MYSTIC (Meropenem Yearly Susceptibility Test Information Collection): a global overview.

The Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) is a global, multicentre surveillance study that compares the activity of meropenem in centres that are prescribers with that of imipenem, ceftazidime, piperacillin/tazobactam, ciprofloxacin and gentamicin. Of the 46 centres (intensive care units, cystic fibrosis units, neutropenia units and general wards) contributing to this study, 29 were in Europe, 14 in the Americas and three in the Middle East and Asia. The results for the most common isolates obtained in the first year of the study from these three regions show that meropenem has a broad spectrum of activity and potency in these centres, with 89% of the 6890 strains tested having an MIC < or = 4 mg/L. The overall susceptibility was lower for the comparator antibiotics. There was evidence in all regions of strains producing beta-lactamases and other resistance mechanisms against the other beta-lactams tested, fluoroquinolones and aminoglycosides. Future years' results from this surveillance study will show whether meropenem will continue to exhibit such activity.