Medical Experimental Center, General Hospital of Ningia Medical University, Yinchuan, Ningxia, 750004, China.
Medical Experimental Center, General Hospital of Ningia Medical University, Yinchuan, Ningxia, 750004, China; Ningxia Key Laboratory of Clinical and Pathogenic Microbiology, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, 750004, China.
Microb Pathog. 2024 Nov;196:106899. doi: 10.1016/j.micpath.2024.106899. Epub 2024 Aug 30.
This study aims to investigate the drug resistance, regulation mechanism of quorum sensing system, expression of related virulence genes, and epidemiological characteristics of carbapenem-resistant Pseudomonas aeruginosa (CRPA).In this study, Polymerase chain reaction amplification was performed to evaluate carbapenemase genes, OprD2 gene, quorum sensing system, and related virulence genes. Bacterial genotypes were analyzed using multilocus sequence typing and evolutionary analysis was conducted based on the goeBURST algorithm. The results demonstrated that a total of 47 CRPA strains were collected in this study, primarily from respiratory specimens in the ICU. Drug sensitivity results showed that the resistance rates of the 47 CRPA strains were highest for imipenem (97.87 %). The loss of OprD2 may be the main factor contributing to carbapenem resistance in our hospital's CRPA strains.All isolates tested positive for the quorum sensing system genes lasI and rhlI/R, and the virulence gene lasB was detected in all isolates, while the algD gene was detected in 19.15 % of the isolates. Among the 47 strains, 6 were untypeable, and the 41 strains with 28 different sequence types were clustered into three clonal complexes (BG1, BG2, and BG3).In conclusion, the CRPA isolates from our hospital exhibit high genetic diversity, with the deletion of the OprD2 gene possibly being the primary determinant of carbapenem resistance in Pseudomonas aeruginosa.Moreover, Las and RhI systems play a key role in quorum sensing signal system. Further research and development of drugs targeting quorum sensing signaling system may provide valuable guidance for the treatment of CRPA.
本研究旨在探讨耐碳青霉烯铜绿假单胞菌（CRPA）的耐药性、群体感应系统调控机制、相关毒力基因表达及流行病学特征。本研究采用聚合酶链反应扩增方法检测碳青霉烯酶基因、OprD2 基因、群体感应系统及相关毒力基因。采用多位点序列分型分析细菌基因型，基于 goeBURST 算法进行进化分析。结果表明，本研究共收集了 47 株 CRPA 菌株，主要来自 ICU 的呼吸道标本。药敏结果显示，47 株 CRPA 菌株对亚胺培南的耐药率最高（97.87%）。OprD2 的缺失可能是我院 CRPA 菌株碳青霉烯耐药的主要因素。所有分离株均检测到群体感应系统基因 lasI 和 rhlI/R 阳性，所有分离株均检测到毒力基因 lasB，而 algD 基因的检出率为 19.15%。47 株菌中 6 株不可分型，41 株具有 28 种不同序列型的菌株聚类为 3 个克隆复合体（BG1、BG2 和 BG3）。综上所述，我院分离的 CRPA 菌株具有较高的遗传多样性，OprD2 基因缺失可能是铜绿假单胞菌碳青霉烯耐药的主要决定因素。此外，Las 和 RhI 系统在群体感应信号系统中起关键作用。进一步研究和开发针对群体感应信号系统的药物可能为 CRPA 的治疗提供有价值的指导。
