Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (2004). III. Secular changes in susceptibility

The bacteria (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella spp. and Pseudomonas aeruginosa) isolated from patients diagnosed as urinary tract infections (UTIs) in 14 institutions in Japan were collected between August 2004 and July 2005. The susceptibilities of these bacteria to various antimicrobial agents were measured. The bacteria were divided into 2 groups consisting of uncomplicated UTIs and complicated UTIs (with and without indwelling catheter) based on their isolation origins. The results were compared with those obtained between 1995 and 2003. The drug sensitivity of S. aureus in this year was similar to those in up to the previous year and S. aureus showed the best susceptibility to vancomycin (VCM) and arbekacin (ABK). The drug sensitivity of E. faecalis in this year also was similar to those in up to the previous year. The susceptibility of E. coli to cephems in this year was generally good and was similar to those in up to the previous year. MIC90 of cefozopran (CZOP) was the most stable and 0.125 microg/mL or less since 1995. The susceptibility of E. coli to cefpirome (CPR) and cefotiam (CTM) also was good but to cefaclor (CCL), cefixime (CFIX), and cefpodoxime (CPDX) was largely decreased in complicated UTI groups. The sensitivity of E. coli to carbapenems also was good but to carumonam (CRMN) tended to decrease. The susceptibility of E. coli to quinolones, however, has largely changed and has decreased since 2003 in uncomplicated UTIs and 2000 in complicated UTIs. That was suggested the development of the resistance to the drug. The susceptibility of Klebsiella spp. to cefazolin (CEZ), CTM, CCL, CPDX, and cefditoren (CDTR) decreased in the previous year and recovered to the year before the previous year in this year. The susceptibility of Klebsiella spp. to other cephems was stable since 1995, especially against CZOP, the highest sensitivity (MIC90: < or = 0.125 microg/mL) was maintained. The susceptibility of Klebsiella spp. to carbapenems and CRMN also was good. The susceptibility of Klebsiella spp. to aminoglycosides was lower than to CZOP but was stable since 1995. The susceptibility of P. aeruginosa was generally low and has largely changed against the majority of the agents since 1995. The susceptibility of P. aeruginosa isolated from uncomplicated UTIs has largely changed against ceftazidime (CAZ), cefsulodin (CFS), CZOP, imipenem (IPM), meropenem (MEPM), aztreonam (AZT), CRMN, gentamicin (GM), and tobramycin (TOB). The susceptibility of P. aeruginosa isolated from complicated UTIs has largely changed against CSF, CZOP, MEPM, GM, and ciprofloxacin (CPFX). The susceptibility of P. aeruginosa isolated from complicated UTIs has been stable against amikacin (AMK). For annual changes in MIC50, TOB and IPM had a relatively stable and high activity (MIC50: 0.5-2 microg/mL).