infections of the gut Flashcards
how is shigella transmitted?
faecal-oral route
how many shigella organisms are required to cause infection?
only 10 (highly infectious)
arrange from mild to most serious form of Shigella
a. Shigella dysenteriae
b. Shigella sonei
c. Shigella flexneri, shigella boydii
- Shigella sonei (mild)
- Shigella flexneri
- Shigella dysenteriae (most serious)
what type of culture is used to diagnose shigellosis?
faecal culture
how many salmonella (non-typhoidal) organisms are required to cause infection?
> 10^5
what bacteria invades macrophages and breaks into the blood?
salmonella typhi/paratyphi
what bacteria causes dysentery, bloody mucous stool?
shigella
what complication is listeria monocytogenes associated with?
meningitis
buzzwords: uncooked chicken, red colonies with black centres on XLD plate, non-lactose fermenting
salmonella spp. (non-typhoidal)
buzzwords: poor sanitation, shellfish, dehydration, rice water stool
cholera (vibrio cholerae)
which pathogen is associated with antibiotic-associated diarrhoea?
clostridium difficile
buzzwords: canned food, floppy baby syndrome
clostridium botulinum
buzzword: poorly kept rice
bacillus cereus
buzzwords: hospital acquired infection, excessive antibiotic use, white plaques on colonic mucosa
clostridium difficile
how is hep A transmitted?
faecal-oral route
how is hep B transmitted?
sexual, parenteral, perinatal
how is hep C transmitted?
IVDU, needlestick injuries
buzzwords: cross placenta, vertical transmission, unpasteurised milk/dairy, meningitis
what is the associated pathogen?
listeria monocytogenes
buzzwords: farm, bird droppings in water tank
what is the associated pathogen?
campylobacter jejuni
what is the most common type of E. coli infection?
enterotoxigenic E. coli –> traveller’s diarrhoea
what are the complications of S. aureus infection?
scalded skin syndrome, toxic shock syndrome
what parasitic infection is associated with foul smelling cystic stool and steatorrhoea?
giardiasis (giardia lamblia)
what parasitic infection is associated with poor sanitation and MSM?
amoebiasis (entamoeba histolytica)
what type of bacteria is clostridium difficile?
gram-positive, spore-forming, anaerobic
Please select which one of the following bacteria does NOT cause toxin‐mediated diarrhoea:
a) Campylobacter jejuni
b) Clostridium difficile
c) Enterotoxigenic E coli
d) Vibrio cholerae
e) Vibrio parahaemolyticus
a) campylobacter jejuni
antibiotic use is discouraged in which of the following infections?
a) enteric fever (salmonella typhi)
b) shigellosis
c) salmonella (non-typhoidal)
d) E. coli
c) salmonella (non-typhoidal)
which exotoxin produced by C. difficile increases intestinal permeability and secretion of fluids?
toxin A enterotoxins
which exotoxin produced by C. difficile causes colon inflammation, haemostasis and necrosis
type B cytotoxin
what does treatment of C. difficile infection include?
- oral vancomycin
- oral metronidazole (anti-anaerobic antibiotic)
Helicobacter pylori has been strongly associated with which of the following?
a. Peptic ulcer disease
b. Gastric MALT lymphoma
c. Gastric adenocarcinoma
all of the above
which of the following microorganisms cause secretive diarrhoea?
a. giardia lamblia
b. EHEC
c. campylobacter jejuni
d. clostridium difficle
e. vibrio cholerae
e. vibrio cholerae
If you suspect an enteric fever, which test should you perform in addition to culturing from the stool?
a. urine antigen test
b. ELISA
c. blood culture
d. Growth on rich media to detect all possible pathogens
c. blood culture
