[In vitro antibacterial activity of a new cephalosporin: cefpirome (HR 810). Comparison with ceftriaxone, cefotaxime, latamoxef and ceftazidime].

In vitro activity of a new cephalosporin, cefpirome (HR 810) was tested using an agar dilution procedure against 393 hospital bacterial isolates. Results were compared to those obtained with ceftriaxone, cefotaxime, latamoxef and ceftazidime. Cefpirome was the most active drug against oxacillin-susceptible staphylococci and the only drug with activity against streptococci D (MIC 90%: 7 mg/l). Against Enterobacteriaceae strains with varying degrees of resistance to cephalosporins, results varied across species: activity of cefpirome was greater than that of the four other drugs for E. cloacae and C. freundii, similar to that of ceftriaxone for E. coli, S. marcescens, P. morganii and Salmonella sp., inferior to that of latamoxef for P. stuartii. However, against all Enterobacteriaceae strains as a whole, cefpirome proved the most active of the five agents tested (99.1% of strains inhibited by 4 mg/l) as a result of its greater activity against strains with resistance to second generation cephalosporins or cefotaxime. Cefpirome in a concentration of 4 mg/l inhibited 50% of tested P. aeruginosa strains (MIC 90%; 13 mg/l) and was inferior only to ceftazidime (MIC 90%: 4 mg/l). However, cefpirome exhibited no activity against A. calcoaceticus and L. monocytogenes.