therapeutic manipulation?
Exposing person to antigenic but non-pathogenic material to stimulate specific immunity.
What are vaccine types?
Killed cells, inactive viruses. Live, attenuated cells or viruses. Antigen molecules from pathogen. Genetically engineered antigens.
Discuss the human as a host.
Constant exposure to microbes - there are “colonists,” “transients,” and “invaders.” Pathogens penetrate host and enter tissues and multipley.
Define disease.
Any deviation from health - many causes - infection, diet, genetics, aging.
Discuss normal flora.
Microbes living in and on body. Transient (temporary), Resident (always present). Come into the world sterile (exposed areas acquire flora, closed areas remain sterile.
Define microbial antagonism.
“good” microbes prevent colonization of “bad” microbes.
What types of microbes are common on the skin?
GPB, GPC, Staphylococcal sp;, cornebacterium, Propionibacterium
What types of microbes are common in the alimentary tract?
Mouth - everything - mostly streptococcus. Large intestine - anaerobic GNB,
What flora is most common in the large intestine?
anaerobic GNB,
What microbes are in your respiratory tract?
Upper - normal flora, Lower is supposed to be sterile.
What microbes are common in the genitourinary tract?
Vagina conditions change with age. When menstruating - Lactobacillus, Nonmenstruating - skin flora. Urethra - normal skin flora and sometimes coliforms (if they don’t wipe right).
What are (supposedly) sterile areas of the body?
Body cavities with serous membranes. (thoracic, abdominal, joint, pericardium, closed organs, blood, CSF, urine
What is an opportunistic pathogen?
If you are healthy, it won’t cause sickness. Causes infection in immuno-compromised host. Normal flora in the wrong place
Discuss the disease process.
Enter (portal of entry, mouth, wound, etc.), Adhesion to tissues, multiplication, infection of target, disease (symptoms), portal of exit (infection to others)
List portals of (disease) entry).
Breaks in skin and mucous membranes. Natural opening (GI respiratory, GU tracts), Cross placenta, Birth canal.
What are the most common things picked up by babies in birth process?
STORCH. Syphilis, toxoplasma, others (HepB, HIV), Rubella, Cytomegalovirus, Herpes
Define “Infectious Dose.”
Minimum number of organisms required to cause disease, varies from organism to organism. (20 for M. tuberculosis, 1000 for N. gonorrhoeae. Less than “ID,” no disease, More than “ID” - may get more rapid onset.
How do microbes “bind” to host?
Bacteria (fimbriae, flagella), viruses (receptors), Protozoa (organelles for locomotion), Helminths (hooks and suckers)
How does a microbe invade (become established in) a host?
Evasion of host defenses, (antiphagocytic factors), Kill phagocytes (leukocidins (toxic substances to WBCs), can inhibit engulfment by phagocytes (secrete a surface layer (slime or capsule), Survive inside phagocytes, ingested but further degradation prevented
Discuss toxins.
Poisoning cells, toxignecity, toxemia (spread in circulating blood, intoxication, spread by ingestion.
What type of organism most frequently produces exotoxins?
gram positive.
Discuss exotoxins.
Secreted, gram posiitive organisms mostly, heat labile, potent (damage cells or disrupt metabolism), tissue specific (neurotic, nephrotoxic, etc>)
Discuss endotoxins.
Released when cell dies, gram negative cells (LPS), Heat stable, Systemic effects.
Define injurious host response.
Damage and/or disease often the result of the immune responses, pathogenicity not an inherent trait of microbe but a consequence of interplay between microbe and host (pneumoniae - capsule prevents phagocytosis, causes constant influx of fluid into lungs).
The more virulence factors and organism has, the more severe the _________.
Disease.
Discuss the process of infection and disease.
Incubation period (contact to symptoms), Prodromal stage (I think I’m coming down with something stage), invasion (maximum symptoms - diagnosis), Convalescence (getting better - possibly still contagious).
Discuss patterns of infection.
Local infection - confined to specific site or tissue. Systemic infection (spreads to several sites or tissues), Focal infection (local infection that could spread - ie, strep throat - scarlet fever), Toxemia, pathogen remains at local infection site, but toxins spread causing focal infection.
What is a mixed infection?
Polymicrobial - more than one organism involved, e.g., dental carries, gas gangrene. Organisms show synergism (1 makes it easier for 2 to thrive).
Define primary infection.
Initial infection.
Define secondary infection.
complicates primary infection, often involves opportunistic pathogens.
Define acute infection.
Rapid, severe, short-lived.
Define chronic infection.
persistent, slow progress.
Define subacute infection.
onset less rapid than acute, but doesn’t last super long.
What is a sign of disease?
Objective, can be noted by an observer.
What is a symptom?
Subjective, felt/sensed by patient.
What are warning signals of disease?
signs & symptoms, inflammation (nonspecific response to damage, edema, granulomas, abscesses, lymphadentis, lesions, skin rashes, eruptions)
Leukocytosis
up in WBCs
Leukopenia
down in WBCs
Septicemia
blood infections - microbes in igh numbers in blood and mulitplying
Bacteremia, viremia
microbe present, not necessarily multiplying, some diseases are asymptomatic or subclinical
Portal s of exit
How a pathogen leaves the host to spread. Secretions (respiratory/salivary), excretion (fecal), Discharges (vaginal/semen), sloughed tissue (warts, boils, etc.)
Discuss the persistence of infection. What’s latency?
State of being present but innactive and not multiplying, may periodically become reactive, herpes, malaria, chicken pox
What is a disease reservoir?
A place where the microbe can just “hang out” - humans can be asymptomatic carriers, chronic carriers (Typhoid Mary), Passive carriers (poor hand hygiene). Animals (vector - carrier, either biological or mechanical), animal diseases that humans can contract, Non-living - environment (soil, water)
Define Zoonoses.
Animal diseases transmittable to humans.
List non-living reservoirs.
Soil, water
Define communicable disease.
Host to host transmission.
Define contagious disease.
Highly transmissible, doesn’t require host to host to contact.
Non-communicable disease.
Acquired from environment (giardia from dirty water), or from your own flora.
Discuss direct transmission.
Skin or mucous membrane contact between hosts; sneezing, coughing; crossing placenta.
Discuss indirect transmission.
Vectors (living animal), Fomite (inanimate object), Vehicle - inantimate material (food, water, air) - droplet nuclei (dried microscopic residues, aerosols (fine dust moisture)
Define droplet nuclei.
When sneezed or coughed, etc. germs dry in air and remained suspended.
Define nosocomial infections.
Result of stay in a hospital or long-term care medical facility, AKA - hospital acquired infections, Average of 5% of patients.
Why is nosocomial infection so common?
Collection of compromised host, availability of endogenous and exogenous organisms., invasive treatment methods
List some common HAI organisms.
E. coli, and other coliforms, Pseudomonas, Staph. aureus, Streptococcus (Enterococcus)
List ways to prevent hospital acquired infection.
Surgical asepsis (sterile technique), Medical asepsis (lower load of infectious agents), Decontamination procedures, isolation procedures, contaminated disposal procedures, HANDWASHING, universal precautions (up)
Define epidemiology.
Study of etiology and transmission of disease.
What is CDC?
Centers for Disease Control.
MMWR - Morbidity and Mortality Weekly Report.
Define disease prevalence.
Number of existing cases in a population.
Define disease incidence.
Number of new cases over a certain period of time.
Define Endemic.
Steady frequency of disease over long period of time. Certain number of cases always present.
Define Epidemic.
More cases than expected.
Define Pandemic.
World-wide epidemic.
What are sporadic outbreaks of disease?
No pattern to outbreaks.
Discuss investigation of disease outbreak.
Disease reported, may have to work backward to collect sufficient data, look for clusters of cases to determine mode of spread, determine possible cause.
What are Koch’s Postulates?
Isolate same microbe from every case of disease, cultivate microbe artificially in pure culture, infect healthy organism with microbe and cause disease.
What are exceptions to Koch’s Postulates?
Humans the only host, microbe will not grow artificially, cant not isolate causative agent in pure culture.
What are the most common GPC?
Staphylococcus, Streptococcus, Enterococcus
What are the most common GNC?
Neisseria, Branhamella, Moraxella, Acinetobacter.
Discuss Staphylococcus.
Spherical cells arranged in irregular clusters; common inhabitant of skin and mucous membranes; Facultative anaerobes, produce catalase.
Discuss Staphylococcus aureus.
Worst - optimum of temperature of 37 (Range 10-46), Extremely resistant - utilize a variety of macromolecules, tolerate high salt and extreme pH, high temps, desiccation (drying), resist many disinfectants, colonize many areas of body (nares, skin, nasopharynx, intestines).
What are pathogenicity and virulence factors of Staph a?
Enzymes (coagulase, hyaluronidase, staphylokinase, many others like lipase, DNase, penicillinase...); Toxins (hemolysins, leukocidins, exotoxins)
List examples of localized cutaneous infections.
abscess, folliculitis, furuncle, carbuncle, bulbous impetigo
Discuss systemic infections.
Most are focal infections (start localized and move), Osteomyelitis, Nasopharynx common colonization site. Bacteremia - high mortality rate - hospitalized pts with chronic disease, liver, kidney, heart, spleen, joints.
Discuss Toxigenic Staphylococcal Diseases.
Enterotoxins (food poisoning), Exfoliative toxin (scalded skin syndrome), Toxic shock toxin II (toxic shock syndrome)
Discuss Staphylococcus epidermidis.
No coagulase or other virulence factors, Part of normal flora (skin, mucous membranes), Infections of indwelling devices. Infections of indwelling devices, Bacteremia, endocarditis, UTI
Discuss Staphylococcus asaprophyticus.
Coagulase-negative, infrequent resident of skin, UTI, subacute, chronic, young, sexually active females.
Discuss MRSA.
Methcillin resistant Staph aureus, Nosocomial. 95% of S. aureus resistant to penicillin - MRSA also resistant to methcillin, oxacillin, gentamicin, cephalosporins, tetracycline, erythromycin. Treat with nancomycin.
Discuss treatment and prevention of infections.
Drain abscesses, treat systemic diseases with antibiotics (lengthy), Humans principle reservoir (HANDWASHING, dressing disposal, isolation; attention to indewelling devices; carriers - ID, restrict, treat.
Discuss Streptococcus.
Spherical cell arranged in chains, facultative anaerobes, some normal flora, some pathogens, sensitive to heat, drying, etc. (not as resistant as staph), Do not readily develop drug resistance. Also identified by hemolysis and Lancefield groups.
Discuss Streptococcus pyogenes.
Group A, Beta hemolytic, humans only reservoir (carriers), Most serious pathogen of genus, Strict parasite. inhabits throat, nasopharynx, skin.
What are pathogenicity and virulence factors of Strep pyogenes?
Surface proteins (resist lysozyme, provide adherence), Toxins (streptolysins - beta hymolsysins), erythrogenic or pyrogenic toxin, Estracellular enzymes (streptokinase (digest clots), hyaluronidase.
What’s the most common skin infection?
Pyoderma - epidermis (Streptococcal impetigo, highly contagious) Not common in adults in industrialized countries) -
List some skin infections.
Pyoderma - epidermis (Streptococcal impetigo, highly contagious) Not common in adults in industrialized countries) - Erysipelas - dermis, subcutaneous (enters through wound). Necrotizing fascitis - can be fatal (flesh eating). Pharyngitis “strep throat”
Discuss Clostridium botulinum
Intoxication - improperly canned food, Botulin is a neurotoxin, Botulism (low acid canned food and vacuum packed foods, appearance, flavor of fodo not changed)
Discuss Infant botulism.
Infant ingests spores in food, spores germinate in intestine, intestinal flora not fully developed, C. botulinum grows to unusual numbers (toxin produced) - produces flaccid paralysis - floppy baby syndrome
Discuss wound botulism.
When Clostridium botulinum infects wound.
What are other forms of clostridial food poisoning.
Clostridium perfingens - meats and vegetable cooked and improperly cooled or not sufficiently and reheated, Ingest live cells - enterotoxin released in intestine. Rapid recovery (usually)
Discuss Listeria monocytogenes.
Widely distributed in nature, resistant to heat, cold, salt, pH extremes, bile. Beta hemolytic intracellular. Causes Listeriosis - associated with dairy products and certain deli, mild flu-like symptoms. More dangerous in immunocompromised.
Discuss Erysipelothrix rhusiopathiae
Widely distruibuted in animals and environment, pigs a primary reservoir - Erysipeloid - infects scratch - painful lesion, usually heals without complication. High risk are pig handlers.
Discuss Corynebacterium.
Corynebacterium diphtheriae - Diphtheria - local infection with toxemia, droplet spread - fomites and milk, organism needs phage to produce toxin, toxin targets heart and nerves, treated by antitoxin, prevent-vaccine. Diphtheroids are non-pathogenic species.
Discuss Propionibacterium.
Normal skin flora, lives in oil glands, contributes to inflammation of acne, breaks down fats in skin oil to fatty acids which further irritate skin.
Discuss Mycobacterium.
Cell wall contains mycolic acid - acid fast, also contributes to resistance, Mycobacterium tuberculosis causes Tuberculosis - primary tuberculosis, reactivation tuberculosis, extrapulmonary tuberculosis.
Discuss the diagnosis of TB.
Skin test (little bubble), X-rays, acid-fast stain, positive culture.
Discuss TB treatment.
At least 2 drugs for 6-24 months. Isoniazid (INH), Ethambutol, Rifampin, strptomycin
Discuss Mycobacterium leprae.
Hansen’s disease - Leprosy. Chronic, progressive disease of skin and nerves. Tuberculoid leprosy (thickening of skin), Lepromatous leprosy (degeneration of tissues), Borderline leprosy.
How do you diagnose leprosy?
History, Biopsy, Feather
What is treatment for leprosy?
Dapsone (DDS), Rifampin
What is NTM?
Non-tuberculous mycobacteria, Mycobacterium avium-intracellulare (Aids marker disease), Mycobcterium kansasii - mimics t.b. but noncommunicable. Mycobacterium fortuitum usually surgical infection in the immunocompromised.
What is Mycobacterium marinum.
Swimming pool granuloma. - Infection in a cut.
Discuss Mycobacterium scrofulaceum
lymph nodes- children, Japan, Great Lakes, Canada
Mycobacterium paratuberculosis.
Crohn’s disease.
Discuss Actinomycetes.
filamentous GPB - Actinomyces are normal oral flora, soil, endogenous infections of the head like Cervicofacial disease (actinomycosis), Bind to teeth - dental plaque. Nocardia - in soil, weakly acid fast, opportunistic pneumonia - pulonary nocardiosis, mycetoma
What is “mycete?”
fungus-like species
All GNB produce _________.
Endotoxins.
Define Iatrogenic infection.
Accidental medical treatment (knick in colon, etc.)
Gram negative septicemia may lead to _______ ________.
septic shock.
Septic shock can be _______.
fatal.
What is GNB endotoxin made of?
lipopolysaccharide in outer cell wall.
Discuss Aerobic, GNB, non-enteric.
Pseudomonas, Burkholderia, Brucella, Fancisella, Bordetella, Legionella
What are some Oxidase positive, non-enteric.
Pasteurella, Haemophilus
Discuss Pseudomonads.
Free-living, soil, seawater, freshwater, colonize plants and animals, single polar flagellum, oxidase and catalase positive, produce pigments
Discuss Pseudomonas aeruginosa.
Highly opportunistic, burn patients, cystic fibrosis, swimmer’s ear, associated with water therapy, Highly drug resistant - must test for sensitivity.
Discuss Burkholderia cepacia.
Closley related to Pseudomonas, Common hospital contaminant, weak pathogen, Lung infection with patients with damages lungs (CF, emphysema)
Discuss Burkholderia pseudomallei
Soil and water, tropics, Causes melioidosis - wound infections from penetrating wounds, lung infections form inhaled environmental source. Mostly Africa, India, Middle East, Southeast Asia
Discuss Acinetobecter baumanii
C or B looking, Environmental contaminant, Highly resistant, persists on surfaces, Severe wound infections - military personnel in Iraq, Afghanistan,
Discuss Stenotrophomonas maltophilia.
Contaminant of disinfectatns, dialysis equipment, respiratory equipment, water dispensers, catheters
Discuss Brucella.
Zoonosis, Bang’s disease in cows (Elk, deer, etc.), Brucellosis, Malta fever, undulant fever. Associated with handling contaminated meat or milk, Lives in phagocytic cells - difficult to culture. Dx - patient history, serology.
Discuss Francisella tularensis.
Tularemia, “rabbit fever,” Zoonosis of several mammals - may be transmitted by arthropod. Most commonly by ticks, but maybe mites. Can penetrate intact skin, Aerosols - handling infected carcass, Small infective dose - bioterrorism. Treat with antibiotics, vaccine available.
TPA fluid (used to supplement nutrition) has a high protein content and cannot be sterilized in the autoclave. An appropriate sterilization technique would be:
filtration.
R Factors are:
Plasmids that transmit resistance to antibiotics from one microbe to another.
Who is responsible for phagocytosis?
neutrophils
Discuss Bordetella pertussis.
Whooping cough, Highly communicable, Vaccine available, can be severe, life-threatening disease - mainly in infants. Virulence factors - receptors for ciliated respiratory epithelial cells, Toxins destroy/dislodge ciliated cells.
Discuss Legionella
Fastidious organism, widely found in aqueous environmental habitats (building ACs, misters, spas), spread through aerosols of environmental water, Legionnaire’s pneumonia (high mortality rate if untreated), Pontiac fever (less serious), Dx by fluorescent stain, DNA probe.
Discuss Family Enterobacteriaceae
Facultative anaerobes, common in nature, normal bowel flora, true or opportunistic enteric pahtogens, coliforms rapidly ferment lactose (normal enteric flora, opportunists), Non-coliforms slow or no lactose fermentation (normal flora, true & opportunistic pathogens).
Discuss Antigenic structures and Virulence fatoers.
Antigens - O antigen - somatic, cell wall, H antigen - flagellar, K antigen - capsular, fimbrial. All have O antigens, H & K vary; O antigen is lipopolysaccharaide; responsible for endotoxic shock; Antigens useful in serotyping and epidemiology.
What family is responsible for half of nosocomial infections?
Enterobacteriaceae
Of GNB, what us the most common infective type?
E. coli
Discuss E. coli.
Escherichia coli, Best known, widely used in lab studies (genetic engineering), Not most common coliform, 150 strains (some pathogenic), Virulence factors obtained through plasmid transfer.
Discuss Enterotoxigenic strains of E. coli.
Mimics cholera, secretion/fluid loss
What are the four main categories of E. coli?
Enterotoxigenic, Enteroinvasive, Enteropathogenic, Enterohemorrhagic
Discuss Enteroinvasive strains of E. coli.
Similar to Shigella dysentery, mucosal ulceration.
Discuss Enteropathogenic strains of E. coli.
Infantile wasting.
Discuss Enterohemorrhagic strains of E. coli.
Permanent kidney damage.
List some clinical Diseases caused by E. coli.
Infantile diarrhea (Tropics, no normal flora, adults may harbor organism), Traveler’s diarrhea (Enterotoxigenic strain), Best response - Pepto Bismol; Food Infections (Ground Meats), E. coli O157:H7, Hemolytic uremic syndrome, UTIs
Discuss Klebsiella
Enteric and respiratory flora; secondary infections; Nosocomial pneumonia and others.
Discuss Enterobacter.
Opportunistic UTI, Lethal if it enters the bloodstream.
Discuss Citrobacter.
Opportunist in UTI and bacteremia, Infects mainly immunocompromised.
Discuss Serratia.
Super common, but opportunistic, Nosocomial, highly drug resistant, Infects mainly immunocompromised. (burn victims, alcoholics)
Discuss Noncoliform opportunists.
Proteus, Providencia, Morganella - normal enteric flora, non-coliforms, lactose negative, normally harmless, Opportunistic UTI, wounds infections, pneumonia, septicemia, Proteus UTI, stimulates renal stones and damage due to urease raising urine pH.
Discuss Salmonella thypi.
inhabits the lympathic tissues of the small intestine, liver, spleen, and bloodstream of infected humans. Not known in animals, most common in developing countries with poor sanitary systems and lack of antibiotics - travelers
Discuss Salmonella enteriditis.
Invades small intestines, food poisoning - poultry, eggs, Contamination with rat feces, Reptiles - Salmonella, Arizona.
Discuss Shigell.
Invades large intestines. Bacillary dysentery, Severe cramps, water diarrhea, Humans (and apes) only source, Lax sanitation.
Discuss Yersinia entercolitica.
Zoonosis, farm animals, pets, wild animals, fish; Ingest fruits, veggies, drinking water; Mimics appendicitis.
Discuss Nonenteric - Yersinia pestis.
Bubonic plague, Several virulence factors, mice and other mammal reservoirs, fleas act as vectors; enters lymph - necrosis of lymph nodes with swelling (bubo)
Discuss Pasteurella.
Normal oral flora in animals, associated with animal bites.
Discuss Haemophilus.
H. influenzae. Causes meningitis, otitis media, epiglottitis, sinusitis, H. aegypticus - pinkeye; H. ducreyi - chanchroid - STD; H. parainfluenza, H. aphrophilus (endocarditis from oral injury, disease, surgery)
Discuss Scarlet Fever.
Result of strep throat, Needs prophage to code for toxin, erythrogenic toxin, high fever and bright red rash.
Discuss Pneumonia.
Usually secondary infection.
List some systemic infections.
Scarlet fever, pneumonia, Streptococcal toxic shock syndrome,
Discuss Streptococcal Toxic Shock Syndrome.
Result of profound bacteremia and deep tissue infection, rapid progression to multiple organ failure - 30% mortality rate.
Define Sequelae.
a pathological condition resulting from a disease, injury, or other trauma.
Discuss Rheumatic fever.
Delayed inflammation of joints, heart, subcutaneous tissues.
List some sequelae of Streptococcal Infections.
Rheumatic fever, Glomerulonephritis,
Discuss Glomerulonephritis.
Glomerulus damaged by Ag-Ab complexes - fails to filter properly, May clear or become chronic
Discuss Streptococcus agalactiae.
Group B, Beta hemolytic, May colonize vagina, pharynx, and large intestine; Infections (neonatal meningitis, screen in third trimester)
Discuss Enterococcus faecalis.
Group D, usually gamma hemolytic but may be beta hemolytic; normal colonist of large intestine; Infections (elderly undergoing surgery, UTI, wound infections, endocarditis, appendix, blood
Discuss Beta Hemolytic Strep.
Group C and Group G; Common in domestic animals; May colonize nasopharynx; Not pathogenic for humans.
Discuss treatment and prevention of Beta Hemolytic Streptococcus.
Diseases have rapid onset, Treat early to prevent systemic disease; Penicillin drug of choice; Prophylaxis for rheumatic fever; Isolate patients with wound infections; Identify carriers, restrict, treat
Discuss Viridans Streptococci.
Alpha hemolytic; No Lancefield carbohydrates; Normal oral flora; Opportunistic pathogens; Common species (Strep. mitis, Strep. salivarius, Strep. mutans, Strep. sanguis, Strep. milleri)
Discuss the pathology of Viridans Strep.
Not invasive, Enter bloodstream through dental or oral surgery - SBE Subacute Bacterial Endocarditis (biofilm on valves), Dental plaque and dental caries.
Discuss Streptococcus pneumoniae.
Alpha hemolytic; 5-50% of population carries as normal flora of nasopharynx, Susceptible to drying, pathogenic strains encapsulated
Discuss the pathology of Pneumonia.
60-70% of all bacterial pneumonias, aspirate mucus with organisms - Lobar pneumonia (excessive fluid), Consolidation pneumonia - bacterial and immune cells solidify.
Discuss otitis media.
Particularly children under 2, may become meningitis. Treatment and prevention - mucus and cilia protect respiratory tract, Penicillin drug of choice, vaccine available. High risk hosts, Recent one for children (Prevnar)
Discuss Neisseria.
GN, Residents of mucous membranes, warm-blooded animals, two species primary human pathogens, all other species commensals, Bean-shaped diplococci, aerobic or microaerophilic.
Discuss Neisseria gonorrhoeae.
STD - Gonorrhea, Strictly a human disease, fimbriae and other attachment molecules increase adherence, evade phagocytosis, protease inactivates antibody (IgA), Males - urethritis with discharge, Females - UTI, ascending infection (Salpingitis, PID, sterility), Homosexuals, postatitis, pharyngitis, gingivitis; Self-inoculation of eyes; Arthritis (rare endocarditis, meningitis), Infants may acquire in birth canal neonatal ophthalmitis.
How is Gonorrhea diagnosed?
Classic Gram stain (particularly in males); Culture-Thayer-Martin Media. Inoculate directly-dies quickly, require increased CO2 atmosphere.
Discuss treatment of Gonorrhea.
Pencillin drug of choice; Penicillin and tetracycline resistant, STD usually mixed infections (Chlamydial) - Cephalosporin + tetracylcline, Reportable disease, Prevention-safe sex
Discuss Neisseria meningitidis.
Sporadic or epidemic meningitis (late winter, early spring) Harbored in nasophyrnx - carriers, target population-children and young adults 10-20 years old, Respiratory spread, Bacteria enter blood - bacteremia (endotoxin), Bacteria cross blood-brain barrier, enter meninges causing meningitis, Damage to blood vessels cause petechiae and Ecchymoses, Damage to adrenals, shock, necrosis, cardiac failure
How is Meningitis diagnosed and treated?
GNC in CSF, Culture. Natural immunity develops - opsonizing antibodies; Aggressive treatment required (Penicillin drug of choice, IV Chloramphenicol), Vaccines for high risk groups, Rifampin or tetracycline - prophylaxis.
Discuss Branhamella.
Normal nasopharyngeal flora - Bronchopulmonary disease, Meningitis, Endocarditis, Otitis media. Opportunist in adults with leukemia, alcoholism, diabetes, rheumatoid disease.
Discuss Moraxella.
Coccobacilli, normal on mucous membranes, Weakly pathogenic - ear infections and conjunctivitis.
Discuss Acinetobcter.
Soil, water, sewage habitat. Common contaminant, rare nosocomial infections.
What causes meningitis in infants?
Streptococcus agalactiae
Discuss Spirochetes.
Baccili, but Helical form - axial filament, Gram negative but best demnostrated by dark-filed microscopy. What else? SLIDE 1!
Discuss Syphilis.
A Spirochete - Treponema pallidum - humans are the only natural source of organism. Can cross placenta - congenital, Primary - chancre, Secondary - invades multiple tissues - fever, rash. During Tertiary or latent - gummas (
Other treponematoses
Bejel, Yaws, Pinta - non STD, seen in tropics, crowding or poor personal hygiene a factor in transmission.
List Spirochetes.
Treponematoses, Leptospira, Borrelia,
Leptospira.
Zoonosis - wild animals and some domesticated animals, mainly in tropics, organism shed in infected urine, Enters human - abraded skin, organism initially in blood and CSF then settles in liver and kidney. Long-term disability and death.
Borrelia.
Transmitted by arthropod vector, Lyme disease - B. burgdorferi - non-fatal but progressive syndrome, Bull’s-eye rash around bite site., causes arthritis, cardiac involvement. Different disease. Relapsing fever - B. hermsii. Changes surface antigens. Seen after natural disasters, Tick borne disease.
Discuss Vibrios.
Comma-shaped GNB, Tolerate salt and alkaline environments - Vibrio cholerae, Vibrio parahaemolyticus, Vibrio vulnificus.
Discuss Vibrio Cholerae.
Similiar metabolic activity to the Enterobacteriaceae, Oxidase +, Possess O and H antigens, Causes cholera, Ingest contaminated food and water - not normal flora of anyone, Cholera toxin disrupts normal physiology of intestinal cells, “Rice Water” stools, Dehydration, electrolyte imbalance - death!
Discuss Vibrio parahaemolyticus.
Acute gastroenteritits, Associated with improperly cooked or raw seafood (oysters), Seen in coastal regions, summer and early fall, vomiting, diarrhea, cramps - 24 hours, Runs course in 3-10 days.
Discuss Vibrio vulnificus.
Similar to V. parahaemolyticius, More severe in individuals w chronic disease, can be fatal.
Discuss Campylobacter.
Slender, curved GNB, Foudn in GI tract of animals and humans, Causes abortion in animals, Gastroenteritis in humans, 3 day onset. Ingest water or meat contaminated with animal feces, Usually resolves.
Discuss Helicobacter.
Curved GNB, Linked to gastric ulcers and other forms of gastritis, Mode of transmission unclear (oral-oral or oral-fecal) Dx, biopsy, Treat with antibiotics, Urea breath test.
Bacteria of Unique Morphology.
Rickettsia, Erlichia, Coxiella, Bartonella, Chlamydia
Ehrlichia
Emerging tick borne disease, lives in WBCs - no sequelae
Discuss Rickettsia.
Rickettsia (true parasite, live inside cells), arthropod vector (usually ticks), Various fevers - typhus, endemic typhus, scrub typhus, Rocky Mount Spotted Fever
Discuss Coxiella
Q fever - Transmitted in milk products
Discuss Bartonella
Trench fever, Cat scratch fever, Bacillary angiomatosus - new AIDS pathogen, Severe cutatneous and systemic infections - not usually life threatening.
Discuss Chlamydia.
Obligate parasite, Elementary body - infective, Reticulate body - metabolically active form in cell,
List AIDS marker pathogen/s?
Bartonella
Discuss Chlamydiolphila
New genus- used to be Chlamydia, C. psitttaci - parrot fever (orinthosis), C. pneumonia- respiratory
Discuss Mycoplamsa.
Bacteria, but lacking cell wall, pleomorphic. Parasites of plants and animals, M. pneumonia - primary atypcial pneumonia - “walking pneumonia”, M. hominis, Ureoplasma ureolyticu, Weak, STD
Discuss L Forms.
Exposure to drugs or enzymes may result in cell-wall deficient bacteria. Organism may regain cell wall, - Group A Strep, Corynebaterium, Proteus fairly common, Cell wall deficient organism found in Crohn’s disease.
Discuss Dental Disease.
Mixed infections, Multiple interactions involving anatomy, diet, physiology, and bacterial flora. Destruction of tooth enamel sets up destruction of deeper tissues. Pellicle formation - mucus immediately coats teeth, salivary proteins form pellicle - Plaque formation - Strep and Actinomyces begin bacterial plaque - other bacteria adhere. Acid production - Lactobacillus, Streps form acid. Enamel etching - acids etch enamel.
Discuss Periodontal Disease.
Have some degree by age 45, Bacterial colonization, Varying degrees of inflammation, Gingival damage. Plaque can become calculus, Inflammation of ginigiva allows invasion of flora. Periodonititis - acute necrotizing ulcerative gingivitis.
List fungi that tend to go systemic.
Histoplasma Coccidioides Blastomyces Paracoccidioides
List common subcutaneous fungal infections.
Sporothrix schenckii Chromoblastomycosis Phaeohyphomycosis Mycetoma
List common cutaneous fungal infections.
Trichophyton Microsporum Epidermophyton
List common superficial fungal infections.
Malassezia furfur Trichosporon beigelii Piedraia hortae
List common fungal opportunists.
Candida Cryptococcus Pneuomcystis Aspergillus Mucormycosis(Rhizopus Absidia Mucor)
List Chromoblastomycosis
Curvularia Alternaria Exophiala
List mycetomas.
Pseudoallescheria Madurella Actinomycetes
List groups of protazoa.
Sarcodina, Mastigophora, Sporozoa, Coccidia, Ciliata
List examples of Sarcondina.
Entamoeba histolytica Naegleria fowleri
List examples of Mastigophora.
Trichomonas Giardia Trypanosoma Leshmania
List examples of Sporozoa.
Plasmodium.
List examples of Coccidia.
Toxoplasma Sarcocystis Cryptosporidium Isospora Cyclospora Babesia
List examples of Ciliata.
Balantidium coli.
List Intestinal Nematodes.
Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis Hookworms—(Necator,Ancylostoma) Strongyloides stercoralis, Trichinella spiralis
List Types of Heminths.
Intestinal Nematodes, Tissue Nematodes, Trematodes - flukes, Trematodes - cestodes.
List examples of Nematodes.
Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis, Hookworms—(Necator, Ancylostoma), Strongyloides stercoralis, Trichinella spiralis
List examples of Tissue Nematodes.
Wuchereria bancrofti Onchocerca volvulus, Loa loa, Drancunculus medinensis
List examples of Trematodes - Flukes.
Schistosoma, Opisthorchis (Clonorchis) sinensis Fasciola hepatica, Paragonimus westermani
List examples of Trematodes - cestodes.
Taenia saginata Taenia solium Diphyllobothrium latum