title: High Prevalence and Genetic Polymorphisms of Legionella in Natural and Man-Made Aquatic Environments in Wenzhou, China.
abstract: Natural and engineered water systems are the main sources of Legionnaires' disease. It is essential from a public health perspective to survey water environments for the existence ofLegionella. To analyze the main serogroups, genotypes and pathogenicity of the pathogen, a stratified sampling method was adopted to collect water samples randomly from shower water, cooling tower water, and local public hot springs in Wenzhou, China. Suspected strains were isolated from concentrated water samples. Serum agglutination assay and real-time PCR (Polymerase chain reaction) were used to identifyL. pneumophila. Sequence-based typing (SBT) and pulsed-field gel electrophoresis (PFGE) were used to elucidate the genetic polymorphisms in the collected isolates. The intracellular growth ability of the isolates was determined through their interaction with J774 cells and plating them onto BCYE (Buffered Charcoal Yeast Extract) agar plates. Overall, 25.56% (46/180) of water samples wereLegionella-positive; fifty-two strains were isolated and two kinds of serogroups were co-detected from six water samples from 2015 to 2016. Bacterial concentrations ranged from 20 CFU/100 mL to 10,720 CFU/100 mL. In detail, theLegionella-positive rates of shower water, cooling tower water and hot springs water were 15.45%, 13.33%, and 62.5%, respectively. The main serogroups were LP1 (30.69%) and LP3 (28.85%) and all strains carried the dot gene. Among them, 52 isolates and another 10 former isolates were analyzed by PFGE. Nineteen distinct patterns were observed in 52 strains isolated from 2015 to 2016 with three patterns being observed in 10 strains isolated from 2009 to 2014. Seventy-three strains containing 52 from this study and 21 former isolates were selected for SBT analysis and divided into 25 different sequence types in 4 main clonal groups belonging to 4 homomorphic types. Ten strains were chosen to show their abilities to grow and multiply in J744 cells. Taken together, our results demonstrate a high prevalence and genetic polymorphism ofLegionellain Wenzhou's environmental water system. The investigated environmental water sources pose a potential threat to the public where intervention could help to prevent the occurrence of Legionnaires' disease.
authors.affiliation: Wenzhou Center for Disease Control and Prevention, Wenzhou 325000, China. zhleyi@126.com.
authors.forename: Leyi
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Wenzhou Center for Disease Control and Prevention, Wenzhou 325000, China. zjwzliyi@126.com.
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.affiliation: Qingjiangpu District Center for Disease Control and Prevention, Huai'an 223001, China. xinwangbiology@hotmail.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Wenzhou Center for Disease Control and Prevention, Wenzhou 325000, China. vicky158564@126.com.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Shangguan
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Centre for Disease Control and Prevention, Beijing 102206, China. zhj_0901@163.com.|Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China. zhj_0901@163.com.
authors.forename: Haijian
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Wenzhou Center for Disease Control and Prevention, Wenzhou 325000, China. spirit995378@126.com.
authors.forename: Yuejin
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Wenzhou Center for Disease Control and Prevention, Wenzhou 325000, China. wz2036894245@163.com.
authors.forename: Lianghuai
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Centre for Disease Control and Prevention, Beijing 102206, China. hongyu2690@sohu.com.|Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China. hongyu2690@sohu.com.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Ren
authors.affiliation: Wenzhou Center for Disease Control and Prevention, Wenzhou 325000, China. wzcdchy@163.com.
authors.forename: Yun
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Wenzhou Center for Disease Control and Prevention, Wenzhou 325000, China. meizi7015@163.com.
authors.forename: Meifen
authors.initials: M
authors.lastname: Lin
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Centre for Disease Control and Prevention, Beijing 102206, China. qintian@icdc.cn.|Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China. qintian@icdc.cn.
authors.forename: Tian
authors.initials: T
authors.lastname: Qin
mesh_terms: D000818:Animals; D058491:Bacterial Load; D002460:Cell Line; D002681:China; D016521:Electrophoresis, Gel, Pulsed-Field; D004784:Environmental Monitoring; D005838:Genotype; D045482:Hot Springs; D007875:Legionella / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D051379:Mice; D011110:Polymorphism, Genetic; D060888:Real-Time Polymerase Chain Reaction; D014871:Water Microbiology; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D014873:Water Pollutants
keywords: L. pneumophila; environmental water source; genetic diversity; molecular typing; pathogen monitoring; public health