IN-VITRO ACTIVITY OF A NEW CEPHALOSPORIN, CEFPIROME - RESULTS OF A MULTICENTER STUDY

The in vitro activity of cefpirome, a new injectable cephalosporin was studied against 1 082 clinical isolates in a multicentre study. Minimum inhibitory concentrations were determined using an agar dilution method. Cefpirome was active against Enterobacteriaceae. On naturally non-producing betalactamase species, cefpirome was active on most of the strains with MICs less than or equal to 0.5 mg/l, including strains producing an acquired penicillinase : E. coli 0.03-0.06, I;I mirabilis 0.06-0.12, Salmonella spp. 0.06-0.06, Shigella spp. 0.016-0.03. MICs of K. pneumoniae (0.06-4) ranged from 0.016 to 32 : MICs were high against expanded - spectrum betalactamase producers strains. Against species producing cephalosporinase, cefpirome was also active on most of the strains with MICs less than or equal to 0.5 : E. cloacae 0.06-2, Citrobacter spp. 0.03-1, S. marcescens 0.06-0.5, P. indol + 0.06-0.25, P. stuartii 0.12-0.5. Cefpirome was less active on Pseudomonas aeruginosa, (8-32) and on A. baumannii (16-32). MICs of cefpirome were low against Haemophilus spp. betalactamase producing or not (0.01-0.03) and M. catarrhalis (0.6-4). Activity of cefpirome on methicillin-sensitive staphylococci, was higher than other third generation cephalosporins (0.25-2) comparable to that of cephalotin and cefamandol. Methicillin-resistant strains should be considered as resistant. Pneumococci (0.01-0.03), except for penicillin-R strains, and streptococci A, B, C, G (0.01-0.06) were very susceptible. Enterococci were of low sensitivity or resistant. Among anaerobes, C. perfringens appeared often susceptible, and Bacteroides spp. resistant.