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76 Cards in this Set
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Motility
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A biological term which refers to the ability to move spontaneously and actively, consuming energy in the process. It can apply to either single-celled or multicellular organisms. Motile marine animals are commonly called free-swimming. The opposite of motility is sessility. Examples of motility include:
* Sperm cells, propelled by the regular beat of their flagellum * The bacterium E. coli, which swims by roting a helical prokaryotic flagellum |
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Principles of a Gram Stain
(what dyes do you use, what is the point of each dye) |
Distinguishes gram positive from gram negative bacteria.
Consists: Primary stain - crystal violet (stains all bacteria purple) Mordant stain - iodine (intensifies the ionic chemical bond between crystal violet and bacteria causing stain to bind more tightly to the cell) Decolorizer - ethyl alcohol (removes the stain from gram negative bacteria making them colorless) Counterstain - safranin (stains any colorless cells, therefore gram negative cells making them red) |
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Resolving Power/Resolution
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The closest distance 2 objects can be, where we can still see them as separate objects. (ex: resolution of human eye is 0.1 mm)
Using a microscopic lenses: Resolving Power = Wavelength/2*Numerical Aperture |
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Brightfield Microscope
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General microscopy, especially for stained cells
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Darkfield Microscope
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Especially good for motile cells
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Phase Contrast Microscope
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Shows details of non-stained cells
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Fluorescent Microscope
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Fluorescent stained cells or structures will glow with color
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Transmission Electron Microscope
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Shows internal cellular organelles greatly magnified; can also be used to observe viruses in sections
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Scanning Electron Microscope
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Shows 3-D surface structures of cells or viruses highly magnified
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Acid Fast
(what is it and what are the major species that are acid fast) |
Acid Fast: refers to a microorganisms resistance to decolorizing by acidified alcohol after staining
Major Acid Fast Species: mycobacterium - different from other species in that it has a layer of mycolic acid (waxy material) outside its cell wall; when it is stained using hot carbol fuchsin, it will penetrate the cell, then when cooled acid alcohol will not decolorize the cell (hence the name "acid fast"), the procedure is finished using a counterstain methylene blue --> (acid fast bacteria are red, other bacteria are blue) |
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Which media are both selective and differential?
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EMB (Eosin-Methylene Blue) agar: selects for gram(-); differentiates between lactose fermenters by turning green from nonlactose fermenters
MacConkey agar: selects for gram(-) bacteria; differentiates between lactose fermenters by turning pink from nonlactose fermenters Mannitol Salt Agar (MSA): selects for staph, differentiates betweeen staph epi (remains red) and staph aureus (turns yellow) |
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Which media is only differential?
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Blood agar: differentiates between different hemolysis patterns
Beta = complete lysis of of RBCs (ex: S.pyrogens) Alpha = discoloring of blood agar (ex: S.viridans, S.pneumonia) Gamma = no change (ex: S.salivarius) |
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What is the Kirby-Baeur method?
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A method of antibiotic testing that uses antibiotic-impregnanted wafers to test whether particular bacteria are sensitive to specific antibiotics.
- A plate is prepared with pathogen spread all over the surface of the agar (a lawn) - Small paper discs containing antibiotic are placed on the bacterial plate - As bacteria grow, the surface of the agar becomes cloudy; however growth will be inhibited (clear zone appears) around the disc if the bacteria is sensitive (based on the diameter, it is approved as sensitive or not approved) |
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What is MIC?
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Minimum Inhibitory Concentration
The lowest concentration of an antimicrobial that will inhibit the visible growth of a microorganism after overnight incubation. |
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What are the 3 mechanisms of genetic recombination/genetic transfer?
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b. Three Mechanisms of Genetic Recombination:
i. Transduction ii. Transformation iii. Conjugation: (the only direct method of recombination) the transfer of genetic material from one bacteria to another via a conjugation pilus 1. There is always one donor and one recipient 2. Only direct method. Capable of sending large quantities of DNA (takes time) 3. F Plasmid or Fertility Plasmid: a. F+ has F plasmid and synthesizes bridge b. F- initially devoid of F plasmid, F- receives bridge and then the copy of F plasmid (once it has the F plasmid, it becomes F+) |
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What happens in Transduction?
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Transduction: the transfer of genetic material from one bacterium to another by means of a bacteriophage vector
a. In order for transduction to occur, you have to have a bacteriophage that enters lysogenic cycle, and wants to come out; can occur when extra bacterial DNA is excised as a prophage moves from lysogenic lytic b. New viral particles are synthesized c. Infection of recipient cell transfers bacterial DNA to a new cell d. Recombination results in two possible outcomes Summary of Process: 1) A phage infects cell A (the donor cell) by normal means 2) During replication and assembly, a phage particle incorporates a segment of bacterial DNA by mistake. 3) Cell A then lyses and releases the mature phages, including the genetically altered one. 4) The altered phage adsorbs to and penetrates another host cell (cell B), injecting the DNA from cell A rather than viral nucleic acid. 5) Cell B receives this donated DNA, which recombines by its own DNA. Because the virus is defective (biologically inactive as a virus), it is unable to complete a lytic cycle. The transduced cell survives and can use this new genetic material. |
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What happens in Transformation?
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Transduction: the transfer of genetic material from one bacterium to another by means of a bacteriophage vector
a. In order for transduction to occur, you have to have a bacteriophage that enters lysogenic cycle, and wants to come out; can occur when extra bacterial DNA is excised as a prophage moves from lysogenic lytic b. New viral particles are synthesized c. Infection of recipient cell transfers bacterial DNA to a new cell d. Recombination results in two possible outcomes Summary of Process: 1) A phage infects cell A (the donor cell) by normal means 2) During replication and assembly, a phage particle incorporates a segment of bacterial DNA by mistake. 3) Cell A then lyses and releases the mature phages, including the genetically altered one. 4) The altered phage adsorbs to and penetrates another host cell (cell B), injecting the DNA from cell A rather than viral nucleic acid. 5) Cell B receives this donated DNA, which recombines by its own DNA. Because the virus is defective (biologically inactive as a virus), it is unable to complete a lytic cycle. The transduced cell survives and can use this new genetic material. |
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What happens in Conjugation?
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a. Conjugation: two types
i. F+ F- : the transfer of the fertility plasmid (i.e. F plasmid) 1. The double strands of the plasmid unwind with one strand moving into the other cell 2. As the two strands unwind, the complimentary copy (second strand) gets re-made so that the DNA is stable 3. The new recipient cell takes the strand and uses its own polymerase to make an identical copy too 4. This is not the only plasmid that gets conjugated, but one of them (the most famous one from E.coli) 5. F factor: the gene that codes for construction of conjugation pilus (the connector between the cell) 6. There are many genes on the plasmid and they will get replicated a. Ex: antibiotic resistance gene hence conjugation is very dangerous because bacteria can transfer resistance ii. Chromosome: you can also transfer a chromosome 1. In order for an E.coli to do this, you have to have an F+ cell that integrates itself into the chromosome once this is done, you no longer have an F+ cell, you have an Hfr cell (High Frequency Recombinant) 2. Origin of transfer: the area where you always start the sending of the information 3. The bacteria likely will not be able to send the entire chromosome over in environmental conditions 4. The recipient cell will not be an F+ cell (in an F+ F- plasmid of transfer, the recipient will receive the whole chromosome) 5. When you transfer the DNA to a F- cell from a Hfr cell, you usually only transfer part of the chromosome over and part of the plasmid but not the whole thing therefore the recipient cell will not receive the whole F plasmid and will remain F- |
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Define the following bacterial shapes: coccus, bacillus, vibrio, spirillum, spirochete
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i. Coccus (round)
ii. Bacillus (rod) 1. Also used as species, but there are many microbes out there that have that same look but not the same species beginning iii. Vibrio (curved rod) 1. Also used as species – same rules apply as above iv. Spirillum (wavy) v. Spirochete (corkscrew) |
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Define the following cell division patterns: diplo-, strepto-, staphylo-
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IV. Prokaryotic Cell Division Patterns: they can divide and stay attached or break off
a. Diplo- : a pair with two cells attached b. Strepto- : a chain c. Staphylo- : bunches *NOTE: all pair up with coccus or bacillus |
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What is an endospore? its purpose?
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a. In 2001, there was a huge scare about Anthrax. People were sending Antrax spores in the mail that would get inhaled and would germinate and be harmful.
b. Spores for bacteria are different than spores for fungi: i. Bacteria: spore forms inside of a vegetative cell 1. Vegetative cell: bacterial cell that is alive, metabolically active, capable of reproduction, etc. 2. Endospore: an internalized structure that houses DNA and is otherwise non-metabolically active a. Once an endospore forms inside the vegetative cell, the cell dies and the endospore is left b. Think of it as a hybernating form of bacteria c. Bacillus (anthrax) and Clostridium (responsible for gangrain, tetanus, botox) are both capable of forming endospores all other types of bacteria cannot form endospores d. Purpose of Endospore: if you think the vegetative cell is going to die, sense a harsh environment/limited nutrients, package genetic material (DNA) in an endospore until better conditions reside like a seed e. Endospores can survive at 120 degrees, they are very hard to kill off III. Sporulation: the process of forming an endospore a. Replication of DNA (b/c one copy of DNA is destined to be enveloped in an endospore, but you need to still access the DNA to build the components to house the endospore) b. DNA gets surrounded by a membrane: Wrap a cell or plasma membrane around DNA and certain molecules (ex ribosomes) c. Water is drawn out to dehydrate and wrap it in a nice protective coat that is resistant to desiccation and protect the internal spore (ex: like a bean’s protective coat) to protect whatever moisture is left d. Vegetative cell lysis occurs leaving only the spore e. Once favorable conditions come in, the spore would then germinate back into a vegetative cell i. Favorable conditions: in a warm, moist environment they would probably germinate – once nutrients are available, they germinate |
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Describe the Reproduction of Bacteria.
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Reproduction of Bacteria
Bacteria reproduce asexually, through some form of cell division. One bacteria cell can theoretically turn into billions given the right environment. Lag Phase In this early phase, cells are not yet mature enough to divide. Instead, they are adapting to environmental conditions, as each type of bacteria has its own specific ideal environment in which it has evolved to grow. Water is the critical component that all types of bacteria need to survive. If the current environment has the appropriate conditions and nutrients, bacteria cells make the RNA and enzymes which enable growth and reproduction. Exponential Phase, Binary Fission The cell increases in size and mass, and produces more protoplasm. The bacterial chromosome duplicates, and a new cell wall is formed. Now there are enough components to create two equal and identical daughter cells. The cell forms a septum, separating the two nascent cells, and divides. Each daughter cell can now grow and divide again. Exponential Phase, Budding Budding is similar to binary fission inasmuch as the cell must grow and duplicate certain organelles. However, instead of dividing into two equal-sized cells, the new daughter cell starts as a small protrusion, and eventually splits off from the parent cell. An example of bacteria that does this is Streptomyces, which is used to create various antifungal and antibiotic preparations |
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Describe the major characteristics of the cell membrane.
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a. Cell Membrane (aka Plasma Membrane) – everything we know about the eukaryotic cell wall is applicable to a prokaryotic cell wall
i. Plasma Membrane is modeled as a Fluid Mosaic Model: phospholipids are always moving, proteins are embedded ii. Phospholipid bilayer: forms a basis, heads face outward, tails face inward iii. Proteins: can span the entire membrane (integral proteins – integrated), or hang outside the membrane (periphery proteins- on the peripheral) 1. Integral proteins: some are involved in molecular transport (moving molecules in and out of the cell) iv. Molecular ID Tags: tags that stick out and always have a sugar component in them (a bunch of sugars attached to the outside) |
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What is RNA polymerase? Transcription? Translation?
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RNA Polymerase: an enzyme that produces RNA from DNA in a process called transcription
Transcription: the process of transcribing DNA nucleotide sequence information into RNA sequence information Translation: the production of proteins by decoding mRNA using ribosomes and tRNA to bind amino acids into polypeptide chains |
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What is a capsule?
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A layer that lies outside the cell wall of bacteria, well organized, not easily washed off, and can be the cause of various diseases
A form of glycocalyx (carbohydrate-containing gelatinous material) Two forms of glycocalyx: 1. Slime layer: loose arrangement and easy to remove 2. Capsule: tight arrangement and very difficult to remove a. Some of these are very important for a bacteria to live b. They are not made all the time because they are so energetically expensive, but are only made when you need them to live or you’ll die |
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Types of organisms:
What is an Autotroph? What types of autotrophs do we know? What is a Heterotroph? What types of heterotrophs do we know? |
d. Types of Organisms:
i. Autotroph: uses CO2 as carbon source 1. Photoautotroph: microbe that uses sunlight energy 2. Chemoautotroph: microbe that uses reduced inorganic substances (i.e. metals and oxidizes them) ii. Heterotroph: get carbon from ingested biomolecules 1. Chemoheterotroph: harness energy from breaking down complex biomolecules 2. Note: all pathogenic microbes are chemoheterotrophs (they break down your energy to give them energy) |
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Species of Bacteria: what is an obligate aerobe? Obligate anaerobe? Facultative anaerobe?
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f. Species of Bacteria:
i. Obligate aerobe: a bacteria that cannot grow unless it has access to oxygen (all can get by for a tiny amount of time without oxygen, but they cant live and cant grow) ii. Obligate anaerobe: a bacteria that is obligated to be without oxygen (it has to be without oxygen – ex: gangrene -those found in dead tissue) iii. Facultative anaerobe: a bacteria that can grow in oxygen or can grow without oxygen (ex: yeast) 1. Usually facultative anaerobes prefer aerobic |
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Define the following terms associated with reducing microbes:
sterilize, disinfection, asceptic, sanitize |
i. Sterilize: you have killed everything (everything on the hardest easiest kill list)
1. Sterilizing agent: one that kills everything (kills the hardest to kill organisms and therefore the moderately and easiest) ii. Disinfection: kills most (but usually not endospores) 1. Disinfecting agent: kills inanimate objects iii. Asceptic: (might want to relisten to) 1. Antiseptic agent: kills microbes, but not living tissue iv. Sanitize: kill very few bacteria, but tend to reduce the load (ex: hand washing) by removing some below the minimum threshold for infection 1. Sanitizing agent: reduce “load” of microbes on a surface to levels below that needed for infection |
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Xrays and other high power rays have high power microbial properties, but we don't use them with people that have infections, why?
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e. Light Rays:
i. UV Rays (low concentration): mutagen that usually kills bacteria, not usually viruses/prions (sterilize only under very high doses). We don't use them with people that have infections because it can cause damage to DNA and cell organelles by producing disruptive ions. ii. Ionizing Rays (X-Rays/Gamma-Rays): damage molecules by creating very reactive molecules that then steal e-‘s away from DNA DNA breaks (sterilizer in long exposure) |
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Techniques for sterilization (chemical and physical)
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Chemical: ETOH (classified as degermination in book)
Physical: autoclaving, ionizing radiation |
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What are the steps of Koch Postulates?
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iii. Robert Koch:
1. Koch Postulates: showed causation 2. Developed a technique on how to isolate a pure culture 3. Would take a pure culture and inject it into an uninjected subject, once it was killed, he would take the agent and inject it into another subject, once it was killed, inject it into another agent, etc.. 4. Established tuberculosis & anthrax & cholera Steps to Koch Postulates: 1. Find evidence of a particular microbe in every case of a disease 2. Isolate that microbe from an infected subject and cultivate it artificially in the laboratory 3. Inoculate a susceptible healthy subject with the laboratory isolate and observe the same resultant disease 4. Reisolate the agent from this subject. |
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Antibiotic Mechanism of Actions:
Name the antibiotics that inhibit Peptidoglycan, DNA synthesis, transcription, translation |
Peptidoglycan: penicillins, cephalosporins, vancomycim
DNA Synthesis: fluoroquinilones Transcription: rifampin Translation: steptomycin, tetracyclines |
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Types of immunity and which lymphocytes for each type:
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Lines of Defense:
1st) Innate - physical barriers (skin, tears, coughing, sneezing); chemical barriers (low pH, lysozyme, digestive enzymes), genetic barriers (resistance inherent in genetic makeup 2nd) Innate - phagocytosis, inflammation, fever, interferon 3rd) Acquired - T lymphocytes, B lymphocytes, antibodies - Humoral (Ab-mediated): macrophages/dendritic cells, Helper T cells, B cells - Cell mediated: macrophages/dendritic cells, Helper T cells, cytotoxic T cells |
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What causes host range?
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Host range: the limitation imposed by the characteristics of the host cell on the type of virus that can successfully invade it
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How do antibodies work?
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3. Antibody: protein-rich, with highly variable component (variable region)
a. Antibodies are highly specific for their antigens (similar to a lock and key) b. There are instances (specific bacteria and viruses) where autoimmune diseases can result after an infection b/c the body has a component that is very similar and the antibodies attack it as well (ex rheumatic fever when antigen looks similar to your heart valve) c. An antibody doesn’t just bind the antigen, but binds the whole cell that the antigen is attached to i. This is important b/c if you take, gonorhhea for example or any other invasive species (invasive meaning it can penetrate the cell), it will get coated with antibodies and not be albe to penetrate the cell anymore |
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Vaccinations - what is artificially acquired immunity? what is passive immunity?
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Artificially acquired immunity: given in vaccine form in the community, you're artificially exposed to it - usually exposed to something similar but not it
Passive immunity: you get injected with a bunch of antibodies, or you can get this through breastfeeding |
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Define antigen.
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A substance that prompts the generation of antibodies and can cause an immune response
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What types of areas are inhabited by microflora?
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a. Mucous Membrane: tissues to target – mucous membranes b/c they are wet; most membranes (mucous & cutaneous) harbor a year-round collection of microbes known as resident microflora (largely beneficial); in general, wet areas (mucous) will have much more resident microflora
i. Line those tissues and organs that open to exterior of body ii. Respiratory, digestive and urogenital systems iii. Epithelial cells block penetration of microbes and secrete mucus b. Anatomical Systems That Harbor Microflora (and are prone to infection) i. Human Skin: 1. Little moisture 2. Skin generates antimicrobial substances that makes it (*finish – she’s posting slides) ii. Oral Cavity & Gastrointestinal Tract 1. Oral/nasopharynx + large intestine/rectum is major site of colonization iii. Respiratory Tract 1. Nasopharynx 2. Upper Respiratory Tract: pharynx, larynx; harbor microflora 3. Lower Respiratory Tract: epiglottis, trachea, bronchus; should be sterile – if not, you have pneumonia or tuberculosis; a supreme site for opportunistic and real infections iv. Urogenital Tract 1. Generally more of a problem in females than males a. Females have vaginal wall that is a mucous membrane that can be problematic b. Both have urethra, but females have mucous membrane that is hospitable to infections, while males have a large distance between penis and urethra with cutaneous membrane (dry) in between which is not hospitable to microbes v. Note: there are areas that are supposed to be sterile that can harbor infections also (ex meningitis: nerve tissue affected by microbes) |
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Define the 3 types of immunity:
innate, inflammation, acquired |
Innate immunity: first line
Inflammation: second line Acquired: third line |
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What are the basic functions of the following types of leukocytes:
Neutrophils Eosinophils Basophils Monocytes Lymphocytes |
Neutrophils - general phagocytosis
Eosinophils - destruction of large eukaryotic pathogens such as worms and fungi Basophils - respond to large eukaryotic pathogens and recruit other leukocytes Monocytes - phagycytosis, followed by final differentiation into macrophages and dendritic cells Lymphocytes - specific (acquired) immunity (ie B and T cells) |
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Food handling techniques and preventing transmission
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m. Wash hands, don’t leave meats out, cook your food
i. Cook your food is not always going to be the catch all – toxins are still in there, even though bacteria is not ii. Two major culprits – staph aereus, bacillus cereus 1. Begin to grow and proliferate on left out food (came from your fingers which were on your hands from your stool), let it sit out for 3 days 2. They proliferate and secrete exotoxins all over the place 3. You cook it, kill bacteria, but don’t dismantle endotoxins iii. Bacteria do not directly cause infection iv. Person gets sick when they ingest large amounts of the toxin – which attacks stomach lining to pull out water and acts on the nervous system to induce you to vomit |
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Foods associated with food poisoning and enteritis
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n. Bacterial enteritis: infants don’t have enough water supply to deal with bacteria, elderly because they are immunocompromised (don’t have a robust microflora)
o. Dysentery: enteritis that is bloody i. The blood comes from hemorrhaging somewhere in the intestine p. Species that can cause dysentery: i. Salmonella ii. Shigella iii. Vibrio Cholera iv. Symptom: 1. Prolongued blood in stool q. Salmonella i. Salmonella that causes dysentery: invasive (causes hemorrhaging) in both the small and large intestine (mostly small intestine) 1. What we worry about when we eat raw eggs 2. Major reservoir: chickens, and some of them end up in raw eggs 3. Locallized ii. Salmonella typhi: can destroy the entire intestinal lining 1. Causes severe hemorrhaging, perforations, and usually travels along the blood stream to a lot of different organs and is systemic iii. Ignore Shigella – other than it causes dysentery r. E.coli: i. Usually associated with some sort of vegetable ii. The most fatal strain iii. Some are not virulent at all iv. How are plasmids involved in the virulence of E. coli – most virulence factors are toxins that are carried on plasmids v. Discovered in 1982, a particularly bad one that can cause death due to kidney failure vi. Starts out as something that you ingest, and you have a significant number of them vii. Reservoir is cattle ruin – which is why you often hear about contaminated beef with E.coli 1. Gets on fertilizer, which is used to grow the spinach, which isn’t washed well, which is why it gets into your grocery store and home viii. Enterotoxin that is extremely necrotic: 1. Kidneys – which leads to kidney failure – which is usually how you die ix. Can contaminate it because it is in the ruin of cows, which becomes fertilizer that is used to grow vegetables and fruits and fruits that fall to the ground s. Oral-fecal route t. Causative agent of cholera: contaminated water (before sanitation techniques were involved) i. Mechanism of Cholera Toxin 1. water and ions move from the lumen into the blood vessel 2. when cholera docks, it secretes a toxin that causes the opposite to happen, where all the water goes out and anything that you have is dumped out a. you die of extreme dehydration b. usually they keep drinking the same infected water and die of dehydration |
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What is Rickettsias?
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iv. RMSF (Rocky Mountains Spotted Fever)
1. Rickettsias – very small, invasive cells 2. Require human cells for certain metabolic elements and therefore want and have to be inside a human cell in order for them to live an grow 3. Like endothelial lining of blood vessels 4. Endemic to the Rocky Mountain area, by a tick 5. Rash due to hemorrhaging of blood vessels a. Affects heart and CNS and causes a lot of damage b. Once the blood vessels that lead to the brain have also hemorrhanged, it will cause not enough blood to brain, leading to death 6. Transferred by tick bites 7. Trend: very small, must live very close or inside a human cell |
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Describe the Virus Timeline
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ii. Timeline of Infection: (on NLN exam usually)
1. Incubation period: from initial exposure to infectious agent and when you actually start expressing any symptoms (period in which bacterial agent is getting a hold of your body) 2. Prodromal stage: general weakness, fatigue, tiredness, etc; start to get mild, unspecific symptoms (you know something is going on, but don’t know what it is) 3. Period of invasion: period where symptoms gets worse and worse (acute symptoms) but get specific and of high intensity 4. Height of infection: the peak where your body is fighting back to level the symptoms 5. Convalescent period: where your immune system/treatment begins to reduce the # of agents, symptoms dissipate (you win the war with bacteria) 6. *Note: a secondary infection tends to occur during the convalescent period b/c immune system is whipped out (tired, you are tired) a. They show up during this period, however, you might have gotten them before |
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What is Botulism
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Botulism: an intoxication associated with eating poorly preserved foods, though it can also occur as an infection
Until recent times, it was relatively prevalent and commonly fatal, but modern techniques of food preservation and medical treatment have reduced both its incidence and its fatality rate. However, botulism is a common cause of death in livestock that have grazed on contaminated food and in aquatic birds that have eaten decayed vegetation. Caused by Clostridium botulinum |
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What is influenza
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ii. Influenza
1. Structure: enveloped, (-)ssRNA, which means you have to have pretty intimate contact with an infected person to also be infected 2. Host Range: Humans, birds, swine (pig) 3. Responsible for: seasonal epidemic, occasional pandemics a. ~2 million influenza-related deaths per year, mostly not from influenza, but from secondary pneumonia 4. What makes it unique? a. They have very fast mutation rates b. Antigenic shift/reassortment: where 2 viruses of different types infect the same cell and when they repackage, they are repackaged as the same strain i. Ex: virus that infects swine, you get a human virus that can infect pig cells, and out comes a novel virus that has part pig, part human virus in it ii. Can recombine bird/swine/human versions into novel strains, some of which increase lethality 5. Pathophysiology: ciliated cells of upper respiratory tract, infects trachea, and sometimes down into the larynx and bronchi a. Results in complete destruction of mucocilliary escalator b. This is usually when you can get a secondary pneumonia infection – which accounts for almost all standard mortality associated with this 6. How do you differentiate a flu from a cold? a. Flu has fever and typically more severe symptoms, coughing, and a more inflamed respiratory tract b. Cold does not have fever 7. Typically lasts about 1-2 weeeks? 8. Why is a yearly vaccine administered? a. Influenza has 3 types of strains: i. A (Swine flu is type A)- highest virulence, uses animals as reservoir (whereas B & C use humans) 1. Subtypes are based on what the spikes look like a. H (>10 types) b. N (~8 types) 2. Swine flu is H1N1 3. 1918 pandemic – H1N1 also ii. B iii. C 9. What is all the fuss about the avian or bird flu? a. Because they recombine so readily and readily combine with different strains of avain and swine flu i. They tend to show up as epidemics when it is cold and dry (dry tends to dry out the mucous membranes making them less effective) ii. Usually starts in Asia and makes its way around the world iii. CDC typically looks at Asia and makes its best guess as to what they think is going to come around (A, B, and C) and mix it up in a yearly vaccination (flu vaccination) iv. The reason that they recommend a yearly vaccination, is because it changes every year b. Birds are the Natural Reservoir for some very nasty strain A (can exceed 50% mortality in humans) 10. What is H5N1? a. Means: i. 5th recorded H spike ever ii. 1st recorded N type ever b. Bird flu c. Thought to be a Naturally Avian Flu – spikes like human receptors better than birds, so it is difficult to get it human to human d. High mortality rate, in some cases exceded 50% but not transmitted from person to person e. They were afraid that it was going to infect somebody and another virus would infect at the same time allowing for reassortment and a very dangerous strain to arise f. This is what is happening, not with birds now but swine 11. Why are some influenza bouts “pandemic” such as the Spanish flu of 1918? a. Standard flu shows a specific tendency to infect elderly and very young (because they are prone to a secondary pneumonia infection) b. In 1918, the Spanish Influenza hit and it was a H1N1 strain, and it was called this because the Spanish experienced such a high mortality in Spain c. Responsible for 30-60 million deaths worldwide, over 600,000 in US alone d. This was flu related, not pneumonia related e. It had a W shaped curve: infants affected, young adults not, healthy adults, and older adults not, and elderly did f. It was unusual, but could have helped due to WWI around the same time g. Chance of death 3-5% (somewhat consistent with the Swine flu) h. Influenza today: 0.001% i. Why is Swine Flu so bad? i. Nobody knows what is going on ii. People are coming down with more severe cases of the flu iii. Severe fever iv. Respiratory problems v. Pneumonia vi. Hemorrhaging of the lung tissue vii. Scientists suspect that viruses make it all the way into your alveoli viii. They are finding pieces of sepsis (from oral cavity) ix. They are finding the influenza virus in spleen, liver, lung x. It seems to be a more aggressive form that is able to cause some hemorrhaging in alveoli and make it into the blood stream 12. Swine Flu a. It is a recombinant that takes pig influenza and human influenza b. There is diarrhea and vomiting associated with them c. Antiviral Medications: i. Inhibit the “Special RNA Pol” ii. Tries to block the ligand binding sites by coating them iii. It is usually not nice on your own body |
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What are the causative agents of meningitis?
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IV. Streptococcus Pneumonia
I. Streptococcus Group B: a. Newborns at risk for contracting from mother during vaginal birth b. Often fatal to newborns as it can cause pneumonia, septicemia or meningitis i. Might be the most common cause of death in newborns (possibly?) ii. ~5000 newborn deaths/year |
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STDs
- Treponema - Chlamydia - Syphylis - disease stages* - Gonorrhea |
IV. Sexually transmitted diseases
a. Transmission: not exclusively sexually transmitted, can be transferred in another way i. Just because it affects the Urogenital tract, doesn’t mean it cannot spread to areas where other mucous organs/tissues exhist ii. Primarily transferred through sexual intercourse because all of the diseases cannot live outside of the host for very long (they are very delicate) – they go immediately from one warm-n-fuzzy mucous membrane environment to another, with no time outside of hosts iii. All sexually transmitted diseases use humans as reservoirs (b/c they can’t live outside of the body) 1. Exception: HIV a. It was thought to cross from a primate to a human sometime in the 1800s b. Then from humans to humans into the 1920s b. Syphilis i. Spirochete caused by Treponema pallidum ii. Used to be one of the biggest STDs 1. King Henry had it and one of the reasons he beheaded his wives is because they continued to miscarry 2. One of the reasons it was thought the wives miscarried is because syphilis causes miscarriages iii. Gram(-), but difficult to stain or find - *does not show up in gram stain or simple stain iv. Major virulence factor is a tip that digs into our cell membranes, which allows for colonization 1. It has an affinity for neural and heart tissues 2. Virulence Factor: a hook on the tip of the spirochete a. It is non-invasive (colonizes), but once it digs into the cell membrane v. Can also penetrate epithelial lining and travel to any other tissues vi. Lifelong disease that progresses through three stages c. Treponema Pathophysiology (how you get the disease) i. If it gets into the heart or nervous system, its presence induces an inflammation response that can cause inflammation ii. Disease problems: 1. Treponema anchors into & proliferates in a tissue where chronic inflammation can be deadly iii. Disease Progression of Syphilis: 1. Incubation (3 weeks) a. Treponema anchors at transmission stop & begins replicating furiously 2. Primary Stage (4-6 weeks) a. Chancre develops at site of infection b. Usually not painful and go away without any problem c. 1st Latency (2 weeks-2 months) i. Chancre disappears, but treponema enters the circulatory system & finds new attachment spots at any available tissue/organ 3. Secondary Stage (few months-several years) a. No consistent symptoms – varied (fever, rash, lesions) that can be mild-severe make it difficult to diagnose i. One defining symptom – a copper colored rash that shows up on palms and feet (not all the time, but ~30% of the time) ii. Many females develop “unseen” lesions on cervix – can be painful, but not necessarily b. 2nd Latency (variable – it can last a lifetime) i. Immune system fights back and cleans up bacteria (for the most part, but a few always stay behind in the nervous system and cardiovascular system) 4. Tertiary Stage a. Chronic outbreaks in nervous system & cardiovascular system & other areas b. About 70% progress to tertiary state c. Can develop gummas (grotesque lesions in cutaneous) iv. Very susceptible to penicillin – interesting because it is gram(-) technically v. In the US, Syphilis is much less common than gonorhhea, but incidences peaked in 1991 among black males and decreased 5 fold since then 1. HIV & AIDS prevention and safe sex practices might have produced the safe sex rates a. Neiserria gonorhaea i. Causative agent of gonorrhea ii. Morphology: diplococcus (looks like 2 beans held together), gram negative iii. Pathology: an obligate intracellular organism iv. Can infect the epithelial lining of the anus, throat, or rectum also – pretty much will infect any mucous membrane, but since it is sexually transmitted, it most commonly affects: 1. Urethra – males 2. Vagina – females 3. *Note: child sexual abuse is apparent if a child has gonorrhea in the throat – it legally must be reported to the authorities 4. Gonorrhea, Syphilis, and Chlamydia all must be reported so that the government can monitor incidences v. Second most common bacterial STD in the US 1. Morbidity: how acute symptoms are a. Not all males show symptoms and even fewer females show symptoms b. Biggest symptoms is puss coming out of the penis c. Most females are asymptomatic, some males are asymptomatic -- therefore people don’t always go get prompt treatment d. If you don’t get prompt treatment: i. Bacteria attach to epithelial cells, replicate, destroy the epithelial lining and continue to lead up urethra and vas deferens (but will not leave the urogenital tract) ii. Because the genital tract has very delicate tubes, you can get scar tissue in vas deferens iii. Females, can have scar tissue in the fallopian tube (make it narrower), so egg can get stuck in the fallopian tube leading to sterilization or a high incidence of epitotic pregnancy 2. Gonorrhea and syphilis incidences have come down due to: a. Practice of safe sex b. Prescription of antibiotics (ex: penicillin which gonorrhea and syphilis are very sensitive to) c. Symptoms get cleared up before you notice it is there and it is reported b. Chlamydia i. A genus – highest incidence of STDs ii. The rates have gone up significantly, while gonorrhea and syphilis have gone down 1. Symptoms of Chlamydia are even less severe, so the symptoms (if they’re even there) may not prompt you to go get treatment for it 2. Penicillins are not effective against it iii. Chlamydia trachomatis is a tiny spherical bacterium with a complex intracellular life cycle iv. A gonorrhea-like STD, but much more mild v. The prevalence of chlamydial infections is greater than that of any other bacterial STDs and is increasing dramatically (carried in up to 10% of all in sexually active individuals) vi. Many females (and some males) are symptomatic, which aids in transmission vii. It is an obligate intracellular pathogen with not much of a cell wall, so penicillins don’t work on them viii. Things that inhibit gene expression do work on them: tetracycline, erythromycin (broad-spectrum drugs, but none of the penicillins) |
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Tuberculosis
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II. Mycobacterium tuberculosis
a. Often called “the forgotten disease,” the causative agent of tuberculosis b. Mycobacterium (the genus) is Acid Fast i. Survivability advantage: Stains gram(+) but has an outer MB that is very waxy, which allows it to stay on the bench top and be viable outside of the host in the environment for a long time 1. A single cell can remain viable for up to 8 months c. Originally called the “white plague” – affected Caucasians primarily (Moulin Rouge – Nicole Kidman dies of it) i. In the last stages, you are coughing up blood ii. Now, the name is paradoxical because it now affects primarily Hispanics, blacks, Filipinos, Asians, etc. 1. Probably due to socioeconomic disadvantages – ex: many people living in small room, exposed to each other 2. Incidences shot up in the early 1980-1990s a. AIDS incidence shot up then, and it was before AZT was common b. Incidences of clinical TB are increasing c. AZT is likely out there, with many people latent, asymptomatic carriers (~1/3 at least a carrier) for tuberculosis d. As a healthy person, your probability of getting clinical tuberculosis is 10-15% if you’re a carrier e. If you are immunocompromised, your probability of getting clinical tuberculosis is ~90% d. 15-20 hours generation time e. They get engulfed by macrophages and use the macrophage to make more of themselves i. Once they lyse the macrophage, the immune response sends all leukocytes, lymphocytes, and one other WBC and surround it ii. Leukocytes all become inactivated and become a solid cheesy coat, like a capsule for the new colony to start replicating, eventually bursting open the capsule, and moving along to colonize both iii. By the end, you have extensize necrosis in the lungs iv. The disease takes a very long time to manifest – the incubation and manifestation takes a long time – usually by the time it shows up in an X ray, you are coughing up blood v. Healthy individuals with active TB, is probably going to die in 60% of the time vi. There has been a recent rise of TB |
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Likely to cause a nasocomial infection of urinary tract
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Streptococcus pyogens:
b. Diseases caused by S. pyogens: i. Localized infections: 1. Skin – impetigo 2. Throat – strep throat a. Need a fever to induce and symptoms are infected pustules ii. Systemic infections: 1. Scarlet Fever 2. Toxic Shock Syndrome 3. Childbed Fever a. Incidence of S. pyogens infections after childbirth after crowded maternity clinics became the “rage.” Handwashing (and avoidance of cadavers) in 1847 reduces incidences dramatically b. S. pyogens had direct access to the mother’s bloodstream from the doctors hands (vaginal access) so it was easy to get a lot in the blood |
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S. pyogens virulence factors
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c. Virulence Factors:
i. Capsule – S.pyogens can make a capsule that is made of hyaluronic acid (which we also make) ii. *M Protein – (part of the fimbria which is used to bind to any cell) has a secondary function that it binds fibrinogen, it’s a huge flag for the immune system, but since it binds proteins as well, it can coat itself in your own protein so that when your immune system runs by (antibodies float by that typically coat it for immune system) they don’t see it iii. Protein G – attracts and binds antibodies, but in the reverse orientation confuses immune system d. Other Virulence Factors: i. Exotoxins 1. Erythrogenic Toxins – when you get a fever (ex scarlet fever) you turn bright red a. Scarlet Fever: the bacteria does not get the genes to cause this fever by itself, but by a bacteriophage, or virus that infects bacteria (in the lytic cycle) 2. Pyrogenic Toxins – when you get a fever ii. Hemolysins (β hemolytic pattern) iii. Enzymes – degrade tissues or clots or dissolve cell joints |
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What infectious agents are related to cervical cancer
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ii. Papilloma virus (*remind her about protein display on MHC I)
1. Structure: small, naked viruses 2. Causes warts, including genital warts (different than on hands) 3. Do not form a provirus, go into the nucleus and start replicating through the lytic cycle 4. The most common sexually transmitted disease out there 5. PAP Smear: tests for abnormal cells that cause cervical cancers (as shown on right). Cytological changes include enlarged nuclei and halo around the nuclei). The more pronounced the changes, the more danger the lesion is. Over 99% of the time the cause is by papillomaviruses. 6. A particular type of HPV can cause cytological changes that lead to cervical cancer. |
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Hepatitis
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Inflammation of the liver
i. Picornavirus 1. Structure: small, naked (+)ssRNA viruses (the smallest human viruses) 2. Very prevalent in humans 3. Diseases caused: a. Polio i. Passes through digestive tract, gets absorbed into blood system, lymphatic system, and moves into neurons b. Hepatitis A (share the same location – liver, but they are unrelated to each other otherwise, one is a DNA issue, another is this strain of virus, etc.) c. Rhinoviruses (common colds) i. Common cold is expensive because you miss work because of it ii. There is such a high mutation rate though, so there are hundreds if not thousands of different strains iii. If you have a cold, unless it is being passed around from family member to family member, then you having a cold does not make you immune to other people’s colds iv. Corona viruses also cause colds 1. SARS (Sever Acute Respiratory Syndrome) is caused by this 4. Because they are naked, they’re capable of resisting a variety of environmental conditions 5. Because they are so small, they can get through organs that they normally wouldn’t be able to get through |
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Malaria Life Cycle
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Plasmodium Life Cycle Summary (see notes for pictures):
1) Mosquito lands on a person that is already infected with malaria, bites human, draws up male & female gametocytes from blood 2) Mosquito flies away. Gametocytes (both male & female) fuse in mosquito gut to make sporozoite form. 3) Sporozoites migrate to salivary glands of mosquito. They are released into blood stream of new host on next bite. 4) In new host, Sporozoites travel to liver, infect liver cells. 5) Inside a liver cell, they differentiate into Merozoite form. 6) Merozoites released into bloodstream by lysing liver cells. 7) Merozoites in blood stream, bind to RBCs, morph into all-consuming & expanding Trophozoite. 8) Trophozoite turns into a bunch of Merozoites, which then lyses allowing merozoites to spill out and go out to infect new RBCs, which get in a cyclic fashion, infecting more RBCs and causing A few of the Trophozoites will differentiate into male and female gametocytes (which don’t do anything functionally except sit and wait to be picked up by another mosquito |
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What does Legionella do?
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d. Legionnaire’s Disease
i. Obscure genus that contains mostly soil and water microbes ii. Legionella pneumophila actually colonizes alveolar macrophages and replicates itself inside them! iii. Produces pneumonia-like symptoms iv. Found DNA markers for 5 new species inside clam guts from deep sea v. Very high fatality rate vi. Epidemics, first showed up in 1976 vii. Allow macrophages to ingest them, but then replicate inside the macrophages (they are used to infecting amoeba’s and making a home within them) viii. Usually the source is some sort of pond or ocean water |
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What is Rheumatic Fever
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g. Rheumatic Fever
i. An autoimmune response that results in your own immune system degrading your heart valves 1. Can be fatal, leading to heart failure in severe cases ii. Why this comes from Strep pyogens: 1. N protein: strongly antigenic (once immune system gets a hold of it, it mounts a very strong immune response to it) 2. When we clear up the strep infection, the antibodies stick around and look for something to bind to a. Our heart valves express a protein that looks almost identical to the N protein b. Neutrophils and macrophages try to eat our cells iii. There are many types of strep and they all produce N proteins, so if you happened to be infected with the specific strain that happens to look identical to your N proteins? 1. That’s why we don’t have vaccinations for it iv. Once antibodies are cleared out of your system, the damage is done, but it can be permanent v. As you age, or fall under different immunocompromised areas, you have leaky valves that can cause secondary infections |
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What happens with bacterial endocarditis?
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h. Bacterial endocarditis during dental surgery –
i. Strep is a load-bearing bacteria ii. If you have bad blood flow, some in your heart can cause serious problems iii. If you have a tooth extraction, you have a pool of blood where that bacteria can thrive. |
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How do we test for HIV?
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4. Rather than fulfill Koch Postulates to prove HIV is the cause of AIDS, they took the approach of “could we prove it is not the causative agent?”
a. If they took blood tests to see if all AIDS patients had HIV in their blood b. Follow transmission groups (people that had blood transfusions – ex: hemophiliacs) c. They needed a diagnostic test that was fairly quick – ELISA test for HIV (allows you to test for antibodies – not the virus itself) i. If you were recently infected, your results may be negative for at least 6 months (since they’re not looking for the virus, but only antibodies) |
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What does the Epstein-Barr virus do?
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Epstein-Barr virus = a type of herpes virus
8. Epstein-Barr virus (EBV): causes infectious mononucleosis (mono) which is known as the kissing disease a. The primary method by which the EBV disease it transferred by young adolescents b. Infectious mononucleosis: the Epstein-Barr virus causes atypical lymphocytes that are evident in a blood smear |
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What is candida?
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Candida = fungal pathogen
a. Candida albicans i. Normal (?) microflora on mucous membranes (especially vaginal canal), skin, GI tract ii. Infections kept at bay by 1. Immune system (especially tissue macrophages) and 2. Competitive exclusion by microflora iii. Most frequent in small children and AIDS patients iv. Characteristic symptoms: 1. Oral thrush 2. Vaginitis (Yeast clumps around cervix) – aka yeast infection. This can happen due to: a. Disturbance in microflora – especially lactobacillus b. Why we say eat yogurt, prevent yeast infections c. Hormones: also affect your propensity for yeast infection d. Wearing a swim suit for a long period of time: an unusually moist environment with no way to air out v. In immunocompromized individuals, you are at risk for developing Candida septsis (candida infection of the blood) vi. Recap: 1. Vaginitis – decreased lactobacillus residencies (most common cause) 2. Oral cavity – oral thrus (usually in immunocompromised individual or if oral cavity microflora is not well established 3. Candida Sepsis – candida multiplying in blood; shows up as a secondary infection after candida colonizes esophagus or large intestine a. Probability of candida sepsis is based on i. Load inoculation ii. Tissue macrophage ability to pull them out before getting into blood |
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Pseudomonas aeroginosa - what can it do?
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burns
ear infections hot tub rash pneumonia/respiratory infections |
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Where is the most common sites for E.coli infections
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r. E.coli:
i. Usually associated with some sort of vegetable ii. The most fatal strain iii. Some are not virulent at all iv. How are plasmids involved in the virulence of E. coli – most virulence factors are toxins that are carried on plasmids v. Discovered in 1982, a particularly bad one that can cause death due to kidney failure vi. Starts out as something that you ingest, and you have a significant number of them vii. Reservoir is cattle ruin – which is why you often hear about contaminated beef with E.coli 1. Gets on fertilizer, which is used to grow the spinach, which isn’t washed well, which is why it gets into your grocery store and home viii. Enterotoxin that is extremely necrotic: 1. Kidneys – which leads to kidney failure – which is usually how you die ix. Can contaminate it because it is in the ruin of cows, which becomes fertilizer that is used to grow vegetables and fruits and fruits that fall to the ground |
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Treatment for Tuberculosis
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Isoniazid and rifampin are the keystones of treatment, but because of increasing resistance to them, pyrazinamide and either streptomycin sulfate or ethambutol HCL are added to regimens. If the patient is unable to take pyrazinamide, a nine-month regimen of isoniazid and rifampin is recommended.
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How do you control Salmonella spread
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q. Salmonella
i. Salmonella that causes dysentery: invasive (causes hemorrhaging) in both the small and large intestine (mostly small intestine) 1. What we worry about when we eat raw eggs 2. Major reservoir: chickens, and some of them end up in raw eggs 3. Locallized ii. Salmonella typhi: can destroy the entire intestinal lining 1. Causes severe hemorrhaging, perforations, and usually travels along the blood stream to a lot of different organs and is systemic iii. Ignore Shigella – other than it causes dysentery |
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Basic terminology with epidemiology:
Reservoire Vector |
e. Reservoirs of infectious pathogens
i. Humans ii. Animals 1. Cows, birds, apes, bats (harbor the infectious agent and the infectious agent makes them sick and when we get into contact with them, we get the disease) 2. Vector: some type of invertebrate, harbors some stage of the infectious agent and transfer it, but do not get sick themselves a. Ex: mosquitoes are the vectors that transfer malaria from person to person iii. Nonliving reservoirs 1. Ex: soil – tetanus uses this 2. Ex: water - cholera uses this |
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Toxic Shock Syndrome
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c. Toxic Shock Syndrome: a particular strain of S. aureus secretes pyrogenic toxin (which is a superantigen) that directly activates TH cells and causes excessive release of cytokines & TNF-α (tumor NECROSIS factor). Both wreak havoc on body shock (often fatal)
i. Typically associated with women (tampon box warning), certain strains of staph that were able to release pyrogenic toxin (called a superantigen - induces fever and causes shock by stimulating helper T cells and activating without any macrophages helping them out, causing T cells to release tumor nicrosis factor and cytokines that cause capillaries to be leaky and allow all substances in) |
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How are you likely to get pneumonia
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Strep pneumonia
Staph aureus Streptococcus Group B I. Other Causative Agents of Pneumonia a. Klebsiella pneumonia – less common, but high fatality rate b. Pseudomonas aeruginosa – causative agent of hot tub rash, causes pneumonia as an opportunist (likely to get it if you are immunocompromised - ex AIDS patient) i. Also destructive in burn victims c. Mycoplasma pneumonia – for their lifecycle, they steal nutrients from a macrophage i. This may be a walking pneumonia because it is a mild, less virulent ii. Extremely small genome - 816 kilobases long iii. Has no cell wall iv. Not invasive (not intracellular), but they do colonize – they grab onto a macrophage and act almost like a parasite d. Legionnaire’s Disease i. Obscure genus that contains mostly soil and water microbes ii. Legionella pneumophila actually colonizes alveolar macrophages and replicates itself inside them! iii. Produces pneumonia-like symptoms iv. Found DNA markers for 5 new species inside clam guts from deep sea v. Very high fatality rate vi. Epidemics, first showed up in 1976 vii. Allow macrophages to ingest them, but then replicate inside the macrophages (they are used to infecting amoeba’s and making a home within them) viii. Usually the source is some sort of pond or ocean water |
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Shigella
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Shigella is a genus of Gram-negative, non-spore forming rod-shaped bacteria closely related to Escherichia coli and Salmonella. The causative agent of human shigellosis, Shigella cause disease in primates, but not in other mammals.
Shigella infection is typically via ingestion (fecal–oral contamination); depending on age and condition of the host as few as ten bacterial cells can be enough to cause an infection. Shigella causes dysentery that results in the destruction of the epithelial cells of the intestinal mucosa in the cecum and rectum. |
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Who is at the highest risk for developing pneumonia?
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Elderly and infants
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Toxic Shock Syndrome - fact
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It is the result of a bacterial mutation
(A bacteriophage that injects its viral DNA into the bacteria that causes a frame-shift mutation) |
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Which of these organs is most frequently affected by rheumatic fever?
Heart, Lungs, Brain, Stomach |
Heart
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Which of these risk factors increases a client's risk of developing TB?
Cigarette smoking, malnutrition, allergies, frequent exercise |
Malnutrition (makes you immunocompromised)
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Which of these diseases is classified of zoolisis?
syphillis, gonorrhea, AIDS, blastomicrosis, plague & rabies |
Plague & rabies
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In which of these ways does a high salt concentration serve as an antimicrobial agent?
it digests DNA, it binds proteins, it dissolves the cell membrane, it shrinks the protoplasm of the cell |
It shrinks the protoplasm of the cell
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Which of these statements about rickettsiae is true?
they are obligate intracellular parasitic organisms, they are larger than most bacteria, they are eukaryotic, they do not respond to antibiotic therapy |
they are obligate intracellular parasitic organisms
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What are the steps of the viral lifecycle?
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Viral Lifecycle – “Adam Plays Under Stairs At Random”
a. Adsorption: (*critical to pathogenicity & host range) the virus attaches to its host cell by specific binding of its spikes to cell receptors 1) Attachment of the virion to host cell 2) Determines an important epidemiology factor called “host range” 1. Host range is determined by whether a host cell has the matching receptor for a particular virus spike 2. Host range can be species or organs a. Ex: hepatitis – virus infects the liver b. Ex: swine flu – transmits from human to human (we do not know if it can infect pigs or birds as well) b. Penetration: the virus is engulfed into a vesicle by endocytosis 1) How the virus gets into the cytoplasm 2) Two options: 1. Receptor-Mediated Endocytosis: a. Happens with all Naked & some Enveloped viruses 2. Fusion (aka “reverse budding”): when it takes the membrane (which was part of yours) and adds it to the host membrane a. Can only happen if you are Enveloped c. Uncoating: the envelope of the virus is removed, and the RNA is freed into the cytoplasm 1) Strip away the coat (capsid and envelope, if enveloped) and release genetic code - free your nucleic acid d. Synthesis: Replication and Protein Production – under the control of viral genes, the cell synthesizes the basic components of new viruses: RNA molecules, capsomers, spikes. 1) Make new viruses by hijacking the cell’s machinery to make copies 2) Need the following: 1. Nucleic Core: lots of copies of ds genetic code 2. Proteins: for capsid, plasma membrane of envelope (if they have one), enzymes to help e. Assembly: viral spike proteins are inserted into the cell membrane for the viral envelope; nucleocapsid is formed from RNA and capsomers. 1) All virus components coming together to make complete virus 2) Virion: virus particle f. Release: enveloped viruses budd off of the membrane, carrying away an envelope with the spikes. This complete virus or virion is ready to infect another cell. 1) Release from your cell 2) Two options 1. Budding: a. If you are Enveloped only 2. Lysing the cell: a. If you are Naked Virus only |
