β-Lactam resistance on the part of the Enterobacteriaceae causes serious therapeutic problems in our institutions due to their production of extended-spectrum β-lactamases (ESβLs). We studied the in vitro activity of β-lactam/β-lactamase inhibitor combinations and third-generation cephalosporins and monobactams against 71 clinically relevant Enterobacteriaceae which produced TEM- and SHV-derivative ESβLs. Of the single drugs and combinations tested, piperacillin/tazobactam proved to be the most effective. Piperacillin/tazobactam was highly active against Proteus mirabilis, with minimum inhibitory concentrations (MICs) ranging from 0.125 to 16 μg/ml; Escherichia coli (MICs from 2 to 16 μg/ml) and Serratia marcescens (MICs from 4 to 8 μg/ml), while its activity against Klebsiella pneumoniae ESβL producers turned out to be closely related to the type and the amount of enzyme produced, the MIC ranging from 1 to 128 μg/ml. The antibacterial activity of piperacillin/tazobactam was stronger than that of ticarcillin/clavulanate, ceftriaxone, cefotaxime, ceftazidime and aztreonam, and the combination shared favorable in vitro activity properties against the ESβL producers with imipenem which, however, should be kept as reserve product.
Comparative activity of piperacillin/tazobactam against clinical isolates of extended-spectrum β-lactamase-producing enterobacteriaceae
PERILLI, MARIAGRAZIA;AMICOSANTE, Gianfranco
1998
Abstract
β-Lactam resistance on the part of the Enterobacteriaceae causes serious therapeutic problems in our institutions due to their production of extended-spectrum β-lactamases (ESβLs). We studied the in vitro activity of β-lactam/β-lactamase inhibitor combinations and third-generation cephalosporins and monobactams against 71 clinically relevant Enterobacteriaceae which produced TEM- and SHV-derivative ESβLs. Of the single drugs and combinations tested, piperacillin/tazobactam proved to be the most effective. Piperacillin/tazobactam was highly active against Proteus mirabilis, with minimum inhibitory concentrations (MICs) ranging from 0.125 to 16 μg/ml; Escherichia coli (MICs from 2 to 16 μg/ml) and Serratia marcescens (MICs from 4 to 8 μg/ml), while its activity against Klebsiella pneumoniae ESβL producers turned out to be closely related to the type and the amount of enzyme produced, the MIC ranging from 1 to 128 μg/ml. The antibacterial activity of piperacillin/tazobactam was stronger than that of ticarcillin/clavulanate, ceftriaxone, cefotaxime, ceftazidime and aztreonam, and the combination shared favorable in vitro activity properties against the ESβL producers with imipenem which, however, should be kept as reserve product.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
