Abstract：
In man-made water distribution systems, Legionella community interactions remain unknown, due to their ability to change from sessile to planktonic states or live in viable but non-culturable forms, in response to anthropic and environmental stress. During 7 years of hospital Legionella surveillance, in 191 hot water positive samples, the interactions among the Legionella species, temperature, and disinfection treatment were evaluated. Legionella was isolated following ISO 11731:2017, and identification was performed by mip gene sequencing and sequence-based typing (SBT) for L. anisa or L. rubrilucens and L. pneumophila, respectively. The species with the higher frequency of isolation was L. pneumophila serogroup 1 (78.53%; 4865.36 ± 25,479.11 cfu/L), followed by L. anisa (54.45%; 558.79 ± 2637.41 cfu/L) and L. rubrilucens (21.99%; 307.73 ± 1574.95 cfu/L), which were sometimes present together. Spearman\'s rho correlation test was conducted among the species with respect to temperature and disinfectant (H2O2/Ag+). The results showed a generally positive interaction among these species sharing the same environment, except for competition between L. anisa and L. rubrilucens. High temperature (48.83 ± 2.59 °C) and disinfection treatment (11.58 ± 4.99 mg/L) affected the presence of these species. An exception was observed with L. anisa, which showed disinfection treatment resistance. For the purposes of environmental surveillance, it is fundamental to better understand the interactions and dynamic of the Legionella community in man-made water systems in order to choose the proper physical or chemical treatments. The simultaneous presence of different Legionella species could result in an increased resistance to high temperature and disinfectant treatment, leading to changes in contamination level and species diversity.
摘要：
在人造配水系统中，军团菌群落相互作用仍然未知，由于它们能够从固着状态转变为浮游状态或以可行但不可培养的形式生活，对人类和环境压力的反应。在医院军团菌监测的7年中，在191份热水阳性样本中，军团菌之间的相互作用，温度,并对消毒处理进行评价。军团菌是根据ISO11731：2017分离的，并通过mip基因测序和基于序列的分型（SBT）进行了鉴定。分别。分离频率较高的物种是嗜肺乳杆菌血清群1（78.53％；4865.36±25,479.11cfu/L），其次是L.anisa（54.45％；558.79±2637.41cfu/L）和L.rubrilucens（21.99％；307.73±1574.95cfu/L），有时一起出现。就温度和消毒剂（H2O2/Ag）而言，在物种之间进行了Spearman的rho相关性测试。结果表明，这些物种之间共享相同的环境，总体上是积极的相互作用，除了L.anisa和L.rubrilucens之间的竞争。高温（48.83±2.59°C）和消毒处理（11.58±4.99mg/L）影响了这些物种的存在。对L.anisa观察到一个例外，表现出消毒处理抗性。就环境监测而言，为了选择适当的物理或化学处理方法，更好地了解人造水系统中军团菌群落的相互作用和动态是至关重要的。不同军团菌的同时存在可能导致对高温和消毒剂处理的抵抗力增加，导致污染水平和物种多样性的变化。
