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) showed 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 2 µg/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 highest activity against S. aureus with the MIC₉₀ of 1 µg/ml. Dicloxacillin (MDIPC) and arbekacin (ABK) were active with the MIC₉₀s of 2 µg/ml. MINO showed the MIC₉₀ of 4 µg/ml. All other agents except ciprofloxacin (CPFX) showed lower activity. 3. Staphylococcus epidermidis MINO showed the highest activity against S. epidermidis. Its MIC₉₀ was 0.25 µg/ml. The followings, ABK and VCM were also active with the MIC₉₀s of 0.5 µg/ml, 2 µg/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 0.125 µg/ml or below. MDIPC, cefazolin (CEZ), cefotiam (CTM) and VCM were also active with the MIC₉₀s of 1 µg/ml. Clindamycin (CLDM) showed lower activity, with the MIC₉₀ of 128 µg/ml. 5. Streptococcus agalactiae CEZ, cefuzonam (CZON), IPM and CLDM showed the potent activity, all strains were inhibited at the MIC of 0.125 µg/ml or below. The followings, cefmenoxime (CMX) and erythromycin (EM) were active with the MIC₉₀s of 0.125 µg/ml or below. PIPC and VCM were also active with the MIC₉₀s 0.25 µg/ml and 0.5 µg/ml, respectively. Amikacin (AMK) showed lower activity. 6. Escherichia coli IPM, CTM, flomoxef (FMOX), CMX, carumonam (CRMN), norfloxacin (NFLX), ofloxacin (OFLX) and CPFX showed the highest activities against E. coli. The MIC₉₀s of them were 0.125 µg/ml or below. Ceftazidime (CAZ) and CZON were also active with the MIC₉₀s of 0.25 µg/ml. Penicillins except mecillinam (MPC) were not so active showing the MIC₉₀s of 32 µg/ml or above. 7. Klebsiella pneumoniae FMOX, CMX, Cefixime (CFIX), IPM, CRMN and NFLX showed the highest activities against K. pneumoniae. The MIC₉₀s of them were 0.125 µg/ml or below. CZON and OFLX were also active with the MIC₉₀s of 0.25 µg/ml. Penicillins except MPC showed lower activities. All other agents were active with the MIC₉₀s of 4 µg/ml or below. 8. Enterobacter cloacae IPM and OFLX showed the highest activities against E. cloacae. The MIC₉₀s of them were 0.25 µg/ml. The followings, gentamicin (GM) and NFLX were active with the MIC₉₀s of 0.5 µg/ml. Penicillins and cephems generally showed lower activities. 9. Proteus mirabilis Most of the agents were active against P. mirabilis. Cephems were generally active with the MIC₉₀s in a range of ≦0.125 µg/m–4 µg/ml. CRMN, NFLX and CPFX were active with the MIC₉₀s of 0.125 µg/ml or below. However MPC and MINO were not so active with the MIC₉₀s of 32 µg/ml. 10. Serratia marcescens Most of the agents were not so active against S. marcescens. Comparatively, IPM and CPFX were active with the MIC₉₀s of 8 µg/ml and 16 µg/ml, respectively. Penicillins and cephems were not active with the MIC₉₀s of over than 256 µg/ml. 11. Pseudomonas aeruginosa Most of the agents showed lower activities against P. aeruginosa. CAZ and IPM showed the MIC₉₀s of 16 µg/ml, and IPM and CPFX showed MIC₅₀s of 1 µg/ml. Activities of penicillins were considerably lower.