Genomic Insights of First erm B-Positive ST338-SCC mec V T /CC59 Taiwan Clone of Community-Associated Methicillin-Resistant Staphylococcus aureu s in Poland.

We report the first Polish representative of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA), luk S/F-PV-positive, encoding the erm B gene, as a genetic determinant of constitutive resistance to macrolides, lincosamides, and streptogramin B antibiotics, cMLS-B. This is the first detection of the CA-MRSA strain responsible for nosocomial infection in the Warsaw Clinical Hospital. Resistance to β-lactams associates with a composite genetic element, SCC mec cassette type V T (5C2&5). We assigned the strain to sequence type ST338 (single-locus variant of ST59), clonal complex CC59, spa -type t437, and agr -type I. Genomic-based comparison was designated SO574/12 as an international Taiwan clone, which has been so far described mainly in the Asia-Pacific region. The erm B gene locates on the chromosome within the 14,690 bp mobile element structure, i.e., the MES PM1-like structure, which also encodes aminoglycoside- and streptothricin-resistance genes. The MES PM1-like structure is a composite transposon containing Tn551, flanked by direct repeats of IS1216V insertion sequences, which probably originates from Enterococcus . The erm B is preceded by the 273 bp regulatory region that contains the regulatory 84 bp erm BL ORF, encoding the 27 amino acid leader peptides. The latest research suggests that a new leader peptide, erm BL2, also exists in the erm B regulatory region. Therefore, the detailed function of erm BL2 requires further investigations.