IN-VITRO ACTIVITY OF CEFPIROME AGAINST SELECTED CLINICAL ENTEROBACTERIAL ISOLATES WITH BETA-LACTAMASE-MEDIATED RESISTANCE

Previous studies have shown that there is a high incidence of resistan ce to cephalosporins among enterobacteria isolated in Greek hospitals. This resistance is mainly due to either the derepression of chromosom al cephalosporinases or the acquisition of plasmids coding for SHV-5 t ype beta-lactamase. In the present study the activity of cefpirome aga inst a number of enterobacteria (Escherichia coli, Klebsiella pneumoni ae, Enterobacter cloacae, Enterobacter aerogenes and Serratia marcesce ns) possessing the mechanisms mentioned above was examined, Cefpirome was found active against all the strains characterized by stable derep ression of chromosomal class-C enzymes, The antibiotic was less potent against strains expressing SHV-5 type beta-lactamase due to its hydro lysis by the enzyme. Also cefpirome exhibited good activity against E. aerogenes strains with reduced susceptibility to imipenem, These ia v itro data suggest that cefpirome might be useful in treating infection s caused by these resistant microorganisms that are frequently encount ered in Greek hospitals.