COMPARATIVE STUDIES ON ACTIVITIES OF ANTIMICROBIAL AGENTS AGAINST CAUSATIVE ORGANISMS ISOLATED FROM PATIENTS WITH URINARY TRACT INFECTIONS (2000): I. SUSCEPTIBILITY DISTRIBUTION

The bacterial strains isolated from patients diagnosed as having urinary tract infections (UTIs) in 10 institutions in Japan were supplied between the period of August 2000 and July 2001. Then, the susceptibilities of them to many kinds of antimicrobial agents were investigated. The number of them were 511 strains. The breakdown of these strains was Gram-positive bacteria as 29.0% and Gram-negative bacteria as 71.0%. Susceptibilities of these bacteria to antimicrobial agents were as follows; vancomycin (VCM), ampicillin (ABPC) and imipenem (IPM) showed strong activities against Enterococcus faecalis. No increase in lowsusceptible strains of E. faecalis observed against these antimicrobial agents. VCM showed a strong activity against MRSA preventing growth of all strains with 1μg/ml. In addition, the activity of arbekacin (ABK) was strong with the MIC90 of 2μg/ml against MRSA and prevented growth of all strains with 4μg/ml. ABK showed a strong activity against Staphylococcus epidermidis preventing growth of all strains with 0.5μg/ml. ABPC, cefotiam (CTM) and cefozopran (CZOP) also showed a relatively strong activity against S. epidermidis (MIC90: 4 to 8μg/ml). Against Escherichia coli, carbapenems showed high activities: meropenem (MEPM) prevented growth of all strains within 0.125μg/ml; IPM prevented growth of all strains with 0.25μg/ml. CZOP and CTM also showed strong activities against E. coli: MIC90 of CZOP was within 0.125μg/ml; MIC, c, and MIC90 of CTM were 0.25 and 0.5μg/ml, respectively. Quinolone resistant E. coli was detected at frequency of 14.0%, which was significantly higher than that in the last year. Almost all drugs showed strong activities against Klebsiella pneumoniae and Proteus mirabilis, and MEPM prevented growth of all strains within 0.125μg/ml. Against Pseudomonas aeruginosa, almost drugs were not so active. The MIC90 of carbapenems and gentamicin (GM) were 16μg/ml and those of all other drugs were more than 32μg/ml. Against Serratia marcescens, the MIC90 of IPM and GM were the lowest value being 2μg/ml, and that of MEPM was 4μg/ml.