Facing the Human and Animal Brucellosis Conundrums: The Forgotten Lessons

Brucellosis is a major zoonotic disease caused by Brucella species. Historically, the disease received over fifty names until it was recognized as a single entity, illustrating its protean manifestations and intricacies, traits that generated conundrums that have remained or re-emerged since they were first described. Here, we examine confusions concerning the clinical picture, serological diagnosis, and incidence of human brucellosis. We also discuss knowledge gaps and prevalent confusions about animal brucellosis, including brucellosis control strategies, the so-called confirmatory tests, and assumptions about the primary-binding assays and DNA detection methods. We describe how doubtfully characterized vaccines have failed to control brucellosis and emphasize how the requisites of controlled safety and protection experiments are generally overlooked. Finally, we briefly discuss the experience demonstrating that S19 remains the best cattle vaccine, while RB51 fails to validate its claimed properties (protection, differentiating infected and vaccinated animals (DIVA), and safety), offering a strong argument against its current widespread use. These conundrums show that knowledge dealing with brucellosis is lost, and previous experience is overlooked or misinterpreted, as illustrated in a significant number of misguided meta-analyses. In a global context of intensifying livestock breeding, such recurrent oversights threaten to increase the impact of brucellosis.Publishe

Brucellosis and One Health: Inherited and Future Challenges

One Health is the collaborative efforts of multiple disciplines to attain optimal health for people, animals and the environment, a concept that historically owes much to the study of brucellosis, including recent political and ethical considerations. Brucellosis One Health actors include Public Health and Veterinary Services, microbiologists, medical and veterinary practitioners and breeders. Brucellosis awareness, and the correct use of diagnostic, epidemiological and prophylactic tools is essential. In brucellosis, One Health implementation faces inherited and new challenges, some aggravated by global warming and the intensification of breeding to meet growing food demands. In endemic scenarios, disease awareness, stakeholder sensitization/engagement and the need to build breeder trust are unresolved issues, all made difficult by the protean characteristics of this zoonosis. Extended infrastructural weaknesses, often accentuated by geography and climate, are critically important. Capacity-building faces misconceptions derived from an uncritical adoption of control/eradication strategies applied in countries with suitable means, and requires additional reference laboratories in endemic areas. Challenges for One Health implementation include the lack of research in species other than cattle and small ruminants, the need for a safer small ruminant vaccine, the need to fill in the infrastructure gap, the need for realistic capacity-building, the creation of reference laboratories in critical areas, and the stepwise implementation of measures not directly transposed from the so-called developed countries.One Healthbrucellosisawarenesscapacity buildingclimateglobal warmingintensificationdiagnosisvaccinesUnpublishe

Application of Bruce-Ladder Multiplex PCR for Identification of Brucella abortus Isolated from Cattle in Kachia Grazing Reserve and Jos Plateau

A study was carried out to isolate Brucella strains from cattle in Kachia Grazing Reserve (KGR) and some communities on Jos Plateau and to carry out phenotypic and molecular characterization of the isolates along with other isolates obtained from field submissions and those in the archive of National Veterinary Research Institute (NVRI), Vom. A total of 63 vaginal swabs, 36 milk samples, and 2 hygroma fluids were collected from KGR while 70 vaginal swabs, 50 milk samples and 2 hygroma fluids were collected on the Jos Plateau for Brucella isolation. They were cultured for Brucella isolation according to standard Brucella isolation protocol. Three Brucella abortus strains were isolated from KGR while 4 Brucella abortus strains were isolated from the Jos Plateau respectively. Eight isolates from field submissions and 5 from the archive were collected and resuscitated. Comprehensive characterization of the isolates in this study revealed that they were all Brucella abortus. Similarly, characterization of archived isolates and those from field submissions showed that they were Brucella abortus. The classical biotyping of all the isolates revealed that they were Brucella abortus biotype 3. Molecular characterization of all the isolates by Bruce-ladder multiplex Polymerase chain reaction (PCR) showed bands consistent with Brucella abortus. This is the first molecular characterization of Brucella isolates from Nigeria using the Bruce-ladder multiplex PCR and the first study that established that Brucella abortus biotype 3 is the predominant Brucella strain in Nigeria. The study established the endemicity of brucellosis due to Brucella abortus, in the two study areas. These findings have great veterinary and public health implications. There is therefore an urgent need for the institution and implementation of brucellosis control measures in these areas.Publishe

A Brucella melitensis H38ΔwbkF rough mutant protects against Brucella ovis in rams

Brucella melitensis and Brucella ovis are gram-negative pathogens of sheep that cause severe economic losses and, although B. 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 of B. ovis. Their control and eradication require vaccination, but B. 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 once B. melitensis is eradicated or where it never existed, hampering B. ovis control and eradication. To develop a B. ovis specific vaccine, we investigated three Brucella live vaccine candidates lacking N-formyl-perosamine O-PS: Bov::CAΔwadB (CO2-independent B. ovis with truncated LPS core oligosaccharide); Rev1::wbdRΔwbkC (carrying N-acetylated O-PS); and H38ΔwbkF (B. melitensis rough mutant with intact LPS core). After confirming their attenuation and protection against B. ovis in mice, were tested in rams for efficacy. H38ΔwbkF yielded similar protection to Rev 1 against B. ovis but Bov::CAΔwadB and Rev1::wbdRΔwbkC conferred no or poor protection, respectively. All H38ΔwbkF vaccinated rams developed a protracted antibody response in ELISA and immunoprecipitation B. ovis diagnostic tests. In contrast, all remained negative in Rose Bengal and complement fixation tests used routinely for B. melitensis diagnosis, though some became positive in S-LPS ELISA owing to LPS core epitope reactivity. Thus, H38ΔwbkF is an interesting candidate for the immunoprophylaxis of B. ovis in B. melitensis-free areas.Publishe

CITA enrichment broth is suitable for the direct isolation of Brucella spp. from field contaminated samples and for direct PCR (póster)

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Correction to: Rev1 wbdR tagged vaccines against Brucella ovis

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