Impact of Extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae on the Outcome of Community-onset Bacteremic Urinary Tract Infections

BACKGROUND/PURPOSE: The number of community-onset bacteremic urinary tract infections (UTIs) caused by Escherichia coli and Klebsiella pneumoniae is increasing. However, the impact of extended-spectrum beta-lactamase (ESBL)-producing E. coli and K. pneumoniae (ESBL-EK) on bacteremic UTI outcomes is unknown. The aim of this study was to retrospectively analyze the impact of ESBL-EK on community-onset bacteremic UTIs. METHODS: Of the 58 patients enrolled, 12 suffered from ESBL-EK-caused community-onset bacteremic UTIs. Patients were categorized into ESBL (n=12) and non-ESBL (n=46) groups. Diagnosis was based on findings of concurrent bacteremia and bacteriuria caused by the same pathogen on admission. RESULTS: The ESBL group had significantly more male patients (66.7% vs. 23.9%; p=0.005), indwelling urinary catheters (41.7% vs. 6.5%; p=0.002), patients admitted from other healthcare facilities (50.0% vs. 8.7%; p=0.001), and patients with higher Acute Physiology and Chronic Health Evaluation II scores (23.3 +/- 7.1 vs. 15.9 +/- 6.3; p=0.001) and intensive care unit admissions (41.7% vs. 4.4%; p=0.003) than the non-ESBL group. Multiple logistic regression analysis revealed that male gender (odds ratio = 9.2; 95%, confidence interval = 1.7-50.6) and healthcare facility residency (odds ratio = 15.5; 95% confidence interval = 2.4-98.9) were independent risk factors for ESBL-producer infections among bacteremic UTIs. Although the mortality rate of both groups was similar (8.3% vs. 4.4%; p=0.403), the ESBL group had longer hospital stays (16.3 +/- 9.3 days vs. 7.9 +/- 5.2 days; p=0.010) and higher antibiotic costs (615.1 +/- 423.5 USD vs. 252.8 +/- 269.2 USD, p=0.014). CONCLUSION: Male gender and healthcare facility residency are risk factors for ESBL-producer infections among patients with community-onset bacteremic UTIs. Patients with bacteremic UTIs caused by ESBL-EK also have prolonged hospital stays and higher antibiotic costs. Early detection of ESBLs and appropriate antibiotic coverage are likely to shorten hospital stays and reduce medical costs.