A study on bacterial contamination of poultry vaccines

Out of 50 examined poultry vaccines, only 15 samples were locally manufactured and remaining 35 were the imported products. These were manufactured for vaccination of poultry birds against ND, ND+IB, IB, IBD, Hydro and A.I. The vaccine samples were processed following certain analytical procedures for examining bacterial contamination. A total of 50 vaccine samples examined, 45 were live vaccines and only 5 were dead vaccines. Among 45 examined samples of live vaccines not a single sample was found positive for bacterial contamination; while among 5 formaldehyde treated (dead) poultry vaccines, 1 was found positive for bacterial contaminants. Thus, the percentage prevalence of bacterial contaminants in live vaccines was zero percent and in dead poultry vaccines it was 20%. The percentage prevalence of bacterial contaminants in local vaccines was 6.67%. Among the 15 samples of locally manufactured vaccines, 10 were live vaccines and 5 were dead vaccines from which none (zero percent) of the live and 1 (20%) dead vaccine was found positive. Of the total examined 35 samples of imported poultry vaccines, none were found positive for bacterial contaminants and percentage prevalence of bacterial contaminants in imported vaccines was 0%. Only Escherichia coli was isolated in one sample out of 50 vaccines and no any other bacterial organism was isolated either with individual or- mixed bacterial species. Escherichia coli was the only individual bacterial species isolated in one vaccine sample. The morphological, staining and cultural characteristics of bacterial species isolated from local poultry vaccines during present investigation indicated that the organisms of Escherichia coli were seen as coccobacillary, straight rods, arranged singly or in pairs, measuring 1.1-1.5 x 2-6 mum. They responded the Gram's staining as negative. These were motile in the nutrient broth. The cultural characteristics recorded were smooth, c onvex, moist, gray and shiny with entire margin colonies on nutrient agar. While on BHI agar circular, glistening, golden brown colonies were appeared. In the liquid medium, organism produced a diffuse cloudiness with heavy sediment but no pellicle. Uniform turbidity was observed in the nutrient broth. Colour of colonies was moist gray on nutrient agar plates, while rose pink on MacConkey's agar plates showing the fermentation of lactose. On blood agar it produced non-hemolytic colonies. Biochemical and sugar fermentation tests against bacterial contaminant suggested that the organism of Escherichia coli interacted positively with TSI agar and changed the medium in A/A (acidic slant and acidic butt) with production of H2S ill the medium. The tests indicated that Escherichia coli was catalase positive and oxidase negative. It also interacted positively with methyl red and nitrate reduction but negatively to indole, urea, Voges-Proskauer (VP), gelatin (GL) and Citrate. The spec ies fermented glucose, mannose, maltose, mannitol, xylose and inositol but did not ferment galactose, creatinine and dulcitol. It was concluded that generally, 6.67% of bacterial contamination was found in locally prepared vaccines, while in local dead vaccines, this contamination was recognized as 20%. The imported poultry vaccines were recorded as free from any bacterial contamination both, live and dead vaccines. Escherichia coli was the only bacterial species recognized from dead vaccine (Hydro-pericardium).