Immunogenicity of capsular extract prepared from a local duck isolate of <i>Pasteurella multocida</i>

Abstract

The immunogenic response and protection of duck with capsular extract of local isolate of duck cholera organism, i.e. Pasteurella multocida was compared with that of conventional fowl cholera vaccine prepared in Bangladesh Agricultural University, Mymensingh. Feces, liver, heart, lungs, trachea and intestinal swabs were collected from a total of 50 sick and apparently healthy ducks. The duck cholera organisms were isolated and characterized by their cultural, physiochemical, staining properties and laboratory animals and also duck and ducklings inoculation. Capsular antigen was prepared from this isolate. Twelve weeks aged ducks of Jinding breeds were divided into three groups such as A, B and C. Each duck of group A was inoculated with 1 ml of capsular antigen containing 200 µl capsular protein and 1 ml of Bangladesh Agricultural University fowl cholera vaccine in group B intramuscularly followed by second vaccination with same vaccine with similar dose and route at 15 days interval in group A and B respectively. Ducks of group C were kept as control. Sera samples of each of the ducks of all the three groups were collected at 7 and 14 days post-vaccination following each of the primary and secondary vaccination. Each of the serum samples of all the three groups of birds was titrated by using passive hemagglutination (PHA) test and results recorded that both the capsular extract (96.00 ± 45.25) and fowl cholera vaccine (108 ± 89.37) produced more or less similar serological response at two weeks after secondary vaccination. Protection test was performed with all birds of three groups after 21 days of secondary vaccination and the results showed that ducks of both group A and B conferred 100% protection. Key words: Pasteurella multocida, capsular extract, fowl cholera vaccine, duck, immunogenicity DOI = 10.3329/bjvm.v6i1.1333 Bangl. J. Vet. Med. (2008). 6 (1): 19-22