Multicenter evaluation of the antimicrobial activity for seven broad-spectrum beta-lactams in Turkey using the Etest method

From March through July 1997, a nine laboratory surveillance project was in itiated in Turkey to monitor the potency and spectrum of seven broad-spectr um antimicrobial agents (cefepime, ceftazidime, cefotaxime, imipenem, aztre onam, cefoperazone/sulbactam, and ticarcillin/clavulanate) tested against a pproximately 100 organisms (average 82; range 70 to 95 isolates) per partic ipant center (736 strains). Eleven groups of organisms were tested by the E test method (AB BIODISK, Solna, Sweden) with results validated by concurren t quality control strain analysis. Results front all centers were tabulated and 91.1% of quality assurance tests were within ranges recommended by the National Committee for Clinical Laboratory Standards. Among the seven beta -lactam-class drugs tested, imipenem and cefepime were the most active beta -lactams tested against all isolates. Overall, the rank order of susceptibi lity of the seven agents was imipenem > cefepime > cefoperazone/sulbactam > ceftazidime > cefotaxime > aztreonam > ticarcillin/clavulanate. Both cefep ime and imipenem were active against ceftazidime-resistant strains of Enter obacteriaceae as well as against Streptococcus spp, and oxacillin-susceptib le Staphylococcus aureus. Resistance phenotypes consistent with extended sp ectrum beta-lactamases were documented among Escherichia coli and Klebsiell a spp., and profiles consistent with stably derepressed Bush-Jacoby-Mederio s group 1 (Amp Ci cephalosporinases were common among Enterobacter spp., Ci trobacter spp., and Serratia spp. These data should be used to guide empiri c therapy with beta-lactams in Turkey, and additionally will provide a refe rence statistical baseline to which future national studies of drugs in thi s class can be compared. (C) 1999 Elsevier Science Inc.