Application of Multilocus Sequence Analysis (MLSA) for Accurate Identification of Legionella spp. Isolated from Municipal Fountains in Chengdu, China, Based on 16S rRNA, mip, and rpoB Genes
Application of Multilocus Sequence Analysis (MLSA) for Accurate Identification of Legionella spp. Isolated from Municipal Fountains in Chengdu, China, Based on 16S rRNA, mip, and rpoB Genes
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DOI：
10.1007/s12275-012-1243-1
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发表时间：
2012-02-01
影响因子：
3
通讯作者：
Chen, Jian-ping
中科院分区：
文献类型：
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作者：
Guan, Wang;Xu, Ying;Chen, Jian-ping
军团病（军团病）是一种由军团菌引起的严重肺炎。由于吸入被军团菌污染的气溶胶被认为是主要的感染途径，因此对热水系统、空调冷却水和市政喷泉等潜在感染源进行常规评估非常重要。本研究利用体外培养和针对16S rRNA、mip、rpoB、mip-rpoB串联的多位点序列分析（MLSA）技术，对四川省成都市5个市政喷泉中的军团菌进行了分离鉴定。结果表明，16S rRNA可用于军团菌的初步鉴定，因为它可以在属水平上识别分离株，而imp、rpoB和mip-rpoB串联基因可以自信地区分军团菌的种类。值得注意的是，通过rpoB分析可以区分出嗜肺乳杆菌的三个亚种。基于mip和rpoB序列的遗传分析，CD-1的血清分型结果与遗传分析一致。尽管采取了定期维护和消毒措施，本研究调查的5个市政喷泉中仍有4个检测出军团菌污染。因此，迫切需要定期监测市政喷泉，并警惕消毒。虽然应用MLSA检查公共场所的潜在感染地点不是标准程序，但进一步的调查可能证明其有用性。
Legionellosis (Legionnaires' disease; LD) is a form of severe pneumonia caused by species of Legionella bacteria. Because inhalation of Legionella-contaminated aerosol is considered the major infection route, routine assessments of potential infection sources such as hot water systems, air-conditioner cooling water, and municipal fountains are of great importance. In this study, we utilized in vitro culture and multi-locus sequence analysis (MLSA) targeting 16S rRNA, mip, rpoB, and mip-rpoB concatenation to isolate and identify Legionella spp. from 5 municipal fountains in Chengdu City, Sichuan Province, China. Our results demonstrated that 16S rRNA was useful for initial identification, as it could recognize isolates robustly at the genus level, while the genes imp, rpoB, and mip-rpoB concatenation could confidently discriminate Legionella species. Notably, the three subspecies of L. pneumophila could be distinguished by the analysis based on rpoB. The serotyping result of strain CD-1 was consistent with genetic analysis based on the concatenation of mip and rpoB. Despite regular maintenance and sanitizing methods, 4 of the 5 municipal fountains investigated in this study were positive for Legionella contamination. Thus, regularly scheduled monitoring of municipal fountains is urgently needed as well as vigilant disinfection. Although the application of MLSA for inspection of potential sites of infection in public areas is not standard procedure, further investigations may prove its usefulness.