[In vitro antibacterial activities of carbapenems against clinical isolates]

Antibacterial activities of four carbapenems, imipenem, panipenem, meropenem, and biapenem, were determined using 353 strains belonging to 18 bacterial species which were isolated from clinical materials at Ehime University Hospital. The MIC values of these carbapenems against MRSA were widely distributed between 0.1 and 100 micrograms/ml, and MIC90 values of these 4 carbapenems were 25-50 micrograms/ml. Any of these carbapenems prevented the bacterial growth of enterobacteriaceae of 8 bacterial species excluding S. macrescens at concentrations of 1 microgram/ml or less. The MIC values against P. aeruginosa showed relatively wide distribution, being 0.39-25 micrograms/ml for imipenem, 0.2-25 micrograms/ml for panipenem, 0.1-12.5 micrograms/ml for meropenem, and 0.2-12.5 micrograms/ml for biapenem. From those results, it was confirmed that any of the carbapenems tested had a wide antibacterial spectrum and strong antibacterial activities.