Iranian Social Security Organization, Urmia, Iran.
Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, 1449614535, Iran.
Mol Biol Rep. 2022 Sep;49(9):8281-8289. doi: 10.1007/s11033-022-07640-6. Epub 2022 Jun 3.
Understanding the mechanisms of antibiotic resistance is important for designing new therapeutic options and controlling resistant strains. The goal of this study was to look at the molecular epidemiology and mechanisms of resistance in carbapenem-resistant Pseudomonas aeruginosa (CRPA) isolates from Tabriz, Iran.
One hundred and forty P. aeruginosa were isolated and antibiotic susceptibility patterns were determined. Overproduction of AmpC and efflux pumps were discovered using phenotypic techniques. Polymerase chain reaction (PCR) was used to determine the presence of carbapenemase-encoding genes. In addition, the expressions of OprD and efflux pumps were evaluated by the Real-Time PCR. Random amplified polymorphic DNA typing (RAPD) was performed for genotyping.
Among 140 P. aeruginosa isolates, 74 (52.8%) were screened as CRPA. Overexpression of efflux systems was observed in 81% of isolates, followed by decreased expression of OprD (62.2%), presence of carbapenemase genes (14.8%), and overproduction of AmpC (13.5%). In most isolates, carbapenem resistance was multifactorial (60.8%). According to our results, the prevalence of CRPA is at alarming levels. Overexpression of efflux systems was the most common mechanism of carbapenem resistance.
Most isolates may originate in patients themselves, but cross-infection is possible. Therefore, we suggest a pattern shift in the strategy of CRPA in our setting.
了解抗生素耐药机制对于设计新的治疗方案和控制耐药菌株非常重要。本研究旨在探讨伊朗大不里士分离的耐碳青霉烯铜绿假单胞菌（CRPA）的分子流行病学和耐药机制。
分离出 140 株铜绿假单胞菌，并测定其抗生素敏感性模式。采用表型技术检测 AmpC 和外排泵的过度表达。聚合酶链反应（PCR）用于确定碳青霉烯酶编码基因的存在。此外，通过实时 PCR 评估 OprD 和外排泵的表达。随机扩增多态性 DNA 分型（RAPD）用于基因分型。
在 140 株铜绿假单胞菌分离株中，74 株（52.8%）被筛选为 CRPA。81%的分离株表现出过表达外排系统，其次是 OprD 表达降低（62.2%）、存在碳青霉烯酶基因（14.8%）和 AmpC 过度表达（13.5%）。大多数分离株的碳青霉烯耐药性是多因素的（60.8%）。根据我们的结果，CRPA 的流行率处于令人担忧的水平。外排系统的过度表达是碳青霉烯类耐药的最常见机制。
大多数分离株可能源自患者自身，但也可能存在交叉感染。因此，我们建议在我们的环境中改变对 CRPA 的策略。
