Gastroenteritis

Question 1

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

Answer 1

moist

Question 2

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

Answer 2

metabolism, colonisation resistance, antibody induction

Question 3

examples of 2 obligate anaerobes

Answer 3

clostridia, bifidobacteria

Question 4

what pathogens are vitamins B12 and k secreted by

Answer 4

commensal eneteric bacteria

Question 5

examples of 2 facultative anaerobes

Answer 5

enterobacteriacea and enterococci.

Question 6

what are the most common bacterial causes of diahorrhea

Answer 6

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

Question 7

what are the most common parasitic causes of diarrhoea

Answer 7

Parasitic- Entamoeba hist, Giardia lamblia, cyrptospodium

Question 8

what are the most common viral causes of diarrhoea

Answer 8

Viral- norovirus- rotavirus

Question 9

what are the presenting complaint symptoms of gastroenetriritis

Answer 9

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

Question 10

complications of gastroenteritis

Answer 10

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

Question 11

common investigations in gastroenteritis

Answer 11

• 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)

Question 12

what is the most common cause of viral gastroenteritis

Answer 12

norovirus

Question 13

what are the symptoms of viral gastroenteritis

Answer 13

diahorrhea and projectile vomitting.

Question 14

treatment of viral gastroenteritis

Answer 14

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

Question 15

how to prevent viral gastroenetitis

Answer 15

rotovirus vaccine

Question 16

how is cryptospordium transferred to humans

Answer 16

water bourne/ food bourne

Question 17

symptoms of cryptospordium parasitic gastroenteritis

Answer 17

watery diahorrhea.

Question 18

what chemical are the oocytes of cryptosporidium resistant to

Answer 18

chlorine

Question 19

2 ways in which bacteria can cause gastroenteritis

Answer 19

produce toxin (eneterotoxin
bacteria itself (adherence)

Question 20

enterotoxin (bacteria producing toxin) organism which causes gastroenteritis

Answer 20

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

Question 21

bacterial which causes gastroenerteritis itself. (adherence)

Answer 21

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

Question 22

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

Answer 22

shiga toxin

Question 23

what is the source of E coli

Answer 23

cattle

Question 24

symptoms associated with E coli infection

Answer 24

HUS (haemolytic uraemic syndrome)

Question 25

pathogenesis of E coli

Answer 25

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

Question 26

where is salmonella transmitted from

Answer 26

abroad from food or drink.

Question 27

4 types of salmonella causing organisms

Answer 27

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

Question 28

what is the difference between typhoid and paratyphoid salmonella

Answer 28

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

Question 29

supporative management of gastroenteritis

Answer 29

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

Question 30

how much time after antibiotic treatment does antibiotic associated diahorrhea occur

Answer 30

months after treatment

Question 31

what causes antibiotic associated diahorrehea.

Answer 31

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

Question 32

most common cause of antibiotic associated diahorrehea.

Answer 32

C.diff

Question 33

severe symptoms of antibiotic associated diahorrehea.

Answer 33

pseudomembranous colitis | - Toxic mega colon, perforation, shock

Question 34

high risk antibiotics for antibiotic associated diahorrehea form C. diff

Answer 34

cephlosporin and clindamycin

Question 35

medium risk antibiotics for antibiotic associated diahorrehea C. diff.

Answer 35

ampicillin, amoxicillin, co-triazole, macrolides, fluroquinolones

Question 36

low risk antibiotics for ntibiotic associated diahorrehea C. diff.

Answer 36

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

Question 37

control mechanism for C diff

Answer 37

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

Question 38

tretament for C diff antibiotic associated diarrhoea

Answer 38

oral metronidazole / oral vancomycin | new drug- oral fidaxomicin

Question 39

potential risk of antibiotic treatment for C diff antibiotic associated diarrhoea

Answer 39

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

Question 40

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

Answer 40

yes

Question 41

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

Answer 41

no

Question 42

define faecal transplant

Answer 42

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