[Treatment of severe Gram-positive infections: current situation and new opportunities].

METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS (MRSA) INFECTIONS: A growing number of MRSA strains with an increased minimum inhibitory concentration (MIC) and intermediary susceptibility to glycopeptides (GISA) or vancomycin (VISA) are encountered in clinical practice. In patients on mechanical ventilation who develop acute pneumonia, it would appear appropriate to achieve a vancomycin concentration in serum and the lung 2 to 4 times above the MIC, while carefully monitoring the risk of toxicity. POSSIBLE SOLUTIONS: Better prevention of severe MRSA infections, a more rational use of glycopeptides, using a recycling scheme, i.e. altering prescriptions with antibiotics other than glycopeptides or using combinations. OTHER AGENTS CURRENTLY AVAILABLE: Several antibiotic classes can now be used to preserve the efficacy of glycopeptides: cotrimoxazole, quinupristine/dalfopristine and linezolide. Linezolide is the first compound of a new family of antibiotics called oxazolidinones which are active against aerobic and anaerobic Gram positive strains, particularly those exhibiting intermediary sensitivity or resistance to other antibiotics. Its pharmacokinetic properties are quite favorable. ANTIBIOTIC COMBINATIONS: In case of severe MRSA infection, antibiotics that can be combined with vancomycin include gentamycin, rifampicin, or fosfonycine. For GISA infections, vancomycin could be combined with a ss-lactam, or quinupristine/dalfopristine. Combination with linezolide appears to be antagonistic.