Isolation of brucella strains in cattle from sedentary and nomadic communities and its public health implication

Brucellosis is a highly infectious disease caused by bacteria of the genus brucella affecting animals leading to high economic loss and an impediment to livestock exportation. It also infects man with serious public health consequences. The disease is one of the world’smost important neglected tropical zoonoses. Brucellosis is considered endemic in Nigeria and current information on isolation in sedentary and nomadic cattle is required. We carried out an active surveillance in sedentary cattle in Kachia Grazing Reserve (KGR), Kaduna State and in nomadic communities on the Jos Plateau to isolate brucella organisms and carry out phenotypic and molecular characterization of the isolates to species leve

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

Isolation of brucella strains in cattle from sedentary and nomadic communities and its public health implication

Brucellosis is a highly infectious disease caused by bacteria of the genus brucella affecting animals leading to high economic loss and an impediment to livestock exportation. It also infects man with serious public health consequences. The disease is one of the world’smost important neglected tropical zoonoses. Brucellosis is considered endemic in Nigeria and current information on isolation in sedentary and nomadic cattle is required. We carried out an active surveillance in sedentary cattle in Kachia Grazing Reserve (KGR), Kaduna State and in nomadic communities on the Jos Plateau to isolate brucella organisms and carry out phenotypic and molecular characterization of the isolates to species leve

Brucellosis as an emerging threat in developing economies: lessons from Nigeria

Nigeria is the most populous country in Africa, has a large proportion of the world’s poor livestock keepers, and is a hotspot for neglected zoonoses. A review of the 127 accessible publications on brucellosis in Nigeria reveals only scant and fragmented evidence on its spatial and temporal distribution in different epidemiological contexts. The few bacteriological studies conducted demonstrate the existence of Brucella abortus in cattle and sheep, but evidence for B. melitensis in small ruminants is dated and unclear. The bulk of the evidence consists of seroprevalence studies, but test standardization and validation are not always adequately described, and misinterpretations exist with regard to sensitivity and/or specificity and ability to identify the infecting Brucella species. Despite this, early studies suggest that although brucellosis was endemic in extensive nomadic systems, seroprevalence was low, and brucellosis was not perceived as a real burden; recent studies, however, may reflect a changing trend. Concerning human brucellosis, no studies have identified the Brucella species and most reports provide only serological evidence of contact with Brucella in the classical risk groups; some suggest brucellosis misdiagnoses as malaria or other febrile conditions. The investigation of a severe outbreak that occurred in the late 1970s describes the emergence of animal and human disease caused by the settling of previously nomadic populations during the Sahelian drought. There appears to be an increasing risk of reemergence of brucellosis in sub-Saharan Africa, as a result of the co-existence of pastoralist movements and the increase of intensive management resulting from growing urbanization and food demand. Highly contagious zoonoses like brucellosis pose a threat with far-reaching social and political consequences

Comparative performance of lateral flow immunochromatography, iELISA and Rose Bengal tests for the diagnosis of cattle, sheep, goat and swine brucellosis

Background Brucellosis is a world-wide extended zoonosis that causes a grave problem in developing economies. Animal vaccination and diagnosis are essential to control brucellosis, and the need for accurate but also simple and low-cost tests that can be implemented in low-infrastructure laboratories has been emphasized. Methodology We evaluated bovine, sheep, goat and swine lateral flow immunochromatography assay kits (LFA), the Rose Bengal test (RBT) and a well-validated protein G indirect ELISA (iELISA) using sera of Brucella culture-positive and unvaccinated brucellosis free livestock. Sera from cattle vaccinated with S19 and RB51 brucellosis vaccines were also tested. Finally, we compared RBT and LFA using sera of white Fulani cattle of unknown bacteriological status from a brucellosis endemic area of Nigeria. Results and conclusions Although differences were not statistically significant, RBT showed the highest values for diagnostic sensitivity/specificity in cattle (LFA, 96.6/98.8; RBT, 98.9/100; and iELISA, 96.6/100) and the iELISA yielded highest values in sheep (LFA, 94.0/100; RBT, 92.0/100; iELISA, 100/100), goats (LFA, 95.7/96.2; RBT, 97.8/100; iELISA, 100/100) and pigs (LFA, 92.3/100; RBT, 92.3/100; iELISA, 100/100). Vaccine S19 administered subcutaneously interfered in all tests but conjunctival application minimized the problem. Although designed not to interfere in serodiagnosis, vaccine RB51 interfered in LFA and iELISA but not in the RBT. We found closely similar apparent prevalence results when testing the Nigerian Fulani cattle by RBT and LFA. Although both RBT and LFA (showing similar diagnostic performance) are suitable for small laboratories in resource-limited areas, RBT has the advantage that a single reagent is useful in all animal species. Considering these advantages, its low cost and that it is also useful for human brucellosis diagnosis, RBT might be a good choice for resource-limited laboratories

Pesquisa de anticorpos anti-Brucella abortus e anti-Brucella ovis em ovinos no município de Uberlândia, MG

The first epidemiologic inquiry to Brucella abortus (B. abortus) and Brucella ovis (B. ovis) was carried out in sheep from Uberlândia county, MG. A total of 334 blood serum samples of sheep from both sexes and different ages and breeds were collected in 12 farms. An epidemiologic questionnaire was applied for each farm. Tests for B. abortus and B. ovis antibodies were Buffered Acidified Antigen and Complement Fixation, respectively. None of the sheep was reactive to B. abortus and B. ovis; however, the adoption of sanitary measures is important to avoid the introduction of infections caused by these bacteria