POU水过滤器对军团菌属及其他水源性病原菌的清除功效

Efficacy of point-of-use water filter on removing Legionella and other waterborne micro-organisms

目的在上海地区自来水水质条件下,评估POU水过滤器在临床实际使用中清除军团菌属及其他病原菌的功效。方法在医院移植监护病房的3个水龙头上分别安装POU水过滤器(Aquasafe AQ14F1S,孔径0.2μm,颇尔公司)和前置过滤装置(孔径:1.2μm,以去除自来水中的颗粒状杂质),每2周更换1次,共18周;每3～4 d检测水样,包括打开水龙头立即采集的POU过滤水,打开水龙头冲洗30 s的POU过滤水,未经过滤的自来水,经前置过滤器过滤的自来水;4种样本均用标准培养方法计数异养菌总数、军团菌属、分枝杆菌属、铜绿假单胞菌和丝状真菌的数量,并采用单因素方差分析进行数据统计和分析。结果共采集229份水样,100份未过滤水中19份分离到各种血清型的军团菌属;自来水中军团菌属、分枝杆菌属、铜绿假单胞菌和丝状真菌的平均浓度分别为:1.0×103、4.9×1023、5 CFU/L和26.5 CFU/L;所有经POU过滤的水样中均未发现军团菌属、分枝杆菌属、铜绿假单胞菌和丝状真菌;POU水过滤器对异养菌的清除率>90%,自来水样本与预过滤水样本中细菌浓度差异无统计学意义。结论 POU水过滤器可彻底清除嗜肺军团菌、分枝杆菌属、铜绿假单胞菌和丝状真菌,有利于降低获得性医院感染的潜在危险。

OBJECTIVE To evaluate the efficacy of point-of-use（POU） water filters（Pall-Aquasafe AQ14F1S,pore size： 0.2 μm） in eliminating Legionella and other pathogens from tap water during routine use in a medical center.Moreover,the study was performed under local water condition.METHODS Three water outlets in liver transplantation ward were equipped with disposable POU water filters and pre-filter（pore size： 1.2 μm,for removal of particles from tap water）,and those filters were changed every 2 weeks.Upon filter changing,POU filtered water was collected immediately after opening the valve（immediate sample）,and a second sample was collected after 30 seconds water flush（post sample）.The unfiltered water sample referred to tap water was served as control,while the water filtered through pre-filter was served as pre-filtered water.All four types of water samples were cultured for bacterium every 3-4 days using standard culture-based methods.Total heterotrophic plate count（HPC） bacteria,Legionella spp.Mycobacterium spp.Pseudomonas aeruginosa and filamentous fungi count was recorded for ANOVA analysis.RESULTS Totally 229 water samples were tested in this study.19 of the 100 unfiltered water samples contained Legionella of various serogroups over 18 weeks.The mean concentration of Legionella,Mycobacterium,Pseudomonas aeruginosa and filamentous fungi from all unfiltered water samples was 1.0×103 CFU/L,4.9×102 CFU/L,35 CFU/L and 26.5 CFU/L,respectively.In contrast,all samples filtered by POU filter either collected immediately or after flushing were Legionella and other micro-organisms free.The POU filters achieved 90% reduction in HPC bacteria in the post flush samples.No significant differences in isolation between pre-filtered and unfiltered water were observed.CONCLUSION Based on our results,POU filters completely eliminate Legionella spp.Mycobacterium spp.Pseudomonas aeruginosa and filamentous fungi from tap water,implying its potential benefit on reducing possible infections.