Seroprevalence of Salmonellosis in Layer Chickens with Isolation, Identification and Antibiogram Study of Their Causal Agents

Salmonellosis is a common problem in poultry farms of our country. Indiscriminate use of antibiotic to control the disease results drug resistance and limits the therapeutic possibilities in the treatment of the disease. This study was conducted during the period from January to May 2006 at Gobindapur of Dinajpur district. The present study was undertaken to determine the seroprevalence of salmonellosis in layer flocks and antibiogram study following isolation of Salmonellae. A total of 225 Star cross 579 brown chickens were studied with rapid serum plate agglutination test. Liver of 200 dead birds was studied for isolation and identification of Salmonellae. In vitro antibiotic sensitivity test of isolated Salmonellae was performed with commercial sensitivity discs. The overall seroprevalence was recorded 23.11%. The prevalence was varied from age to age. The highest rate was 28% in above 20 weeks of age. The antibiogram study revealed that the isolates were sensitive to ciprofloxacin (80%), nitrofurantoin (100%), sulphamethoxazole/ trimeoprim and amoxycillin (50%), tetracycline (60%) but resistant to penicillin-G and erythromycin. Further studies should be conducted on serotyping of the isolated Salmonellae, isolation and identification of Salmonellae from different feed and environmental sample.