Rods Flashcards
Regular Rods
Listeria. Erysipelothrix
Irregular rods
Corynebacterium. Actinomycetes. Mycobacterium. Propionibacterium. Nocardia
Charac. Listera monocytogenes
Small, Gram (+) coccobacilli in pairs. Can grow in refridgerator. Foodborne mortality.
L. monocytogenes Virulence
Can penetrate placental barrier, withstands proteases/acid/bile, Mediated by PrfA. LLO
Listeriolysin
A cholesterol dependent cytolysin. Helps to rupture endosomes/releasing Listeria. If has more cytotoxic LLO, listeria is less virulent
Motility of L. monocytogenes
Flagella-mediated (only respiratory). Actin-mediated (helps to spread in host)
Adherence of L. monocytogenes
Bacterial alpha-D-galactose binds E-cadherin of intestinal cells
Internalin (Inl A/B/C)
Promotes bacterial endocytosis. Helps Listera cross BBB and feto-placental barriers
What helps listeria build a tail?
Listerial ActA helps with the actin nucleation
Immunity towards listeria
Cell mediated. NO ANTIBODIES
Listeria in healthy adults
Gastroenteritis (about 48 hrs after) for about 2-3 days
Listeria in pregnant women
100% risk of vertical transmission to fetus. Can cause premature delivery and still birth
Listeria and neonates
Early onset: High mortality, Granulomatosis infantiseptica. Late onset: meningoencephalitis
What is cultures to find Listeria?
Blood, CSF, placents, amniotic fluid
Positive tests for Listeria
Catalase and CAMP test