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Flashcards in bacteria and toxins Deck (32):
1

influenza

2 antigens: hemagglutinin (promotes viral entry), neuraminidase (promotes progeny virion release)

2

clostridium perfringens

alpha-toxin/ lecithinase: phospholipase that degrades phospholipids--> degrades tissue and cell membranes--> death of these tissues

3

clostridium botulinum

botulinum toxin: preformed, heat labile toxin that inhibits ACh release at NMJ (also via cleaving snare)

4

bacillus cereus

cereulide: preformed toxin

5

mycobacteria

cord factor: inhibits macrophage maturation, damages mitochondria, and induces the release of TNF-alpha

sulfatides: surfae glycolipids that inhibit phagolysosomal fusion

6

corynebacterium diphtheriae

diphtheria exotoxin: encoded by beta-prophages (specialized transduction/ lysogenation), protein synthesis via ADP- ribosylation of EF-2

7

bacillus anthracis

edema/ anthrax toxin: mimics adenylate cyclase enzyme (--> increases cAMP)

8

chlamydiae

Elementary body: small/dense, enters cell via endocytosis and transforms into reticulate body

reticulate body: replicates in cell by fission then reorganizes into elementary bodies

9

strep pneumo

encapsulated bacteria, IgA protease

10

salmonella (NOT typhi)

endotoxin

11

shigella

endotoxin

shiga toxin (enterotoxin)

invasion in the key to pathogenicity (toxin not necessary to still have disease)

12

salmonella typhi

endotoxin

Vi capsule: protects from opsonization

13

pseudomonas aeruginosa

endotoxin (fever, shock)

exotoxin A: inactivates EF-2

mucoid polysaccharide capsule may contribute to chronic pneumonia in CF pts (via biofilm formation)

14

vibrio cholerae

enterotoxin: permanently activates Gs, increases cAMP--> NaCl efflux--> water loss

15

staph epidermidis

glycocalyces

16

ETEC

Heat labile enterotoxin: overactivates adenylate cyclase (increases cAMP)--> increased chloride secretion and water efflux in gut

heat stable enterotoxin: overactivates guanylate cyclase (increases cGMP)--> decreased resorption of NaCl and water in the gut

note: no inflammation or infvasion

17

neisseria gonorrheae

IgA protease

pili

18

neisseria meningitidis

IgA protease

polysaccharide capsule

LPS/LOS endotoxin: severity of disease correlates with blood concentration of LOS

pili: attach to respiratory mucosa (help gain access to blood stream)

19

H flu

IgA protease: allows for colonization of the respiratory mucosa

HiB: antiphagocytic polysaccharide capsule

20

EIEC

microbe invades the intestinal mucosa and causes necrosis and inflammation

21

EPEC

no toxin; adheres to apical surface, flattens villi, prevents absorption

22

listeria monocytogenes

only gram positive organism to produce endotoxin


form actin "rocket tails" that allow for intracellular movement and cell-to-cell spread across cell membranes (avoiding antibody)

23

staph aureus

Protein A

24

group A strep (strep pyogenes)

Protein M= major virulence factor (inhibits phagocytosis and complement activation)

streptolysin O= toxin

25

EHEC

shiga-like toxin: inactivates 60s ribsosome by removing adenine from rRNA; enhances cytokine release

26

parainfluenza

surface F (Fusion) protein which causes respiratory epithelial cells to fuse and form multinucleated cells

27

RSV

surface F (Fusion) protein which causes respiratory epithelial cells to fuse and form multinucleated cells

28

measles (Rubeola) virus

surface F (Fusion) protein which causes respiratory epithelial cells to fuse and form multinucleated cells

29

mumps virus

surface F (Fusion) protein which causes respiratory epithelial cells to fuse and form multinucleated cells

30

clostridium tetani

tetanospasmin/tetanus toxin: exotoxin causing tetanus; protease that cleaves SNARE (set of proteins required for NT release via vesicular fusion)--> prevents release of inhibitory (GABA, glycine) neurotransmitters from Renshaw cells in the spinal cord

31

clostridium difficile

toxin A (enterotoxin): binds brush border of the gut (--> diarrhea)

toxin B (cytotoxin): causes actin depolymerizatin--> cytoskeletal disruption--> necrosis

32

rotavirus

villous destruction with atrophy leads to decreased absorption on Na+ and loss of K+