Gastroenteritis and Antibiotic Associated Colitis Flashcards
In which areas is there the most normal flora?
> Oral cavities
> Colon
What is an obligate anaerobic bacteria?
One that is poisoned by oxygen.
What is a facultative anaerobic bacterium?
One that can either be aerobic or anaerobic.
What metabolic capacity does faecal flora equal?
That of the liver.
What are the benefits of gut commensal flora?
> Antibody induction
Colonisation resistance
Metabolism
What are the most common commensal flora types in the gut?
“In the gut gym, steroides are most prevalent”
> Bacteroides
> Prevotella
Clostridia and Bifidobacteria are examples of what type of commensal flora?
Obligate Anaerobes
Enterobactericae and Enterococchi are examples of what type of commensal flora?
Facultative Anaerobes
What are the presenting symptoms of Gastroenteritis?
> Vomiting
Diarrhoea
Abdominal pain
Systemic FX i.e fever
What complications can occur because of Gastroenteritis?
> Toxic Megacolon > Guillan Barre > Dehydration > Renal failure > Haemolytic Uraemic Syndrome > Salmonella
What investigations for gastroenteritis should be done?
> FBC > Abdominal xray if severe disease > Stool - Ova, parasites and cysts - Microscopy, culture and sensitivity - C.Difficile Toxin - Viral PCR
What is the cause of, symptoms, duration and transmission of Viral Gastroenteritis ?
Cause : Most common - Norovirus
Symptoms: Diarrhoea and projectile vomiting.
Duration: 48-72 hours
Transmission: Faecal-oral
What parasites cause Parasitic Gastroenteritis?
> Guardia Lamblia
Entamoeba Histolytica
Cryptosporidium
What are Cryptosporidium oocysts resistant to?
Chlorine disinfectants
In whom are Cryptosporidium infections common in?
Children
Which bacteria produces both enterotoxins and does adherence?
E. Coli
What type of E.Coli causes colitis/haemolytic uraemic syndrome?
EHEC = Enterohaemorrhagic
What type of E.Coli causes Traveller’s diarrhoea?
ETEC = Enterotoxigenic EAggEC = Enteroaggregative
What type of E.Coli causes Children’s diarrhoea?
EPEC = Enteropathogenic
What type of E.Coli causes Dysentery like symptoms?
EIEC = Enteroinvasive
What is the source of E.Coli 0157?
Cattle
What is the mechanism of action of E.Coli ?
Hint: Similar to Cholera
1) Toxin activates G protein.
2) Increases cAMP levels
3) Chloride ions move out of cell
4) Water follows = Diarrhoea
How is Salmonella transmitted?
Food/drink
What does Salmonella cause?
Food poisoning, typhoid, paratyphoid.
Why should antibiotics in Gastro-E be avoided?
> Worsens E. Coli
> Prolongs salmonella carriage.
What happens if you disrupt gut flora with antib’s?
Diarrhoea
What are the symptoms of antibiotic associated diarrhoea?
> Mild diarrhoea to pseudomembranous colitis
> Toxic megacolon, shock, perforation
Which antibiotics cause a high risk of C.Difficile Infection?
> Clindamycin
Cephalosporins
” Linda spotted a high risk of C.Diff”
Which antibiotics cause a medium risk of C.Difficile infection?
> Macrolides
Flouroquinolones
Co-trimoxazole
Ampi/Amoxycillin
” Sliding alone isn’t as good as co-chillin”
What two antibiotics are used to treat CDI?
> Oral Metronidazole
> Oral Vancomycin
Which antibiotic should be used in severe CDI?
> Vancomycin
