Facts about Pathogenic Escherichia coli: Flashcards Preview

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Flashcards in Facts about Pathogenic Escherichia coli: Deck (37):
1

what important common features does pathogenic Escherichia coli strains have?

  • Lactose Fermenter (pink on MacConkey)
  • Strict pathogens cause GI infections

2

all strains will be identified using what E. coli biology facts?

Gram negative bacilli

Motile

Lactose fermenter

Oxidase negative

Catalase +

3

what are the 4 clinical diseases Escherichia coli causes?

1) Entero Toxin E. coli (ETEC)

2) Entero Pathogenic E. coli (EPEC)

3) Entero-Invasive E. coli (EIEC)

4) Entero-Hemorragic E. coli (EHEC)

4

how does EPEC spread?

fecal-oral in developing countries

5

how does ETEC spread?

fecal-oral in developing countries

6

how does EIEC spread?

fecal-oral in developing countries

7

how does EHEC spread?

through fecal-oral found in beef or produce

8

In ETEC, what is another name for entero-toxigenic E. coli?

traveler's diarrhea

9

what is another name for ETEC, other than traveler's diarrhea?

Montezuma's Revenge

10

what does Entero-toxigenic E. coli do?

it attaches to the small intestine using fimbreae

11

what 2 entero toxins will cause the symptoms seen with ETEC?

  1. ​LT (heat-liable toxin)
  2. ST (heat-stable toxin)

12

what is the presentation of Entero-toxic E.coli?

self-resolving profuse watery secretory diarrhea without fever

13

how does the LT toxin from ETEC cause diarrhea?

it increases levels fo cAMP through activation of adenylyl cyclase. 

14

how does the ST toxin cause profuse watery diarrhea in ETEC?

it activates guanylate cyclase and increases cGMP

15

what is another name for EPEC (entero-pathogenic e.coli)?

Pediatric diarrhea

16

where is EPEC common?

in developing countries

17

what is the pathogenic mechanism of action in EPEC?

EPEC attaches to small intestine using T3SS (attaching and effacing lesions and kills microvilli.

leads to reduced absorption of water leading to symptoms

18

how does EPEC present clinically?

self-resolving secretory watery diarrhea without fever

19

what is another name for EIEC?

invasive diarrhea

20

what is the pathological presentation of EIEC?

EIEC attaches to colon using fimbriae and it rockets from cell to cell causing severe destrion of epithelial layer and releases hemolysin killing RBC's

21

what is the clinical presentation fo EIEC?

dysentery (low volume bloody stool with WBC present) with high fever

22

what is another name for EHEC?

hemorrhaging diarrhea

23

outbreaks in the US is due to what?

bacteria uses cattle as a reservoir

24

what is the pathological presentation of EHEC?

EHEC forms A/E lesions in the small intestine causing the diarrhea, then is uses shiga-toxin to destroy endothelial cells leading to the blood in the stool

25

the shiga toxin found in EHEC, can spread to what other organ endothelial tissue?

kidney

26

what is the clinical presentation of EHEC?

watery diarrhea followed by profuse bloody diarrhea without fever or WBC

27

what can EHEC lead to after a while?

Hemolytic Uremic Syndrome

28

what is EHEC serotype O157:H7 named after?

named based on LPS O and H antigen on its flagella

29

is EHEC invasive? how is your answer related to fever?

no, which is why fever is most often absent

30

what symptom is shiga-toxin responsible for?

it is responsible for the destruction of endothelial cells which leads to hemorrhaging

31

what does shiga toxin do to kill intestinal villi?

cleaves hosts 28s RNA ribosome

32

on who is hemolytic uremic syndrome most common?

5 years or less on TMP/SMX antibiotics

33

what is the clinical presentation for hemolytic uremic syndrome?

thrombocytopenia

Microangiopathic hemolytic anemia

Neurological manifestations

34

in EHEC, where will it not ferment? colonies will look how?

Sorbitol-MacConkey agar (S-Mac), colonies look white

35

can other e.coli ferment Sorbitol-MacConkey agar (S-Mac)?

yes

36

what e.coli is this?

Q image thumb

EHEC

37

on what food is EHEC mostly found?

burgers