Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (2001). 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 September and December 2001. Then, the susceptibilities of them to a variety of antimicrobial agents were investigated. The number of them were 496 strains. The breakdown of these strains was Gram-positive bacteria as 29.6% and Gram-negative bacteria as 70.4%. Susceptibilities of these bacteria to antimicrobial agents were as follows; against Staphylococcus aureus, vancomycin (VCM) showed a strong activity, and this drug also had a strong activity against MRSA in preventing growth of all strains at 1 microgram/mL. In addition, arbekacin (ABK) showed strong activity with the MIC90 of 2 micrograms/mL against MRSA and prevented growth of all strains at 4 micrograms/mL. ABK also showed a strong activity against Staphylococcus epidermidis in preventing growth of all strains at 0.5 microgram/mL. Ampicillin (ABPC) and cefozopran (CZOP) showed a relatively strong activity against S. epidermidis (MIC90: 8 micrograms/mL). ABPC, imipenem (IPM), and VCM showed strong activities against Enterococcus faecalis. No increase of low-susceptible strains in E. faecalis was observed against these antimicrobial agents. Against Escherichia coli, carbapenems showed the highest activities: meropenem (MEPM) prevented growth of all strains at 0.25 microgram/mL; IPM prevented growth of all strains at 0.5 microgram/mL. CZOP and cefotiam (CTM) also showed strong activities against E. coli: MIC90 of CZOP was within 0.125 microgram/mL; MIC90 of CTM was within 0.5 microgram/mL. Quinolone-resistant E. coli was detected at frequency of 9.3%, which was lower than that in the last year, and was higher level than those in up to 1999. MEPM showed the strongest activity against Citrobacter freundii in preventing growth of all strains at 0.125 microgram/mL. Almost all drugs showed strong activities against Klebsiella pneumoniae and Proteus mirabilis, and MEPM prevented growth of all strains within 0.125 microgram/mL. Against Serratia marcescens, the MIC90 of gentamicin (GM) was the lowest value being 2 micrograms/mL, and those of IPM and carumonam were 8 and 16 micrograms/mL, respectively. Against Pseudomonas aeruginosa, almost all drugs were not so active. The MIC90 of GM was 8 micrograms/mL, those of IPM and amikacin were 16 micrograms/mL, and those of all other drugs were over than 32 micrograms/mL.