Molecular detection of Brucella species from apparently healthy camels slaughtered at the Akaki abattoir, Ethiopia

Abstract BACKGROUND ANDMETHODS: Brucellosis is a dreadful zoonotic disease affecting humans and all domestic animals including camels worldwide. Serological evidence for Brucella infection in camels has been reported from all pastoralist and agro-pastoralist regions of Ethiopia. Investigations have shown that antibody concentrations are lower in camels than in cattle. However, serological diagnostic kits have been developed for cattle brucellosis is directly transposed for camels without adequate assay validation and genotyping of Brucella species is still absent in camel population in Ethiopia. This study aimed to evaluate gaps associated with Rose Bengal Plate Test (RBPT) and molecular detection of Brucella species from apparently healthy camels slaughtered at the Akaki abattoir. The study applied Brucella genus specific, Brucella abortus (B.abortus) and Brucella melitensis (B.melitensis) species-specific primers on RBPT-positive and retropharyngeal lymph node samples collected from 100 camels’ heads. RESULTS: RBPT revealed the presence of anti-Brucella antibodies in 5 of 100 (5%) slaughtered camels. All RBPT-positive were also positive for PCR. Among the100 lymph node samples examined, 35 (35%) were Brucella positive by PCR. All were found to be B. abortus;however, B. melitessis was not detected in either the serum or lymph node samples. CONCLUSION: To the authors’ knowledge, this investigation is the first report on the molecular detection of B.abortus from camel in Ethiopia. Sequence data confirmed the presence of B. abortus from apparently healthy camels slaughtered at Akaki abattoir, Ethiopia. B. abortus molecular detection rate on lymph nodes samples was seven times greater than that of RBPT. We recommend that advanced research be conducted on camel milk and meat and those camel herders emphasize Ethiopian pastoral areas in particular to understand Brucella epidemiology and its public health significance.