Molecular Diagnostic of Drug Resistant Klebsiella Pneumoniae Isolates Containing SHV, PER and VEB Genes in Samples Collected from Patients in Tehran

Extended-spectrum beta-lactamase of SHV, PER and VEB types are considered as important and widely increasing resistance mechanisms to beta-lactamases in gram- negative pathogens. Also K. pneumonia species are able to produce extended-spectrum beta- lactamase (ESBLs). The aim of this study was to detect the prevalence of SHV, PER and VEB genes in ESBLs producing Klebsiella pneumoniae isolates which were collected from patients of different regions of Tehran city between January 2017 to January 2018 using PCR method. In this analytical- descriptive study, antibacterial susceptibility of 176 K. pneumonia isolates were defined to Cefepime, Ampicillin, Gentamicin, Cefalotine, Ceftazidime, Ciprofloxacin, Imipenem, Cefotaxime and Nitrofurantoin using disk diffusion method. In addition, confirmatory test for detecting ESBLs phenotypes was performed using Cefotaxime-Clavulanic acid combination disk. The presence of SHV, PER and VEB genes were assessed using PCR.
Results and Confirmatory phenotypic test showed that 56.81% of the isolates were ESBL positive. The prevalence of SHV, PER and VEB genes in K. pneumonia isolates was 34%, 13% and 17% respectively. In this study, the most resistance rate was observed to ampicillin (89%) and the lowest resistance rate was observed to imipenem (7%). High frequency of SHV, PER and VEB genes in ESBL producing isolates, indicates that these enzymes play important roles 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 spread.