COMPARATIVE STUDIES ON ACTIVITIES OF ANTIMICROBIAL AGENTS AGAINST CAUSATIVE ORGANISMS ISOLATED FROM URINARY TRACT INFECTIONS (1989): I. SUSCEPTIBILITY DISTRIBUTION

The frequencies of isolation and susceptibilities to antimicrobial agents were investigated on 1,032 bacterial strains isolated from patients with urinary tract infections in 10 hospitals during the period of June 1989 to May 1990. Of the above total bacterial isolates, Gram-positive bacteria accounted for 30.8% and a majority of them were Enterococcus faecalis. Gram-negative bacteria accounted for 69.2% and most of them were Escherichia coli. 1.Enterococcus faecalis Imipenem (IPM) sho wed the highest activity against E. faecalis isolated from patients with urinary tract infections. The followings, ampicillin (ABPC) and vancomycin (VCM) showed potent activities, with the MIC90s of 2μg/ml. Piperacillin (PIPC), minocycline (MINO) and chloramphenicol (CP) were also active with the MIC90s of 8 μg/ml. The others were not so active with the MIC90s of 32 μg/ml or above. 2.Staphylococcus aureus VCM showed the high est activity against S. aureus with the MIC90 of 1μg/ml. Dicloxacillin (MDIPC) and arbekacin (ABK) were active with the MIC90s of 2μg/ml. MINO showed the MIC90 of 4μg/ml. All other agents except ciprofloxacin (CPFX) showed lower activity. 3.Staphylococcus epidermidis MINO showed the highest activity against S. epidermidis. Its MIC90 was 0.25μg/ml. The followings, ABK and VCM were also active with the MIC90s of 0.5μg/ml, 2μg/ml, respectively. The others except CPFX were not so active. 4. Coagulase-negative staphylococci (CNS) Most of the agents were active against CNS. IPM, ABK and MINO showed the highest activities with the MIC90s of 0.125μg/ml or below. MDIPC, cefazolin (CEZ), cefotiam (CTM) and VCM were also active with the MIC90s of 1μg/ml. Clindamycin (CLDM) showed lower activity, with the MIC90 of 128μg/ml. 5.Streptococcus agalactiae CEZ, cefuzonam (CZO N), IPM and CLDM showed the potent activity, all strains were inhibited at the MIC of 0.125μg/ml or below. The followings, cefmenoxime (CMX) and erythromycin (EM) were active with the MIC90s of 0.125μg/ml or below. PIPC and VCM were also active with the MIC90s 0.25μg/ml and 0.5μg/ml, respectively. Amikacin (AMK) showed lower activity. 6.Escherichia coli IPM, CTM, fl omoxef (FMOX), CMX, carumonam (CRMN), norfloxacin (NFLX), ofloxacin (OFLX) and CPFX showed the highest activities against E. coli. The MIC90s of them were 0.125μg/ml or below. Ceftazidime (CAZ) and CZON were also active with the MIC90s of 0.25μg/mi. Penicillins except mecillinam (MPC) were not so active showing the MIC90s of 32μg/ml or ab