Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Infect Genet Evol. 2019 Apr;69:142-145. doi: 10.1016/j.meegid.2019.01.030. Epub 2019 Jan 23.
There has been an alarming health-related concern about the growth of New Delhi metallo-β-lactamase. The aims of this study include the phenotypic detection of β-lactamases and molecular characterization of NDM in Klebsiella pneumoniae isolates in Tehran, Iran. A total of 120 K. pneumoniae isolates were collected from hospitalized haemodialysis patients, Tehran, Iran from March 2014 to February 2017. Antibiotic susceptibility tests were conducted using Kirby-Bauer disc diffusion and Broth Microdilution methods according to Clinical and Laboratory Standards Institute guidelines. Metallo-β-lactamase was detected using the Combined Disc Diffusion Test (CDDT), and production of carbapenemase was screened using the Modified Hodge Test. NDM-producing K. pneumoniae strains were screened for the presence of mcr-1 gene, β-lactamase genes, and 16S rRNA methylase genes by Polymerase Chain Reaction and sequencing. Molecular typing of the strains was determined using Repetitive Sequence Based-PCR and Multilocus Sequence Typing. The bla gene was detected in 3 (2.5%) out of 120 isolates from dialysis patients. Also, the three isolates were positive for blabla extended-spectrum β-lactamase genes, armA type plasmid-mediated 16S rRNA methylase and CMY-type plasmid-mediated AmpC β-lactamase. The isolates were identified as MLST sequence type 147 (ST147). This is the first report of bla in K. pneumoniae strains, isolated in Iran.
新德里金属β-内酰胺酶的增长引起了人们对健康的严重关注。本研究的目的包括在伊朗德黑兰从住院血液透析患者中分离的肺炎克雷伯菌中检测β-内酰胺酶的表型和分子特征，并对其进行鉴定。2014 年 3 月至 2017 年 2 月，从伊朗德黑兰的住院血液透析患者中收集了 120 株肺炎克雷伯菌。根据临床和实验室标准协会的指南，使用 Kirby-Bauer 圆盘扩散和肉汤微量稀释法进行抗生素敏感性试验。使用联合圆盘扩散试验（CDDT）检测金属β-内酰胺酶，使用改良 Hodge 试验筛选碳青霉烯酶的产生。使用聚合酶链反应和测序筛选产 NDM 肺炎克雷伯菌菌株是否存在 mcr-1 基因、β-内酰胺酶基因和 16S rRNA 甲基化酶基因。通过重复序列基元 PCR 和多位点序列分型确定菌株的分子分型。从透析患者的 120 株分离株中，有 3 株（2.5%）检测到 bla 基因。此外，这 3 株分离株还对 bla 扩展谱β-内酰胺酶基因、armA 型质粒介导的 16S rRNA 甲基化酶和 CMY 型质粒介导的 AmpC β-内酰胺酶呈阳性。分离株被鉴定为 MLST 序列型 147（ST147）。这是首次在伊朗分离的肺炎克雷伯菌中发现 bla 基因的报道。
