Diseases of GI Tract - Gastroenteritis and Antibiotic Associated Colitis (24) Flashcards Preview

Clinical Pathology > Diseases of GI Tract - Gastroenteritis and Antibiotic Associated Colitis (24) > Flashcards

Flashcards in Diseases of GI Tract - Gastroenteritis and Antibiotic Associated Colitis (24) Deck (37):
1

Commensal flora of gut

- Faecal flora metabolic capacity = liver
- Anaerobic bacteria (Bacteroides outnumber E.coli)

2

What are the beneficial effects of commensal flora of gut?

Metabolism, colonisation, resistance and antibody induction

3

Bottle-fed baby

Adult microflora

4

Breast fed baby

Bifidobacteria

5

Most common commensal flora of gut

Bactericides and prevotella

6

Obligate anaerobes

Clostridia, bifidobacteria

7

Facultative anaerobes

Enterobacteriacea, enterococci

8

Bacterial causes

Salmonella, Shigella, E.coli, Campylobacter, Vibrio cholerae, C.diff, Staph aureus, Bacillus cereus

9

Parasitic (protozoa) causes

Entamoeba hist, Giardia lambila, Cryptosporidium

10

Viral causes

Norovirus, Rotavirus

11

Presenting complaint

Acute onset, vomiting, diarrhoea (frequency, mucous, blood), abd pain, fever

12

Complications

Dehydration, renal failure, haemolytic uraemia syndrome, toxic megacolon, Guillain-Barre syndrome, Salmonella

13

Investigations

- Bloods (FBC, U&E, CRP, cultures)
- AXR
- Stool (Ova, parasites and cysts OCP, microscopy culture and sensitivity MC&S, C.diff toxin CDT, viral PCR)

14

Viral gastroenteritis caused by

Norovirus (commonest gut infection UK)

15

Symptoms of viral gastroenteritis

Diarrhoea and projective vomiting

16

Transmission of viral gastroenteritis

Aerosols (air particles)

17

How long does viral gastroenteritis last?

24-48 hours

18

Parasitic gastroenteritis caused by

Cryptosporidium, Giarda, Entamoeba etc

19

Who is Cryptosporidium infection most common in?

Children

20

Transmission of Cryptosporidium

Waterborne (oocysts resistant to Cl- disinfectants)

21

Presentation of Cryptosporidium

Watery diarrhoea

22

Bacteria gastroenteritis caused by entertoxin production

Vibrio cholerae, E.coli (ETEC/VTEC), C.perfringens, Bacillus cereus, C.diff

23

Bacteria gastroenteritis caused by adherence

Shigella sonnei/flexneri, E.coli (EAEC), Campylobacter jejuni, Salmonellae

24

What toxin is produced by E.coli?

Shiga

25

Which toxin is the 'model' toxin?

Cholera

26

Types of Salmonella

S. typhi, S. paratyphi, S.enteritidis, S.typhimurium

27

Salmonella causes..

Food poisoning, typhoid and paratyphoid

28

Treatment

Avoid antibiotics may increase duration of salmonella and worsen E. Coli HUS

29

When do you use antibiotics?

Very young and old, campylobacter and invasion (positive blood cultures)

30

Organisms that causes antibiotic-associtaed diarrhoea

C. diff, C.perfringens, S.aureus, Candida, Klebsiella, Salmonella

31

Symptoms of antibiotic-associated diarrhoea

Mild diarrhoea > toxic megacolon/perforation/shock

32

How does antibiotic associated diarrhoea come about?

Disruption of gut microflora > change in metabolism > overgrowth of pathogenic organism

33

High risk antibiotics of CDI

Cephalosporins and Clindamycin

34

Medium risk antibiotics of CDI

ampicillin/amoxycillin
co-trimoxazole
macrolides
fluoroquinolones

35

Low risk antibiotics of CDI

aminoglycosides
metronidazole
anti-pseudomonal penicillins + β- lactamase inhibitor
Tetracyclines
rifampicin
vancomycin

36

CDI therapy

Oral metronidazole/vancomycin

37

New CDI therapy

Oral fidaxomicin

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