A Brucella melitensis H38 ΔwbkF rough mutant protects against Brucella ovis in rams

AbstractBrucella melitensis andBrucella ovis are gram-negative pathogens of sheep that cause severe economic losses and, althoughB. ovis is non-zoonotic,B. melitensis is the main cause of human brucellosis.B. melitensis carries a smooth (S) lipopolysaccharide (LPS) with an N-formyl-perosamine O-polysaccharide (O-PS) that is absent in the rough LPS ofB. ovis. Their control and eradication require vaccination, butB. melitensis Rev 1, the only vaccine available, triggers anti-O-PS antibodies that interfere in the S-brucellae serodiagnosis. Since eradication and serological surveillance of the zoonotic species are priorities, Rev 1 is banned onceB. melitensis is eradicated or where it never existed, hamperingB. ovis control and eradication. To develop aB. ovis specific vaccine, we investigated threeBrucella live vaccine candidates lacking N-formyl-perosamine O-PS: Bov::CA ΔwadB (CO2-independentB. ovis with truncated LPS core oligosaccharide); Rev1::wbdRΔwbkC (carrying N-acetylated O-PS); and H38 ΔwbkF (B. melitensis rough mutant with intact LPS core). After confirming their attenuation and protection againstB. ovis in mice, were tested in rams for efficacy. H38 ΔwbkF yielded similar protection to Rev 1 againstB. ovis but Bov::CA ΔwadB and Rev1::wbdRΔwbkC conferred no or poor protection, respectively. All H38 ΔwbkF vaccinated rams developed a protracted antibody response in ELISA and immunoprecipitationB. ovis diagnostic tests. In contrast, all remained negative in Rose Ben...
Source: Veterinary Research - Category: Veterinary Research Source Type: research