METHICILLIN-RESISTANT STAPHYLOCOCCUS-AURE US AND GLYCOPEPTIDES - IN-VITRO SELECTION OF RESISTANCE

By repeated and successive treatments of five strains of methicillin-r esistant aureus with sub-inhibitory concentrations of vanco-mycin and of teicoplanin, the authors have confirmed that selection of resistant strains could be obtained more easily with teicoplanin than with vanc omycin. Moreover, we have shown that treatments with sub-inhibitory co ncentrations of teicoplanin could also influence the activity of vanco mycin, although the strains have never been in contact with the latter antibiotic. This could account, at least in part, for the downhill ev olution of the activity of glycopeptides against staphylococci, observ ed this last years. Indeed, the efficacy of these antibodies upon whic h treatment of severe infections due to multiresistant staphylococci r elies, is lowering. Considering the challenge, this risk is worth-bein g not only evaluated by a reinforced epidemiologic surveillance, but a lso limited by more severe criteria for the prescription and the follo w-up of treatments with glycopeptides.