Resistance and clonality in Escherichia coli and Klebsiella spp. and relationship with antibiotic consumption in major Lebanese hospitals.

OBJECTIVES

Extended-spectrum β-lactamases (ESBLs) are increasingly detected globally among Escherichia coli and Klebsiella spp. Studies show a link between inappropriate use of antibiotics and resistance. In this study, the profiles of ESBLs in E. coli and Klebsiella spp. isolated from three Lebanese hospitals and their relationship to antibiotic consumption were determined.

METHODS

A total of 300 E. coli and 91 Klebsiella spp. isolates resistant to third- or fourth-generation cephalosporins were collected between May 2011 and December 2012. Antibiotic susceptibility and consumption data were also collected from 2010-2012. Double-disk synergy and Etest ESBL assays were performed, followed by PCR for ESBL genes. Pulsed-field gel electrophoresis (PFGE) was performed for representative isolates. Statistical analysis for consumption and susceptibility data over 3 years was performed.

RESULTS

Similar to other Lebanese studies, CTX-M-15 was predominant. Among the Klebsiella spp. isolated in hospitals 1 and 2, 43% harboured four different ESBLs. Eight Klebsiella spp. and fourteen E. coli pulsotypes were detected, showing genetic diversity among isolates. A significant correlation was detected between total use of antimicrobial agents and resistance to various antibiotics. A correlation was also detected between use of penicillins and resistance to aztreonam, ceftazidime and ciprofloxacin, and use of third- and fourth-generation cephalosporins and resistance to ceftazidime, cefuroxime, cefoxitin and ciprofloxacin in Klebsiella spp. (P<0.05).

CONCLUSIONS

This study shows the predominance of CTX-M-15 among cephalosporin-resistant E. coli and Klebsiella spp. in Lebanese hospitals. It also shows that the heightened use of antibiotics could be a driving factor for resistance emergence.