Listeriosis
Introduction.
Listeriosis is primarily a food-borne illness. Listeria are
common in soils, water and vegetation. Uncooked or inadequately cooked foods can
be responsible for outbreaks. Listeria are intracellular bacteria
(macrophages). Meningitis is a complication.
Summary
- Cause: Listeria monocytogenes
- Microscopy: Gram-positive rods
- Symptoms: Muscle aches, nausea, diarrhea and fever; may progress to
meningitis with headache, stiff neck, confusion, loss of balance
- Transmission: Food borne; soft cheese, cabbage
- Pathogenesis: Intracellular
pathogen: Listeria produce invasins that allow them to enter
host cells and macrophages, hiding from the immune system. Hemolysins cause
red blood cell lysis
- Complications: Meningitis; disseminated disease in
immunocompromised due to importance of cell-mediated immunityto fighting
infection; serious infections in neonates.
- Treatment: Penicillin or ampicillin (+/- gentamycin)