Department of Biological, Geological, and Environmental Sciences, University of Bologna, via San Giacomo 12, 40126 Bologna, Italy.
GVM Care & Research, Lugo di Ravenna, 48022 Ravenna, Italy.
Int J Environ Res Public Health. 2020 Nov 21;17(22):8662. doi: 10.3390/ijerph17228662.
In this study, we aimed to associate the molecular typing of isolates with a culture technique during routine hospital environmental surveillance in hot water distribution systems (HWDSs) to develop a risk map able to be used to prevent nosocomial infections and formulate appropriate preventive measures. Hot water samples were cultured according to ISO 11731:2017. The isolates were serotyped using an agglutination test and genotyped by sequence-based typing (SBT) for or macrophage infectivity potentiator () gene sequencing for non- species. The isolates' relationship was phylogenetically analyzed. The distribution and level of contamination were studied in relation to temperature and disinfectant residues. The culture technique detected 62.21% of positive samples, characterized by serogroup 1, non-, or both simultaneously. The SBT assigned two sequence types (STs): ST1, the most prevalent in Italy, and ST104, which had never been isolated before. The gene sequencing detected and . The phylogenetic analysis showed distinct clusters for each species. The distribution of isolates showed significant differences between buildings, with a negative correlation between the measured level of contamination, disinfectant, and temperature. The molecular approach introduced in HWDSs environmental surveillance permits (i) a risk map to be outlined that can help formulate appropriate disinfection strategies and (ii) rapid epidemiological investigations to quickly identify the source of infections.
在这项研究中，我们旨在将 分离株的分子分型与热水分配系统（HWDS）中常规医院环境监测的培养技术相关联，以开发能够用于预防医院感染和制定适当预防措施的风险图。热水样本按照 ISO 11731:2017 进行培养。使用凝集试验对分离株进行血清分型，并用基于序列的分型（SBT）对非 种进行基因测序，以确定巨噬细胞感染增强因子（macrophage infectivity potentiator，MIP）基因。对分离株的关系进行系统发育分析。研究了温度和消毒剂残留与 分布和污染水平的关系。培养技术检测到 62.21%的 阳性样本，特征为血清群 1、非 或两者同时存在。SBT 分配了两种序列类型（ST）：在意大利最常见的 ST1 和以前从未分离到的 ST104。 基因测序检测到 和 。系统发育分析显示，每个物种都有明显的聚类。 分离株的分布在建筑物之间存在显著差异，测量的污染水平、消毒剂和温度之间呈负相关。HWDS 环境监测中引入的 分子方法允许（i）概述风险图，以帮助制定适当的消毒策略，（ii）快速进行流行病学调查，以快速确定 感染的来源。
