Systems microbiology Flashcards
Which common systems can be infected by pathogens
Upper respiratory tract
lower respiratory tract
GI tract
What is a source of microbes for upper and lowery tract infections
the mouth
What happens to the number of microbes going down the respiratory tract
decreases
gets more sterile
What is a type of common oral microbe
oral streptococci
What inhibitory factors for microorganisms does the GIT express
anaerobic
acid and bile salts
Why can some bacteria pass through stomach acid/enter gut
acid tolerance
surrounded by food particles
How do most microbes enter the GIT
food ingestion
What is the bacteria arrangement in the stomach
sparsely populated
streptococci
lactobacilli
What is the arrangement of bacteria in the colon
very densely populated
complex microflora
what kind of species dominates the colon
obligatory anaerobic species
How is the duodenum of the GIT populated
sparsely
complex microflora
What microbes is the duodenum mainly populated with
streptococci
lactobacilli
Which parts of the GIT are the most populated
ileum
colon
What are coliform
species of gram negative bacilli that look like E.coli on gram film or when cultured on blood agar
What are the properties of coliforms
can be grown aerobically and anaerobically
part of normal bowel flora
How are coliform best grown
aerobically
how are coliforms differentiated
biochemical reactions
O antigens
H antigens
What are antigens associated with
Cell wall
what are H antigens associated with
flagella
How does the GIT tract stop the proliferation of microbes
stomach acid
replacement of mucosa (shedding)
movement of food
bile salt
antibodies
natural flora
How does the gut natural flora provide protection against microbes
symbiotic/host compatible community
colonisation resistance
competition for nutrients
How do bile salts kill microbes
damage bacterial membrane
What are examples of viral diseases of the GI tract
norovirus (winter vomiting bug)
rotavirus
What is the most common eukaryotic disease of the GI tract
Cryptosporidium
What are the types of prokaryotic (bacterial) infections of the GI tract
endogenous
exogenous (ingested)
What are the most common exogenous prokaryotic infections of the GI tract
E.coli
C.diff
campylobacter
What are prokaryotic infections of the GIT linked to
microbial dysbiois
IBD
What range of E.coli variants are linked to disease
Shiga toxin-producing (S/VTEC)
What are CPE organisms
Carbapenemase producing enterobacterals
Where do CPE organisms live
Gut
What are CPE’s thought to cause
bacteraemia
Where can HGT between organisms occur efficiently
the gut
Why are CPE’s so resistant to antibiotics
horizontal gene trasferì
Which infections is C.diff associated with
HAI
disease from prescription druga
How is the GIT colonised
ingestion of nutrients and organisms
