Genetic evolution of Mycobacterium bovis causing tuberculosis in livestock and wildlife in France since 1978

PLoS One. 2015 Feb 6;10(2):e0117103. doi: 10.1371/journal.pone.0117103. eCollection 2015.

Abstract

To study the dynamics of bovine tuberculosis (bTB) in France, 4,654 M. bovis strains isolated mainly from livestock and wildlife since 1978 were characterized by spoligotyping and MLVA based on MIRU-VNTR. In our study spoligotyping allowed the discrimination of 176 types although 3 spoligotypes are predominant and account for more than half of the total strain population: SB0120 (26%), SB0134 (11%) and SB0121 (6%). In addition, 11% of the isolates, principally from Southern France, showing close spoligotypes and MIRU-VNTR types have been gathered in a family designated as the "F4-family". MLVA typing allowed extensive discrimination, particularly for strains with predominant spoligotypes, with a total of 498 genotypes, several of which were highly regionalized. The similarity of the strains' genetic relationships based on spoligotyping and MIRU-VNTR markers supports the co-existence of different clonal populations within the French M. bovis population. A genetic evolution of the strains was observed both geographically and in time. Indeed, as a result of the reduction of bTB due to the national control campaigns, a large reduction of the strains' genetic variability took place in the last ten years. However, in the regions were bTB is highly prevalent at present, cases in both livestock and in wildlife are due to the spread of unique local genotype profiles. Our results show that the highly discriminating genotyping tools used in this study for molecular studies of bTB are useful for addressing pending questions, which would lead to a better insight into the epidemiology of the disease, and for finding proper solutions for its sustainable control in France.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Wild / microbiology*
  • Bacterial Typing Techniques
  • Cattle
  • Evolution, Molecular*
  • France / epidemiology
  • Genetic Variation
  • Genotype
  • Mycobacterium bovis / genetics*
  • Mycobacterium bovis / isolation & purification
  • Tandem Repeat Sequences / genetics
  • Tuberculosis / epidemiology
  • Tuberculosis / microbiology
  • Tuberculosis / veterinary*
  • Tuberculosis, Bovine / epidemiology
  • Tuberculosis, Bovine / microbiology*
  • Tuberculosis, Bovine / pathology

Grants and funding

This work was partly funded by a CNRS-MIE project (MLB, ALB and SG). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The rest of the funding was internal to the authors’ organization.