In vitro evaluation of cefepime and other broad-spectrum beta-lactams in eight medical centers in Thailand

The introduction of cephalosporins has had an important impact on the resis tance rates to several clinically utilized beta-lactam antimicrobial agents . Most Thailand medical centers have not documented the levels of emerging resistant pathogens causing invasive infections. This study shows using ref erence-quality MIC techniques (Etest, AB BIODISK, Solna, Sweden), that carb apenems (imipenem), "fourth-generation" cephalosporins (cefepime and cefpir ome), and piperacillin/tazobactam were the most active agents tested agains t Gram-negative bacilli (Escherichia coli, Klebsiella spp., Enterobacter sp p., Citrobacter spp., Serratia spp., indole-positive Proteae, Acinetobacter spp., Pseudomonas aeruginosa, and oxacillin-susceptible Staphylococcus spp . when compared to "third-generation" cephalosporins (ceftazidime and ceftr iaxone). The rank order of activity for all species was imipenem (2.9% resi stant) > eefepime (7.7%) > piperacillin/ tazobactam (11.1%) > ceftazidime ( 13.11%) > ceftriaxone (21.1%) > ceftazidime (29.9%). The incidence of exten ded spec -trum beta-lactamase production among E. coli (15.7%) and K. pneum oniae (45.6%) was significant. Cefepime and imipenem were active against th e majority of these isolates. The activity of cefepime was also shown to be very good against, 1) organisms capable of producing AmpC enzymes, 2) stap hylococci species that were susceptible to oxacillin, and 3) many strains o f nonfer- mentative Gram-negative bacilli. The prevalence of antimicrobial resistance iii Thailand seems to be quite high among certain commonly encou ntered pathogens, and imipenem and cefepime have activity (susceptible and intermediate potency) against > 90% of these organisms. (C) 1999 Elsevier S cience Inc.