VMC 311: Systematic Veterinary Bacteriology and Mycology (2+1)

PATHOGENESIS

• The carrier animals are an important source of the organism.
• Entry of the organism may be by the oral, cutaneous or respiratory route.
• Ingestion of contaminated feed or water or contamination of abraded skin are the most common means of infection in swine.
  • Contaminate environment
  • Carrier animals
  • Organism ingested
  • Enter small intestine
  • Adhere to epithelium
  • Penetrate intestine
  • Blood stream
  • Localization Vascular damage
  • Immune complex Thrombosis
  • Fever
  • Vascular damage
  • Arthritis
  • Endocarditis
  • Skin lesions
• Erysipelothrix rhusiopathiae is able to adhere to epithelial cells, and that they invade the blood stream and cause localization.
• The more virulent strains produce high levels of neuraminidase that can cause vascular damage and thrombus formation.
• Congestion of dermal capillaries results in diamond skin disease.
• Arthritis is associated with initial infection of joints and prolonged retention of bacterial antigen in the joints.
• The diseases caused by Erysipelothrix rhusiopathiae are as follows

Main host (s)	Disease syndrome
Pigs	Swine erysipelas Acute septicaemic form (Pregnant sows may abort) Urticarial form (Diamond skin disease) Vegetative endocarditis and Polyarthritis (Chronic form)
Sheep	Poly arthritis in lambs Post-dipping lameness Valvular endocarditis and pneumonia
Turkeys , Geese and other birds	Acute septicaemia (Turkey erysipelas) Vegetative endocarditis and arthritis (Chronic form)