Background: Urinary tract infection (UTI) is the most common infection associated with antibiotic misuse. Catheter-associated UTI (CAUTI) is the largest reservoir of nosocomial antibiotic-resistant pathogens, including Pseudomonas aeruginosa. Health-care associated urinary tract infection is also a known risk factor for antibiotic-resistant bacteria, and an important entity that has yet to be characterized. The aim of our study was to determine risk factors for fluoroquinolone resistance among hospitalized patients with pseudomonal UTIs and to see if there was a significant difference in resistance between those with health-care associated and community acquired infection, as well as those with CAUTI to those without catheters. This will ultimately facilitate determination of inpatient populations with UTI who will benefit from empiric anti-pseudomonal coverage other than fluoroquinolones.
Methods: We performed a retrospective chart review of all patients hospitalized with pseudomonal bacteuria from June 30, 2014 to June 30, 2015. Data collection included demographic factors, CAUTI criteria, and health-care associated risk factors. We used the definition of CAUTI from the center for disease control, and health-care associated UTI was extrapolated from criteria used for pneumonia as occurring in patients hospitalized for 2 or more days within past 90 days of infection; residing in a long-term care facility; who received intravenous antibiotics, chemotherapy, or wound care within the past 30 days of infection; or who attended a hospital or hemodialysis clinic. We analyzed fluoroquinolone resistance rates between those with CAUTI and no urinary catheters, as well as those with health-care associated risk factors and those with community acquired UTIs.
Results: A total of 270 patients were analyzed. Health-care associated UTI accounted for 221 infections (82%) and community associated accounted for the other 49 cases (18%). 165 (61%) met definition for CAUTI and 105 (39%) were not catheter associated. The rate of fluoroquinolone resistance was significantly higher in CAUTI patients as compared to patients without CAUTI (26% vs 15%, p=0.036). There was no difference in fluoroquinolone resistance in patients with health-care associated infection and those with community acquired (23 vs 18%, p = 0.514). Overall fluoroquinolone resistance was found to be 22%, n=59.
Conclusions: This study shows that there are non-CAUTI health-care associated UTIs, which have a lower resistance to fluoroquinolones. Patients with pseudomonal CAUTI have an increased risk for fluoroquinolone resistance and may benefit from empiric coverage with alternative anti-pseudomonal agents. Interestingly, health care association alone is not associated with an increased fluoroquinolone resistance compared to community-acquired. This study also reveals a unique subset of community acquired pseudomonal UTIs associated with catheter use that have no health-care associated risk factors.