Pharm Sci. 2016;22(4):279-284 doi: 10.15171/PS.2016.43
Characterization of Antimicrobial Resistance Pattern
and Molecular Analysis among Extended Spectrum β-Lactamase-Producing Escherichia
Background: Infection is a serious problem in medicine and
appropriate antibiotic therapy is very important. Because of broad spectrum
activity and low toxicity of β-lactam antibiotics, they are the most commonly
used drugs. But, bacterial resistance to β-lactam antibiotics, has been
considered as the global healthcare concern. The aim of study was to evaluate
the antimicrobial resistance pattern and molecular characterization among
ESBL-producing Escherichia coli isolated from patients with diarrhea
admitted to a hospital in Ilam, Iran.
Methods: Totally, fifty E. coli isolates were
investigated. Confirmatory tests for phenotypic detection of ESBLs
were performed. Molecular identification of the blaTEM and blaSHV
genes was carried out by PCR method. To identify genetic relatedness among
isolates, Randomly Amplified Polymorphic DNA (RAPD) analysis was performed.
Results: The antibiotic susceptibility results showed that the
most effective antibiotic was imipenem and minimum effect was related to
gentamicin. Thirty-one isolates (62%) were ESBL-producing organisms according
to phenotypic method. The distribution of blaTEM and blaSHV genes
among ESBL-producing isolates were 20 (64.5%) and 6 (19.3%), respectively.
RAPD-PCR typing among isolates gave us eight different types. Twelve isolates
were clustered in genotype A and all of them were ESBL-producer.
Conclusion: The present study showed noticeable incidence of
ESBL-producing E. coli isolated from outpatients and hospitalized
patients with diarrhea. Therefore, it seems that constant supervision is
crucial to monitor the ESBL-producing microorganisms in hospitals and