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Flashcards in bacterial gasteroenteritis Deck (67):
1

predominant aerobe in the gut

e coli

2

noninflammatory diarrhea

watery, large volume stools with no blood, pus or severe pain

3

inflammatory diarrhea

lower volume stools with blood,pain, pus and fever

4

enterotoxins cause

noninflammatory diarrhea

5

cytotoxins cause

inflammatory diarrhea

6

definition of coliform

lactose positive

7

fecal pathogens that are lactose negative

salmonella and shigella

8

gram negative rod, ferments lactose

e coli

9

red colonies on macConkey indicate

lactose fermentor

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habitat of e coli

GI tract of vertebrates and soil/water contaminated with feces

11

virulence factors of e coli

Pili
Locus for Enterocyte Effacement
Type 3 Secretion System
LT/ST enterotoxins
Shiga Toxin

12

MOA of LT toxin

ribosylates adenylyl cyclase --> increases cAMP --> causes secretion of water and electrolytes --> diarrhea

13

MOA of ST toxin

increases cGMP --> increases cAMP --> causes secretion of water and electrolytes --> diarrhea

14

produces shiga toxin

enterohemorrgagic e coli (EHEC) (O157:H7)

15

MOA of shiga toxin

inhibits protein synthesism provokes apoptosis --> capillary thrombosis and mucosal inflammation --> hemorrhagic colitis

16

bad end result of shiga toxin

hemolytic uremic syndrome

17

primary resivoir of e coli (O157:H7)

cattle gut

18

most important early virulence factor of EHEC

type III seretion lesion causing attaching and effacing lesions

19

intense abdominal pain, bloody diarreha, no or slight fever

EHEC

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ID of e coli (O157:H7)

lactose positive colonies that do not ferment sorbitol, then test for O157 and H7 antisera

21

sx of HUS

acute renal failure, hemolyic anemia and thrombocytopenia

22

What NOT to EVER do in EHEC infection

give antibiotics (releases shiga toxin)

23

remains extra cellular, attached by lesions and injects toxin by integreated bacteriophage

e coli EHEC

24

causes watery diarrhea in bottle fed infants in developing countries

Enteropathic E coli (EPEC)

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causes "traveler's diarrhea"

enterotoxigenic e coli (ETEC)

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"traveler's diarrhea" very similar to

cholera

27

pathenogenies of ETEC

activates adenylate cyclase or guanylyl cyclase --> activates CHTR --> induces hypersecretion --> diarrhea

28

general treatmene of e coli infections

supportive - rehydration or electrolyte replacement. Antibiotics only in invasive disease

29

leading cause of infant diarrhea and death in developing countries

shigella

30

lactose negative gram negative rods

shigella

31

resivoir of shigella

human GI tract

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virulance factor only found in shigella

neurotoxin endotoxin

33

MOA of shigella neurotoxin

binds the 60S ribosomal subunit, inhibiting protein synthesis

34

severe abdominal cramps, frequent painful passage of low-volume stools containing blood and mucus

shigella

35

sudden onset of diarrhea with fever and bloody stools in kids

shigella

36

invades colonic epithelial M cells, multiplies in cytoplasm and spreads cell to cell

Shigella

37

treatment for shigella

hydration by mouth, antibiotics (sulfonamides, streptomycin)

38

gram negative rods, lactose negative, faculative anareobes

salmonella

39

pet reptiles can carry

salmonella

40

virulence factors include enterotoxin and pathogenicity island

salmonella

41

sudden onset of headache, chills, abdominal pain followed by n/v and severe diarrhea

salmonella

42

most common strain of salmonella causing "food poisoning"

S enterica Typhimurium

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systemic salmonella poisoning

enteric fever

44

pathogenesis of salmonella

adheres to mucosal epithelial cells and induces actin movement. engulfed into vaculole which is transported through the basal membrane to the lymphatics --> to liver spleen and bone marrow

45

treatment of salmonella

fluid and electolyte replacement, and control of n/v. Cholramphenicol for enteric fever

46

frontal headache, decrease in appetite, fever, constipation, flu-like sx

typhoid fever

47

DOC for typhoid

chloramphenicol

48

where do long-term carriers of typhoid carry the bug

gall bladder

49

common with poor sanitation,improper sewage disposal or flood contaminated water supplies

Cholera

50

short, curved, gram negative rods

V cholerae, or campylocater jejuni

51

infects shellfish

vibrios

52

rice water diarrhea with massive fluid loss

cholera

53

v cholerae viriulance factor (main 2)

CT (AB5) toxin, priduction of mucinase

54

MOA of cholera toxin

locks sdenylate cyclase into active state --> hyperproduction of cAMP --> pushes large amounts of electrolytes and water out of cells

55

needs a large dose to become infectious and attaches (does not enter cell) to outside of intestinal surface

V cholerae

56

treatment of cholera

rapid IV injection of bicarb in acute - oral fluid/electrolyte replenishment

57

species of vibrio caused by shellfish

vulnificus/parahaemolyticus

58

needs a massive bolus of bacteria to infect

camylobacter

59

virulence factor of camplobacter

enterotoxin similar to cholera

60

complication of campylobacter

Guillain-Barre

61

how campylobacter can cause GB

anti-bodies of the lipo-oligosaccharide of C jejuni cross-react with peripheral nerve gangliosides

62

causes stomach ulcers

H pylori

63

slender, curved, gram negative rods with polar flagella

H pylori

64

non stomach ulcer diseases that H pylori can cause

gastric adenocarcinoma and Gastric MALT lymphoma

65

vurulance factor fo H pylori

produces urase, producting ammonia and raising the pH in the vicinity.

66

dx for pylori

c-urea breath test

67

treatment for h pylori

antibiotics with PPI