Molecular Identification of Extended- Spectrum β-lactamase Genes in Klebsiella pneumoniae Strains by Multiplex PCR in Arak, Iran

One of the enzymes that is produced by Gram negative bacteria is Extended spectrum-β-lactamases (ESBLs) which was first described in the 1980s. This study aims at identifying three common genes (blaTEM, blaSHV and blaCTX-M) in Klebsiella pneumoniae isolated from patients in Arak, Iran.

A total number of 112 isolates were selected during 2012-2013. To identify phenotypic specifications, Combination Disk Method based on CLSI guidelines. The ESBL’s genotype was analyzed by multiplex PCR and DNA sequencing.

Among 10 examined antibiotics, the most resistant and susceptible antibiotics were ampicillin and imipenem, respectively. The phenotypic determination of ESBL showed that 46.42% of isolates produced ESBL. The molecular survey of genes showed that 35.89% had CTX-M, 5.12% had both CTX-M and TEM and 2.56% had TEM, SHV, CTX-M.

According to the findings, the high prevalence (73.07%) of ESBL producing K. pneumoniae was observed with a new pattern of blaCTX-M distribution differed from other countries.