A pathologic study on experimental Erysipelothrix rhusiopathiae cellulitis in broiler chickens

Avian cellulitis is a serious problem for the commercial broiler industry. Although various agents were isolated from cellulitis lesions, the ability of Erysipelothrix rhusiopathiae in reproduction of cellulitis is not known. Therefore, the objective of this study was to evaluate the ability of these bacteria for induction of avian cellulitis. The study involved two experimental groups, each consisting of twenty randomly selected 15-day-old, mixed sex, healthy, commercially grown broiler chickens of the same strain. A single scratch was induced with a 1.5-inch 18-gauge needle, creating a lesion 2 cm in length on the right dorsolateral surface of the body parallel to the vertebrae. In Group 1, 1ml of 102 bacterial suspension isolated from a turkey cock with erysipelas was inoculated into the scratches. Birds in Group 2 received 1ml of the sterile phosphate-buffered saline as negative controls. At 48-hr post inoculation the birds were killed and pathologic and bacteriologic examinations were carried out. Birds in Group1 showed weakness, depression and mild diarrhoea. In this group, 65% of birds showed swelling of the skin with necrosis, infiltration of heterophils and fibrinous exudates, which was characteristic of cellulitis. The remaining 35% of birds were dead within 24-hrs post inoculation, with signs of mild cellulitis. Erysipelothrix rhusiopathiae was recovered from skin and some other internal organs from birds in Group 1. Birds in Group 2 were normal. Results of the present study revealed that E. rhusiopathiae can be considered as a causative agent of avian cellulitis, with public health hazards.