Characterization of Multidrug Resistant ESBL-Producing Escherichia coli Isolates from Hospitals in Malaysia

Abstract EN

The emergence of Escherichia coli that produce extended spectrum β-lactamases (ESBLs) and are multidrug resistant (MDR) poses antibiotic management problems.

Forty-seven E.

coli isolates from various public hospitals in Malaysia were studied.

All isolates were sensitive to imipenem whereas 36 were MDR (resistant to 2 or more classes of antibiotics).

PCR detection using gene-specific primers showed that 87.5% of the ESBL-producing E.

coli harbored the blaTEM gene.

Other ESBL-encoding genes detected were blaOXA, blaSHV, and blaCTX-M.

Integron-encoded integrases were detected in 55.3% of isolates, with class 1 integron-encoded intI1 integrase being the majority.

Amplification and sequence analysis of the 5′CS region of the integrons showed known antibiotic resistance-encoding gene cassettes of various sizes that were inserted within the respective integrons.

Conjugation and transformation experiments indicated that some of the antibiotic resistance genes were likely plasmid-encoded and transmissible.

All 47 isolates were subtyped by PFGE and PCR-based fingerprinting using random amplified polymorphic DNA (RAPD), repetitive extragenic palindromes (REPs), and enterobacterial repetitive intergenic consensus (ERIC).

These isolates were very diverse and heterogeneous.

PFGE, ERIC, and REP-PCR methods were more discriminative than RAPD in subtyping the E.

coli isolates.