Public Health Bio Test 2

mutalism

all partners benefit

commensalism

one partner benefits while other partner is indifferent

parasitism

one partner lives at the expense of another partner

peritonitis

location of bacteria growing in the body matter

miasmas

-bad/swamp air

-people thought that you got sick because you breathed in bad air that damaged your body

Koch's postulates

1- association: causative agent must be present in every case of specific disease

2- isolation: causative agent must be isolated in every case of the disease and grown in pure culture

3- causation: causative agent in the pure culture must cause the disease when inoculated into a healthy and susceptible lab animal

4- reisolation: causative agent must be reisolated from the lab animal and be identical to the original caustive agent

infections

multiplication of microbes in or on the body

disease

possible outcome of an infection (pathology or illness)

subclinical disease

you don't have any symptoms but the infection could be damaging your body

dose

The amount of substance given at one time.

virulence

the degree of pathology caused by the organism

- combination of offense and defensive capabilities of the microbe

resistance

Capacity of an organism to defend itself against disease

D= nV/R

disease = number of microbes x virulence/resistance

infectious dose

the amount of pathogen required to cause an infection in the host

LD50

50% lethal dose = number of microbes required to kill 50% of animals infected

defensive strategy

-adhesins

-capsules

-antigenic variation

-enzyme secretion

-miscellaneous

offensive strategy

-enzymes

-exotoxins

-endotoxins

M protein

- streptococcus (strep throat) bacteria

-generally interfere w/ uptake during phagocytosis

enzyme

destroy the integrity of tissue structure

hyaluronidase

enzyme equivalent of plow

collagenase

breaks down collagen

collagen

holds tissue together

debridement

cutting away necrotic (dead) tissue as an alternative to amputation

hemolysins

destroy red blood cells

bacterial kinases

break down blood clots that might confine bacteria

streptokinase

made by streptococci bacteria but can be used to prevent strokes and treat heart attacks

coagulase

forms a network of threads around bacteria protecting them from phagocytosis

phagocytosis

the process by which a cell engulfs large particles or whole cells, either as a defense mechanism or as a means to obtain food

leukocidins

destroys white blood cells

toxin

poison or other damaging substance

exotoxin

made as part of bacteria metabolism then released into the cellular environment

-3 types

-cytotoxins

-neurotoxins

-enterotoxins

endotoxin

structural components that can induce an immune response

toxigenicity

the ability to produce toxins

cytotoxins

kill or damage host cells

neurotoxins

interfere with transmission of nerve impulses

enterotoxins

affect the cells lining the GI tract, leading to diarrhea

prophage

a virus that integrates its genome into the DNA of a bacterial genome

lysogenized

Viral DNA is part of the bacterial DNA

phage conversion

when a temperate phage induces a change in the phenotype of the infected bacteria that is not part of a usual phage cycle

lipopolysaccharides

important outer membrane components of gram-negative bacteria

incubation stage

-time between entry into the body and first display of symptoms

prodromal stage

-vague and mild symptoms, relatively short

-period between infection and initial symptoms

illness stage

-peak disease

-length determined by the battle between the immune system and microbe

stage of decline

-immune system wins the battle and you begin to feel better

convalenscence stage

-recover and regain your strength

gram positive vs. gram negative bacteria

positive = no cell wall negative = cell wall

capsules

-interfere with uptake of bacteria during phagocytosis

-you can't eat what you can't hold onto

virulence factors

????

commensalism vs symbiosis vs mutualism vs parasitism

-commensalism- one or more partners benefits while other partners are indifferent

-symbiosis- tow or more species "living together"

-mutualism- best of all worlds, blissful marriage, all partners benefit

-parasitism- one partner lives at the expense of another partner

defensive structures and their function

-adhesins= help fix microbes to cell surface and linings

-capsules= interfere with uptake of bacteria during phagocytosis

-antigenic variation= evade the immune system by changing your surface antigens

-enzyme secretion= helicobacter pylori excretes an enzyme that neutralized stomach acid

-miscellaneous= interfere with uptake during phagocytosis

Koch's hypothesis

-The microorganism must be found in abundance in all organisms suffering from the disease, but should not be found in healthy organisms

stages of microbial disease

1- incubation stage

2- prodromal stage

3- illness stage

4- stage of decline

5- convalescence stage

spreading factors

-hyaluronidase

-collagenase

-coagulase

mechanisms of virulence in bacteria

-ability to enter host

-ability to evade hose defenses

-ability to grow in host environment

-ability to counteract immune responses

-ability to acquire nutrients from host

advantages of antigen variation in trypanosomes

-helps these protozoans escape immune recognition

- (equivalent of changing coats to escape police surveillance)

AB model of exotoxin activity

-

discuss a specific offensive and defensive bacterial strategy

-defensive= changing antigen coat

-offensive= lyse cells, shut down protein synthesis, damage cell membrane, inhibit metabolism

small animalcules

The name for microbes first described by Antony van Leeuwenhoek during his examination of tooth scrapings with a primitive microscope.

binary fission

-how bacteria reproduce

-literally split into 2 parts

bacilli/bacillus

rod shaped

spirilla/spirillum

spiral shaped, rigid

cocci/coccus

spherical shaped

streptococci

string of pearls

staphylococci

bunch of grapes

diplococci

pairs of spheres

tetrads

group of 4 spheres

spirochetes

flexible rods

vibrios

comma shaped rods

bionomial nomenclature

two names

1- first name = genus (larger grouping

2- second name = species (smaller grouping)

envelope

a membranelike layer that covers the capsids of some viruses

capsule

-not integral to bacteria life (some have them some don't)

-can be washed away

-contributes to virulence (prevents phagocytosis)

slime layer

-when capsule become thick that it looks like slime

-like trying to grab slippery fish

ropy milk

problem for the milk industry caused by bacteria capsules

cell wall

-all bacteria have these

-rigid like structure

-confers resistance to diffusion of water

peptidoglycans

-makes up the cell wall and gives it rigidity

outer membrane

-only in gram negative bacteria

-gate keeper

-controls passage of molecules from external environment into bacteria

osmosis

-passive movement of water to "balance" concentration of things dissolved in wat-passive movement of water to "balance" concentration of things dissolved in waterer

selectively permeable

allows some molecules into the bacteria

cytoplasm

-part of cell enclosed by the cell membrane or cell wall

-contains cellular components that help cell grow and multiply

chromosome

-carries genetic info in the form of genes

-many bacteria only have one

-most bacteria have a single long circular chromosome

plasmid

-small molecules of non-chromosomal DNA

-confer different abilities of bacteria

-genes that make bacteria more virulent

-can be exchanged among bacteria

infectious agent

plasmids

R (resistance) factors

make a bacteria resistant to antibiotics

spores

-hardy structures highly resistant to heat, drying, radiation, and a variety of chemical including alcohol

-state of dormancy lets them survive thousands of years

vegetative cells

cells that are happily growing, but can become spores

flagella

-confer mobility

-moves bacteria through liquids

flagellin

protein that makes up flagella

basal bodies

anchor flagella to the cell wall and membrane

hanging drop

technique to measure the mobility of live unstained bacteria

chemotaxis

bacteria sense good and made things and move toward them or away from them

pili

-confer mobility

-shorter and thinner than flagella

-stick out of cell wall

-made up of pilin protein

sex pili

specialized pili that function to exchange genetic material between bacteria

growth vs multiplication

-for single celled organisms like bacteria these two events are the same

colony

individual bacterium multiply on a petri dish until visible by eye

generation time

explosive growth governed only by how long it takes a bacteria to divide

petri dish

dish contains a mix of nutrients and agar

agar

a semi-solid gel, kinda like jello

disease producing "odd ball" bacteria

-chlamydiae= have to live inside cells to survive

-richettsiae= have to live inside cells to survive as well

part of bacteria that causes different gram staining

differences in the thickness of a peptidoglycan layer in the cell membrane gram positive and negative bacteria

-stained purple = positive (cell wall)

-stained pink = gram negative (no cell wall)

bacteria without a cell wall

mycoplasmas