The Prevalence and Molecular Distinguishing of Brucella melitensis Rev1 Strain among Field Isolates the Brucella from Sheep and Goat Milk through PCR-RFLP Analysis of omp2 Gene Polymorphism

Abstract

The present study was undertaken to characterize the prevalence and molecular distinguishing of Brucella melitensis field and vaccine Rev1 strains isolated from milk among the sheep and goat population. The study was carried out on flocks of sheep and goats suffering from Brucella infection outbreaks. A total of 171 milk samples were collected from different districts of the West Bank, part of Palestine, and isolated on Brucella agar. 86 cultures were confirmed by standard biochemical methods and screened for Brucella melitensis 16M of IS711 element by a conventional PCR technique. All these samples were also amplified for the omp2 gene to identify differences between field and Rev 1 strains in an infected flock. The results obtained from the PstI restriction enzyme pattern revealed that only 2 (4.5%) samples have specific polymorphism accomplished with the Brucella melitensis Rev1 strain. All other samples were restricted according to the Brucella melitensis 16M polymorphism pattern and originated from nonvaccinated flocks. Despite the adverse side effects of the Brucella melitensis vaccine, only a well-organized whole-flock vaccination and awareness campaign may inhibit the virulence of the field strain and, subsequently, reduce the prevalence of brucellosis infection among animals and humans in Palestine.