Agriculture & Food, Volume 4, 2016

Abstract: Brucellosis is an endemic zoonotic disease of the small ruminants in Palestine. The previous study revealed that the lpsB gene (responsible for the biosynthesis of mannosyltransferase) of Brucella melitensis has a degree of genetic diversity. Despite these variations, the bacteria keep its virulence and ability to produce abortion and human infection. The aim of this study was to identify the evolutionary relationships between 18 field strains of Brucella melitensis isolated from herds from West Bank, and to compare them with strains from different countries, using phylogenetic analysis, in order to characterize their epidemiological pattern. The sequencing of the lpsB gene of the 18 field strains has been performed with ABI PRISM 3500 Genetic Analyzer. The alignment and the phylogenetic analysis between field isolates, Brucella melitensis reference strain and Rev 1 strains were done with CLC Workbench version 6.1.5 software. The analysis revealed that all field isolates were closely related to each other: isolates from neighboring districts have had close variations, but the strongest relationship was among strains from flocks of the same village. The isolates from some flocks were closer to Brucella melitensis Rev 1, suggesting the exposure or infection of these with the vaccinal strain. Viewed in a global context, the West Bank isolates were phylogenetically closest to the Spanish isolates. This study highlights the input of the phylogenetic tree analysis as an epidemiological tool for the investigation of Brucella infection.