Department of Microbiology, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran.
Department of Infectious and Tropical Diseases, Tehran University of Medical Sciences, Tehran, Iran.
Mol Biol Rep. 2022 Jun;49(6):4769-4776. doi: 10.1007/s11033-022-07328-x. Epub 2022 Jun 3.
The objective of the current study is to evaluate the phenotypic and molecular characterization of ESBL/AmpC- and carbapenemase-producing K. pneumoniae isolates in Iran.
From October 2018 until the end of April 2020, different clinical samples were collected and K. pneumoniae isolates were identified using conventional biochemical tests and PCR assay. Antibiotic susceptibility pattern was determined using the Kirby-Bauer disk diffusion method. Modified Hedge Test (MHT) was applied to the identification of carbapenemase-producing K. pneumoniae. ESBL and AmpC-producing K. pneumoniae were detected using Double Disc Test (DDT) and Disc Potentiation Test (DPT), respectively. The presence of carbapenemase, ESBL, and AmpC encoding genes was screened by Polymerase Chain Reaction (PCR) assay.
A total of 100 K. pneumoniae isolates were collected. K. pneumoniae isolates had the highest resistance rate to cefazolin (66%) and cefotaxime (66%). Meropenem and amikacin with sensitivity rates of 76% and 69% were the most effective antimicrobial agents on K. pneumoniae isolates. It was found that 12 (12%), 27 (27%), and 9 (9%) K. pneumoniae isolates were positive in MHT, DDT, and DPT tests, respectively. Among the carbapenemase-encoding genes, bla (24%) and bla (13%) genes had the highest frequency, while bla and bla genes were not detected among K. pneumoniae isolates. bla (48%) and bla (8%) genes had the highest frequency among ESBL and AmpC β-lactamase-encoding genes, respectively.
It is vital to adopt effective control strategies for K. pneumoniae infections and ensure rapid identification of antibiotic resistance profile.
本研究的目的是评估伊朗产 ESBL/AmpC-和碳青霉烯酶型肺炎克雷伯菌的表型和分子特征。
从 2018 年 10 月至 2020 年 4 月底，采集不同的临床样本，使用常规生化试验和 PCR 法鉴定肺炎克雷伯菌分离株。采用 Kirby-Bauer 纸片扩散法测定抗生素敏感性模式。采用改良 Hedge 试验（MHT）鉴定产碳青霉烯酶肺炎克雷伯菌。采用双纸片扩散试验（DDT）和纸片增效试验（DPT）检测 ESBL 和 AmpC 型肺炎克雷伯菌。采用聚合酶链反应（PCR）法筛选碳青霉烯酶、ESBL 和 AmpC 编码基因。
共收集 100 株肺炎克雷伯菌。肺炎克雷伯菌对头孢唑林（66%）和头孢噻肟（66%）的耐药率最高。美罗培南和阿米卡星对肺炎克雷伯菌的敏感性率分别为 76%和 69%，是最有效的抗菌药物。MHT、DDT 和 DPT 试验中，12（12%）、27（27%）和 9（9%）株肺炎克雷伯菌阳性。在碳青霉烯酶编码基因中，bla（24%）和 bla（13%）基因的频率最高，而肺炎克雷伯菌中未检测到 bla 和 bla 基因。bla（48%）和 bla（8%）基因在 ESBL 和 AmpCβ-内酰胺酶编码基因中频率最高。
采取有效的控制策略来控制肺炎克雷伯菌感染，并确保快速鉴定抗生素耐药谱至关重要。
