Clinical and molecular epidemiology of community-onset, extended-spectrum beta-lactamase-producing Escherichia coli infections in Thailand: a case-case-control study.

BACKGROUND

Extended-spectrum beta-lactamase (ESBL)-producing organisms, first identified in Germany in 1983, are now widely recognized as clinically relevant causes of infections in community.

METHODS

Our objective was to evaluate the clinical and molecular epidemiology of community-onset, extended-spectrum beta-lactamase (CO-ESBL)-producing Escherichia coli infections. We used a case-case-control study undertaken in a 450-bed, tertiary care hospital. Patients included case group (CG) I, which had confirmed CO-ESBL-producing E coli infections (n=46). Case group (CG) II (n=46) included patients with CO-non-ESBL-producing E coli infections. Controls (n=138) were patients without infections.

RESULTS

By multivariate analysis, diabetes (95% confidence interval [CI]: 1.9-13.2, P< .001), prior ESBL E coli colonization (<90 days) (95% CI: 1.2-67.8, P< .001), recent receipt of antibiotics (<90 days) (95% CI: 4.2-44.2, P= .004), and previous exposure to third-generation cephalosporins (95% CI: 2.2-16.4, P= .001) and fluoroquinolones (95% CI: 1.4-18.3; P= .003) were associated risks among CG I. Diabetes (95% CI: 1.6-15.4, P= .005), stroke (95% CI: 1.5-17.1, P= .001), and diarrhea (95% CI: 3.8-65.8, P= .001) were risks among CG II. Patients with CO-ESBL in CG I versus controls were more likely to die (30% vs 0%, respectively; P< .001), had prolonged hospital length of stay (8 vs 5 days, respectively; P< .001), and had higher hospitalization costs (median, US $528 vs $108, respectively; P< .001). The plasmid carrying the CTX-M-15 gene was identified in 13 of 25 (52%) available CO-ESBL-producing E coli isolates.

CONCLUSION

CO-ESBL-producing E coli is an emerging multidrug-resistant microorganism in Thailand. Patients with prior ESBL colonization and recent antibiotic exposures, especially to third-generation cephalosporins and fluoroquinolones, were at risk for CO-ESBL-producing E coli infection.