Microbiological Characteristics of Unresolved Acute Uncomplicated Cystitis

This study sought to compare the antimicrobial susceptibility rates between acute uncomplicated cystitis patients with failed initial antimicrobial treatment, who were considered unresolved cases, and newly presenting acute uncomplicated cystitis patients without recent antimicrobial use within 3 months and to determine whether different treatment strategies should be applied according to recent antimicrobial exposure (RAE). Female acute uncomplicated cystitis patients with Escherichia coli growth, who visited our hospital's urology department from 2010 to 2014, were divided according to RAE. The antimicrobial susceptibility of E. coli was compared between the group with RAE and the group with no antimicrobial exposure (NAE) within 3 months. The total number of acute uncomplicated cystitis patients with E. coli growth was 259: 40 patients comprised the RAE group and 219 patients formed the NAE group. The mean age was significantly older and previous recurrent cystitis history was higher in the RAE group (p < 0.05). Furthermore, the antimicrobial susceptibility of E. coli to amoxicillin-clavulanic acid, cefotaxime, cefoxitin, ciprofloxacin, and trimethoprim-sulfamethoxazole was significantly lower in the RAE group, with susceptibility results of 64.7%/88.0% (RAE/NAE), 77.5%/89.0%, 79.4%/95.3%, 31.3%/64.2%, and 42.5%/70.6%, respectively. RAE was an independent factor for antimicrobial resistance. This study showed that antimicrobial susceptibilities were significantly lower in acute uncomplicated cystitis patients with failed initial antimicrobial treatment, who are defined as unresolved cases. Our results suggest that first-line antimicrobials might show poor efficacy in cases of unresolved, acute uncomplicated cystitis and alternative or secondary antimicrobials should be considered in these cases.