HIGH-RATES OF RESISTANCE TO PIPERACILLIN TAZOBACTAM AMONG ESCHERICHIA-COLI AND KLEBSIELLA-PNEUMONIAE STRAINS ISOLATED IN A GREEK HOSPITAL/

The activities of piperacillin/tazobactam (PTZ) and 10 other beta-lact ams were evaluated by a broth microdilution method using the PASCO sys tem in 1078 Escherichia coli and 447 Klebsiella pneumoniae strains iso lated from hospitalized patients in a Greek hospital. Overall, 10.5% o f the former and 62.6% of the latter strains displayed resistance to P TZ. Most of the PTZ-resistant strains (71.2%) expressed extended spect rum beta-lactamases and were also resistant to broad spectrum cephalos porins and aztreonam. The high rates of PTZ resistance in E. coil and K. pneumoniae and the extensive cross-resistance to other beta-lactams suggest that PTZ should be used with caution in our clinical setting. (C) 1997 Elsevier Science Inc.