Comparative studies on activities on antimicrobial agents against causative organisms isolated from patients with urinary tract infections (2000). III. Secular changes in susceptibility

The bacteria (Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Klebsiella spp. and Pseudomonas aeruginosa) isolated from patients diagnosed as having urinary tract infections (UTIs) in 10 institutions in Japan were supplied between August 2000 and July 2001. Then, the susceptibilities of these bacteria to various antimicrobial agents were examined, and the results were compared with those obtained between 1992 and 1999. Comparison was made by classifying strains isolated from patients into those in uncomplicated UTIs and those in complicated UTIs (including with or without indwelling catheter). E. faecalis showed good susceptibility to ampicillin (ABPC) and imipenem (IPM), and the MIC90s were 2 micrograms/ml. Also, E. faecalis showed good susceptibility to vancomycin (VCM). However, the MIC90, which was 2 micrograms/ml between 1992 and 1999, rose to 4 micrograms/ml in patients with complicated UTIs because the strains inhibited at 4 micrograms/ml increased more than before. The low susceptibility of S. aureus to arbekacin (ABK) in complicated UTIs, as shown in 1998 and 1999, recovered in 2000, and no strains inhibited at > or = 4 micrograms/ml were detected. E. coli showed good susceptibility to CTM (MIC90: 0.25-0.5 microgram/ml) and CZOP (MIC90: < or = 0.125 microgram/ml) and was not resistant to those. E. coli also showed good susceptibility to the other drugs except to penicillins. Decreases in susceptibility of E. coli to quinolones, ciprofloxacin (CPFX), and sparfloxacin (SPFX) were observed in the patients with complicated UTIs. The susceptibility of Klebsiella spp. to all drugs did not significantly change in 2000 and was generally good except to penicillins. Although the susceptibility of P. aeruginosa to carbapenems was notable, the MIC90 went up from 4 micrograms/ml to 16 micrograms/ml in complicated UTIs compared with those observed in the previous year.