Multicentre surveillance of Pseudomonas aeruginosa susceptibility patterns in nosocomial infections.

OBJECTIVES

To determine susceptibility rates and patterns in Pseudomonas aeruginosa strains isolated from nosocomial infections.

METHODS

Seven hundred and sixteen P. aeruginosa isolates from 40 different hospitals in Belgium and the Grand Duchy of Luxembourg were collected in 1999.

RESULTS

Resistance rates varied significantly between hospitals. Of the fluoroquinolones, ciprofloxacin showed least resistance (24%), levofloxacin showed 27.5% resistance and ofloxacin 37.5%. Of the aminoglycosides, amikacin was the most potent antibiotic (10.5% resistance), followed by isepamicin (12%), tobramycin (19.5%) and gentamicin (23.5%). Of the beta-lactam antibiotics, meropenem was the most active (9.5% resistance); piperacillin and piperacillin/tazobactam had, respectively, 24% and 17.5% resistance, ceftazidime 28.5%, cefepime 29.5%, ticarcillin/clavulanic acid 37% and aztreonam 55.5%. MIC distribution curves show the presence of significant subpopulations, with MICs just below breakpoint for many antibiotics.

CONCLUSION

Resistance of P. aeruginosa to penicillins, cephalosporins, fluoroquinolones and aminoglycosides varies between hospitals, but is increasing.