CEFPIROME (HR 810), A NEW CEPHALOSPORIN - AN INVITRO INVESTIGATION

Using the standard agar dilution method we compared the in vitro activity of cefpirome (HR 810) with other broad spectrum antibiotics against clinical isolates of Enterobacteriaceae (478 strains), Pseudomonas aeruginosa (91), Xanthomonas maltophilia (27), Acinetobacter (36), Aeromonas hydrophila (28), Weeksella (1), staphylococci (361) and enterococci (50 strains). Against members of Enterobacteriaceae, Acinetobacter and A. hydrophila, cefpirome showed excellent activity with mean inhibitory concentrations required to inhibit 50% of strains (MIC50) ranging from < 0.03 to 2.0 mg/L, and MIC90 values ranging from 0. 12 to 4.0 mg/L. 87% of P. aeruginosa isolates had an MIC of 4.0 to 16.0 mg/L. However, only 37% of X. maltophilia had an MIC of < 16.0 mg/L. All the 154 isolates of methicillin-susceptible Staphylococcus aureus were inhibited by cefpirome less-than-or-equal-to 1.0 mg/L, whereas 53% of methicillin-resistant S. aureus had an MIC of less-than-or-equal-to 16.0 mg/L. Of the 50 isolates of enterococci tested, 48 (96%) were inhibited by cefpirome less-than-or-equal-to 16.0 mg/L Against Enterobacteriaceae the activity of cefpirome was superior to that of the other drugs tested, including ceftazidime, aminoglycosides and imipenem. The in vitro activity of cefpirome was superior or comparable to that of other antibiotic agents tested against methicillin-susceptible S. aureus, coagulase-negative staphylococci and enterococci.