Genetic Characterization of the WboA Gene from the Predominant Biovars of Brucella Isolates in Iran

Introduction: Brucella spp. are gram-negative, facultative intracellular bacteria pathogens responsible for brucellosis, a zoonotic disease that can cause abortion, fetal death, and genital infections in animals and undulant fever in humans. Lipopolysaccharide (LPS) is known as a major virulence factor of Brucella spp. The wboA gene is capable of encoding a glycosyltransferase that appears to play a major role in LPS biosynthesis. Hence, the characterization of this gene can help in the clarification of the pathogenicity of Brucella spp.

Methods: This study was carried out at Razi Vaccine and Serum Research Institute in 2011. Briefly, the wboA gene in B. abortus biovar 3 and B. melitensis biovar 1, the predominant biovars in Iran, were amplified by using two pairs of specific primers. Polymerase chain reaction (PCR) products were cloned into a thymine-adenine (TA) cloning vector and transformed into an E. coli DH5α before being sequenced. Multiple alignments of identified sequences were performed, with all wboA sequences deposited in the GenBank sequence database.

Results: This study showed that a mismatch has occurred in B. melitensis biovar 1; this biovar is predominant in Iran. In contrast, the wboA gene from B. abortus biovar 3 was similar to that of other B. abortus variations.

Conclusion: The comparison and alignment of the wboA gene of native Brucella strains in Iran to all wboA sequences deposited in GenBank revealed that the wboA gene has changed in the long term; hence, because of its unique nucleotide pattern, the gene can be used for specific diagnosis of B. abortus and B. canis.