Isolation and molecular characterization of Brucella abortus and Brucella melitensis from samples received by the Regional Veterinary Laboratory, Bukit Tengah, Malaysia

A study was carried out to report the phylogenetic analysis of Brucella abortus and Brucella melitensisby using molecular techniques from samples submitted to the Regional Veterinary Laboratory, Bukit Tengah.In this study, identification and genetic characterization of Brucella isolated samples using molecular analysis based on IS711 sequence between localisolates and foreign countries accesses in GenBank was done successfully. A total of 31 samples were isolated for Brucella species and then were amplified byPCR, directly sequenced and compared genetically to published sequences which were obtained from GenBank. The most common Brucella species that was found in both bovine (76.5%) and caprine (85.7%) through diagnostic samples in Regional Veterinary Laboratory, Bukit Tengah, was Brucella melitensis. PCR and sequencing were confirmed positive with 76.5% for Brucella melitensis, 23.5% for Brucella abortus and 23.5% for mixed infectionfrom the total of 17 bovine samples. In caprine, the detection of Brucella melintesis and Brucella abortus showed 85.7% and 21.4% respectively meanwhile total mixedinfection showed 21.4%. These clustering between local isolates of Brucella melitensis were phylogenetically related to other Asian countries such as Singapore,Yemen and Saudi Arabia. The Neighbour Joining Analysis clustered the Brucella abortus local isolates for both bovine and caprine were most closely related to India,Iran, Italy and USA. Interestingly, all the isolates within Malaysia have a close relationship (>95%) with the low level of genetic diversity. When local isolates arecompared to GenBank data, it gives an indication on the possible sources of these infections. Eventually, it will improve the import and export policies to controlbrucellosis in Malaysia.