Sensitivities of major causative organisms isolated from patients with acute uncomplicated cystitis against variousantibacterial agents: Results of subanalysis based on the presence of menopause

We investigated whether the presence of menopause influenced the species and distribution of causative bacteria isolatedfrom patients with acute uncomplicated cystitis (the most common urinary tract infection), and we also investigated thesensitivity of the isolated species to antibacterial agents. Using multivariate analysis, we also investigated risk factorsfor infection with quinolone-resistant Escherichia coli, because its frequency has increased and it is now a clinical problemin Japan. Six hundred and thirty-four strains were isolated from 489 premenopausal patients (mean age 32.3 ± 10.1years). Major causative bacteria detected were Escherichia coli (65.0 %), Enterococcus faecalis (12.0 %), Streptococcusagalactiae (5.5 %), and Klebsiella pneumoniae (1.6 %). From 501 postmenopausal patients (mean age 68.7 ± 10.29 years),657 strains were isolated, and the major causative bacteria detected were E. coli (61.5 %), E. faecalis (13.7 %), K.pneumoniae (5.2 %), and S. agalactiae (4.0 %). The sensitivities to fluoroquinolones (FQs) and cephems of E. coli isolatedfrom premenopausal patients were both ≥90 %, while the sensitivities to FQs of E. coli isolated from postmenopausalpatients were about 5 % lower. In regard to infection with quinolone-resistant E. coli (minimal inhibitory concentration oflevofloxacin [LVFX] ≥4 μg/mL), significant risk factors were observed in patients with more than two episodes ofcystitis within a year (p = 0.0002), patients to whom antibacterial agents were used previously for this episode of cystitis(p = 0.0175), and patients who had a history of FQ administration within 1 month. Although the species and distribution ofcausative bacteria of acute uncomplicated cystitis were the same regardless of the presence of menopause, the sensitivitiesto FQs of E. coli detected in postmenopausal patients were significantly lower than those in the premenopausal women. Themajor risk factors for infection with quinolone-resistant E. coli were a history of FQ administration and the morbidity ofcystitis rather than the menopausal status. It was considered that taking an appropriate history including the morbidity ofcystitis and history of FQ administration, and the appropriate selection of an antibacterial agent, would be important whenempirical therapy is required.