PLoS ONE (Jan 2016)

A Look into the Melting Pot: The mecC-Harboring Region Is a Recombination Hot Spot in Staphylococcus stepanovicii.

  • Torsten Semmler,
  • Ewan M Harrison,
  • Antina Lübke-Becker,
  • Rainer G Ulrich,
  • Lothar H Wieler,
  • Sebastian Guenther,
  • Ivonne Stamm,
  • Anne-Merethe Hanssen,
  • Mark A Holmes,
  • Szilvia Vincze,
  • Birgit Walther

DOI
https://doi.org/10.1371/journal.pone.0147150
Journal volume & issue
Vol. 11, no. 1
p. e0147150

Abstract

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INTRODUCTION:Horizontal gene transfer (HGT) is an important driver for resistance- and virulence factor accumulation in pathogenic bacteria such as Staphylococcus aureus. METHODS:Here, we have investigated the downstream region of the bacterial chromosomal attachment site (attB) for the staphylococcal cassette chromosome mec (SCCmec) element of a commensal mecC-positive Staphylococcus stepanovicii strain (IMT28705; ODD4) with respect to genetic composition and indications of HGT. S. stepanovicii IMT28705 was isolated from a fecal sample of a trapped wild bank vole (Myodes glareolus) during a screening study (National Network on "Rodent-Borne Pathogens") in Germany. Whole genome sequencing (WGS) of IMT28705 together with the mecC-negative type strain CM7717 was conducted in order to comparatively investigate the genomic region downstream of attB (GenBank accession no. KR732654 and KR732653). RESULTS:The bank vole isolate (IMT28705) harbors a mecC gene which shares 99.2% nucleotide (and 98.5% amino acid) sequence identity with mecC of MRSA_LGA251. In addition, the mecC-encoding region harbors the typical blaZ-mecC-mecR1-mecI structure, corresponding with the class E mec complex. While the sequences downstream of attB in both S. stepanovicii isolates (IMT28705 and CM7717) are partitioned by 15 bp direct repeats, further comparison revealed a remarkable low concordance of gene content, indicating a chromosomal "hot spot" for foreign DNA integration and exchange. CONCLUSION:Our data highlight the necessity for further research on transmission routes of resistance encoding factors from the environmental and wildlife resistome.