Introduction: Recurrent urinary tract infections (UTIs) are a frequent health problem and a common reason for treatment resistance.
Objectives: The purpose of the study was to evaluate the etiology of community‑ acquired lower recurrent UTI and bacterial antibiotic susceptibility.
Patients and methods: A total of 796 microbiological urine cultures from 332 patients (280 women and 52 men) treated in a single nephrology outpatient department in central Poland in years 2016 to 2018 were analyzed. The most frequent species responsible for recurrent lower UTI were identified and the susceptibility of all the microbes to specific antibiotics was assessed. The patients' kidney function and inflammation parameters were evaluated.
Results: The median (interquartile range [IQR]) age of the patients was 65 (59-77) years (women, 69 [57-78] years; men, 67 [62-77] years), median (IQR) glomerular filtration rate was 56.6 (40.2-81.3) ml/min/1.73 m2 with median (IQR) C‑ reactive protein concentration of 3.2 (1.5-7.0) mg/l. There were 43 bacterial species identified: 24 gram‑positive and 19 gram-negative. The analyzed urine cultures contained 977 microbial samples (563 gram‑negative bacteria, 408 gram-positive, 6 fungi). The most common bacteria was Escherichia coli (39.6%) which showed 100% susceptibility to carbapenems, 98.9% to amikacin, 96.5% to piperacillin / tazobactam, and 94.3% to gentamicin. With regard to oral antibiotics, its highest susceptibility was to fosfomycin 95.5%, nitrofurantoin 85.5%, and cefuroxime 82.3%. In 39.9% of cases, E. coli was resistant to fluoroquinolones and in 46.6% to trimethoprim / sulfamethoxazole.
Conclusions: The most frequently occurring bacteria causing recurrent lower UTI are characterized by significant resistance to the antimicrobial therapy recommended as the first‑ line treatment: fluoroquinolones and trimethoprim / sulfamethoxazole. It seems that the first choice in the treatment of lower UTIs should be: fosfomycin, nitrofurantoin, or cefuroxime.