SURVEY OF THE SENSITIVITIES OF CLINICAL ISOLATES TO ANTIBACTERIAL AGENTS (ANNUAL REPORT)

Resarch groups were formed in 21 institutions nationwide to investigate carbapenem resistance. The activities of various antibacterial agents, principally carbapenems were tested against clinical isolates collected from these institutions. The broth microdilution method was used to determine the minimum inhibitory concentrations (MIC) of 17 antibacterial agents for 1,282strains of 11 bacterial species isolated at all institutions between October and December 1995. The results were as follows: 1. Carbapenems exhibited strong antibacterial activities against MSSA andStreptococcus pneumoniae.Their activities againstEnterococcus faecalis were comparable to that of ABPC. Carbapenems showed low activities against MRSA. 2. OFLX exhibited the greatest antibacterial activity againstHaemophilus influenzae, followed by MEPM. The antibacterial activities of the other carbapenems were comparable to those of FMOX and CTM. 3. The carbapenems showed high activities againstEscherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, andBacteroides fragilis group. Their activities were greater than that exhibited by other β-lactam antibacterial agents. The carbapenems also exhibited greater antibacterial activities againstSerratia marcescens than the other β-lactam antibacterial agents, but some resistant strains were detected. 4. The antibacterial activities of carbapenems againstPseudomonas aeruginosa were comparable to those of CAZ, AZT, AMK.