ABSTRACT
Mycoplasma gallisepticum and Mycoplasma synoviae are worldwide in distribution including India and causes heavy economic losses to the poultry industry. The present study confirms the incidence of M. gallisepticum and M. synoviae infections by gross and microscopic pathology and PCR in broiler chickens. Incidence of pathogenic Mycoplasma spp. in broiler chickens with respiratory lesions was found to be 26.66%. Out of total 60 flocks, 6 flocks (10%) were found positive for M. gallisepticum and 12 (20%) were positive for M. synoviae. The incidence of M. synoviae was found to be higher than M. gallisepticum. Catarrhal tracheitis, focal pneumonic consolidation of lungs and airsacculitis were consistent lesions in M. gallisepticum and M. synoviae positive broiler chickens. However, synovitis/arthritis was not observed in any of the flock positive for M. synoviae. Incidence of E. coli amongst broiler chickens with respiratory lesions was found to be 40% by PCR targeting 16S rRNA gene and was higher than Mycoplasma spp. Mixed infection of M. gallisepticum and E. coli was detected in 3(9.09%) flocks, M. synoviae and E. coli in 4 (12.13%), M. gallisepticum and M. synoviae in 1(3.03%) and M. gallisepticum, M. synoviae and E. coli combined infection was detected in 1 (3.03%) flock. Mixed infection of M. gallisepticum and E. coli, M. synoviae and E. coli and M. gallisepticum, M. synoviae and E. coli revealed moderate to severe lesions of chronic complicated respiratory disease