microbiology Flashcards
what is gastroenteritis
inflammation of the intestine, normally colon bringing blood and mucus often associated with food poisoning. can cause, D&V, fever, dehydration
which bacteria have short incubation periods (1-6 hours)
bacillis cereus and staph A
which bacteria have a medium incubation period (12- 48 hours)
salmonella and CI perfringens
which bacteria have a long incubation period (2-14 days)
E.coli and campylobacter
which bacteria is most likely to cause food poisoning
campylobacter
what type of bacteria is shigella and why is it important
gram -ive, releases toxic shiga factor that binds to RBC cells and causes cell death. lots of other bacteria have shiga-like toxins
describe bacillus cereus and how you get it
short incubation, +ive bacilli, heat resistant spores, reheated rice
describe staph A and how you get it
+ive cocci, short incubation, preformed toxins in off food milk/ meat/ fish, causes vomiting
describe salmonella and how you get it
salmonella eneritis, non-typhoidal (bloods), D&V, infectious, poultry/ meat/ eggs
describe E.coli 0157
shiga toxin (veratoxin), low infectious dose = highly contagious from person to person, causes bloody diarrhoea
how does E.coli 0157 spread
person to person contact
what syndome can e.coli 0157 cause
haemolytic uremic syndrome (HUS): abdo pain, fever, pallor
what food does campylobacter normally colonise
poultry, cannot be spread from person to person
what is antimicrobial stewardship
prescribing optimum dosage and duration that tackles infection and reduces resistance
what order of stool investigations would be done for infectious agents
stool culture, microscopy, toxin, PCr
what normally causes C diff in hospitals
broad spectrum antibiotics that wipe out normal flora
what toxins does C diff contain
toxin A and toxin B
what 4 antibiotics notoriously cause C diff
co-amoxiclav, ciprofloxacin, clindamycin, cephalosporins
which antibiotics are given for less severe C diff
oral metronidazole
when is the only reason to give oral vancomycin
sever C diff
what is listeria monocytogenes, who gets it and from where
Ive rod, normally in immunosupressed and pregnant ladies, unpasteurised milk and deli counters
what are the symptoms of listeria monocytogenes
fever, muscle aches, diarrhoea
what viruses can cause gastroenteritis
rotavirus, norovirus
describe the rotavirus
common in kids, low infectious dose, non bloody diarrhoea
describe the norovirus
faecal-oral transmission, explosive D&V, cruise trips
what is main treatment o viruses
rehydration
should you normally give antibiotics in food poisoning
no - unless complications or not going away
how does cholera kill people
severe watery diarrhoea = dehydration
what bacteria would you use serology to identify
E.coli, salmonella, escherichia
what would you do to identify typhoid
blood
what bacteria would you use stool cultures to identify
campylobacter, shiegella
what bacteria would you use stool microscopy to identify
giardia, parasites and amoebas
what bacteria would you use stool toxins to identify
C diff
what virus would you use stool PCR to identify
norovirus
what is dysentery
inflammation of the intestine, particularly colon causing bloody/ mucousy diarrhoea
what bacteria normally cause bloody diarrhoea and dysentery
shiegella, campylobacter
