Yersinia

• Cause intestinal disease

Overview

• Cause disease in animals and are important zoonoses

Characteristics

• Enterobacteria, but grow more slowly and at lower temperatures than other enterobacteria
• Non-lactose fermentors
• Facuiltative intracellular pathogens

Pathogenesis

• Invasive Yersinia grow inside macrophages
• Survive in phagolysosomes and do not interfere with degranulation or lysosomal fusion
• Resistant to macrophage killing mechanisms
• The bacteria destroy the macrophages in lymph nodes, liver and spleen, causing septicaemia