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Flashcards in 132 GI Pathogens Deck (20):
1

most common causes of food-borne illnesses in US - bacterial? parasite? viral?

Campylobacteria (bacterial)

Giardia lamblia (parasite)

noroviruses (viral)

2

inflammatory diarrhea vs noninflammatory diarrhea

inflamm - mucous or blood from mucosa tissue destruction by pathogen;RBC, WBC + fever + incubation period of 2-4 days

noninflamm - watery stool without blood; due to toxins/virus NOT invasion into musosa; shorter incubation (1-12 hours); No fever

3

noninflammatory diarrhea - most common causes

vibro cholerae
Enterotoxigenic E Coli
Clostridium
Bacilius cereus
Staph Aureus
Rotavirus
Norovirus
Giardia
Crytpsporidium

4

vibro cholerae - shape/appearance? where does it live in environment? What are the types?

gram negative rod ("comma shaped")

salt water in marine crustaceans

2 biotypes - El Tor (less severe) and Classic

5

cholera toxin - what encodes? what type of toxin? what does it increase in the cell? what does this activate?

encoded by phage

AB toxins (A is active, B is binding subunit)

activates enzyme increasing cAMP

activates CFTR channel --> increased Cl secretion and decreased Na uptake

6

cholera - clinical disease; death? how acquired? stool appearace? fever? oxidase +/-? treatment?

severe dehydration and death in 12 hours --> need massive amount of IV fluid

acquired via raw fish or water

stool is watery with mucus flecks

negative fever

oxidase+

IV + antibiotics

7

Clostridium perfringens
appearance/stain?
symptoms?
duration?
treatment?

Anaerobic gram + bacillus

food poisoning --> diarrhea + cramping without vomiting

<24 hours - self limited

dont need antibiotics

8

Bacillus cereus
appearance/stain?
toxins?
found in what?
length?
treatment?

Gram + rod

2 toxins --> vomitting + watery diarrhea

toxins found in rice

< 24 hours --> dont need antibiotics

9

Staph Aureus
causes what?
symptoms and length?
found in what?
treatment?

food poisoning from heat stable toxins (A-->E)

cause wide spread outbreaks

vomiting + diarrhea < 10 hours

creams, potato salad, mayo

illness is from toxin so no antibiotics

10

rotovirus
who gets infected?
symptoms?

common world wide - everyone gets infected

vomiting then diarrhea w/ fever (exception to noninflam diarrhea rule)

**Everyone rotates through rotovirus and rotates through symptoms (vomiting --> diarrhea + fever)

11

Noroviruses
spread?
symptoms?

Fecal-oral + contaminated food/water

nausea, vomiting, diarrhea

24-48 hours (no treatment required)

12

Giardia lamblia
type?
who gets it?
symptoms and duration?
Rx?

parasite

fecal - oral --> campers

2 forms - trophozoites + cyst in environment

1-4 weeks

diarrhea, bloating, gas

Rx - metronidazole, furazolidone

13

traveler's diarrhea - common cause and course?

enterotoxigenic E Coli is most common cause

short lived and self limited

14

inflammatory diarrhea

shigella
salmonella
campylobacter
enterhemorrhavic E Coli
Yersinia
C. Diff
Entamoeba histolytica

15

Shigella
appearance/stain?
spread?
spread?
type of diarrhea?

gram negative rods (closely related to E Coli)

tolerates stomach acid --> fingers, food, flies, feces, fomites (forks)

invades colon via M cells --> enterocyte spreading via host actin tails (like listeria)

mild watery diarrhea --> blood and pus w/ pain diarrhea

16

Salmonella enterica
appearance?
what does it cause?

gram negative bacillus

food poisoning - chicken and eggs

17

Campylobacter jejuni
appearance and stain?
type of diarrhea? what other disease?
reservoirs?
course?

curved gram negative rod "sea gull"

bloody diarrhea followed by Guillain-Barre syndrome on occasion (ascending neuropathy --> respiratory failure)

animals - food, poultry

self-limited usually

18

Yersinia enterocolitica
appearance?
spread?
mimics?

gram negative rod

blood transfusion spread

mimics appendicitis

19

clostridium difficile
appearance?

gram + rod

antibiotic assoicated diarrhea --> antiobtiocs allow organism to get a foot hold --> pseudomembrance formation

20

entamoeba histolytica

amoeba w/ 2 forms

flask shaped ulcers from toxins