Genetic profiles of Mycobacterium bovis from a cattle herd in southernmost Brazil

Antonio Francisco de Souza Filho, Ana Luiza Alves Rosa Osório, Klaudia dos Santos Gonçalves Jorge, Flábio Ribeiro Araújo, Carlos Eugênio Soto Vidal, Cristina Pires Araújo, Letícia Alves Gomes Albertti, Daniela de Oliveira Cazola, José Soares Ferreira Neto, Marcos Bryan Heinemann

Abstract


Mycobacterium bovis is the agent of bovine tuberculosis, a disease endemic to all Brazilian states. Molecular typing techniques help to stratify and refine data, providing information that facilitates epidemiological research. In this study, MIRU-VNTR, targeting 24 loci, was employed to identify and characterize the genetic groups of M. bovis isolates obtained from an outbreak of bovine tuberculosis. Eighteen acid-fast bacilli isolates, obtained from bovine tissue samples, and reactive to the comparative cervical tuberculin test, were identified as species of the M. tuberculosis complex, and were genotyped by MIRU-VNTR with 24 primer pairs. Genotyping revealed three genetic profiles comprising one with 15 isolates (83.3%), one with two isolates (11.1%), and one profile with one unique isolate (5.6%). This distinction was achieved with the MIRU 31 primer, which resulted in clustering of two isolates into the same profile, and ETR A, B, and C, which discriminated the isolate with a unique profile. The occurrence of clustered isolates is indicative of recent transmission, whereas isolates with a unique profile suggest reactivation of latent infection. The presence of different M. bovis genotypes in the same herd suggests movement of infected animals or different sources of intra-herd infection. Use of the MIRU-VNTR molecular epidemiology technique in M. bovis isolates obtained from an outbreak of bovine tuberculosis in Rio Grande do Sul state demonstrated the genetic diversity of circulating strains, despite the presence of a predominant group.

Keywords


Bovine tuberculosis; Genetic diversity; MIRU-VNTR; Mycobacterium bovis.

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DOI: http://dx.doi.org/10.5433/1679-0359.2016v37n5Supl2p3719

Semina: Ciênc. Agrár.
Londrina - PR
E-ISSN 1679-0359
DOI: 10.5433/1679-0359
E-mail: semina.agrarias@uel.br
Este obra está licenciado com uma Licença Creative Commons Atribuição-NãoComercial 4.0 Internacional