Pathology of Colibacillosis and its Molecular Detection from Recent Outbreaks in Chicks
Abstract:
Colibacillosis is caused by avian pathogenic Escherichia coli (APEC) that affects poultry. This disease causes great economic losses. Prevention of colibacillosis is becoming challenging due to the emergence of virulent and multi drug resistant strain. Early detection is essential to prevent colibacillosis. For this reason, this study was designed to investigate the pathology and to detect causal agent of colibacillosis. Dead birds and cloacal swabs from sick live birds were collected and enriched in tetrathionate broth. Then the bacteria were charac terized by different bacteriological media and biochemical test, and confirmed by PCR and histological studies. The organisms showed metallic sheen on EMB agar. It revealed pink colored, short rod to coccoid shaped, single or paired on Gram’s staining. Escherichia coli was confirmed through biochemical test. Postmortem f indings showed congested and consolidated lungs and liver. The intestine showed hemorrhage with mucus. Histologically, sections of heart showed pericarditis with thickening of pericardium. The livers exhibited coag ulation type of focal necrosis with infiltration of heterophils and lymphocytes densely located in the portal area. These findings will help field veterinarians and also poultry farmers for effective management. However, further studies are warranted to identify the genes responsible for emergences of E. coli infection.
