Molecular epidemiology of Brucella abortus isolated from cattle in Brazil, 2009-2013

The aims of the present study were to genotype Brucella abortus strains isolated from cattle in Brazil between 2009 and 2013, and to analyze their distribution to support the Programa Nacional de Controle e Erradicação de Brucelose e Tuberculose (PNCEBT) (National Brucellosis and Tuberculosis Control and Eradication Program). One hundred forty B. abortus strains isolated from cattle in Brazil between 2009 and 2013 were genotyped using a set of 18 variable number of tandem repeats (VNTR) (MLVA16+HOOF-Print 3 and 4). The multiple locus VNTR analysis (MLVA) composed by eight markers (MLVA8) revealed eight different genotypes among B. abortus strains, including five previously described and three new ones. Analysis of the MLVA16 loci revealed fifty-eight distinct genotypes, from which three were identical, thirty-eight were considered very close, and seventeen were considered distant compared to those previously described and deposited in MLVAbank. Analysis of the HOOF-Prints 3 and 4 revealed the larger number of different alleles among all VNTR assessed, exhibiting maximum resolution when associated with MLVA16 markers. This study also provides insights on the genotypes of B. abortus circulating in Brazil, which certainly contribute for the better understanding of the epidemiology and control of bovine brucellosis in the country. Moreover, our data showed a high genetic diversity among the B. abortus strains isolated between 2009 and 2013, and a close relationship among these strains and Brazilian B. abortus deposited by MLVAbank.