Identification of Brucella isolated from goats using Pst I site polymorphism at Omp2 gene loci

Abstract

In present study Brucella was isolated from different target tissues of goats. The isolated brucellae cultures were primarily characterized using classical biotyping methods. For molecular typing of Brucella isolates we used, PCRRFLP, which relies on DNA polymorphism. We used the Omp2 gene of Brucella as a locus of two nearly homologous repeated copies that differ slightly among Brucella species and biotypes in presence or absence of the Pst I site to ifferentiate between them. Our results revealed that DNA fragments obtained from B. melitensis 16M strain isolated from goats and B. melitensis Rev1strain produced three bands, an intact 282-bp fragment from the amplified omp2a gene that lacks the Pst I site and two smaller fragments of 238 and 44 bp, the product obtained from digestion of the omp2b amplified fragment. In contrast B. melitensis biovar 3 produced only two smaller fragments from both genes omp2a and omp2b), a 238-bp fragment and a 44-bp fragment. Because of the existing Pst I site polymorphism between Brucella strains, the test may distinguishes between different strains of B. melitensis Rev1 vaccine strain from B. melitensis biovar 3 field strains in less than 12 hours. This method can be used in clinical samples directly.