Detection of Brucella abortus and Brucellla melitensis in cattle and sheep from southern Cameroon

Abstract Background: Brucellosis is an infectious disease caused by bacterial of the genus Brucella. Although investigations have identified Brucella antibodies in many animal species, little attention has been paid towards specific identification of different Brucella species in animals in Sub-Saharan African countries. This study was designed to identify Brucella abortus and Brucellla melitensis in cattle and sheep of several villages of southern Cameroon in order to improve our epidemiological knowledge on brucellosis in central AfricaMethods: Blood samples were collected from 597 cattle and 315 sheep from 15 villages of two regions of Cameroon. DNA was extracted from blood samples and primers amplifying the bcsp31 gene locus were used for the identification of Brucella spp infections in these animals. Amongst animals found with Brucella spp infections, specific primes were used to identify B. abortus and B. melitensis respectively. Results: Of the 912 animals analyzed in this study, 159 (17.4%) were infected with Brucella spp. This gives a Brucella infection rate of 20.9% in cattle and 10.8% in sheep. Of the 159 animals harboring Brucella spp infections, 119 (74.8%) were infected by B. abortus and 35 (22.0%) by B. melitensis. The overall infection rates were 18.4% (110/597) for B. abortus and 1.7% for B. melitensis in cattle; 2.9% for B. abortus and 7.9% for B. melitensis in sheep. Co-infections of B. abortus and B. melitensis were found in 9 (1%) animals; 6 (1%) cattle and 3 (1%) sheep. The Brucella infection rate was significantly higher in animals from the Noun division (20.6%) compared to those of Yoko (12.4%). Between animal species, significant differences (P = 0.0001) were observed in infection rates of both abortus and B. melitensis. Within and between sampling sites, significant differences (P = 0.02) were observed in the B. abortus infection rates. Conclusion: This study revealed B. melitensis and B. abortus infections in cattle and sheep from the Noun and Yoko divisions in southern Cameroon. The identification of B. melitensis and B. abortus in animals suggests further investigations on human brucellosis. Results of this study highlight the need of developing and implementing control measures against brucellosis in Cameroon.