[Study on in-vitro susceptibility of ESBL-positive Escherichia coli isolated from urine specimens].

Treatment of infections by beta-lactamase-producing microorganisms is very difficult. Our aim was to determine the in vitro susceptibility of 430 ESBL-positive Escherichia coli strains isolated from urinary tract infections. All the microorganisms were isolated in the Microbiology Unit at the Ospedale dell'Angelo in Mestre (Venice) between May 2008 and September 2009 and were confirmed by the double-disk test. All microorganisms were sensitive to imipenem and meropenem, 98.4% to tigecycline, 95.1% to amikacin, 89.3% to nitrofurantoin, 67.5% to gentamycin and 63.2% to piperacillin/tazobactam. Only 22.6% were sensitive to cotrimoxazole, while fluoroquinolone (norfloxacin and levofloxacin) activity was found to be very low (6%).