Susceptibility of multi-drug-resistant Pseudomonas aeruginosa in intensive care units: results from the European MYSTIC study group.

The MYSTIC program monitors worldwide in vitro susceptibilities of clinical bacterial isolates from centers that prescribe meropenem. This report focuses on 107 isolates of multi-drug resistant (MDR) Pseudomonas aeruginosa, which commonly causes infections that are difficult to treat in hospitalized patients. We chose samples from patients from 33 European intensive care units (ICUs). There was considerable inter-country variation in the proportion of P. aeruginosa that were MDR, ranging from 50% in Turkey to < or =3% in Spain, the UK, Germany, Bulgaria and Malta. Amongst the MDR isolates, the percentage resistance (MIC50/90 in mg/L) to the antibiotics tested were amikacin 18.7% (32/>128), meropenem 29.1% (8/64), imipenem 44.9% (16/64), cefepime 49.5% (32/64) and piperacillin/tazobactam 57.9% (128/>128).