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

Abstract

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.