ROLE OF PLASMIDS IN MEDIATING ANTIBIOTIC RESISTANCE AND EXTENDED – SPECTRUM BETA – LACTAMASE PRODUCTION IN ESCHERICHIA COLI

Abstract

This study was carried out in order to investigate the role of plasmids in mediating antimicrobial agents’ resistance in extended-spectrum beta-lactamase (ESBL) producing E. coli isolates collected from community acquired urinary tract infections in Gaza Strip. The results of the study showed that, out of 300 E. coli isolates collected during the year 2001, 11 (3.7%) of the isolates were ESBL-producers. When the susceptibility of the ESBL-producers to 12 antimicrobial agents was tested, high resistance especially, to amoxycillin (100.0%), cephalosporins (100.0%) and gentamicin (81.8%) was observed. Plasmid DNA analysis of the 11 ESBL-producing isolates revealed that, all the ESBL-producers harbored plasmids of different sizes. The results of plasmid transfer (by conjugation) showed that, all ESBL-producing trsnscojugants and resistance to various antimicrobial agents is plasmid associated.