Listeria monocytogenes

• Gram positive coccobacilli.
• Entry: ingestion.
• Point source spread.
• Colonizes intestinal epithelial cells, M-cells, macrophages and neutrophils, replicating in the cytoplasm.
• Influenza like illness with or without gastroenteritis (called Listeriosis). Self limiting in adults. Can cause bacteremia or meningitis (in immune compromised or neonates).
• Antibiotics: penicillin.
• Can survive in low temperature and high salt content.
• Uses 'zipper method' to be taken up by non-phagocytic cells.
• Uses ActA to anchor the outer membrane and form branched actin filaments to move around inside of the cell.
• One day incubation followed by two days of watery diarrhea, fever, nausea, headache, myalgia.
• In pregnant woman: can cause miscarriage.
• Escapes the phagosome.