Molecular identification of coding genes of beta-lactamase (CTX-M) in Klebsiella pneumoniae isolates from patients reffer to hospitals of Tehran city

Aim and Extended-spectrum beta-lactamase of CTX-M type is considered as an Important mechanism resistant to beta-lactamases in gram- negative pathogen and is widely increasing. Klebsiella pneumoniae species are able to produce extended-spectrum beta- lactamase (ESBLs). The aim of this study was to detect the prevalence of CTX-M gene in ESBLs produsing Klebsiella pneumoniae isolated form patients in different region of TEHRAN city from December2016 to july 2017 by using PCR method.
Material and In this analytical- descriptive study antibacterial susceptibility patterns of 176 Klebsiella pneumoniae tested to Cefepime, Ampicillin, Gentamicin, Amikacin, Cefalotine, Ceftazidime, Piperacillin, Ciprofloxacin, Imipenem, Cefotaxime , Nitrofurantoin, Trimethoprim using disk diffusion method. In addition, confirmatory test for detecting ESBLs phenotypes was performed using Cefotaxim-Clavulanic acid combination disk. The presence of CTX-M gene was assessed by using PCR.
Confirmatory phenotypic test showed 56.81% of the isolates were ESBL positive. The prevalence of CTX-M gene in isolated Klebsiella pneumoniae was 28%. In this study, the highest resistance was observed for ampicillin antibiotics (24.88%) and the least resistance to antibiotic imipenem (6.06).
High frequency of CTX-M gene in ESBL produsing isolates indicates that this enzyms plays an important role in resistance to beta lactam containing anti biotics. Therefore, proper infection control tools and appropriate therapeutic approaches in different parts of the hospitals are necessary to prevent their release.