Evaluation of Brucella melitensis MLVA Genotyping for sheep and goats Milk in Iran

Background and Aim : In Iran brucellosis is an endemic disease characterized by high infection rate in both humans and animals. Overall, data on the epidemiological situation of brucellosis in the country are limited. The aim of this study was to evaluate MLVA (multiple-locus variable-number tandem repeat (VNTR) analysis) for diagnostic and epidemiological use in animal brucellosis.Methods : Isolates of Brucella melitensis (B. melitensis) collected in sheep and goat milk samples from six provinces of Iran. To identify B. melitensis biovars, omp۲a and omp۲b genes was amplified by TD-PCR, and PCR products digested with PstI and HinfI restriction enzymes. Genotyping was performed using MLVA-۸ and MLVA-۱۱, panel ۱ for species identification and MLVA-۱۶ panels ۲A and ۲B for further subspecies differentiation.Results : PCR-RFLP analysis confirmed the ۶۴ strains isolated as belonging to B. melitensis biovar ۱ and single strain being a B. melitensis biovar ۲. Using panel ۱ (MLVA-۸) two genotypes were observed namely genotype ۴۷ and genotype ۶۳. The genotypes ۴۷ belonged to the American group and genotype ۶۳ belonged to East Mediterranean group.And using the combination of panels ۱ and ۲A loci (MLVA-۱۱), five genotypes were obtained while using the complete panels ۱, ۲A and ۲B (MLVA-۱۶), ۲۵ genotypes were obtained.Conclusion : This study showed that the prevalence of B. melitensis bv. ۱ was the biovar most frequently isolated in small ruminants. Also representing the first MLVA typing results of animal Brucella isolates from Iran, indicated that B. melitensis isolates were most closely related to the the isolates included in the American group.

کلیدواژه ها:

MLVA ، RFLP ، B. melitensis ، sheep ، goat ، Milk