author(s)
P Suvethika, S Subapriya, S Vairamuthu, S Suresh Kannan and K Sangli Vikram Kumar

abstract
The success of poultry industry is being hampered by various pathogenic bacteria causing remarkable morbidity and mortality losses. Hence a study was designed to isolate and identify the bacterial pathogens causing infection in layer birds. A total of 279 samples were collected from ailing layer birds of which 252 samples gave 341 isolates. 272 of the isolates were Gram negative bacteria and the remaining 69 isolates were Gram positive bacteria. Based on colony characteristics and biochemical tests, four different types of bacteria E. coli, Pasterurella spp Salmonella spp and Staphylococcus spp were identified.