Virulence Traits of Environmental and Clinical Legionella pneumophila Multilocus Variable-Number Tandem-Repeat Analysis (MLVA) Genotypes
Virulence Traits of Environmental and Clinical Legionella pneumophila Multilocus Variable-Number Tandem-Repeat Analysis (MLVA) Genotypes
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DOI：
10.1128/aem.00429-18
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发表时间：
2018-03
影响因子：
4.4
通讯作者：
Y. Sharaby;S. Rodríguez-Martínez;Marina Pecellín;R. Sela;A. Peretz;M. Höfle;M. Halpern;I. Brettar
中科院分区：
文献类型：
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作者：
Y. Sharaby;S. Rodríguez-Martínez;Marina Pecellín;R. Sela;A. Peretz;M. Höfle;M. Halpern;I. Brettar
摘要嗜肺军团菌可引起以水为基础的感染，导致严重的肺炎。最近，我们发现，不同的MLVA-8（多位点可变数目串联重复分析使用8个位点）基因型占主导地位的不同网站的饮用水分配系统。每种基因型都表现出独特的温度依赖性生长行为。在这里，我们比较了不同的MLVA-8基因型的环境和临床菌株的致病潜力。研究的毒力特性是溶血活性和对阿米巴和巨噬细胞的细胞毒性。临床菌株的溶血性显著高于环境菌株，而在30°C下，它们对阿米巴的细胞毒性显著降低。临床菌株和环境菌株对巨噬细胞的细胞毒性无显著差异。环境基因型（Gt）之间的毒力观察到显着差异。Gt 15菌株表现出明显较高的溶血活性。Gt 4和Gt 6菌株对卡氏阿米巴的感染性较强。此外，Gt 4菌株表现出对巨噬细胞的细胞毒性增加，并表现出比Gt 6和Gt 15菌株更宽的阿米巴溶解温度范围。了解军团菌基因型的毒力特性有助于提高对饮用水中军团菌公共卫生风险的评估。重要性嗜肺军团菌是一种严重肺炎的病原体。在这里，我们证明了临床菌株对红细胞的细胞毒性明显高于环境菌株，而它们对巨噬细胞的细胞毒性相似。基因型4（Gt 4）菌株对阿米巴原虫和巨噬细胞具有高度细胞毒性，并在较宽的温度范围内裂解阿米巴原虫。结果可以解释Gt 4在环境和临床样品中的相对较高的成功率;因此，Gt 4菌株应被视为饮用水中军团菌公共卫生风险评估的主要因素。本研究结果为了解不同菌株的生态、毒力和致病潜力提供了依据。pneumophila基因型，这可能是一个有价值的参数，为未来的建模和定量微生物的风险评估军团菌在饮用水系统。
ABSTRACT Legionella pneumophila causes water-based infections resulting in severe pneumonia. Recently, we showed that different MLVA-8 (multilocus variable-number tandem-repeat analysis using 8 loci) genotypes dominated different sites of a drinking-water distribution system. Each genotype displayed a unique temperature-dependent growth behavior. Here we compared the pathogenicity potentials of different MLVA-8 genotypes of environmental and clinical strains. The virulence traits studied were hemolytic activity and cytotoxicity toward amoebae and macrophages. Clinical strains were significantly more hemolytic than environmental strains, while their cytotoxicity toward amoebae was significantly lower at 30°C. No significant differences were detected between clinical and environmental strains in cytotoxicity toward macrophages. Significant differences in virulence were observed between the environmental genotypes (Gt). Gt15 strains showed a significantly higher hemolytic activity. In contrast, Gt4 and Gt6 strains were more infective toward Acanthamoeba castellanii. Moreover, Gt4 strains exhibited increased cytotoxicity toward macrophages and demonstrated a broader temperature range of amoebal lysis than Gt6 and Gt15 strains. Understanding the virulence traits of Legionella genotypes may improve the assessment of public health risks of Legionella in drinking water. IMPORTANCE Legionella pneumophila is the causative agent of a severe form of pneumonia. Here we demonstrated that clinical strains were significantly more cytotoxic toward red blood cells than environmental strains, while their cytotoxicity toward macrophages was similar. Genotype 4 (Gt4) strains were highly cytotoxic toward amoebae and macrophages and lysed amoebae in a broader temperature range than to the other studied genotypes. The results can explain the relatively high success of Gt4 in the environment and in clinical samples; thus, Gt4 strains should be considered a main factor for the assessment of public health risks of Legionella in drinking water. Our findings shed light on the ecology, virulence, and pathogenicity potential of different L. pneumophila genotypes, which can be a valuable parameter for future modeling and quantitative microbial risk assessment of Legionella in drinking-water systems.