Searching for Staphylococcus aureus strains with reduced susceptibility to glycopeptides among clinical isolates obtained during the year of 2002

The methicillin-resistant strains of S. aureus (MRSA) isolated in our laboratory were searched for strains with decreased susceptibility to glycopeptides, GISA (glycopeptide intermediate Staphylococcus aureus) and hetero-GISA strains. 103 strains isolated in 2002 were investigated. Five h-VISA and none VISA strain were found. There was not observed any increase in the frequency of VISA and h-VISA comparing to the former years. In the case of some clinical as well as standard strains (susceptible, GISA and especially h-GISA) the start inoculum significantly influenced a shape of the growth curve obtained as a result of the population analysis.