Etiopathological Study of Colisepticemia with Coinfection of Low Pathogenic Avian Influenza and Mycoplasma in Broilers

The present study was conducted to detect Low Pathogenic Avian Influenza (LPAI) and Mycoplasma in 30 broiler flocks (5 birds per flock) showing gross lesions of colisepticemia (Fibrinous pericarditis and perihepatitis) without any significant gross lesion in trachea and bronchi. The study comprised of flock wise mortality, gross and histopathological examination of colisepticemia and molecular identification from pooled sample of trachea for the presence of E. coli, LPAI, Mycoplasma gallisepticum and Mycoplasma synoviae. The mortality among 30 flocks varied between 0.32 and 6.75% with an average of 1.89%. Gross and histopathological lesions were predominantly found in liver, heart, spleen and lungs. All the 30 flocks were found positive for phoA gene of E. coli, whereas 5 (16.60%), 9 (30%) and 4 (13.30%) flocks were positive for H9N2 subtype of Avian influenza virus, i.e. LPAI, Mycoplasma gallisepticum and Mycoplasma synoviae, respectively. Findings of the present study confirmed the concurrent infection of colisepticemia with other primary pathogens such as LPAI, M. gallisepticum and M. synoviae, which indicate that Escherichia coli is a major secondary opportunistic pathogen in a respiratory disease complex of chicken.