hard topics (e coli, digestive protozoans and hepatitis viruses) Flashcards
Epidemic E coli (especially in infants) is associated with
Enteropathogenic E. coli
EPEC is
Invasive, non-toxigenic
Traveler’s diarrhoea is associated with
Enterotoxigenic E coli
ETEC is
non-invasive, toxigenic
Which toxins are produced by ETEC
Labile LT toxin and stable ST toxin
Enteroinvasive E. coli causes what symptom and has a mechanism similar to which bacteria
bloody diarrhoea, invades epithelial cells, similar to Shigella
EIEC is
invasive, non-toxigenic
EHEC is
invasive, toxigenic
What conditions is EHEC associated with
Haemorrhagic colitis, haemorrhagic diarrhoea, haemolytic uraemic syndrome
What is the most important strain of EHEC
O157H7
What toxin is produced by EHEC
Vero-toxin (similar to Shiga toxin- shiga like toxin)
What symptoms are caused by enteroaggregative and enteroadhesive e. coli?
Watery diarrhoea
What toxin is produced by enteroaggregative e. coli
ST (same as enterotoxigenic e coli)
Are enteroadhesive and enteroaggregative e coli invasive? Differentiate between the appearance of the two in the GI tract
Agg = stacked brick
Adhesive = single layer of bacterial cells that coats mucosa
No they are not invasive
Hepatitis A transmission
Faecal-oral (food contaminated by faeces)
Hepatitis A structure
No envelope, ss RNA
Hepatitis A causes damage to
Liver, kidneys and spleen
Hepatitis B structure
ds DNA, envelope
Hepatitis B transmission
Blood (contaminated equipment, nonsterile needles) and bodily fluids (semen, breast milk, saliva), transplacental
Who is at high risk of contracting HBV
Health care workers
Complications of Hepatitis B
Liver cirrhosis and cancer
How is hepatitis B cultured
Cultured in yeast cells
Hepatitis C structure
ssRNA, envelope
How is Hepatitis c transmitted
Mostly in blood (organ transplant and injection equipment), can occur less commonly by sexual contact
What are the complications of chronic Hepatitis c infection
Liver cirrhosis and cancer
Hepatitis D structure
ss RNA, technically no envelope (acquires envelope from HBV)
Hepatitis e structure
No envelope, ss RNA
Hepatitis E transmission
faecal oral
How is hepatitis E relevant to pregnant women?
Causes 20% mortality in this group of people
Does Hepatitis E cause liver disease
No
