Department of Environmental Health Engineering, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran.
Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran.
Antimicrob Resist Infect Control. 2024 Sep 27;13(1):111. doi: 10.1186/s13756-024-01468-4.
Several healthcare-associated infection outbreaks have been caused by waterborne Pseudomonas aeruginosa exhibiting its ability to colonize water systems and resist conventional chlorine treatment. This study aims to investigate the occurrence of Pseudomonas aeruginosa in hospital drinking water systems and the antimicrobial resistance profiles (antibiotic and chlorine resistance) of isolated strains.
We investigated the presence of Pseudomonas aeruginosa in water and biofilms developed in nine hospital water systems (n = 192) using culture-based and molecular methods. We further assessed the survival of isolated strains after exposure to 0.5 and 1.5 ppm concentrations of chlorine. The profile of antibiotic resistance and presence of antibiotic resistance genes in isolated strains were also investigated.
Using direct PCR method, Pseudomonas aeruginosa was detected in 22% (21/96) of water and 28% (27/96) of biofilm samples. However, culturable Pseudomonas aeruginosa was isolated from 14 samples. Most of P. aeruginosa isolates (86%) were resistant to at least one antibiotic (mainly β-lactams), with 50% demonstrating multidrug resistance. Moreover, three isolates harbored intI1 gene and two isolates contained blabla and bla genes. Experiments with chlorine disinfection revealed that all tested Pseudomonas aeruginosa strains were resistant to a 0.5 ppm concentration. However, when exposed to a 1.5 ppm concentration of chlorine for 30 min, 60% of the strains were eliminated. Interestingly, all chlorine-resistant bacteria that survived at 30-minute exposure to 1.5 ppm chlorine were found to harbor the intI1 gene.
The detection of antimicrobial resistant Pseudomonas aeruginosa in hospital water systems raises concerns about the potential for infections among hospitalized patients. The implementation of advanced mitigation measures and targeted disinfection methods should be considered to tackle the evolving challenges within hospital water systems.
一些与医疗保健相关的感染爆发是由能够在水中定殖并抵抗常规氯处理的水传播铜绿假单胞菌引起的。本研究旨在调查医院饮用水系统中铜绿假单胞菌的发生情况以及分离株的抗菌药物耐药谱（抗生素和氯耐药性）。
我们使用基于培养和分子的方法调查了九个医院水系统（n=192）中的水和生物膜中铜绿假单胞菌的存在情况。我们进一步评估了分离株在暴露于 0.5 和 1.5 ppm 浓度的氯后存活情况。还研究了分离株的抗生素耐药谱和抗生素耐药基因的存在情况。
使用直接 PCR 方法，在 22%（21/96）的水和 28%（27/96）的生物膜样本中检测到铜绿假单胞菌。然而，从 14 个样本中分离出可培养的铜绿假单胞菌。大多数铜绿假单胞菌分离株（86%）对至少一种抗生素（主要是β-内酰胺类抗生素）具有耐药性，50%表现出多药耐药性。此外，三个分离株携带 intI1 基因，两个分离株含有 blabla 和 bla 基因。氯消毒实验表明，所有测试的铜绿假单胞菌菌株均对 0.5 ppm 浓度的氯具有耐药性。然而，当暴露于 1.5 ppm 浓度的氯 30 分钟时，60%的菌株被消除。有趣的是，所有在 1.5 ppm 氯暴露 30 分钟后存活的耐氯细菌均携带 intI1 基因。
在医院水系统中检测到具有抗菌药物耐药性的铜绿假单胞菌引起了对住院患者感染风险的关注。应考虑实施先进的缓解措施和有针对性的消毒方法，以应对医院水系统中不断出现的挑战。
