Staphylococcus aureus isolates with reduced susceptibility to glycopeptides belong to accessory gene regulator group I or II

Abstract

We used multiplex PCR to determine the agr group membership of 18 European glycopeptide heterointermediate and intermediate-resistant Staphylococcus aureus strains. Of the 15 agr group I strains, 13 were resistant and 2 were susceptible to methicillin. The remaining three strains, like the United States and Japanese control strains, belonged to agr group II.

FIG. 1.

PFGE patterns and phylogenetic tree of 22 GISA and hGISA isolates and 35 non-GISA and non-hGISA S. aureus isolates from the United States, Japan, and Europe. Isolate designations in boldface characters indicate the GISA-hGISA phenotype. SmaI macrorestriction patterns were digitized and analyzed with Taxotron software (Institut Pasteur, Paris, France) to calculate Dice coefficients of correlation and to generate a dendrogram by the unweighted pair group method using arithmetic averages (unweighted pair group method with arithmetic mean) clustering. The scale indicates the levels of pattern similarity. The fragment size (in kilobases) of reference strain NCTC8325 is indicated on the bottom lane.