Poor Clinical Outcomes Associated with Community-Onset Extended-Spectrum Cephalosporin-Resistant Enterobacteriaceae Urinary Tract Infections

BACKGROUND: Urinary tract infections (UTIs) are the most common bacterial infection among adults in the community. Recent data suggest an increase in bacterial resistance to first line antibiotics used for UTI, though the impact on clinical outcomes is unclear. The objective of our study was to determine clinical outcomes associated with community-onset extended-spectrum cephalosporin-resistant (ESC-R) Enterobacteriaceae (EB) UTI. METHODS: A retrospective cohort study was conducted in a large health system from 2010 to 2013. All patients presenting to an emergency department or outpatient clinic with UTI due to EB were included. Exposed subjects were those with an EB demonstrating resistance to an ESC (ceftriaxone or ceftazidime). Unexposed subjects were those with ESC-susceptible EB UTIs and were matched to cases 1:1 based on study year. Multivariable logistic regression analyses were performed to evaluate the association between ESC-R EB UTI and 1) clinical failure (defined as ongoing symptoms, repeat positive culture, or need for additional antibiotics within 7 days); 2) inappropriate initial antibiotic therapy (IIAT) (defined as failure to receive an antibiotic to which the organism was susceptible within 48 hours of presentation). RESULTS: A total of 302 patients with community-onset EB UTI were included. On multivariable analyses, a UTI with an ESC-R EB was significantly associated with clinical failure (odds ratio [OR] 5.12, 95% confidence interval [CI] 2.79–9.39, P < 0.01). Other variables independently associated with clinical failure included presence of pyelonephritis at the time of UTI diagnosis (OR 2.15, 95% CI 1.14–4.03, p 0.02) and infection with Citrobacter species (OR 29.56, 95% CI 4.46–195.91, P < 0.01). ESC-R EB UTI was also associated with IIAT on multivariable analysis (OR 3.73, 95% CI 2.25–6.21, P < 0.01). CONCLUSION: Community-onset UTI due to an ESC-R EB organism is associated with a significantly increased risk of clinical failure, which may be due in part to the use of inappropriate initial antibiotic therapy. Further studies are needed to determine which patients in the community are at high risk for drug-resistant infection to help inform prompt urine culture ordering and appropriate antibiotic prescribing for ESC-R EB. DISCLOSURES: All authors: No reported disclosures.