what are some features of gram positive rods?
they can be spore forming such as clostridium or non.spore forming
what shapes might non.spore forming gram positive rods have?
regular or irregular
what kind of staining feature would regular non.spore forming have
they might be acid fast such as mycobacterium or not acid fast such as corynebacterium
what feature irregular shape nonspore forming might have
they might have branched filaments such as nocardia or don't have them such has corynebacterium.
what bacteria's are part of CMN group?
Mycobacterium,corynebacterium and nocardia
List characteristic's of Listeria
- short rods
- gram positive
- not motile at 37 but motile at 25
- grow at 4
- beta hemolytic and high salt
- facultative anaerobe
- not acid fast
- non.spore forming
- flagella at room temp but not at body temp
where is listeria mostly found ?
ubiquitous but also found in water, soil and feces
what is listeria mostly associated with?
It is mostly associated with contaminated food ( Meat, soft cheese, raw vegetables and non pasteurized milk. grows in fridge
what people listeria is more common in
it is more common in pregnant woman 20*, neonates , immunocomprimised 300* patients.
what are some pathogenisis mechanisem's of listeria
- 1)it is able to cross three body barriers. after injestion it can invade the intestinal epitheluim, after bacteremia it can cross blood barriers and in pregnant woman crosses fetoplecental.
- 2)facultative interacellular
- 3) induces phagocytosis in non-phagocytic
what are some virulence factors of listeria?
- interanalin A and B ( adhesin/ Invasion)> induced phagocutosis
- listeriolysin O > essential for escape of bacteria into host cell cystol
- phospholipase C ( plc A and B) > secreted
- > important for escape
- > uses CAMP , disrupts phagosome bilayer
- Act A > directly deactivates Arp 2/3
- > essential for cell to cell spread pf bacteria
what are some characteristic clinical disease on neonatal
- Early onset
- .high mortality
- .disseminated absecesses
- Late onset
- . meningites
- .symptoms similar to group B streptococall meningites ( immidiate antibiotic treatment important)
what are some clinical characteristics in healthy adults, elderly and AIDS patients?
in healthy adults can have flu lke symptoms in elderly meningitis and in AIDS patients can lead to meningitis and bacteremia
what are some ways to prevent listeriosis
- cook raw food
- wash raw vegetable
- keep cooked and uncooked separate
- avoid raw milk
- wash everything
- consume perishable food ASAP
what should people with high risk avoid
- . don't eat hot dogs or deli meat unless cooked
- . wash hands and avoid meat liquids
- . avoid soft cheese
- .don't eat refrigurated pates
what actions should infected people take
there are no vaccines so immidiate treatment with ampicilin and gentamicin
what are some diognostic tools
- > Blood and CSF media
- >Camp, hippurate and catalase +
- > motile in semisolid agar