[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (2004) II. Background of patients].

Six hundred six bacterial strains isolated from 490 patients diagnosed as having urinary tract infections (UTIs) in 14 institutions in Japan were collected between August 2004 and July 2005. The frequency of bacteria isolation stratified with patient clinical background was compared. The clinical background investigated included sex, age, type of infections, timing of antibiotics administration, and presence or absence of surgery affecting a decrease in defense against infection. The bacterial strains were stratified with the age and sex of the patients and the types of infections. In males, the number of patients aged less than 60 years was few and the complicated UTIs without indwelling catheter was observed most frequently. In females, the number of patients aged less than 60 years was comparatively more than in males. In all of ages except 0-19 and > or = 80 years, the ratio of the uncomplicated UTIs was high, accounting for 44.1-90.0% of all types of infections. In the present time, the bacteria most frequently isolated were Escherichia coli. Pseudomonas aeruginosa and Enterococcus faecalis also were relatively frequently isolated. E. coli most frequently isolated with the uncomplicated UTIs and P. aeruginosa and E. faecalis most frequently isolated with the complicated UTIs. With respect to the relation of these results to the age of the patients, in the uncomplicated UTIs, the isolation frequency of E. coli was the highest in all age groups except 0-19 years, accounting for 50% or higher. In the complicated UTIs without indwelling catheter, the isolation frequency of E. coli tended to be high in all age groups. In the complicated UTIs with indwelling catheter, P. aeruginosa were more frequently isolated. In comparison of causative bacteria in UTIs between before and after the administration of antibiotics, P. aeruginosa increased after the administration in any types of UTIs. In comparison of causative bacteria in UTIs with or without surgery, E. coli was more frequently isolated in the patients without surgery, while P. aeruginosa and E. faecalis were more frequently isolated in the patients with surgery in any UTIs.