Temperature-dependent growth modeling of environmental and clinical Legionella pneumophila MLVA-genotypes
Temperature-dependent growth modeling of environmental and clinical Legionella pneumophila MLVA-genotypes
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DOI：
10.1128/aem.03295-16
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发表时间：
2017
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通讯作者：
Y. Sharaby;S. Rodríguez-Martínez;Olga Oks;Marina Pecellín;Hila;Mizrahi;A. Peretz;I. Brettar;M. Höfle;M. Halpern
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作者：
Y. Sharaby;S. Rodríguez-Martínez;Olga Oks;Marina Pecellín;Hila;Mizrahi;A. Peretz;I. Brettar;M. Höfle;M. Halpern
嗜肺军团菌引起水传播感染，导致严重的肺炎。L.的高分辨率基因分型可以通过多位点可变数目串联重复序列分析（MLVA）来获得嗜肺菌分离株。最近，我们发现不同MLVA基因型的L。pneumophila，占主导地位的不同网站在一个小的饮用水网络，与基因型相关的温度和丰度制度。目前的研究重点是了解温度依赖的生长动力学的基因型占主导地位的水网络。我们的目的是数学模型的温度对不同的环境和临床L。pneumophila基因型，并与其生态位进行比较。环境菌株表现出明显的温度偏好性，三种研究基因型（Gt 4，Gt 6和Gt 15）的生长动力学之间存在显着差异。Gt 4菌株在较低温度（25-30 °C）下表现出上级的生长，而Gtl 5菌株似乎最适合于相对较高的温度（42-45 °C）。环境基因型的温度依赖性生长性状与其在水网中的分布和温度偏好一致。与环境菌株相比，临床分离株在37°C和42°C下表现出显著更高的生长速率并达到更高的最大细胞密度。进一步研究了L.对嗜肺菌临床和环境基因型的研究将有助于更好地了解其在饮用水系统以及人体中的生态位。重要性：嗜肺军团菌是一种水媒病原体，在发达国家威胁人类。这种细菌栖息在自然和人造的淡水环境中。在这里，我们证明了不同的环境L。嗜肺菌基因型具有不同的温度依赖性生长动力学。此外，属于同一种但从环境和临床来源分离的军团菌菌株具有在不同温度下生长的适应性。这些生长偏好可能会影响细菌定植在特定的生态位内的饮用水网络。在人体温度下生长的适应性可能有助于某些L。嗜肺菌菌株能够感染人类并引起人类疾病。我们的研究结果可以作为一种工具，以改善军团菌监测饮用水网络。用于预测军团菌病风险的风险评估模型不仅应考虑军团菌浓度，还应考虑分离株的温度依赖性生长动力学。
Legionella pneumophila cause waterborne infections resulting in severe pneumonia. High resolution genotyping of L. pneumophila isolates can be achieved by Multiple-Locus Variable number of tandem repeat Analysis (MLVA). Recently, we found that different MLVA genotypes of L. pneumophila , dominated different sites in a small drinking-water network, with a genotype-related temperature and abundance regime. The current study focuses on understanding the temperature-dependent growth kinetics of the genotypes that dominated the water network. Our aim was to model mathematically the influence of temperature on the growth kinetics of different environmental and clinical L. pneumophila genotypes and compare it with their ecological niches. Environmental strains showed a distinct temperature preference with significant differences among the growth kinetics of the three studied genotypes (Gt4, Gt6 and Gt15). Gt4 strains exhibited superior growth at lower temperatures (25-30 °C) while Gt15 strains appeared to be best adapted to relatively higher temperatures (42-45 °C). The temperature-dependent growth traits of the environmental genotypes were consistent with their distribution and temperature preferences in the water network. Clinical isolates exhibited significantly higher growth rates and reached higher maximal cell densities at 37°C and 42°C than the environmental strains. Further research on the growth preferences of L. pneumophila clinical and environmental genotypes will result in better understanding of their ecological niches in drinking water systems as well as in the human body. Importance: Legionella pneumophila is a waterborne pathogen that threatens humans in developed countries. The bacteria inhabit natural and man-made freshwater environments. Here we demonstrate that different environmental L. pneumophila genotypes have different temperature-dependent growth kinetics. Moreover, Legionella strains that belong to the same species but were isolated from environmental and clinical sources possess adaptations for growth at different temperatures. These growth preferences may influence the bacterial colonization at specific ecological niches within the drinking-water network. Adaptations for growth at the human body temperatures may facilitate some L. pneumophila strains abilities to infect and cause illness in humans. Our findings may be used as a tool to improve Legionella monitoring in drinking-water networks. Risk assessment models for predicting the risk of legionellosis should take into account not only Legionella concentrations but also the isolates temperature-dependent growth kinetics.