A retrospective analysis of risk factors and outcomes in patients with extended-spectrum beta-lactamase-producing Escherichia coli bloodstream infections.

OBJECTIVE

Risk factors and outcomes associated with extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) bloodstream infections (BSI) are not yet fully understood.

METHODS

This was a retrospective analysis of patients with E. coli BSI treated over a 4-year period. The characteristics of bacteremia caused by ESBL-producing versus non-ESBL-producing E. coli were compared. Factors influencing mortality were also assessed.

RESULTS

Of 554 eligible patients, 58.9% developed ESBL-producing E. coli. Multivariate analysis showed that urinary tract infections, stomach tube catheterization, and prior cephalosporin exposure were independent risk factors for the emergence of ESBL-producing E. coli BSI. No significant differences in 30-day mortality were seen in patients with BSI caused by ESBL-producing or non-ESBL-producing E. coli (11.1% vs. 9.2%; P=0. 642). Factors independently associated with a higher risk of mortality were previous carbapenem exposure, high APACHE II score, and respiratory tract origin.

CONCLUSIONS

This study showed that prior UTIs and previous cephalosporin exposure represent significant risk factors for the development of ESBL-producing E. coli BSI. Previous carbapenem exposure, high APACHE II score, and a respiratory tract origin were seen to be independent mortality risk factors in patients with E. coli BSI.