In-vitro evaluation of cefpirome (HR 810), teicoplanin and four other antimicrobials against enterococci

Abstract

In-vitro activities of cefpirome (HR 810), a fourth generation cephalosporin, and teicoplanin were compared with those of ampicillin, piperacillin, and vancomycin against 56 clinical isolates of enterococci. Cefpirome had good activity with the MIC₉₀ and MBC₉₀ being 4 and 16 mg/l. Ampicillin and piperacillin had MBC₉₀ of 4 and 16 mg/l. Teicoplanin was extremely active with the MIC₉₀ being 1·6 mg/l while vancomycin had poor cidal activity with the MBC₉₀ being 16 mg/l. A decrease in activity of cefpirome was noted when the inoculum size was increased from 10³ to 10⁷ organisms per ml. Synergy was demonstrated against most Streptococcus faecium isolates with a combination of cefpirome and gentamicin or piperacillin. Against Str. faecalis, with a similar combination, synergy was seen in less than 50% isolates. No antagonism was noted with any of the antibiotic combinations.