Annual changes in susceptibility of clinical isolates to biapenem

Abstract

Annual changes in susceptibility of biapenem (BIPM), a new injectable carbapenem, against 1, 032clinical strains (14 species) including Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli, Pseudomonas aeruginosa, etc., were determined by agar dilution. Strains were isolated from patients in the Nagasaki University Hospital from January 1994 to December 1996. Comparison of annual changes of MIC₅₀ and MIC₉₀ against S. aureus including methicillin-resistant strains, S. pneumoniae including penicillin-resistant strains, Streptococcus pyogenes, Enterococcus faecalis, E. coli, Klebsiella pneumoniae, Enterobacter cloacae, Proteus mirabilis, Acinetobacter baumannii, and Moraxella catarrhalis did not show increased resistance. Staphylococcus epidermidis and Serratia marcescens showed a slight increase in carbapenem-resistant strains, judging from MIC₅₀. Although P. aeruginosa also showed an increase in carbapenem-resistant strains by the comparison of MIC₉₀, the tendency toward BIPM resistance against this species was lower than those of other carbapenems. Among Haemophilus influenzae isolated in 1996, some strains were resistant strains toβ-lactams including carbapenems, so we must note this tendency.