GI Pathogens Flashcards
colonisation
establishment of microorganisms within host - beneficial indigenous microbiota present in GI tract from birth
ecological niches of bacteria in GI tract
oral cavity
pharynx
small bowel
large bowel
normal flora/mirobiome of GI tract - oral cavity
viridans strep
anaerobic gram positive/negative bacilli
candida spp.
principles of identifying gram negative rods
does the enterobacteriaceae ferment carbohydrate (lactose)
gram positive organisms in GI tract - mouth
aerobic;
strep viridans
candida sp
molecular tests
determines biochemical and antigenic characterises
e.g. MALDI-TOF mass spectrometry
principles of serotyping
immunoreactivity of various antigens
normal flora/mirobiome of GI tract - large bowel
enterobacteriaceae
enterococci
miller group strep
anaerobic gram postive/negative bacilli
what bug do phagocytes respond to
bacteria
fungi
what bug do T lymphocytes respond to
viruses
fungi
protozoa
what bug do antibody and B lymphocytes respond to
viruses
what bug do eosinophils respond to
fungi
protozoa
worms
what bugs do mast cells respond to
worms
what bugs do complement cells respond to
bacteria
describe MALDI-TOF mass spectrometry
analyses protein composition of bacterial cell wall
discriminates between highly genetically similar organisms with identical rRNA
tests for identifying enterobacteriaceae
MacConkey agar - pink if lactose present
CLED agar
chromogenic agar
describe enterobacteriaceae
gram negative - endotoxin non spore forming fermet sugar anaerobic motile or non-motile increasing resistance
gram postive organisms of GI tract - small bowel
anaerobic;
coliforms
gram postive organisms of GI tract - colon
anaerobic;
colifros
enterococcus faecalis
organisms of bile ducts
sterile
