Gastroenteritis Flashcards Preview

Clinical Pathology > Gastroenteritis > Flashcards

Flashcards in Gastroenteritis Deck (42):
1

what is the perfect environment for organisms to grow in- dry or moist sites

moist

2

what are the main beneficial effects of commensal flora of the gut.

metabolism, colonisation resistance, antibody induction

3

examples of 2 obligate anaerobes

clostridia, bifidobacteria

4

what pathogens are vitamins B12 and k secreted by

commensal eneteric bacteria

5

examples of 2 facultative anaerobes

enterobacteriacea and enterococci.

6

what are the most common bacterial causes of diahorrhea

salmonela, shinglla, E coli, Campylobacter, vibrio cholera, clostridium difficile, staph auerus, bacillus cerues

7

what are the most common parasitic causes of diarrhoea

Parasitic- Entamoeba hist, Giardia lamblia, cyrptospodium

8

what are the most common viral causes of diarrhoea

Viral- norovirus- rotavirus

9

what are the presenting complaint symptoms of gastroenetriritis

• Acute onset
• Vomiting AND/OR diarrhoea (frequency, mucous, blood).
• Abdominal pain
• Systemic-fever

10

complications of gastroenteritis

dehydration, renal failure, Haemolytic urea syndrome, toxic mega colon, salmonella, GBS (Guillain-Barre Syndrome)

11

common investigations in gastroenteritis

• Bloods – FBC, U&E, CRP, blood cultures- what is causing the infection
• AXR (abdominal X-ray) – if severe
• Stool
– Ova, parasites and cysts ‘OCP’
– Microscopy, culture and sensitivity ‘MC&S’
– Clostridium difficile toxin ‘CDT’
– Viral PCR- difficult to interpret due to 100’s of normal gut flora(coliforms)

12

what is the most common cause of viral gastroenteritis

norovirus

13

what are the symptoms of viral gastroenteritis

diahorrhea and projectile vomitting.

14

treatment of viral gastroenteritis

drinks water to avoid dehydration, stay away from work and good hygiene.

15

how to prevent viral gastroenetitis

rotovirus vaccine

16

how is cryptospordium transferred to humans

water bourne/ food bourne

17

symptoms of cryptospordium parasitic gastroenteritis

watery diahorrhea.

18

what chemical are the oocytes of cryptosporidium resistant to

chlorine

19

2 ways in which bacteria can cause gastroenteritis

produce toxin (eneterotoxin
bacteria itself (adherence)

20

enterotoxin (bacteria producing toxin) organism which causes gastroenteritis

– Vibrio cholerae
– Escherichia coil (entertoxigenic – ETEC, verotoxigenic - VTEC)
– Clostridium perfringens
– Staphylococcus aureus
– Bacillus cereus
– Clostridium difficile

21

bacterial which causes gastroenerteritis itself. (adherence)

– Shigella sonnei / flexneri
– Escherichia coil (entertoadherent – EAEC)
– Campylobacter jejuni
– Salmonellae

22

what is the name of the toxin produced by E.coli

shiga toxin

23

what is the source of E coli

cattle

24

symptoms associated with E coli infection

HUS (haemolytic uraemic syndrome)

25

pathogenesis of E coli

toxin activates G protein leading to increased cAMP, activates ion channels, chloride ions leave and water follows.
killing bacteria can result in release of more toxin and making the disease worse

26

where is salmonella transmitted from

abroad from food or drink.

27

4 types of salmonella causing organisms

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

28

what is the difference between typhoid and paratyphoid salmonella

typhoid- affects cells outside the GI tract
Parathyphoid- stays within the Gl tract

29

supporative management of gastroenteritis

avoid antibiotics- salmonella and E. coli
antibiotics- prolonged camplyobacter and very young/old.

30

how much time after antibiotic treatment does antibiotic associated diahorrhea occur

months after treatment

31

what causes antibiotic associated diahorrehea.

disruption to gut flora
1. Change in metabolism (carbohydrates / bile acids), leads to osmotic change and diarrhoea.
2. Overgrowth of pathogenic organisms

32

most common cause of antibiotic associated diahorrehea.

C.diff

33

severe symptoms of antibiotic associated diahorrehea.

pseudomembranous colitis
- Toxic mega colon, perforation, shock

34

high risk antibiotics for antibiotic associated diahorrehea form C. diff

cephlosporin and clindamycin

35

medium risk antibiotics for antibiotic associated diahorrehea C. diff.

ampicillin, amoxicillin, co-triazole, macrolides, fluroquinolones

36

low risk antibiotics for ntibiotic associated diahorrehea C. diff.

aminoglycosides, metronidazole, anti pseudomonal penicillin, B lactamase inhibitor, tetracycline, rifampicin, vancomycin.

37

control mechanism for C diff

early warning system
reduce risk of transmission
early isolation/cohorting of patients with diarrhoea
• Environmental cleaning, chlorine
• Hand hygiene soap & water
• Examine/optimise/reduce overall antibiotic use
• Limit high risk agents in high risk patients
• Feedback CDI & antibiotic data on a regular basis

38

tretament for C diff antibiotic associated diarrhoea

oral metronidazole / oral vancomycin
new drug- oral fidaxomicin

39

potential risk of antibiotic treatment for C diff antibiotic associated diarrhoea

increased risk of vancomycin resistant enterococci selection
• Potential for emergence of resistance to vancomycin / metronidazole in C. difficile.

40

do patients relapse with antibiotic treatment for C diff antibiotic associated diarrhoea

yes

41

so patients relapse with Faecal transplant for antibiotic treatment for C diff antibiotic associated diarrhoea

no

42

define faecal transplant

• Family faeces used orally or rectally- increases gut flora diversity similar to donor.