Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10965398 | Vaccine | 2015 | 7 Pages |
Abstract
Brucella abortus S19 is a smooth strain used as live vaccine against bovine brucellosis. Smooth lipopolysaccharide (LPS) is responsible for its residual virulence and serological interference. Rough mutants defective of LPS are more attenuated but confers lower level of protection. We describe a modified B. abortus S19 strain, named as S19Îper, which exhibits intermediate rough phenotype with residual O-polysaccharide (OPS). Deletion of perosamine synthetase gene resulted in substantial attenuation of S19Îper mutant without affecting immunogenic properties. It mounted strong immune response in Swiss albino mice and conferred protection similar to S19 vaccine. Immunized mice produced higher levels of IFN-γ, IgG2a and thus has immune response inclined towards Th1 cell mediated immunity. Sera from immunized animals did not show agglutination reaction with RBPT antigen and thus could serve as DIVA (Differentiating Infected from Vaccinated Animals) vaccine. S19Îper mutant displayed more susceptibility to serum complement mediated killing and sensitivity to polymyxin B. Pregnant guinea pigs injected with S19Îper mutant completed full term of pregnancy and did not cause abortion, still birth or birth of weak offspring. S19Îper mutant with intermediate rough phenotype displayed remarkable resemblance to S19 vaccine strain with improved properties of safety, immunogenicity and DIVA capability for control of bovine brucellosis.
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Authors
Jonathan Lalsiamthara, Neha Gogia, Tapas K. Goswami, R.K. Singh, Pallab Chaudhuri,