In vitro activity of cefpirome (HR810) against antibiotic-resistant gram-positive and gram-negative bacteria including organisms with inducible resistance.

The activity of cefpirome (HR810) was compared with seven beta-lactam antibiotics against selected gram-positive and gram-negative bacteria. Cefpirome was the most active antibiotic tested against all groups of Enterobacteriaceae; 46% of the isolates of Pseudomonas aeruginosa were inhibited by less than or equal to 8 micrograms/ml of cefpirome. Fifty percent of the oxacillin-resistant Staphylococcus aureus isolates and 82% of the Streptococcus faecalis isolates were inhibited by less than or equal to 8 micrograms/ml of cefpirome. All Enterobacteriaceae and two of five P. aeruginosa isolates that were induced to produce beta-lactamase by prior exposure to cefoxitin remained susceptibile to cefpirome.