RESUMEN
The aim of this study was to detect extended-spectrum beta-lactamases [ESBL] in Enterobacteriaceae isolates in the intensive care unit [ICU] of Tlemcen hospital in north-western Algeria. Antimicrobial susceptibility testing, molecular typing, characterization of ESBL-encoding genes and the genetic environment, conjugation experiments and plasmid analysis were carried out. In all, 28 Enterobacteriaceae isolates were isolated from specimens recovered from patients in the ICU and 2 from surfaces of the unit. Of these, 11 isolates [4 Escherichia coti, 5 Klebsiellapneumoniae and 2 Enterobacter cloacae] produced ESBL of the CT-X-M-15 type. Molecular typing of the isolates showed the clonal nature of 4 K, pneumonlae isolates. The bla[CTMX-15] gene was genetically linked to insertion sequence ISEcp1B and was transferable by conjugation from 3 isolates. Regular monitoring of resistance mechanisms, the establishment of a prevention strategy, and more rational and appropriate use of antibiotics are needed