Listeriosis?

Question

Can anyone tell me the methods in isolating listeria? I know it may take up to 4 weeks, but if hospital were running routine blood culture tests could they find listeria monocytogenes?

Answer 1

the first thing to tip them off would be the presence of colonies of gram positive rods which cause hemolysis on blood agar plates. blood culture bottles are subcultured onto blood agar and other plates when bacterial growth is detected, either by turbidity in the broth, or as detected by specialized instruments. in this way, it could be picked up in 48 hours (24 hours after innoculation time to bottle broth, to plating the sample on the subculture plates, and checking the plates after 24 hours).