Prevalence of SHV β-lactamases in Escherichia coli

Abstract

Resistance to β-lactam antibiotics by Gram-negative bacteria, especially Escherichia coli, is a major public health issue worldwide, and is often caused by the production of β-lactamase enzymes. Specifically, extended-spectrum β-lactamases (ESBLs), which cannot be diagnosed by phenotypic tests recommended by the Clinical and Laboratory Standards Institute (CLSI), are often produced. In this study, the use of designed primers with high ability to detect the sub family SHV gene was preferred. We focused on evaluating the prevalence of extended-spectrum β-lactamases using the disk diffusion method and confirmatory test (combined disk), as well as polymerase chain reaction (PCR) for the following gene (SHV). Our findings indicate that the prevalence of ESBLs in Iran is rising, which may lead to the ineffective treatment of these infections using β-lactam antibiotics. The development of non-phenotypic diagnostic methods capable of detecting β-lactamase enzymes is essential for the control of resistant strains as well as successful treatment through the administration of an appropriate β-lactam drug. Key words: Escherichia coli, beta lactamase enzymes, SHV-type extended spectrum beta-lactamases.