Detection of New Delhi Metallo-β-lactamase-۱ amongPseudomonas aeruginosa isolated from adult and Pediatric patients inIranian hospitals

Background and Aim : Gram-negative bacteria cause an alarming level of resistance tocarbapenems by producing carbapenemases which can become a global epidemic. According to areport about Pseudomonas aeruginosa released by the World Health Organization in ۲۰۱۷,carbapenem resistance is classified as highest priority. The main objectives of the present studyare to evaluate the frequency of carbapenem resistance, detect Metallo-β-Lactamases and β-lactamases, identify the molecular characterization of blaNDM-۱ in Pseudomonas aeruginosaisolates, and report blaNDM-۱ for the first time among children in Iran. This study selected ۷۰clinical isolates from different cities of Iran during ۲۰۱۹–۲۰۲۰.Methods : Disk diffusion method and Minimum Inhibitory Concentration were employed to runantimicrobial susceptibility testing. In order to detect carbapenemases and Metallo-β-Lactamases,mCIM and CDDT were used, respectively. In addition, PCR technique and DNA sequencing wereutilized to identify and confirm the genes related to β-lactamases and Metallo-β lactamases(blaNDM, blaVIM, blaIMP, blaSIM, blaGIM, blaSPM, and blaKPC)Results : The highest resistance rates were observed for Meropenem ۶۷.۱% (۴۷) and Imipenem۶۵.۷% (۴۶) while the lowest resistance rate was observed for Piperacillin/Tazobactam ۳۵.۷% (۲۵).Of all isolates, ۵۵.۷% (۳۹) and ۵۴.۳% (۳۸) constituted carbapenemase-producing and MBLisolates, respectively. PCR results exhibited blaNDM-۱ ۲۱.۴%, followed by blaIMP ۷.۱% andblaVIM ۲.۹% of genes. Moreover, ۱.۴% of these isolates co-produced blaNDM-۱ and blaVIMgenes. These isolates did not comprise blaSIM, blaSPM, blaGIM, and blaKPC genes. Threeisolates of positive blaNDM-۱ isolates were notably detected among children.Conclusion : The results showed that Metallo-β-Lactamases, especially blaNDM-۱, were highlyprevalent among adults and children of Iran.

کلیدواژه ها:

Pseudomonas aeruginosa ، Carbapenem ، blaNDM-۱ gene ، Metallo-β-Lactamase genes