COMPARATIVE IN-VITRO ACTIVITY OF CEFEPIME - A MULTICENTER STUDY IN AQUITAINE

Over a 6 month-period (Ist January to 30th June 1995), the results of antibiotic susceptibility testing routinely performed for beta-lactams against enterobacteria, Pseudomonas aeruginosa, and Acinetobacter in 7 laboratory hospitals of Aquitaine, have been collected and divided i n susceptibility profiles. A total of 9269 strains (7323 enterobacteri a, 1667 P. aeruginosa, 279 Acinetobacter) have been examined. On the w hole, cefepime (91,5%) and ceftazidime (91,7%) were the most active ce phalosporins, followed by cefpirome (87,9%) and cefotaxime (80,4%); im ipenem was the most active beta-lactam agent (97,4%). When the strains were divided according to their susceptibility profiles, the advantag e of cefepime was shown to be related to its excellent activity agains t enterobacteria: all strains susceptible to cefotaxime and ceftazidim e (CTX/CAZ-S) were susceptible to cefepime, as were most of the strain s with an intermediate susceptibility or resistant to these drugs (CTX /CAZ-I/R, approximate to 5% of the enterobacterial. The latter strains exhibited a phenotype corresponding either to the overproduction of t heir chromosomal cephalosporinase (approximate to 20% of the species b elonging to group 3) or to the synthesis of an extended spectrum beta- lactamase (19% of the strains of Klebsiella pneumoniae). Cefepime was active against 93% of the derepressed mutants of enterobacteria, inclu ding 3 imipenem resistant isolates of Enterobacter. CAZ-S strains of P . aeruginosa (84%) were usually susceptible to cefepime (80%), as were 6% of the CAZ-I/R strains. CAZ-S strains of A. baumannii (16,3%) were generally susceptible to cefepime (83%), as were 3,2% of the CAZ-I/R strains.