Royer G, Virieux-Petit M, Aujoulat F, Hersent C, Baranovsky S, Hammer-Dedet F, Masnou A, Marchandin H, Corne P, Jumas-Bilak E, Romano-Bertrand S
Hydrosciences Montpellier, IRD, CNRS, Univ Montpellier, Service de Prévention des Infections et de la Résistance, CHU Montpellier, Montpellier, France; Département de prévention, diagnostic et traitement des infections, Hôpital Henri Mondor, AP-HP, Créteil, France.
Hydrosciences Montpellier, IRD, CNRS, Univ Montpellier, Service de Prévention des Infections et de la Résistance, CHU Montpellier, Montpellier, France; Hydrosciences Montpellier, Univ Montpellier, IRD, CNRS, Montpellier, France.
J Hosp Infect. 2024 Jul;149:155-164. doi: 10.1016/j.jhin.2024.04.012. Epub 2024 May 3.
To assess the residual risk of waterborne contamination by Pseudomonas aeruginosa from a water network colonized by a single genotype [sequence type (ST) 299] despite the presence of antimicrobial filters in a medical intensive care unit (ICU).
During the first 19-month period since the ICU opened, contamination of the water network was assessed monthly by collecting water upstream of the filters. Downstream water was also sampled to assess the efficiency of the filters. P. aeruginosa isolates from patients were collected and compared with the waterborne ST299 P. aeruginosa by multiplex-rep polymerase chain reaction (PCR), pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing. Cross-transmission events by other genotypes of P. aeruginosa were also assessed.
Overall, 1.3% of 449 samples of filtered water were positive for P. aeruginosa in inoculum, varying between 1 and 10 colony-forming units/100 mL according to the tap. All P. aeruginosa hydric isolates belonged to ST299 and displayed fewer than two single nucleotide polymorphisms (SNPs). Among 278 clinical isolates from 122 patients, 10 isolates in five patients showed identical profiles to the hydric ST299 clone on both multiplex-rep PCR and PFGE, and differed by an average of fewer than five SNPs, confirming the water network reservoir as the source of contamination by P. aeruginosa for 4.09% of patients. Cross-transmission events by other genotypes of P. aeruginosa were responsible for the contamination of 1.75% of patients.
DISCUSSION/CONCLUSION: Antimicrobial filters are not sufficient to protect patients from waterborne pathogens when the water network is highly contaminated. A microbiological survey of filtered water may be needed in units hosting patients at risk of P. aeruginosa infections, even when all water points-of-use are fitted with filters.
评估尽管在医疗重症监护病房（ICU）安装了抗菌过滤器，但由单一基因型[序列型（ST）299]定植的水网络中铜绿假单胞菌引起水传播污染的残留风险。
在ICU开业后的前19个月期间，每月通过收集过滤器上游的水来评估水网络的污染情况。还对下游水进行采样以评估过滤器的效率。收集患者的铜绿假单胞菌分离株，并通过多重重复聚合酶链反应（PCR）、脉冲场凝胶电泳（PFGE）和全基因组测序与水传播的ST299铜绿假单胞菌进行比较。还评估了其他基因型铜绿假单胞菌的交叉传播事件。
总体而言，449份过滤水样本中有1.3%的接种物对铜绿假单胞菌呈阳性，根据水龙头不同，每100 mL中菌落形成单位在1至10个之间变化。所有水传播的铜绿假单胞菌分离株均属于ST299，且单核苷酸多态性（SNP）少于两个。在来自122名患者的278份临床分离株中，5名患者的10份分离株在多重重复PCR和PFGE上显示出与水传播的ST299克隆相同的图谱，平均差异少于5个SNP，证实水网络储库是4.09%患者铜绿假单胞菌污染的来源。其他基因型铜绿假单胞菌的交叉传播事件导致1.75%的患者受到污染。
讨论/结论：当水网络受到高度污染时，抗菌过滤器不足以保护患者免受水传播病原体的侵害。即使所有用水点都安装了过滤器，在有铜绿假单胞菌感染风险患者的病房中，可能仍需要对过滤水进行微生物学调查。
