COMPARATIVE STUDIES ON ACTIVITIES OF ANTIMICROBIAL AGENTS AGAINST CAUSATIVE ORGANISMS ISOLATED FROM PATIENTS WITH URINARY TRACT INFECTIONS (1996)

The frequencies of isolation and susceptibilities to antimicrobial agents were investigated on 680 bacterial strains isolated from patients with urinary tract infections (UTIs) in 10 hospitals during the period of June 1996 to May 1997. Of the above bacterial isolates, Gram-positive bacteria accounted for 30.4% and a majority of them were Enterococcus faecalis. Gram-negative bacteria accounted for 69.6% and most of them were Escherichia coli.<BR>Susceptibilities of several isolated bacteria to antimicrobial agents were as followed;<BR>1.Enterococcus faecalis<BR>Ampicillin (ABPC) showed the highest activity against E. faecalis isolated from patients with UTIs.Its MIC₉₀ was 1 μg/ml. Imipenem (IPM) and vancomycin (VCM) were also active with the MIC₉₀s of 2,μg/ml. The others had low activities with the MIC₉₀s of 16 μg/ml or above.<BR>2.Staphylococcus aureus including MRSA<BR>Arbekacin (ABK) and VCM showed the highest activities against both S. aureus and MRSA isolated from patients with UTIs. The MIC₉₀s of them were 1 or 2 μg/ml. The others except minocycline (MINO) had low activities with the MIC₉₀s of 32,μg/ml or above.<BR>3.Staphylococcus epidermidis<BR>ABK and VCM showed the strongest activities against S. epidermidis isolated from patients with UTIs. The MICs for all strains were equal to or lower than 2 μg/ml. Cefazolin (CEZ), cefotiam (CTM) and cefozopran (CZOP) were also active with the MIC₉₀s of 4 μg/ml. Compared with antimicrobial activities of cephems in 1995, the MIC₉₀s of them had changed into a better state. They ranged from 4 μg/ml to 16 μg/ml in 1996.<BR>4.Streptococcus agalactiae<BR>All drugs except MINO were active against S. agalactiae. ABPC, CZOP, IPM, and clarithromycin (CAM) showed the highest activities. The MICs for all strains were equal to or lower than 0.125 μg/ml. Tosufloxacin (TFLX) and VCM were also active with the MIC₉₀s of 0.5 μg/ml.<BR>5.Citrobacter freundii<BR>Gentamicin (GM) showed the highest activity against C. freundii isolated from patients with UTIs. Its MIC₉₀ was 0.5,μg/ml. IPM and amikacin (AMK) were also active with the MIC₉₀s of 1μg/ml and 2μg/ml, respectively. Cefpirome (CPR) and CZOP were also active with the MIC₉₀s of 8 gg/ml. The MIC₉₀s of the others were 16 μg/ml or above.<BR>6.Enterobacter cloacae<BR>IPM showed the highest activity against E. cloacae. The MICs for all strains were equal to or lower than 0.5μg/ml. The MIC₉₀s of ciprofloxacin (CPFX) and TFLX were 1μg/ml, the MIC₉₀ of AMK was 2 μg/ml, the MIC₉₀s of CZOP, GM and ofloxacin (OFLX) were 4μg/ml. The MIC50s of cephems except CEZ, cefmetazole (CMZ) and cefaclor (CCL) had changed into a better state in 1996, compared with those in 1995.<BR>7.Escherichia coli<BR>All drugs except penicillins and MINO were active against E. coli. Particularly CPR, CZOP and IPM showed the highest activities against E. coli. The MIC₉₀s of them were 0.125μg/ml or below. Among E. coli strains, those with low susceptibilities to cephems except CEZ, cefoperazone (CPZ), latamoxef (LMOX) and CCL have increased in 1996, compared with those in 1995.<BR>8.Klebsiella pneumoniae<BR>K. pneumoniae was susceptible to all drugs except penicillins, with the MIC₉₀s of 2 μg/ml or below. CPR had the strongest activity, the MICs for all strains were equal to or lower than 0.25μg/ml. Flomoxef (FMOX), cefixime (CFIX), CZOP and carumonam (CRMN) were also active with the MIC₉₀s of 0.125 μg/ml or below.<BR>9.Pseudomonas aeruginosa<BR>All drugs except quinolones were not so active against P.aeruginosa with the MIC₉₀s were 32μg/ml or above.