Production of formalin killed fowl typhoid vaccine using local isolates of <i>Salmonella</i> Gallinarum in Bangladesh

Abstract

A locally isolated Salmonella Gallinarum (SG) was used for fowl typhoid vaccine production. 2 x 107 colony forming unit (CFU) of SG was used for the vaccine production. The fowl typhoid vaccine was produced with the local isolates of SG (LRI 49) strain. Efficacy study of the vaccine was performed primarily in laboratory trial in 6 weeks and then in 8 weeks old commercial layers in the field. Chickens were boasted after 4 wks of vaccination. Rapid serum plate agglutination (SPA) test and ELISA were carried out for the detection of antibody response against SG vaccinated and non-vaccinated birds. Positive results of the rapid plate agglutination and the ELISA were 81% and 77% in laboratory trial, and 76.4% and 73.8% in field trial, respectively. The chickens of vaccinated and non-vaccinated groups were challenged with the infective dose (2 x 2 x 107CFU) of freshly prepared live SG bacteria and lesions were not detected in vaccinated birds at necropsy. The vaccine was proved safe and effective in terms of preventing of fowl typhoid in chickens in Bangladesh.  Key words: Fowl typhoid vaccine, potency, ELISA, plate agglutination test, Salmonella Gallinarum   DOI = 10.3329/bjvm.v5i1.1306 Bangl. J. Vet. Med. (2007). 5 (1 & 2): 33-38