GENUS: LISTERIA Most important species: Listeria monocytogenes
L. monocytogens General characteristics: . Widely present in plants, soil and surface water . Zoonotic pathogen of domestic animals . Non-sporulating, facultative anaerobe, intracellular. Gram positive rods Antigenic structure: . Listreriolysin( hemolysin) Pathogenesis and clinical features: Transmitted to humans through ingestion of poorly coooked meat and unpasteurized milk and milk products
Perinatal human infantisepticum
. Early onset syndrome: Intrauterine sepsis . Late onset syndrome: Neonatal meningitis Adult human listeriosis . Meningoencephalitis . Bacteremia Lab. Diagnosis: Specimen: Blood/ CSF Culture: Grow in blood agar and demonstrate narrow zone of -hemolysis Produce “umbrella” growth pattern below the motility media surface at room T0, demonstrating motility at room temperature 2.