title: Intermediate rough Brucella abortus S19Δper mutant is DIVA enable, safe to pregnant guinea pigs and confers protection to mice.
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 S19Δper, which exhibits intermediate rough phenotype with residual O-polysaccharide (OPS). Deletion of perosamine synthetase gene resulted in substantial attenuation of S19Δper 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. S19Δper mutant displayed more susceptibility to serum complement mediated killing and sensitivity to polymyxin B. Pregnant guinea pigs injected with S19Δper mutant completed full term of pregnancy and did not cause abortion, still birth or birth of weak offspring. S19Δper 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.
authors: Division of Bacteriology & Mycology, Indian Veterinary Research Institute, Izatnagar, India.
authors: Jonathan
authors: J
authors: Lalsiamthara
authors: Division of Bacteriology & Mycology, Indian Veterinary Research Institute, Izatnagar, India.
authors: Neha
authors: N
authors: Gogia
authors: Immunology Section, Indian Veterinary Research Institute, Izatnagar, India.
authors: Tapas K
authors: TK
authors: Goswami
authors: Division of Bacteriology & Mycology, Indian Veterinary Research Institute, Izatnagar, India; Immunology Section, Indian Veterinary Research Institute, Izatnagar, India.
authors: R K
authors: RK
authors: Singh
authors: Division of Bacteriology & Mycology, Indian Veterinary Research Institute, Izatnagar, India. Electronic address: pallab.chaudhuri@gmail.com.
authors: Pallab
authors: P
authors: Chaudhuri
mesh_terms: D000818:Animals; D002004:Brucella Vaccine / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D002003:Brucella abortus / Q000166:cytology / Q000235:genetics* / Q000254:growth & development / Q000276:immunology*; D002006:Brucellosis / Q000517:prevention & control*; D016207:Cytokines / Q000097:blood / Q000276:immunology; D005260:Female; D006168:Guinea Pigs; D007111:Immunity, Cellular; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000276:immunology; D051379:Mice; D009154:Mutation; D019081:O Antigens / Q000032:analysis; D010641:Phenotype; D011112:Polymyxin B / Q000494:pharmacology; D011247:Pregnancy; D017384:Sequence Deletion; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology
chemical_list: D002004:Brucella Vaccine; D016207:Cytokines; D007074:Immunoglobulin G; D019081:O Antigens; D014613:Vaccines, Attenuated; D007371:Interferon-gamma; D011112:Polymyxin B
keywords: Brucella abrtus S19; Challenge study; DIVA; Lipopolysaccharide; Mutant, Immunization