Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
83 Cards in this Set
- Front
- Back
|
What is a pathogen?
|
A disease producing microorganism
|
|
|
What is an etiological agent?
|
Genus and species of the disease causing microorganism
|
|
|
What does communicable mean?
|
Spread by person-to-person contact
|
|
|
What is incubation time?
|
Acquisition of disease until symptoms ensue
|
|
|
What is period of illness?
|
Time periods the symptoms last
|
|
|
What is period of convalescence?
|
Time in which the body is weak from the disease
|
|
|
What is an endemic?
|
Low numbers of infection in a given area
|
|
|
What is an epidemic?
|
Higher numbers of infection than normal in a given area
|
|
|
What is a pandemic?
|
Worldwide epidemic
|
|
|
What is an acute infection?
|
Rapid, short incubation time, high fever, short illness
|
|
|
What is a chronic infection?
|
Long incubation and illness time, often leads to death
|
|
|
What is invasivness?
|
Ability to cause disease
|
|
|
What is portal of entry?
|
Anatomical location of entry into host
|
|
|
What is focus of infection?
|
Area where microorganism first grows in the host
|
|
|
What is an opportunist?
|
A microorganism which becomes a pathogen if immune system is compromised.
|
|
|
What is a primary infection?
|
first pathogen to gain entry into host
|
|
|
What is a secondary infection?
|
opportunistic due to effects of primary infection
|
|
|
What is inapparent?
|
disease with mild or no symptoms (assymptomatic)
|
|
|
What is bacteremia?
|
bacteria in blood
|
|
|
What is septicemia?
|
bacteria and their toxins in blood
|
|
|
What is virulence?
|
degree of pathogenicity
|
|
|
What is a carrier?
|
person with pathogen but without symptoms (e.g. "Typhoid Mary")
|
|
|
What is a vector?
|
"Low animal" which transmits a pathogen to humans
|
|
|
What is a fomite?
|
any inanimate object which can harbor microorganism (e.g., towel)
|
|
|
Capsule
|
Polysaccharide coat protecting against phagocytosis
|
|
|
Fimbriae
|
similar to cilia, also called common pili, function is cell adhesion
|
|
|
Endotoxins
|
remain within cell until lysed by host
|
|
|
Exotoxins
|
secreted from cell into host
|
|
|
Enzymes
|
substrate in host tissue
Examples: hyaluronidase, coagulase, hemolysin, collagenase |
|
|
1st line of defense
|
-mechanical/chemical aspects
-keratinized, dead skin has poor nutrients -sweat-->fatty acids toxic to microorganism -eye-->tears with lysozyme -upper respiratory tract --> ciliated epithelium w/goblet cells -stomach--> pH labile, pepsin |
|
|
2nd line of defense
|
-activation occurs once inside host
-inflammation and phagocytosis (WBC mediated) |
|
|
3rd line of defense
|
-antibodies (B Cells--> plasma cells & memory-->immunoglobulins)
|
|
|
Flagellum
|
used for motility, often chemotaxis triggers
|
|
|
Fimbriae
|
-used for adhesion
-Gram Negative bacteria rods -composed of lecitin complex -referred to as common pili |
|
|
F-pilus
|
-Used for sexual conjugation
-Only in gram negative bateria |
|
|
Functions of Capsule
|
food reserve
prevent dehydration (prevents osmosis) prevent phagocytosis (adds to virulence) emits a foul odor which repels protozoa, etc. |
|
|
Slime Layer (Glycocalyx)
|
a polysaccharide coating that is secreted by many bacteria. It covers the surface like a film and allows the bacteria to adhere firmly to various structures, e.g., skin, heart valves, catheters. It also mediates adherence of bacteria to the surface of teeth which is important in the formation of dental plaque.
|
|
|
Plasmids
|
extra-chromosomal, double-stranded, circular DNA molecules that are capable of replicating independently of the bacterial chromosome
|
|
|
Endospores
|
-coat of enamel-like substance (dipicolinic acid and Ca++)
- only pathogens in Bacillus and Clostridium (genera) - stain with Malachite Green (Ca++ chelator- has affinity to attach to Ca++) |
|
|
GRAM-POSITIVE BACTERIA
|
-Cell wall is thick 20-80nm
-All possess NAG and NAM -60-80% Peptidoglycan -Some possess tichoic acids |
|
|
What color are gram positve bacteria when stained?
|
-Violet or purple colored when stained
|
|
|
What color are gram negative bacteria when stained and what is found in gram negative bacterias
|
-Red or Pink
-Lipids in cell wall |
|
|
GRAM-NEGATIVE BACTERIA
|
-The cell wall are chemically complex
-10-20% peptidoglycan -has a 2nd layer composed of proteins, phospholipids and lipopolysaccharides |
|
|
What is the lipopolysaccharide in gram negative bacteria called?
|
Endotoxin (responsible for fever and shock).
|
|
|
Generation Time Equation
|
b = B x 2^n
b= # after some time, B= # started |
|
|
What are the phases in a microbial growth curve
|
Lag Phase
Exponential Phase Stationary Phase Death Phase |
|
|
Assume that at 1:00pm there were 100 log phase bacteria growing in a broth tube with a generation time of 15 minutes. How many bacteria would be in the tube at 2:00pm ( 1 hour later)?
|
b=Bx2^n
=100 x 2^4 =100 x 16 =1600 bacteria at 2pm |
|
|
Glycolysis
|
Anaerobic Respiration, 2 ATP
|
|
|
Fermentation
|
Anaerobic Respiration, 2ETOH, 2 CO2, Net: 2ATP
|
|
|
Citric Acid Cycle
|
Starting Point: Acetyl CoA
Net Result-Acetyl Group, CO2 and H2O, lots of ATP Aerobic Respiration |
|
|
Genotype
|
The sume total of all your genes
|
|
|
Phenotype
|
Appearance
|
|
|
Alleles
|
Types of genes for a trait (blue eyed and brown eyed)
|
|
|
Haploid
|
Has 1 chromosome, 1 gene for each strain, the only cells that are this are our mature sex cell, also bacteria
|
|
|
Diploid
|
Has 2 chromosomes, seen in endospores
|
|
|
Gene
|
little piece of DNA that determines a specific trait (in bacteria: genes to make capsules, fimbriae)
|
|
|
Chromosome
|
Collection of genes-thousands of genes linked end to end
|
|
|
Gene Locus
|
Exact area on a chromosome where a specific gene is found
|
|
|
Ames Test
|
Detects Carcinogens and Mutants
|
|
|
Transformation
|
Naked DNA passing into a cell with broth
|
|
|
Transduction
|
Process by which genes being transformed
|
|
|
Spontaneuous mutation
|
Process just by chance, change of nucleic acid doesn’t completely replicate daughter cells
|
|
|
Sexual Conjugation
|
Gram Negative, F+ Attaches to a female, Hfr
|
|
|
Characteristics of Gram Positive
|
No F pilus
forms conjugation bridges recipient secretes pheromones donor secretes adhesin and recipient has receptors on cell matrix |
|
|
Col Factors
|
Chemicals tht kill other types of microorganisms; we call these antibiotics
|
|
|
R Factor
|
the bacteria that are resistant to 20 different drugs would have 20 different factors of this
|
|
|
Simple Stain with Basic Dye
|
Add Crystal Violet (methylene blue or safranin
Bacteria will be the color of the dye |
|
|
Simple Stain with an Acid Dye
|
Add nigrosin (india ink) Bacteria appears white and background will be black-purple color.
|
|
|
Gram Stain
|
Add Crystal Violet, Later add Gram's Iodine, de-colorize with alcohol, add safranin
Gram +=Purple Gram -=Red |
|
|
Endospore Stain
|
Add malachite green, counterstain later with safranin
Endospores are green and vegetative cells are red |
|
|
Acid Fast Stain
|
Add Carbol Fushin, later de-colorize with acid alcohol and counter stain with methylene blue
Acid fast stain RED Non-Acid fast stain BLUE |
|
|
What grows on EMB Agar
|
Enterics (i.e. E-coli)
|
|
|
Sim Agar Contents
|
Hydrogen Sulfide-sulfur reacts with iron to form black color
Indole-breakdown product of tryptophan Motility |
|
|
How do you obtain pure cultures from mixed cultures?
|
Streak Plate
Pour Plate |
|
|
Mycoplasma Pneumonia
a.Etiological Agent b.Gram Reaction c.Usual Mode of transmission |
a. Mycoplasma Penumoniae
b. No Gram stain, Pleomorphic or rod shaped c. Droplet formation |
|
|
Mycoplasma Hominis
|
Cause of Pelvic Inflammatory disease, others in arthritis
|
|
|
Ureaplasma Urealyticum
|
Causes 20% of non-gonococcal urethritis cases. Sexually transmitted
|
|
|
Actinomycosis
a.Etiological Agent b.Gram Reaction c.Usual Mode of transmission |
a. Actinomyces israelii
b. Gram positive, branching rods, sulfur granules, lumpy jaw c. found in mouth, your own flora, you infect yourself (endogenous) |
|
|
Nocardiosis
a. Etiological Agent b.Gram Reaction and Shape c.Usual Mode of transmission |
a. Nocardia species (usually nocardia asteroides or nocardia brasiliensis)
b. Gram +, branching rods c. through soil or breathing it in |
|
|
Tuberculosis
a. Etiological Agent b. Gram Reaction and Shape c. Mode of Transmission |
a. mycobacterium tuberculosis
b. Gram negative, rod shaped c. droplet formation |
|
|
Leprosy (Hansen's Disease)
a. Etiological Agent b. Gram Reaction and Shape c. Mode of Transmission |
a. Mycobacterium Leprae
b. Acid fast stain, rod shaped c. continual touch |
|
|
Chlamydiae
|
-all are gram negative coccobacilli
-very small 0.3 micrometers -all obligate intracellular parasites (must have living host) -enzyme deficient "energy parasites" -no binary fission |
|
|
Psittacosis
Etiological Agent b. Gram Reaction and Shape c. Mode of Transmission |
a. Chlamydia psittaci
b. Gram negative, rods c. inhaled from air |
