Characteristics of the extended collection of representative MRSA strains.

Abbreviations: neg., negative; pos., positive; WT, wild-type; ND, not determined.Notes:a)Clonal types as defined by MLST sequence type (ST) and SCCmec type.b)neg. – negative (due to IS1272 or IS431 insertions); WT – wild-type sequence (N315); * - mutated non-functional mecI.c)IS::ΔmecR1 – mecR1 with no C-terminal sensor domain (due to IS1272 or IS431 insertions).d)The production of β-lactamase was tested for induced and no induced cultures (see text for details). All strains positive for β-lactamase were inducible. Strains negative for the nitrocefin assay were tested for the presence of blaZ, blaI, and blaR1 by PCR.e)MIC as determined by E-test strips.f)Parental strains transformed with a high copy number plasmid containing the wild-type mecI coding region (pGC2-mecIWT).