GI Acute Inflammatory Diarrhea II Flashcards Preview

Micro Term 4 > GI Acute Inflammatory Diarrhea II > Flashcards

Flashcards in GI Acute Inflammatory Diarrhea II Deck (40):
1

describe the shape of Campylobacter 

small, curved-spiral rods

2

Campylobacter are (G+ve/G-ve) and are motile

Campylobacter are G-ve and are motile

3

Campylobacter are G-ve and are (motile/non-motile)

Campylobacter are G-ve and are motile (single polar flagellum)

4

Campylobacter are microaerophilic and DO NOT ferment ____

Campylobacter are microaerophilic and DO NOT ferment CH2O (carbohydrates)

5

Campylobacter are (catalase +ve/catalase -ve)

Campylobacter are catalase +ve

6

____ are the leading cause of bacterial food-borne disease

60% of cases are caused by....

Campylobacter are the leading cause of bacterial food-borne disease

60% of cases are caused by ingestion of contaminated liquid or solid food (unpasteurized milk, raw/partially cooked poultry & contaminated water)

7

describe the pathogenesis of Campylobacter

  1. ingestion of pathogen
  2. invasion of SI and LI
    • histologic damage to mucosal surfaces
  3. toxin production
    • endotoxin (since it is inherent to G-ve)
    • enterotoxin: watery diarrhea
    • cytotoxin: verotoxin similar to Shiga toxin

8

describe the clinical features of Campylobacter infection

symptoms appear 3-5 days after ingestion

  • vomiting
  • diarrhea (often profuse, green?)
  • abdominal pain, often severe
  • prostration, often severe
  • fever, often present
  • bloodstained feces

9

name associations/complications of Campylobacter

  • reactive arthritis 
    • knee joint
  • acute inflammatory demyelinating polyneuropathy; Guillan-Barre syndrome

10

describe how Campylobacter infection can lead to GBS

11

describe the detection of C. jejuni

12

describe the Sketchy

13

Yersinia enterocolytica is common among _____ (population)

Yersinia enterocolytica  is common among children <7 yrs old and adults

14

describe the growth temperature of Yersinia enterocolytica

-1 to 40 C = psychrotroph - facultative psycrophiles

(grows in ​cold temperatures)

15

describe the pathogenesis of Yersinia enterocolytica

  • invasive induces inflammatory response
  • distal ileum (gut-associated lymphoid tissue)
  • adjacent tissues & mesenteric lymph nodes also infected (mimic appendicitis)
  • releases chromosomally encoded ST enterotoxin (which leads to an increase in cGMP)

16

Yersiniosis infects adjacent tissues in the distal ileum and mesenteric lymph nodes and often mimics ____

Yersiniosis infects adjacent tissues in the distal ileum and mesenteric lymph nodes and often mimics appendicitis

17

the ___ enterotoxin produced by Y. enterocolytica is ___-encoded and causes a rise in ____

the ST enterotoxin produced by Y. enterocolytica is chromosomally-encoded and causes a rise in cGMP

18

describe the clinical features of Y. enterocolytica

  • self-limiting enterocolitis
  • incubation = 3-7 days
  • lasts 14-21 days
  • symptoms:
    • abdominal pain and diarrhea
    • mild fever
    • vomiting rare 

19

Yersiniosis has an incubation period of ____ and lasts for _____

Yersiniosis has an incubation period of 3-7 days and lasts for 14-21 days

20

Yersiniosis can lead to post-infective _____

Yersiniosis can lead to post-infective reactive arthritis (autoimmunity arthritis)

21

Y. enterocolytica looks like ____ colonies on MacConkey agar

Y. enterocolytica  looks like pinpoint colonies on MacConkey agar

22

describe the Sketchy

23

V. parahaemolyticus infection is caused by ingestion of ____

V. parahaemolyticus  infection is caused by ingestion of raw/poorly cooked seafood

24

V. vulnificus is associated with abrasions/cuts exposed to ____

V. vulnificus is associated with abrasions/cuts exposed to sea/salt water

25

V. parahaemolyticus produces ___ and ____

V. parahaemolyticus  produces enterotoxin and haemolysin

26

describe signs of V. vulnificus 

  • intense skin lesions
  • gastroenteritis & even severe bacteremia

27

deaths caused by V. vulnificus are predominantly associated with patients with _____

deaths caused by V. vulnificus  are predominantly associated with patients with underlying liver conditions

28

describe diagnosis and ID of non-cholera species

29

enteroaggregative E. coli (EAEC) does NOT possess ____ but does possess _____ which allows it to aggregate on the surface of SI/LI

enteroaggregative E. coli (EAEC) does NOT possess EAF (enteric adherence factor) but does possess AAF (aggregative adherence factor) which allows it to aggregate on the surface of SI/LI

 

30

describe the pathogenesis of EAEC

  1. agglutination of bacteria
  2. adherence to intestinal epithelium and colonization
  3. formation of biofilm
  4. release of toxins (damage to epithelium + increased secretion)
  5. establishment of additional biofilm

31

name the 3 life-threatening conditions caused by EHEC/STEC/VTEC

  • hemorrhagic colitis = approx. 3 days after ingestion
    • mainly adults/elderly
    • blood diarrhea (begins watery)
  • hemolytic uremic syndrome (HUS) = 5-13 days post-diarrhea
    • mainly affects children
    • microangiopathic hemoltyic anemia
    • thrombocytopenia
    • acute renal failure
  • thrombotic thrombocytopenia purpura
    • mainly elderly
    • HUS + fever + neurological involvement

32

hemorrhagic colitis, caused by ____, occurs ___ days after ingestion and affects mainly ____

hemorrhagic colitis, caused by STEC/VTEC/EHEC, occurs ~3 days after ingestion and affects mainly adults/elderly

33

hemolytic uremic syndrome, caused by ____, occurs ___ days after diarrhea and affects mainly ____

hemolytic uremic syndrome, caused by STEC/VTEC/EHEC, occurs 5-13 days post-diarrhea and affects mainly children

34

thrombotic thrombocytopenia purpura, caused by ____, affects mainly ____

thrombotic thrombocytopenia purpura, caused by STEC/VTEC/EHEC, affects mainly elderly

35

describe the pathogenesis of STEC/VTEC/EHEC

  1. ingestion
  2. attachment (similar to EPEC)
  3. production of phage-encoded: cytotoxin (verotoxin)
    • 2 types VT1 and VT2, both AB toxins
      • Shiga-like toxin (rRNA) blocks protein synthesis
  4. hemorrhagic colitis
  5. toxin enters circulation binds to glomerular endothelium
  6. hemolytic anemia, renal damage → renal failure

36

STEC/VTEC/EHEC is also associated with _____

STEC/VTEC/EHEC is also associated with  county fairs/petting zoos

37

STEC do not ferment ____ and therefore appear colorless on MacConkey's agar

STEC do not ferment sorbitol and therefore appear colorless on MacConkey's agar

38

in order to diagnose STEC, a blood culture can be taken and ____ can be seen

in order to diagnose STEC, a blood culture can be taken and schistocytes (fragmented RBCs) can be seen

39

describe the Sketchy

40

describe the identification of G-ve rods grown on MacConkey agar