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Background and objectives: In 2011, a novel mecA homologue (mecC) harbored by SCCmecXI was described for methicillin resistant Staphylococcus aureus (MRSA). To gain deeper insights into the chromosomal integration site (attBSCC) of a mecC-positive S. stepanovicii, we conducted whole genome sequencing (WGS).
Materials and methods: The Staphylococcus stepanovicii strain IMT27065 (ODD4) was isolated in 2011 from wild bank vole as part of a screening study of the Network “Rodent-Borne Pathogens”. WGS was carried out on a HiSeq (Illumina, USA). Annotation of ORFs and prediction of (protein) coding sequences (CDS) was performed by The RAST Server. For comparative genomic analyses Geneious 7.1.5 was employed.
Results: Genome sequencing revealed that IMT27065 harbors a mecC gene which shares 99.2% nucleotide sequence identity with mecC from S. aureus strain LGA251. In addition, the mecC encoding region harbors the typical class E mec complex, but lacked transposases as well as ccr recombinase homologues. Analysis of the 15bp direct repeats (DR) flanking attBSCC revealed similar DRs widely distributed downstream of orfX within the genus Staphylococcus, including SCCmec elements, indicating the possibility of a broad genetic exchange.
Conclusion: Our data highlights the necessity of research on putative transmission routes of resistance encoding factors from the environmental resistome in terms of wildlife reservoirs to opportunistic bacteria such as S. aureus.