Abstract
AIM: This study was carried out for the detection of Avibacterium paragallinarum from outbreaks of infectious coryza of poultry. MATERIALS AND METHODS: The polymerase chain reaction (PCR) was standardized for the diagnosis of infectious coryza by using infectious coryza Killed vaccine, ventri biologicals, Pune as source of DNA of A. paragallinarum. Five outbreaks of infectious coryza from Andhra Pradesh were investigated in the present study. A total of 56 infra orbital sinus swabs and 22 nasal swabs were tested by PCR. RESULTS: PCR analysis showed 56 positives (71.7%) for infectious coryza out of total 78 samples tested. Of 56 infra orbital sinus swabs tested, 47 were positive (83.9%) and 9 nasal swabs (40.9%) out of 22 tested had given positive results for infectious coryza. Samples collected from birds at acute stage of disease and samples collected before treatment with antibiotics were given better results on PCR. CONCLUSION: For preventing the economic losses associated with the disease, an early, accurate and rapid diagnosis is essential. PCR is a rapid and highly sensitive diagnostic technique which can substitute conventional cultural examination.