intro to bacterial infection

Question 1

diff in cell structure btwn eukaryotes and bact

Answer 1

bact have no intracellular microtubules, nucleus, and lots of ribosomes

Question 2

what are oligotrophs?

Answer 2

grow w/ limited nutrients

Question 3

what are microaerophiles

Answer 3

bact that require some oxygen but lower levels of it

Question 4

what are mesophiles

Answer 4

bact taht grow well in milk temperatures (15-45’)

Question 5

typical categories of medically imp bact

Answer 5

microaerophiles, mesotrophes, oligotrophs

Question 6

diff btwn gram + and - bact

Answer 6

both have lipid membrane but …
neg = has an outter and inner membrane around cell wall and stains red/pink and has LPS
pos = has thick murein (thick peptidoglycan) and stains purple and techoic acids

Question 7

murein is made up of…

Answer 7

n-acetylmuramic acid and n acetylglucosamine linked by peptides off NAM

Question 8

peptide bonds in murein of gram + and - bact

Answer 8

+ btwn L-lys and D-ala

- btwn DAP and D-ala

Question 9

what parts of murein synth occurs where?

Answer 9

linking of polymers in periplasmic space

liking of NAM to NAG and peptide are w/in cytoplasm

Question 10

tcn of teichoic acids and types

Answer 10

maintains rigidity: glycerol and ribotol and lipo

Question 11

techoic acids are only found…

Answer 11

on gram + bact

Question 12

LPS is only found on _____ and is aka _____

Answer 12

gram - bact.

endotoxin

Question 13

components of LPS

Answer 13

lipid -A
polysaccharide core
O-antigen subunits (differs btwn baact)

Question 14

why is LPS also know as endotoxin?

Answer 14

induces TNF-a and can lead to septic shock.

Question 15

why are techoic acids and LPS important for us?

Answer 15

considered PAMPs that are recognized by our body’s pattern recognition receptors PRRs
(receptor 4 recognizesLPS and 2 rec. techoic acids)

Question 16

what are accessory microbe structures?

Answer 16

fimbriae - helps bact have sex and attach to host thru adhesin proteins on tips
flagella - help move

Question 17

ways you can categorize bact based on flagella

Answer 17

mono- (one), lopho- (a few), and peri- (many) trichous

Question 18

bact movement is considered run and tumble based on…

Answer 18

CCW or CW rotation of their flagella

Question 19

different things bact can move to..

Answer 19

chem: chemotaxis
oxygen: aerotaxis
[gradient]: osmotaxis
heat: thermotaxis

Question 20

glycocalyx can be considered a _____ or ______ based on organization

Answer 20

slime layer or capsule, either way it’s a virulence factor thou capsule is harder to phagocytose or recognize

Question 21

when a bact is recognized it becomes_____ and _______ are released

Answer 21

phagocytosed

cytokines

Question 22

letters in path name refer to

Answer 22

O- LPS
H-flagella
K-capusle

Question 23

what does a microbe need to do to be considered a pathogen

Answer 23

adhere (can be specific or not), invade, colonize, replicate and cause damage (thru invasion, toxins, or activation of immune system)

Question 24

how do primary pathogens use specific adherence?

Answer 24

irreversible and anchoring attachment thru adhesins to specific regions

Question 25

common adhesin that’s found on the cell surface binds to …

Answer 25

fibronectin

Question 26

how do bact take up nutrients?

Answer 26

carrier-mediated diffusion (facilitated by prot down [ ] gradient)
phosphorylation-linked transposrt (group translocation of nutrient by adding Pi to it)
active transport using ATP to create [ ] gradient

Question 27

how does enteropathogenic E coli damage the host?

Answer 27

thru actin polymerization during colonization.

Question 28

what enzymes help bact invade into host cell?

Answer 28

halurondiase (degrades hyaluronic acid) and collagenase

Question 29

diff btwn endo and exotoxin

Answer 29

endo=LPS, connected to outter membrane of gram - bact

exotoxins=secreted diffusible proteins

Question 30

diff btwn type 1, 2 and 3 endotoxins

Answer 30

1: membrane acting toxins bind surface receptors and stimulate transmembrane signals
2: membrane damaging by creating pores
3: intracellular effectors that help toxin get into host cell

Question 31

some ways host cells can get damaged:

Answer 31

lytic viral infections (multiply in host cell till it ruptures)
invasions damaging host tissue
toxin producing microbes
host responst thru phagogytes and cytotoxic T cell activity can also result in tissue damage