Clinical impact of extended-spectrum β-lactamase-producing Enterobacteriaceae in patients with biliary tract infection.

BACKGROUND

Clinical outcomes associated with Gram-negative bacterial isolates with extended spectrum beta-lactamase (ESBL) in patients with biliary tract infection are largely unknown. The objective of the present study was to compare the demographics, risk factors, and clinical outcomes between patients with biliary tract infection caused by ESBL-producing and non-producing Klebsiella pneumoniae and Escherichia coli.

METHODS

Between February 2005 and August 2010, we collected 159 cases with biliary tract infection caused by K. pneumoniae and E. coli identified by blood or bile cultures obtained before endoscopic or surgical treatment performed at our institution. We also retrospectively collected the data of patients' demographic characteristics, co-morbid conditions, antimicrobial therapy, and clinical outcomes.

RESULTS

Among the 159 strains isolated, 21 strains (13.2 %) were positive for phenotypical ESBL-test. Sepsis was more common in ESBL-positive strains, but did not reach statistical significance (23.8 % for ESBL-positive strains and 9.4 % for ESBL-negative strains, P = 0.066). Thirty-day mortality was significantly higher in ESBL-positive strains (3/21, 14.3 %) compared to ESBL-negative strains (4/138, 2.9 %, P = 0.049). However, there were no significant differences in overall survival between ESBL-positive and ESBL-negative strains. By multivariate analysis, inadequate antimicrobial therapy (HR 4.06, 95 % CI 1.08-16.46, P = 0.049) and sepsis (HR 6.54, 95 % CI 1.26-33.85, P = 0.025) were independent and significant predictors of 30-day mortality.

CONCLUSION

ESBL status of bacterial isolates for patients with biliary tract infection caused by K. pneumoniae and E. coli has clinical impact, especially on the short-term outcomes of those patients.