Extended Spectrum β-Lactamase in Escherichia coli and Klebsiella pneumoniae: Trends in Hematopoietic Stem Cell Transplant Recipients

Objectives: We conducted a survey of extended spectrum ?-lactamase (ESBL) among infectious Escherichia coli and Klebsiella pneumoniae clinical isolates in the Bone Marrow Transplant Centre of Tunisia during a period of 10 years (from 2002 to 2011). Methods: Bacterial identification was carried on the basis of biochemical characteristics and API identification systems. Antibiotic susceptibility was tested by disc diffusion method on Muller-Hinton agar. Results: During the study period, 34.5% of 142 K. pneumoniae strains and 11.46% of 218 E. coli strains were ESBL producing. An increasing trend was observed for ESBL production in the selected bacteria. Conclusion: Screening for ESBL poduction among infectious K. pneumoniae and E. coli strains is paramount to guide the use of antimicrobial agents for the treatment of these pathogens in the hematopoietic stem cell transplant recipients population.