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Komatsu S, Tanaka S, Nakanishi N. Prevalence and genetic distribution of Legionella spp. in public bath facilities in Kobe City, Japan. JOURNAL OF WATER AND HEALTH 2023; 21:1727-1734. [PMID: 38017602 PMCID: wh_2023_247 DOI: 10.2166/wh.2023.247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
Legionella is an important waterborne pathogen that causes legionellosis. Public baths are considered the primary cause of legionellosis infection in Japan. We investigated the prevalence and genetic distribution of 338 Legionella spp. isolates from 81 public bath facilities, including 35 hot springs and 46 other facilities, through annual periodic surveillance in Kobe, Japan, from 2016 to 2021. In addition, the genotypes of nine clinical strains of unknown infectious source from the same period were compared to those of bathwater isolates. We elucidated the differences in the distribution of Legionella species, serogroups, and genotypes between hot springs and other public baths. Legionella israelensis, L. londiniensis, and L. micdadei colonized hot springs along with L. pneumophila. The minimum spanning tree analysis based on multiple-locus variable number tandem repeat analysis (MLVA) also identified four major clonal complexes (CCs) in L. pneumophila SG1 and found that CC1 of the four CCs is a specific novel genotype with the lag-1 gene in hot springs. The same MLVA genotypes and sequence types as those of the clinical strains were not present among the strains isolated from bath water. Thus, our surveillance is useful for estimating the sources of legionellosis infection in Japan and developing prevention strategies.
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Affiliation(s)
- Shoko Komatsu
- Department of Infectious Diseases, Kobe Institute of Health, Kobe, Japan E-mail:
| | - Shinobu Tanaka
- Department of Infectious Diseases, Kobe Institute of Health, Kobe, Japan
| | - Noriko Nakanishi
- Department of Infectious Diseases, Kobe Institute of Health, Kobe, Japan
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Zhan XY, Yang JL, Sun H, Zhou X, Qian YC, Huang K, Leng Y, Huang B, He Y. Presence of Viable, Clinically Relevant Legionella Bacteria in Environmental Water and Soil Sources of China. Microbiol Spectr 2022; 10:e0114021. [PMID: 35438512 PMCID: PMC9241679 DOI: 10.1128/spectrum.01140-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 03/11/2022] [Indexed: 12/12/2022] Open
Abstract
The distribution of pathogenic Legionella in the environmental soil and water of China has not been documented yet. In this study, Legionella was detected in 129 of 575 water (22.43%) and 41 of 442 soil samples (9.28%) by culture. Twelve Legionella species were identified, of which 11 were disease-associated. Of the Legionella-positive samples, 109 of 129 (84.50%) water and 29 of 41 (70.73%) soil were positive for L. pneumophila, which accounted for about 75% of Legionella isolates in both water and soil, suggesting L. pneumophila was the most frequent species. Soil showed a higher diversity of Legionella spp. as compared with water (0.6279 versus 0.4493). In contrast, serogroup (sg) 1 was more prevalent among L. pneumophila isolates from water than from soil (26.66% versus 12.21%). Moreover, many disease-associated sequence types (STs) of L. pneumophila were found in China. Intragenic recombination was acting on L. pneumophila from both water and soil. Phylogeny, population structure, and molecular evolution analyses revealed a probable existence of L. pneumophila isolates with a special genetic background that is more adaptable to soil or water sources and a small proportion of genetic difference between water and soil isolates. The detection of viable, clinically relevant Legionella demonstrates soil as another source for harboring and dissemination of pathogenic Legionella bacteria in China. Future research should assess the implication in public health with the presence of Legionella in the soil and illustrate the genetic and pathogenicity difference of Legionella between water and soil, particularly the most prevalent L. pneumophila. IMPORTANCE Pathogenic Legionella spp. is the causative agent of Legionnaires' disease (LD), and L. pneumophila is the most common one. Most studies have focused on L. pneumophila from water and clinical samples. However, the soil is another important reservoir for this bacterium, and the distribution of Legionella spp. in water and soil sources has not been compared and documented in China yet. Discovering the distribution of Legionella spp. and L. pneumophila in the two environments may help a deep understanding of the pathogenesis and molecular evolution of the bacterium. Our research systematically uncovered the distributions of Legionella spp. in different regions and sources (e.g., water and soil) of China. Moreover, phylogeny, population structure, and molecular evolution study revealed the possible existence of L. pneumophila with a special genetic background that is more adaptable to soil or water sources, and genetic difference may exist.
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Affiliation(s)
- Xiao-Yong Zhan
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Jin-Lei Yang
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Honghua Sun
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Xuefu Zhou
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Yi-Chao Qian
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Ke Huang
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Yang Leng
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Bihui Huang
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Yulong He
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
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Wee BA, Alves J, Lindsay DSJ, Klatt AB, Sargison FA, Cameron RL, Pickering A, Gorzynski J, Corander J, Marttinen P, Opitz B, Smith AJ, Fitzgerald JR. Population analysis of Legionella pneumophila reveals a basis for resistance to complement-mediated killing. Nat Commun 2021; 12:7165. [PMID: 34887398 PMCID: PMC8660822 DOI: 10.1038/s41467-021-27478-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 11/19/2021] [Indexed: 11/09/2022] Open
Abstract
Legionella pneumophila is the most common cause of the severe respiratory infection known as Legionnaires' disease. However, the microorganism is typically a symbiont of free-living amoeba, and our understanding of the bacterial factors that determine human pathogenicity is limited. Here we carried out a population genomic study of 902 L. pneumophila isolates from human clinical and environmental samples to examine their genetic diversity, global distribution and the basis for human pathogenicity. We find that the capacity for human disease is representative of the breadth of species diversity although some clones are more commonly associated with clinical infections. We identified a single gene (lag-1) to be most strongly associated with clinical isolates. lag-1, which encodes an O-acetyltransferase for lipopolysaccharide modification, has been distributed horizontally across all major phylogenetic clades of L. pneumophila by frequent recent recombination events. The gene confers resistance to complement-mediated killing in human serum by inhibiting deposition of classical pathway molecules on the bacterial surface. Furthermore, acquisition of lag-1 inhibits complement-dependent phagocytosis by human neutrophils, and promoted survival in a mouse model of pulmonary legionellosis. Thus, our results reveal L. pneumophila genetic traits linked to disease and provide a molecular basis for resistance to complement-mediated killing.
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Affiliation(s)
- Bryan A Wee
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, Scotland, UK
| | - Joana Alves
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, Scotland, UK
| | - Diane S J Lindsay
- Bacterial Respiratory Infections Service (Ex Mycobacteria), Scottish Microbiology Reference Laboratory, Glasgow, Scotland, UK
| | - Ann-Brit Klatt
- Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Fiona A Sargison
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, Scotland, UK
| | - Ross L Cameron
- NHS National Services Scotland, Health Protection Scotland, Glasgow, Scotland, UK
| | - Amy Pickering
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, Scotland, UK
| | - Jamie Gorzynski
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, Scotland, UK
| | - Jukka Corander
- Department of Mathematics and Statistics, University of Helsinki, Helsinki, Finland
- Department of Biostatistics, University of Oslo, Oslo, Norway
| | - Pekka Marttinen
- Helsinki Institute for Information Technology, Department of Computer Science, Aalto University, Aalto, Finland
| | - Bastian Opitz
- Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Andrew J Smith
- Bacterial Respiratory Infections Service (Ex Mycobacteria), Scottish Microbiology Reference Laboratory, Glasgow, Scotland, UK
- College of Medical, Veterinary & Life Sciences, Glasgow Dental Hospital & School, University of Glasgow, Glasgow, UK
| | - J Ross Fitzgerald
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, Scotland, UK.
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Sequence-based typing of clinical and environmental Legionella pneumophila isolates in Shenyang, China. ACTA ACUST UNITED AC 2021; 39:383-389. [PMID: 34620473 DOI: 10.1016/j.eimce.2020.06.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 06/04/2020] [Indexed: 11/23/2022]
Abstract
INTRODUCTION We performed SBT (sequence-based typing) on clinical and environmental Legionellapneumophila isolates in Shenyang (China). We analyzed and compared the results with those obtained by PFGE (pulsed field gel electrophoresis). METHODS Twenty-two L. pneumophila isolates were collected from two patients with L. pneumophila infection, two hospitals, and 13 office buildings. There were two clinical isolates, one strain isolated from domestic tap water, another from shower water and 18 strains from cooling tower water. All these isolates were analyzed by SBT and PFGE methods. RESULTS The 22 isolates were divided into 7 types by SBT. Five isolates belonged to novel sequence types (ST2345, ST2344, ST2406, ST2407, and ST2408) and one isolate belonged to ST328. The STs were not obtained for two of the isolates. The remaining 14 isolates belonged to ST1. PFGE typing divided the 22 isolates into 14 pulsotypes. The main pulsotype was SYC, which included seven isolates. CONCLUSION Both typing methods showed that predominant clonal lines exist in the Shenyang region, with high levels of genetic polymorphisms. Five novel STs were identified, indicating a unique genetic composition of L. pneumophila strains in this region, which are significantly different from those found in other environmental water systems in the world.
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Sreenath K, Chaudhry R, Vinayaraj EV, Dey AB, Kabra SK, Thakur B, Guleria R. Distribution of Virulence Genes and Sequence-Based Types Among Legionella pneumophila Isolated From the Water Systems of a Tertiary Care Hospital in India. Front Public Health 2020; 8:596463. [PMID: 33330340 PMCID: PMC7719716 DOI: 10.3389/fpubh.2020.596463] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 10/12/2020] [Indexed: 01/06/2023] Open
Abstract
Background: Legionnaires' disease (LD) is a potentially fatal pneumonia predominantly caused by infection due to Legionella pneumophila although more than 50 other Legionella species are described. Water systems contaminated with Legionella spp. are the implicated sources of Legionnaires' disease. In this study, we aimed to assess Legionella contamination in the water sources of a tertiary care hospital and to determine the virulence properties and molecular characteristics of L. pneumophila environmental isolates. Methods: During May 2015 through August 2018, a total of 201 hospital water samples were tested for L. pneumophila by standardized culture procedures; environmental isolates were examined for the presence of two virulence genes: Legionella vir homolog (lvh) and repeats in structural toxin (rtxA) by PCR. The genotyping of isolates was performed by sequence-based typing (SBT) according to the protocol of the European Study Group for Legionella Infections (ESGLI). Results:L. pneumophila was isolated from 38/201 (18.9%) water samples; among the 46 isolates, the lvh locus was present in 45 (97.8%), the rtxA locus was found in 45 (97.8%), and both loci were found in 44 (95.7%) isolates. A total of 23 sequence types (STs) were identified among the 44 isolates (index of discrimination [IOD] of 0.929), and 11/23 (47.8%) STs were new to the ESGLI database. Conclusions: The study results showed genetic diversity in L. pneumophila isolates from the hospital environment along with a high percentage of pathogenicity loci. Besides, certain STs may have an increased ability to cause legionellosis, thus requires specific infection control and prevention strategies whenever identified.
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Affiliation(s)
- K Sreenath
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
| | - Rama Chaudhry
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
| | - E V Vinayaraj
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
| | - A B Dey
- Geriatric Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - S K Kabra
- Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Bhaskar Thakur
- Biostatistics, All India Institute of Medical Sciences, New Delhi, India
| | - Randeep Guleria
- Pulmonary, Critical Care, and Sleep Medicine, All India Institute of Medical Sciences, New Delhi, India
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Zayed AR, Pecellin M, Salah A, Alalam H, Butmeh S, Steinert M, Lesnik R, Brettar I, Höfle MG, Bitar DM. Characterization of Legionella pneumophila Populations by Multilocus Variable Number of Tandem Repeats (MLVA) Genotyping from Drinking Water and Biofilm in Hospitals from Different Regions of the West Bank. Pathogens 2020; 9:E862. [PMID: 33105606 PMCID: PMC7690423 DOI: 10.3390/pathogens9110862] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/17/2020] [Accepted: 10/19/2020] [Indexed: 01/26/2023] Open
Abstract
The West Bank can be considered a high-risk area for Legionnaires' disease (LD) due to its hot climate, intermittent water supply and roof storage of drinking water. Legionella, mostly L. pneumophila, are responsible for LD, a severe, community-acquired and nosocomial pneumonia. To date, no extensive assessment of Legionella spp and L. pneumophila using cultivation in combination with molecular approaches in the West Bank has been published. Two years of environmental surveillance of Legionella in water and biofilms in the drinking water distribution systems (DWDS) of eight hospitals was carried out; 180 L. pneumophila strains were isolated, mostly from biofilms in DWDS. Most of the isolates were identified as serogroup (Sg) 1 (60%) and 6 (30%), while a minor fraction comprised Sg 8 and 10. Multilocus Variable number of tandem repeats Analysis using 13 loci (MLVA-8(12)) was applied as a high-resolution genotyping method and compared to the standard Sequence Based Typing (SBT). The isolates were genotyped in 27 MLVA-8(12) genotypes (Gt), comprising four MLVA clonal complexes (VACC 1; 2; 5; 11). The major fraction of isolates constituted Sequence Type (ST)1 and ST461. Most of the MLVA-genotypes were highly diverse and often unique. The MLVA-genotype composition showed substantial regional variability. In general, the applied MLVA-method made it possible to reproducibly genotype the isolates, and was consistent with SBT but showed a higher resolution. The advantage of the higher resolution was most evident for the subdivision of the large strain sets of ST1 and ST461; these STs were shown to be highly pneumonia-relevant in a former study. This shows that the resolution by MLVA is advantageous for back-tracking risk sites and for the avoidance of outbreaks of L. pneumophila. Overall, our results provide important insights into the detailed population structure of L. pneumophila, allowing for better risk assessment for DWDS.
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Affiliation(s)
- Ashraf R. Zayed
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research (HZI), Inhoffenstrasse 7, 38124 Braunschweig, Germany; (A.R.Z.); (M.P.); (R.L.); (I.B.)
- Department of Microbiology and Immunology, Al-Quds University, Abu-Dies, East Jerusalem 19356, Palestine; (A.S.); (H.A.); (S.B.); (D.M.B.)
| | - Marina Pecellin
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research (HZI), Inhoffenstrasse 7, 38124 Braunschweig, Germany; (A.R.Z.); (M.P.); (R.L.); (I.B.)
| | - Alaa Salah
- Department of Microbiology and Immunology, Al-Quds University, Abu-Dies, East Jerusalem 19356, Palestine; (A.S.); (H.A.); (S.B.); (D.M.B.)
| | - Hanna Alalam
- Department of Microbiology and Immunology, Al-Quds University, Abu-Dies, East Jerusalem 19356, Palestine; (A.S.); (H.A.); (S.B.); (D.M.B.)
| | - Suha Butmeh
- Department of Microbiology and Immunology, Al-Quds University, Abu-Dies, East Jerusalem 19356, Palestine; (A.S.); (H.A.); (S.B.); (D.M.B.)
| | - Michael Steinert
- Department of Life Sciences, Institute of Microbiology, Technical University of Braunschweig, Universitätsplatz 2, 38106 Braunschweig, Germany;
| | - Rene Lesnik
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research (HZI), Inhoffenstrasse 7, 38124 Braunschweig, Germany; (A.R.Z.); (M.P.); (R.L.); (I.B.)
| | - Ingrid Brettar
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research (HZI), Inhoffenstrasse 7, 38124 Braunschweig, Germany; (A.R.Z.); (M.P.); (R.L.); (I.B.)
| | - Manfred G. Höfle
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research (HZI), Inhoffenstrasse 7, 38124 Braunschweig, Germany; (A.R.Z.); (M.P.); (R.L.); (I.B.)
| | - Dina M. Bitar
- Department of Microbiology and Immunology, Al-Quds University, Abu-Dies, East Jerusalem 19356, Palestine; (A.S.); (H.A.); (S.B.); (D.M.B.)
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Jiang L, Zhao S, Cai X, Mu D, Zhang X, Kang J, Zhao L, Chen Y. Sequence-based typing of clinical and environmental Legionella pneumophila isolates in Shenyang, China. Enferm Infecc Microbiol Clin 2020; 39:S0213-005X(20)30243-3. [PMID: 32718496 DOI: 10.1016/j.eimc.2020.06.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 05/29/2020] [Accepted: 06/04/2020] [Indexed: 11/20/2022]
Abstract
INTRODUCTION We performed SBT (sequence-based typing) on clinical and environmental Legionellapneumophila isolates in Shenyang (China). We analyzed and compared the results with those obtained by PFGE (pulsed field gel electrophoresis). METHODS Twenty-two L. pneumophila isolates were collected from two patients with L. pneumophila infection, two hospitals, and 13 office buildings. There were two clinical isolates, one strain isolated from domestic tap water, another from shower water and 18 strains from cooling tower water. All these isolates were analyzed by SBT and PFGE methods. RESULTS The 22 isolates were divided into 7 types by SBT. Five isolates belonged to novel sequence types (ST2345, ST2344, ST2406, ST2407, and ST2408) and one isolate belonged to ST328. The STs were not obtained for two of the isolates. The remaining 14 isolates belonged to ST1. PFGE typing divided the 22 isolates into 14 pulsotypes. The main pulsotype was SYC, which included seven isolates. CONCLUSION Both typing methods showed that predominant clonal lines exist in the Shenyang region, with high levels of genetic polymorphisms. Five novel STs were identified, indicating a unique genetic composition of L. pneumophila strains in this region, which are significantly different from those found in other environmental water systems in the world.
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Affiliation(s)
- Luxi Jiang
- Department of Pulmonary and Critical Care Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China; Department of Respiratory Medicine, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Sihong Zhao
- Department of Pulmonary and Critical Care Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China; Department of Respiratory Medicine, the First Hospital of Shijiazhuang, Hebei, China
| | - Xu Cai
- Institute of Respiratory Disease, The First Hospital of China Medical University, Shenyang, China
| | - Deguang Mu
- Department of Respiratory Medicine, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Xianghua Zhang
- Department of Respiratory Medicine, the First Hospital of Shijiazhuang, Hebei, China
| | - Jian Kang
- Institute of Respiratory Disease, The First Hospital of China Medical University, Shenyang, China
| | - Li Zhao
- Department of Pulmonary and Critical Care Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Yu Chen
- Department of Pulmonary and Critical Care Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China.
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Yakunin E, Kostyal E, Agmon V, Grotto I, Valinsky L, Moran-Gilad J. A Snapshot of the Prevalence and Molecular Diversity of Legionella pneumophila in the Water Systems of Israeli Hotels. Pathogens 2020; 9:pathogens9060414. [PMID: 32471136 PMCID: PMC7350324 DOI: 10.3390/pathogens9060414] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/19/2020] [Accepted: 05/23/2020] [Indexed: 11/16/2022] Open
Abstract
Exposure to Legionella spp. contaminated aerosols in hotel settings confers risk for travel-associated Legionnaire’s disease (TALD). In this study, we investigated the prevalence of Legionella contamination and its molecular diversity in hotels and resorts across Israel. The study was comprised of a convenience sample of water systems from 168 hotels and resorts countrywide, routinely inspected between March 2015 and February 2017. Isolation and quantitation of Legionella were performed in a water laboratory using the ISO 11731 method. The distribution of Legionella isolates was analyzed according to geography and source. The genetic diversity of a subset of isolates was analyzed by sequence-based typing (SBT) at the National Reference Laboratory for Legionella and compared to the national database. Out of 2830 samples tested, 470 (17%) obtained from 102 different premises (60% of hotels) were positive for Legionella spp. In 230 samples (49% of all positive, 8% of total samples), accounting for 37% of hotels, Legionella spp. counts exceeded the regulatory threshold of 1000 CFU/L. The most frequently contaminated water sources were cooling towers (38%), followed by faucets, hot tubs, water lines, and storage tanks (14–17% each). Furthermore, 32% and 17% of samples obtained from cooling towers and hot tubs, respectively, exceeded the regulatory thresholds. SBT was performed on 78 strains and revealed 27 different sequence types (STs), including two novel STs. The most prevalent STs found were ST1 (26%), ST87 (10%), ST93 (6%), and ST461 and ST1516 (5% each). Several L. pneumophila STs were found to be limited to certain geographical regions. This is the first study to investigate the prevalence and diversity of Legionella in hotels and resorts in Israel during non-outbreak environmental inspections. These findings will inform risk assessment, surveillance, and control measures of TALD.
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Affiliation(s)
- Eugenia Yakunin
- Central Laboratories and Public Health Services, Ministry of Health, Jerusalem 9134302, Israel; (E.Y.); (V.A.); (I.G.); (L.V.)
| | - Eszter Kostyal
- Department of Water Microbiology, Biolab Ltd., Jerusalem 9134001, Israel;
| | - Vered Agmon
- Central Laboratories and Public Health Services, Ministry of Health, Jerusalem 9134302, Israel; (E.Y.); (V.A.); (I.G.); (L.V.)
| | - Itamar Grotto
- Central Laboratories and Public Health Services, Ministry of Health, Jerusalem 9134302, Israel; (E.Y.); (V.A.); (I.G.); (L.V.)
- Department of Health Systems Management, School of Public Health, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Lea Valinsky
- Central Laboratories and Public Health Services, Ministry of Health, Jerusalem 9134302, Israel; (E.Y.); (V.A.); (I.G.); (L.V.)
| | - Jacob Moran-Gilad
- Central Laboratories and Public Health Services, Ministry of Health, Jerusalem 9134302, Israel; (E.Y.); (V.A.); (I.G.); (L.V.)
- Department of Health Systems Management, School of Public Health, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
- Correspondence:
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Ginevra C, Chastang J, David S, Mentasti M, Yakunin E, Chalker VJ, Chalifa-Caspi V, Valinsky L, Jarraud S, Moran-Gilad J. A real-time PCR for specific detection of the Legionella pneumophila serogroup 1 ST1 complex. Clin Microbiol Infect 2019; 26:514.e1-514.e6. [PMID: 31525518 DOI: 10.1016/j.cmi.2019.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 08/28/2019] [Accepted: 09/01/2019] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Legionella pneumophila serogroup 1 (Lp1) sequence type (ST) 1 is globally widespread in the environment and accounts for a significant proportion of Legionella infections, including nosocomial Legionnaires' disease (LD). This study aimed to design a sensitive and specific detection method for Lp ST1 that will underpin epidemiological investigations and risk assessment. METHODS A total of 628 Lp genomes (126 ST1s) were analyzed by comparative genomics. Interrogation of more than 900 accessory genes revealed seven candidate targets for specific ST1 detection and specific primers and hydrolysis probes were designed and evaluated. The analytical sensitivity and specificity of the seven primer and probe sets were evaluated on serially diluted DNA extracted from the reference strain CIP107629 and via qPCR applied on 200 characterized isolates. The diagnostic performance of the assay was evaluated on 142 culture-proven clinical samples from LD cases and a real-life investigation of a case cluster. RESULTS Of seven qPCR assays that underwent analytical validation, one PCR target (lpp1868) showed higher sensitivity and specificity for ST1 and ST1-like strains. The diagnostic performance of the assay using respiratory samples corresponded to a sensitivity of 95% (19/20) (95% CI (75.1-99.9)) and specificity of 100% (122/122) (95% CI (97-100)). The ST1 PCR assay could link two out of three culture-negative hospitalized LD cases to ST1 during a real-time investigation. CONCLUSION Using whole genome sequencing (WGS) data, we developed and validated a sensitive and specific qPCR assay for the detection of Lp1 belonging to the ST1 clonal complex by amplification of the lpp1868 gene. The ST1 qPCR is expected to deliver an added value for Lp control and prevention, in conjunction with other recently developed molecular assays.
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Affiliation(s)
- C Ginevra
- CIRI, Centre International de Recherche en Infectiologie, Legionella Pathogenesis Team, Univ Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, F-69007, Lyon, France; National Reference Centre of Legionella, Institute of Infectious Agents, Hospices Civils de Lyon, Lyon, France; ESCMID Study Group for Legionella Infections (ESGLI), Basel, Switzerland
| | - J Chastang
- National Reference Centre of Legionella, Institute of Infectious Agents, Hospices Civils de Lyon, Lyon, France
| | - S David
- ESCMID Study Group for Legionella Infections (ESGLI), Basel, Switzerland; Pathogen Genomics, Welcome Trust Sanger Institute, Cambridge, UK; Respiratory and Vaccine Preventable Bacteria Reference Unit, Public Health England, London, UK
| | - M Mentasti
- ESCMID Study Group for Legionella Infections (ESGLI), Basel, Switzerland; Respiratory and Vaccine Preventable Bacteria Reference Unit, Public Health England, London, UK
| | - E Yakunin
- ESCMID Study Group for Legionella Infections (ESGLI), Basel, Switzerland; Central Laboratories, Public Health Services, Ministry of Health, Jerusalem, Israel
| | - V J Chalker
- ESCMID Study Group for Legionella Infections (ESGLI), Basel, Switzerland; Respiratory and Vaccine Preventable Bacteria Reference Unit, Public Health England, London, UK
| | - V Chalifa-Caspi
- National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - L Valinsky
- Central Laboratories, Public Health Services, Ministry of Health, Jerusalem, Israel
| | - S Jarraud
- CIRI, Centre International de Recherche en Infectiologie, Legionella Pathogenesis Team, Univ Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, F-69007, Lyon, France; National Reference Centre of Legionella, Institute of Infectious Agents, Hospices Civils de Lyon, Lyon, France; ESCMID Study Group for Legionella Infections (ESGLI), Basel, Switzerland
| | - J Moran-Gilad
- ESCMID Study Group for Legionella Infections (ESGLI), Basel, Switzerland; School of Public Health, Faculty of Health Sciences, Ben-Gurion University of the Negev. Beer-Sheva, Israel; Public Health Services, Ministry of Health, Jerusalem, Israel.
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10
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Jiang L, Amemura-Maekawa J, Ren H, Li Y, Sakata M, Zhou H, Murai M, Chang B, Ohnishi M, Qin T. Distribution of lag-1 Alleles, ORF7, and ORF8 Genes of Lipopolysaccharide and Sequence-Based Types Among Legionella pneumophila Serogroup 1 Isolates in Japan and China. Front Cell Infect Microbiol 2019; 9:274. [PMID: 31448241 PMCID: PMC6691400 DOI: 10.3389/fcimb.2019.00274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 07/17/2019] [Indexed: 01/08/2023] Open
Abstract
Approximately 85% of cases of Legionnaires' disease are caused by Legionella pneumophila serogroup 1. In this study, we analyzed the distribution of lag-1 alleles, ORF 7 and ORF 8 genes of lipopolysaccharide (LPS) and sequence-based types of 616 L. pneumophila serogroup 1 strains isolated in Japan (206 clinical, 225 environmental) and China (13 clinical and 172 environmental). The lag-1 gene was harbored by significantly more of the clinical isolates compared with the environmental isolates (90.3 vs. 19.1% and 61.6 vs. 3.0%, respectively; both P < 0.001). ORF 7 genes were detected in 51.0% of Japanese clinical and 36.0% of Japanese environmental (P = 0.001) isolates, as well as 15.3% of Chinese clinical and 9.9% of Chinese environmental isolates (P = 0.544). ORF 8 genes were detected in 12.1% of Japanese clinical and 5.8% of Japanese environmental (P = 0.017) isolates, as well as 7.7% of Chinese clinical and 3.4% of Chinese environmental isolates (P = 0.388). The Japanese and Chinese isolates were assigned to 203 and 36 different sequence-types (ST), respectively. ST1 was predominant. Most isolates with the same ST also had the same lag-1, ORF 7, and ORF 8 gene subgroups. In conclusion, the lag-1 was present in most of the clinical isolates, but was absent from most of the environmental isolates from both China and Japan, regardless of the water source and SBT type. PCR-based serotyping and subgrouping methods can be used to define a hierarchy of virulence genotypes that require stringent surveillance to prevent human disease.
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Affiliation(s)
- Luxi Jiang
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Centre for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China.,Department of Respiratory Medicine, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Junko Amemura-Maekawa
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Hongyu Ren
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Centre for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Yinan Li
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Centre for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Miho Sakata
- Department of Health Sciences, Saitama Prefectural University, Saitama, Japan
| | - Haijian Zhou
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Centre for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Miyo Murai
- Department of Health Sciences, Saitama Prefectural University, Saitama, Japan
| | - Bin Chang
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Makoto Ohnishi
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Tian Qin
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Centre for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
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11
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Nakanishi N, Nomoto R, Tanaka S, Arikawa K, Iwamoto T. Analysis of Genetic Characterization and Clonality of Legionella pneumophila Isolated from Cooling Towers in Japan. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16091664. [PMID: 31086119 PMCID: PMC6540132 DOI: 10.3390/ijerph16091664] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 05/09/2019] [Accepted: 05/10/2019] [Indexed: 01/01/2023]
Abstract
We investigated the genetic characteristics of 161 Legionella pneumophila strains isolated over a period of 10 years from cooling towers in Japan. Minimum spanning tree analysis based on the sequence-based typing (SBT) of them identified three clonal complexes (CCs); CC1 (105/161, 65.2%), CC2 (22 /161, 13.7%), and CC3 (20/161, 12.4%). CC1 was formed by serogroup (SG) 1 and SG7, whereas CC2 was mainly formed by SG1. All of the CC3 isolates except two strains were SG13. The major sequence types (STs) in CC1 and CC2 were ST1 (88/105, 83.8%) and ST154 (15/22, 68.2%), respectively. These STs are known as typical types of L. pneumophila SG1 in Japanese cooling tower. Additionally, we identified 15 strains of ST2603 as the major type in CC3. This ST has not been reported in Japanese cooling tower. Whole genome sequencing (WGS) analysis of the representative strains in the three CCs, which were isolated from various cooling towers over the 10 years, elucidated high clonal population of L. pneumophila in Japanese cooling tower. Moreover, it revealed that the strains of CC2 are phylogenetically distant compared to those of CC1 and CC3, and belonged to L. pneumophila subsp. fraseri.
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Affiliation(s)
- Noriko Nakanishi
- Department of Infectious Diseases, Kobe Institute of Health, 4-6-5 Minatojima-nakamichi, Chuo-ku, Kobe 650-0046, Japan.
| | - Ryohei Nomoto
- Department of Infectious Diseases, Kobe Institute of Health, 4-6-5 Minatojima-nakamichi, Chuo-ku, Kobe 650-0046, Japan.
| | - Shinobu Tanaka
- Department of Infectious Diseases, Kobe Institute of Health, 4-6-5 Minatojima-nakamichi, Chuo-ku, Kobe 650-0046, Japan.
| | - Kentaro Arikawa
- Department of Infectious Diseases, Kobe Institute of Health, 4-6-5 Minatojima-nakamichi, Chuo-ku, Kobe 650-0046, Japan.
| | - Tomotada Iwamoto
- Department of Infectious Diseases, Kobe Institute of Health, 4-6-5 Minatojima-nakamichi, Chuo-ku, Kobe 650-0046, Japan.
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12
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De Giglio O, Napoli C, Apollonio F, Brigida S, Marzella A, Diella G, Calia C, Scrascia M, Pacifico C, Pazzani C, Uricchio VF, Montagna MT. Occurrence of Legionella in groundwater used for sprinkler irrigation in Southern Italy. ENVIRONMENTAL RESEARCH 2019; 170:215-221. [PMID: 30594053 DOI: 10.1016/j.envres.2018.12.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 12/17/2018] [Accepted: 12/18/2018] [Indexed: 06/09/2023]
Abstract
Legionellae are opportunistic bacteria that cause various conditions after exposure to contaminated aerosols, ranging from a serious type of pneumonia to a mild case of an influenza-like illness. Despite the risks of exposure, little is known about the occurrence of Legionella in natural environments and, even though studies have shown that there is a potential risk of transmission via inhalation, it does not have to be detected in groundwater that is used for irrigation. The culture methods traditionally used to detect Legionella have several limits that can be partly solved by applying molecular techniques. Samples from 177 wells in Apulia, Southern Italy, were collected twice, in winter and in summer, and analyzed. When compared with the guidelines, 145 (81.9%) of the sampled wells were suitable for irrigation use. The culture-based method highlighted the presence of different species and serogroups of Legionella in 31 (21.2%) of the 145 wells that were shown to be suitable for irrigation use. A greater number of wells returned positive results for Legionella in summer than in winter (p = 0.023), and the median concentrations were mostly higher in summer (500 CFU/L) than in winter (300 CFU/L). The median temperature in the Legionella positive well waters was significantly higher than that in the negative ones, both in winter and in summer (p < 0.001). Using molecular techniques, Legionella non-pneumophila was found in 37 of the 114 wells earlier detected as suitable for irrigation use but negative for Legionella by the culture-based methods. The distribution of Legionella differ significantly in porous aquifers compared to the karst-fissured ones both with quantitative polymerase chain reaction (qPCR) (p = 0.0004) and viable cells by propidium monoazide (PMA-qPCR) (p = 0.0000). Legionella concentrations were weakly correlated with temperature of water both with qPCR (ρ = 0.47, p = 0.0033) and PMA-qPCR (ρ = 0.41, p = 0.0126). Our data suggest that water that aerosolizes when sprinkled on plants represents a potential source of Legionellosis, with a higher risk from exposure in summer. On a practical level, this finding is important for workers (farmers and gardeners) who are in contact with waters used for irrigation.
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Affiliation(s)
- Osvalda De Giglio
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Bari, Italy.
| | - Christian Napoli
- Department of Medical and Surgical sciences and translational Medicine, Sapienza University of Rome, Italy.
| | - Francesca Apollonio
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Bari, Italy.
| | - Silvia Brigida
- Water Research Institute, National Research Council, Bari, Italy.
| | - Angelo Marzella
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Bari, Italy.
| | - Giusy Diella
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Bari, Italy.
| | - Carla Calia
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Bari, Italy.
| | - Maria Scrascia
- Department of Biology, University of Bari "Aldo Moro", Bari, Italy.
| | - Claudia Pacifico
- Centre of Biostatistics for Clinical Epidemiology, School of Medicine and Surgery, University of Milano-Bicocca, Milano, Italy
| | - Carlo Pazzani
- Department of Biology, University of Bari "Aldo Moro", Bari, Italy.
| | | | - Maria Teresa Montagna
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Bari, Italy.
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13
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Mercante JW, Caravas JA, Ishaq MK, Kozak-Muiznieks NA, Raphael BH, Winchell JM. Genomic heterogeneity differentiates clinical and environmental subgroups of Legionella pneumophila sequence type 1. PLoS One 2018; 13:e0206110. [PMID: 30335848 PMCID: PMC6193728 DOI: 10.1371/journal.pone.0206110] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 10/05/2018] [Indexed: 11/19/2022] Open
Abstract
Legionella spp. are the cause of a severe bacterial pneumonia known as Legionnaires' disease (LD). In some cases, current genetic subtyping methods cannot resolve LD outbreaks caused by common, potentially endemic L. pneumophila (Lp) sequence types (ST), which complicates laboratory investigations and environmental source attribution. In the United States (US), ST1 is the most prevalent clinical and environmental Lp sequence type. In order to characterize the ST1 population, we sequenced 289 outbreak and non-outbreak associated clinical and environmental ST1 and ST1-variant Lp strains from the US and, together with international isolate sequences, explored their genetic and geographic diversity. The ST1 population was highly conserved at the nucleotide level; 98% of core nucleotide positions were invariant and environmental isolates unassociated with human disease (n = 99) contained ~65% more nucleotide diversity compared to clinical-sporadic (n = 139) or outbreak-associated (n = 28) ST1 subgroups. The accessory pangenome of environmental isolates was also ~30-60% larger than other subgroups and was enriched for transposition and conjugative transfer-associated elements. Up to ~10% of US ST1 genetic variation could be explained by geographic origin, but considerable genetic conservation existed among strains isolated from geographically distant states and from different decades. These findings provide new insight into the ST1 population structure and establish a foundation for interpreting genetic relationships among ST1 strains; these data may also inform future analyses for improved outbreak investigations.
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Affiliation(s)
- Jeffrey W. Mercante
- Pneumonia Response and Surveillance Laboratory, Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Jason A. Caravas
- Pneumonia Response and Surveillance Laboratory, Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Maliha K. Ishaq
- Pneumonia Response and Surveillance Laboratory, Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Natalia A. Kozak-Muiznieks
- Pneumonia Response and Surveillance Laboratory, Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Brian H. Raphael
- Pneumonia Response and Surveillance Laboratory, Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Jonas M. Winchell
- Pneumonia Response and Surveillance Laboratory, Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
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14
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Legionella pneumophila and Other Legionella Species Isolated from Legionellosis Patients in Japan between 2008 and 2016. Appl Environ Microbiol 2018; 84:AEM.00721-18. [PMID: 29980559 DOI: 10.1128/aem.00721-18] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 06/27/2018] [Indexed: 12/13/2022] Open
Abstract
The Legionella Reference Center in Japan collected 427 Legionella clinical isolates between 2008 and 2016, including 7 representative isolates from corresponding outbreaks. The collection included 419 Legionella pneumophila isolates, of which 372 belonged to serogroup 1 (SG1) (87%) and the others belonged to SG2 to SG15 except for SG7 and SG11, and 8 isolates of other Legionella species (Legionella bozemanae, Legionella dumoffii, Legionella feeleii, Legionella longbeachae, Legionella londiniensis, and Legionella rubrilucens). L. pneumophila isolates were genotyped by sequence-based typing (SBT) and represented 187 sequence types (STs), of which 126 occurred in a single isolate (index of discrimination of 0.984). These STs were analyzed using minimum spanning tree analysis, resulting in the formation of 18 groups. The pattern of overall ST distribution among L. pneumophila isolates was diverse. In particular, some STs were frequently isolated and were suggested to be related to the infection sources. The major STs were ST23 (35 isolates), ST120 (20 isolates), and ST138 (16 isolates). ST23 was the most prevalent and most causative ST for outbreaks in Japan and Europe. ST138 has been observed only in Japan, where it has caused small-scale outbreaks; 81% of those strains (13 isolates) were suspected or confirmed to infect humans through bath water sources. On the other hand, 11 ST23 strains (31%) and 5 ST120 strains (25%) were suspected or confirmed to infect humans through bath water. These findings suggest that some ST strains frequently cause legionellosis in Japan and are found under different environmental conditions.IMPORTANCELegionella pneumophila serogroup 1 (SG1) is the most frequent cause of legionellosis. Our previous genetic analysis indicated that SG1 environmental isolates represented 8 major clonal complexes, consisting of 3 B groups, 2 C groups, and 3 S groups, which included major environmental isolates derived from bath water, cooling towers, and soil and puddles, respectively. Here, we surveyed clinical isolates collected from patients with legionellosis in Japan between 2008 and 2016. Most strains belonging to the B group were isolated from patients for whom bath water was the suspected or confirmed source of infection. Among the isolates derived from patients whose suspected infection source was soil or dust, most belonged to the S1 group and none belonged to the B or C groups. Additionally, the U group was discovered as a new group, which mainly included clinical isolates with unknown infection sources.
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15
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Hamilton KA, Hamilton MT, Johnson W, Jjemba P, Bukhari Z, LeChevallier M, Haas CN. Health risks from exposure to Legionella in reclaimed water aerosols: Toilet flushing, spray irrigation, and cooling towers. WATER RESEARCH 2018; 134:261-279. [PMID: 29428779 DOI: 10.1016/j.watres.2017.12.022] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 11/30/2017] [Accepted: 12/12/2017] [Indexed: 05/05/2023]
Abstract
The use of reclaimed water brings new challenges for the water industry in terms of maintaining water quality while increasing sustainability. Increased attention has been devoted to opportunistic pathogens, especially Legionella pneumophila, due to its growing importance as a portion of the waterborne disease burden in the United States. Infection occurs when a person inhales a mist containing Legionella bacteria. The top three uses for reclaimed water (cooling towers, spray irrigation, and toilet flushing) that generate aerosols were evaluated for Legionella health risks in reclaimed water using quantitative microbial risk assessment (QMRA). Risks are compared using data from nineteen United States reclaimed water utilities measured with culture-based methods, quantitative PCR (qPCR), and ethidium-monoazide-qPCR. Median toilet flushing annual infection risks exceeded 10-4 considering multiple toilet types, while median clinical severity infection risks did not exceed this value. Sprinkler and cooling tower risks varied depending on meteorological conditions and operational characteristics such as drift eliminator performance. However, the greatest differences between risk scenarios were due to 1) the dose response model used (infection or clinical severity infection) 2) population at risk considered (residential or occupational) and 3) differences in laboratory analytical method. Theoretical setback distances necessary to achieve a median annual infection risk level of 10-4 are proposed for spray irrigation and cooling towers. In both cooling tower and sprinkler cases, Legionella infection risks were non-trivial at potentially large setback distances, and indicate other simultaneous management practices could be needed to manage risks. The sensitivity analysis indicated that the most influential factors for variability in risks were the concentration of Legionella and aerosol partitioning and/or efficiency across all models, highlighting the importance of strategies to manage Legionella occurrence in reclaimed water.
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Affiliation(s)
- Kerry A Hamilton
- Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA.
| | | | - William Johnson
- American Water Research Laboratory, 213 Carriage Lane, Delran, New Jersey 08075, USA
| | - Patrick Jjemba
- American Water Research Laboratory, 213 Carriage Lane, Delran, New Jersey 08075, USA
| | - Zia Bukhari
- American Water Research Laboratory, 213 Carriage Lane, Delran, New Jersey 08075, USA
| | - Mark LeChevallier
- American Water Research Laboratory, 213 Carriage Lane, Delran, New Jersey 08075, USA
| | - Charles N Haas
- Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA
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16
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Population structure of Environmental and Clinical Legionella pneumophila isolates in Catalonia. Sci Rep 2018; 8:6241. [PMID: 29674708 PMCID: PMC5908911 DOI: 10.1038/s41598-018-24708-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 04/09/2018] [Indexed: 11/13/2022] Open
Abstract
Legionella is the causative agent of Legionnaires’ disease (LD). In Spain, Catalonia is the region with the highest incidence of LD cases. The characterisation of clinical and environmental isolates using molecular epidemiology techniques provides epidemiological data for a specific geographic region and makes it possible to carry out phylogenetic and population-based analyses. The aim of this study was to describe and compare environmental and clinical isolates of Legionella pneumophila in Catalonia using sequence-based typing and monoclonal antibody subgrouping. A total of 528 isolates were characterised. For data analysis, the isolates were filtered to reduce redundancies, and 266 isolates (109 clinical and 157 environmental) were finally included. Thirty-two per cent of the clinical isolates were ST23, ST37 and ST1 while 40% of the environmental isolates were ST284 and ST1. Although the index of diversity was higher in clinical than in environmental ST isolates, we observed that clinical STs were similar to those recorded in other regions but that environmental STs were more confined to particular study areas. This observation supports the idea that only certain STs trigger cases or outbreaks in humans. Therefore, comparison of the genomes of clinical and environmental isolates could provide important information about the traits that favour infection or environmental persistence.
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17
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Veenendaal HR, Brouwer-Hanzens AJ, van der Kooij D. Incubation of premise plumbing water samples on Buffered Charcoal Yeast Extract agar at elevated temperature and pH selects for Legionella pneumophila. WATER RESEARCH 2017; 123:439-447. [PMID: 28689128 DOI: 10.1016/j.watres.2017.06.077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 05/30/2017] [Accepted: 06/26/2017] [Indexed: 06/07/2023]
Abstract
Worldwide, over 90% of the notified cases of Legionnaires' disease are caused by Legionella pneumophila. However, the standard culture medium for the detection of Legionella in environmental water samples, Buffered Charcoal Yeast Extract (BCYE) agar of pH 6.9 ± 0.4 with or without antimicrobial agents incubated at 36 ± 1 °C, supports the growth of a large diversity of Legionella species. BCYE agar of elevated pH or/and incubation at elevated temperature gave strongly reduced recoveries of most of 26 L. non-pneumophila spp. tested, but not of L. pneumophila. BCYE agar of pH 7.3 ± 0.1, incubated at 40 ± 0.5 °C (BCYE pH 7.3/40 °C) was tested for selective enumeration of L. pneumophila. Of the L. non-pneumophila spp. tested, only L. adelaidensis and L. londiniensis multiplied under these conditions. The colony counts on BCYE pH 7.3/40 °C of a L. pneumophila serogroup 1 strain cultured in tap water did not differ significantly from those on BCYE pH 6.9/36 °C when directly plated and after membrane filtration and showed repeatability's of 13-14%. By using membrane filtration L. pneumophila was detected in 58 (54%) of 107 Legionella-positive water samples from premise plumbing systems under one or both of these culture conditions. The L. pneumophila colony counts (log-transformed) on BCYE pH 7.3/40 °C were strongly related (r2 = 0.87) to those on BCYE pH 6.9/36 °C, but differed significantly (p < 0.05) by a mean of - 0.12 ± 0.30 logs. L. non-pneumophila spp. were detected only on BCYE pH 6.9/36 °C in 49 (46%) of the samples. Hence, BCYE pH 7.3/40 °C can facilitate the enumeration of L. pneumophila and their isolation from premise plumbing systems with culturable L. non-pneumophila spp., some of which, e.g. L. anisa, can be present in high numbers.
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Affiliation(s)
- Harm R Veenendaal
- KWR Watercycle Research Institute, PO Box 1072, 3430 BB, Nieuwegein, The Netherlands
| | | | - Dick van der Kooij
- KWR Watercycle Research Institute, PO Box 1072, 3430 BB, Nieuwegein, The Netherlands.
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18
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Kanatani JI, Isobe J, Norimoto S, Kimata K, Mitsui C, Amemura-Maekawa J, Kura F, Sata T, Watahiki M. Prevalence of Legionella species isolated from shower water in public bath facilities in Toyama Prefecture, Japan. J Infect Chemother 2017; 23:265-270. [PMID: 28188095 DOI: 10.1016/j.jiac.2017.01.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 01/04/2017] [Accepted: 01/14/2017] [Indexed: 11/20/2022]
Abstract
AIMS We investigated the prevalence of Legionella spp. isolated from shower water in public bath facilities in Toyama Prefecture, Japan. In addition, we analyzed the genetic diversity among Legionella pneumophila isolates from shower water as well as the genetic relationship between isolates from shower water and from stock strains previously analyzed from sputum specimens. METHODS The isolates were characterized using serogrouping, 16S rRNA gene sequencing, and sequence-based typing. RESULTS Legionella spp. were isolated from 31/91 (34.1%) samples derived from 17/37 (45.9%) bath facilities. Isolates from shower water and bath water in each public bath facility were serologically or genetically different, indicating that we need to isolate several L. pneumophila colonies from both bath and shower water to identify public bath facilities as sources of legionellosis. The 61 L. pneumophila isolates from shower water were classified into 39 sequence types (STs) (index of discrimination = 0.974), including 19 new STs. Among the 39 STs, 12 STs match clinical isolates in the European Working Group for Legionella Infections database. Notably, ST505 L. pneumophila SG 1, a strain frequently isolated from patients with legionellosis and from bath water in this area, was isolated from shower water. CONCLUSIONS Pathogenic L. pneumophila strains including ST505 strain were widely distributed in shower water in public bath facilities, with genetic diversity showing several different origins. This study highlights the need to isolate several L. pneumophila colonies from both bath water and shower water to identify public bath facilities as infection sources in legionellosis cases.
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Affiliation(s)
- Jun-Ichi Kanatani
- Department of Bacteriology, Toyama Institute of Health, 17-1 Nakataikoyama, Imizu-City, Toyama 939-0363, Japan.
| | - Junko Isobe
- Department of Bacteriology, Toyama Institute of Health, 17-1 Nakataikoyama, Imizu-City, Toyama 939-0363, Japan
| | - Shiho Norimoto
- Department of Bacteriology, Toyama Institute of Health, 17-1 Nakataikoyama, Imizu-City, Toyama 939-0363, Japan
| | - Keiko Kimata
- Department of Bacteriology, Toyama Institute of Health, 17-1 Nakataikoyama, Imizu-City, Toyama 939-0363, Japan
| | - Chieko Mitsui
- Department of Bacteriology, Toyama Institute of Health, 17-1 Nakataikoyama, Imizu-City, Toyama 939-0363, Japan
| | - Junko Amemura-Maekawa
- Department of Bacteriology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Fumiaki Kura
- Department of Bacteriology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Tetsutaro Sata
- Department of Bacteriology, Toyama Institute of Health, 17-1 Nakataikoyama, Imizu-City, Toyama 939-0363, Japan
| | - Masanori Watahiki
- Department of Bacteriology, Toyama Institute of Health, 17-1 Nakataikoyama, Imizu-City, Toyama 939-0363, Japan
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19
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Ishizaki N, Sogawa K, Inoue H, Agata K, Edagawa A, Miyamoto H, Fukuyama M, Furuhata K. Legionella thermalis sp. nov., isolated from hot spring water in Tokyo, Japan. Microbiol Immunol 2017; 60:203-8. [PMID: 26865126 DOI: 10.1111/1348-0421.12366] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 01/24/2016] [Accepted: 02/02/2016] [Indexed: 10/22/2022]
Abstract
Strain L-47(T) of a novel bacterial species belonging to the genus Legionella was isolated from a sample of hot spring water from Tokyo, Japan. The 16S rRNA gene sequences (1477 bp) of this strain (accession number AB899895) had less than 95.0% identity with other Legionella species. The dominant fatty acids of strain L-47(T) were a15:0 (29.6%) and the major ubiquinone was Q-12 (71.1%). It had a guanine-plus-cytosine content of 41.5 mol%. The taxonomic description of Legionella thermalis sp. nov. is proposed to be type strain L-47(T) (JCM 30970(T) = KCTC 42799(T)).
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Affiliation(s)
- Naoto Ishizaki
- School of Life and Environmental Science, Azabu University, Kanagawa, 252-5201
| | - Kazuyuki Sogawa
- School of Life and Environmental Science, Azabu University, Kanagawa, 252-5201
| | - Hiroaki Inoue
- Tsukuba Research Laboratories, Aquas Corporation, Ibaraki, 300-2646
| | - Kunio Agata
- Tsukuba Research Laboratories, Aquas Corporation, Ibaraki, 300-2646
| | - Akiko Edagawa
- Department of Environmental Health, Osaka Prefectural Institute of Public Health, Osaka, 537-0025.,Faculty of Medicine, Saga University, Saga, 849-8501, Japan
| | | | - Masafumi Fukuyama
- School of Life and Environmental Science, Azabu University, Kanagawa, 252-5201
| | - Katsunori Furuhata
- School of Life and Environmental Science, Azabu University, Kanagawa, 252-5201
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Multiplication of Legionella pneumophila Sequence Types 1, 47, and 62 in Buffered Yeast Extract Broth and Biofilms Exposed to Flowing Tap Water at Temperatures of 38°C to 42°C. Appl Environ Microbiol 2016; 82:6691-6700. [PMID: 27613680 DOI: 10.1128/aem.01107-16] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 09/01/2016] [Indexed: 12/11/2022] Open
Abstract
Legionella pneumophila proliferates in freshwater environments at temperatures ranging from 25 to 45°C. To investigate the preference of different sequence types (ST) for a specific temperature range, growth of L. pneumophila serogroup 1 (SG1) ST1 (environmental strains), ST47, and ST62 (disease-associated strains) was measured in buffered yeast extract broth (BYEB) and biofilms grown on plasticized polyvinyl chloride in flowing heated drinking water originating from a groundwater supply. The optimum growth temperatures in BYEB were approximately 37°C (ST1), 39°C (ST47), and 41°C (ST62), with maximum growth temperatures of 42°C (ST1) and 43°C (ST47 and ST62). In the biofilm at 38°C, the ST47 and ST62 strains multiplied equally well compared to growth of the environmental ST1 strain and an indigenous L. pneumophila non-SG1 strain, all attaining a concentration of approximately 107 CFU/cm-2 Raising the temperature to 41°C did not impact these levels within 4 weeks, but the colony counts of all strains tested declined (at a specific decline rate of 0.14 to 0.41 day-1) when the temperature was raised to 42°C. At this temperature, the concentration of Vermamoeba vermiformis in the biofilm, determined with quantitative PCR (qPCR), was about 2 log units lower than the concentration at 38°C. In columns operated at a constant temperature, ranging from 38 to 41°C, none of the tested strains multiplied in the biofilm at 41°C, in which also V. vermiformis was not detected. These observations suggest that strains of ST47 and ST62 did not multiply in the biofilm at a temperature of ≥41°C because of the absence of a thermotolerant host. IMPORTANCE Growth of Legionella pneumophila in tap water installations is a serious public health concern. The organism includes more than 2,100 varieties (sequence types). More than 50% of the reported cases of Legionnaires' disease are caused by a few sequence types which are very rarely detected in the environment. Strains of selected virulent sequence types proliferated in biofilms on surfaces exposed to warm (38°C) tap water to the same level as environmental varieties and multiplied well as pure culture in a nutrient-rich medium at temperatures of 42 and 43°C. However, these organisms did not grow in the biofilms at temperatures of ≥41°C. Typical host amoebae also did not multiply at these temperatures. Apparently, proliferation of thermotolerant host amoebae is needed to enable multiplication of the virulent L. pneumophila strains in the environment at elevated temperatures. The detection of these amoebae in water installations therefore is a scientific challenge with practical implications.
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van Heijnsbergen E, van Deursen A, Bouwknegt M, Bruin JP, de Roda Husman AM, Schalk JAC. Presence and Persistence of Viable, Clinically Relevant Legionella pneumophila Bacteria in Garden Soil in the Netherlands. Appl Environ Microbiol 2016; 82:5125-31. [PMID: 27316958 PMCID: PMC4988192 DOI: 10.1128/aem.00595-16] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 06/01/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Garden soils were investigated as reservoirs and potential sources of pathogenic Legionella bacteria. Legionella bacteria were detected in 22 of 177 garden soil samples (12%) by amoebal coculture. Of these 22 Legionella-positive soil samples, seven contained Legionella pneumophila Several other species were found, including the pathogenic Legionella longbeachae (4 gardens) and Legionella sainthelensi (9 gardens). The L. pneumophila isolates comprised 15 different sequence types (STs), and eight of these STs were previously isolated from patients according to the European Working Group for Legionella Infections (EWGLI) database. Six gardens that were found to be positive for L. pneumophila were resampled after several months, and in three gardens, L. pneumophila was again isolated. One of these gardens was resampled four times throughout the year and was found to be positive for L. pneumophila on all occasions. IMPORTANCE Tracking the source of infection for sporadic cases of Legionnaires' disease (LD) has proven to be hard. L. pneumophila ST47, the sequence type that is most frequently isolated from LD patients in the Netherlands, is rarely found in potential environmental sources. As L. pneumophila ST47 was previously isolated from a garden soil sample during an outbreak investigation, garden soils were investigated as reservoirs and potential sources of pathogenic Legionella bacteria. The detection of viable, clinically relevant Legionella strains indicates that garden soil is a potential source of Legionella bacteria, and future research should assess the public health implication of the presence of L. pneumophila in garden soil.
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Affiliation(s)
- E van Heijnsbergen
- National Institute for Public Health and the Environment, Bilthoven, the Netherlands
| | - A van Deursen
- National Institute for Public Health and the Environment, Bilthoven, the Netherlands
| | - M Bouwknegt
- National Institute for Public Health and the Environment, Bilthoven, the Netherlands
| | - J P Bruin
- Regional Public Health Laboratory Kennemerland, Haarlem, the Netherlands
| | - A M de Roda Husman
- National Institute for Public Health and the Environment, Bilthoven, the Netherlands Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands
| | - J A C Schalk
- National Institute for Public Health and the Environment, Bilthoven, the Netherlands
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Garcia-Nuñez M, Quero S, Pedro-Botet ML, Barrabeig I, Avarez J, Campoy I, Sala MR, Parraga-Niño N, Minguell S, Caylà J, Mateu L, Sabria M. Characterization of unrelated clinical Legionella pneumophila isolates in Catalonia by monoclonal subgrouping and sequence-based typing. Future Microbiol 2016; 11:865-75. [PMID: 27357520 DOI: 10.2217/fmb-2016-0013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM To characterize the genetic diversity of unrelated Legionella pneumophila clinical isolates in Catalonia and compare with other European regions. METHODS 95 unrelated isolates were analyzed using monoclonal antibodies and sequence-based typing, 1989-2013. RESULTS The isolates showed a high diversity (IOD 0.964) with a predominance of some profiles (ST37-Phialdelphia, ST23-Philadelphia and ST1-OLDA). All regions had predominant sequence types (STs) that differed between regions, and only 3% of STs were shared between the three regions. CONCLUSION L. pneumophila clinical isolates from Catalonia presented a high diversity and can be used in epidemiological surveillance studies. The heterogeneous predominance of STs between European regions suggested a relationship between geographical distribution and virulence of some STs.
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Affiliation(s)
- Marian Garcia-Nuñez
- Infectious Diseases Unit, Fundació Institut d'Investigació Germans Trias i Pujol, Hospital Germans Trias i Pujol, Badalona, Spain E-08916.,Grupo de estudio de la Legionelosis, Autonomous University of Barcelona, Cerdanyola, Spain E-08913.,Ciber de Enfermedades Respiratorias, Madrid, Spain E-28029
| | - Sara Quero
- Infectious Diseases Unit, Fundació Institut d'Investigació Germans Trias i Pujol, Hospital Germans Trias i Pujol, Badalona, Spain E-08916.,Grupo de estudio de la Legionelosis, Autonomous University of Barcelona, Cerdanyola, Spain E-08913.,Ciber de Enfermedades Respiratorias, Madrid, Spain E-28029
| | - Maria Lluisa Pedro-Botet
- Infectious Diseases Unit, Fundació Institut d'Investigació Germans Trias i Pujol, Hospital Germans Trias i Pujol, Badalona, Spain E-08916.,Grupo de estudio de la Legionelosis, Autonomous University of Barcelona, Cerdanyola, Spain E-08913.,Ciber de Enfermedades Respiratorias, Madrid, Spain E-28029
| | - Irene Barrabeig
- Epidemiological Surveillance, Publich Health Agency of Catalonia, Barcelona, Spain E-08005
| | - Josep Avarez
- Epidemiological Surveillance, Publich Health Agency of Catalonia, Barcelona, Spain E-08005
| | - Irene Campoy
- Infectious Diseases Unit, Fundació Institut d'Investigació Germans Trias i Pujol, Hospital Germans Trias i Pujol, Badalona, Spain E-08916
| | - Maria Rosa Sala
- Epidemiological Surveillance, Publich Health Agency of Catalonia, Barcelona, Spain E-08005
| | - Noemí Parraga-Niño
- Infectious Diseases Unit, Fundació Institut d'Investigació Germans Trias i Pujol, Hospital Germans Trias i Pujol, Badalona, Spain E-08916.,Grupo de estudio de la Legionelosis, Autonomous University of Barcelona, Cerdanyola, Spain E-08913.,Ciber de Enfermedades Respiratorias, Madrid, Spain E-28029
| | - Sofia Minguell
- Epidemiological Surveillance, Publich Health Agency of Catalonia, Barcelona, Spain E-08005
| | - Joan Caylà
- Epidemiological Surveillance, Publich Health Agency of Catalonia, Barcelona, Spain E-08005.,Ciber de Salud Publica, Madrid, Spain, E-28029
| | - Lourdes Mateu
- Infectious Diseases Unit, Fundació Institut d'Investigació Germans Trias i Pujol, Hospital Germans Trias i Pujol, Badalona, Spain E-08916.,Grupo de estudio de la Legionelosis, Autonomous University of Barcelona, Cerdanyola, Spain E-08913.,Ciber de Enfermedades Respiratorias, Madrid, Spain E-28029
| | - Miquel Sabria
- Infectious Diseases Unit, Fundació Institut d'Investigació Germans Trias i Pujol, Hospital Germans Trias i Pujol, Badalona, Spain E-08916.,Grupo de estudio de la Legionelosis, Autonomous University of Barcelona, Cerdanyola, Spain E-08913.,Ciber de Enfermedades Respiratorias, Madrid, Spain E-28029
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23
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Quero S, García-Núñez M, Párraga-Niño N, Barrabeig I, Pedro-Botet ML, de Simon M, Sopena N, Sabrià M. Discriminatory usefulness of pulsed-field gel electrophoresis and sequence-based typing in Legionella outbreaks. Future Microbiol 2016; 11:757-65. [DOI: 10.2217/fmb-2015-0030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Aim: To compare the discriminatory power of pulsed-field gel electrophoresis (PFGE) and sequence-based typing (SBT) in Legionella outbreaks for determining the infection source. Materials & methods: Twenty-five investigations of Legionnaires’ disease were analyzed by PFGE, SBT and Dresden monoclonal antibody. Results: The results suggested that monoclonal antibody could reduce the number of Legionella isolates to be characterized by molecular methods. The epidemiological concordance PFGE–SBT was 100%, while the molecular concordance was 64%. Adjusted Wallace index (AW) showed that PFGE has better discriminatory power than SBT (AWSBT→PFGE = 0.767; AWPFGE→SBT = 1). The discrepancies appeared mostly in sequence type (ST) 1, a worldwide distributed ST for which PFGE discriminated different profiles. Conclusion: SBT discriminatory power was not sufficient verifying the infection source, especially in worldwide distributed STs, which were classified into different PFGE patterns.
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Affiliation(s)
- Sara Quero
- Unitat de Malalties Infeccioses, Fundació Institut d'Investigació Germans Trias I Pujol, Badalona, Spain E-08916
- Universitat Autònoma de Barcelona, Cerdanyola, Spain E-08193
| | - Marian García-Núñez
- Unitat de Malalties Infeccioses, Fundació Institut d'Investigació Germans Trias I Pujol, Badalona, Spain E-08916
- Universitat Autònoma de Barcelona, Cerdanyola, Spain E-08193
- CIBER de Enfermedades Respiratorias, Madrid, Spain E-28029
| | - Noemí Párraga-Niño
- Unitat de Malalties Infeccioses, Fundació Institut d'Investigació Germans Trias I Pujol, Badalona, Spain E-08916
- Universitat Autònoma de Barcelona, Cerdanyola, Spain E-08193
- CIBER de Enfermedades Respiratorias, Madrid, Spain E-28029
| | - Irene Barrabeig
- Vigilancia Epidemiologica, Agencia de Salut Publica de Catalunya, Barcelona, Spain E-08005
| | - Maria L Pedro-Botet
- Universitat Autònoma de Barcelona, Cerdanyola, Spain E-08193
- CIBER de Enfermedades Respiratorias, Madrid, Spain E-28029
- Unitat de Malalties Infeccioses, Hospital Universitari Germans Trias i Pujol, Badalona, Spain E-08916
| | - Mercè de Simon
- Laboratori de l'Agència de Salut Pública de Barcelona, Barcelona, Spain E-08001
| | - Nieves Sopena
- Universitat Autònoma de Barcelona, Cerdanyola, Spain E-08193
- CIBER de Enfermedades Respiratorias, Madrid, Spain E-28029
- Unitat de Malalties Infeccioses, Hospital Universitari Germans Trias i Pujol, Badalona, Spain E-08916
| | - Miquel Sabrià
- Universitat Autònoma de Barcelona, Cerdanyola, Spain E-08193
- CIBER de Enfermedades Respiratorias, Madrid, Spain E-28029
- Unitat de Malalties Infeccioses, Hospital Universitari Germans Trias i Pujol, Badalona, Spain E-08916
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Prevalence and Molecular Characteristics of Waterborne Pathogen Legionella in Industrial Cooling Tower Environments. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 12:12605-17. [PMID: 26473896 PMCID: PMC4626988 DOI: 10.3390/ijerph121012605] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/25/2015] [Accepted: 09/30/2015] [Indexed: 11/17/2022]
Abstract
Cooling towers are a source of Legionnaires' disease. It is important from a public health perspective to survey industrial cooling towers for the presence of Legionella. Prospective surveillance of the extent of Legionella pollution was conducted at factories in Shijiazhuang, China between March 2011 and September 2012. Overall, 35.7% of 255 industrial cooling tower water samples showed Legionella-positive, and their concentrations ranged from 100 Colony-Forming Units (CFU)/liter to 88,000 CFU/liter, with an average concentration of 9100 CFU/liter. A total of 121 isolates were obtained. All isolates were L. pneumophila, and the isolated serogroups included serogroups 1 (68 isolates, 56.2%), 6 (25, 20.7%), 5 (12, 9.9%), 8 (8, 6.6%), 3 (6, 5.0%) and 9 (2, 1.6%). All 121 isolates were analyzed by pulsed-field gel electrophoresis (PFGE) and 64 different patterns were obtained. All 121 isolates were analyzed sequence-based typing (SBT), a full 7-allele profile was obtained from 117 isolates. One hundred and seventeen isolates were divided into 49 sequence types. Two virulence genes, lvh and rtxA, are analyzed by polymerase chain reaction (PCR). 92.6% (112/121) and 98.3% (119/121) isolates carried lvh and rtxA respectively and 90.9% (110/121) of tested isolates carried both genes. Our results demonstrated high prevalence and genetic polymorphism of L. pneumophila in industrial cooling tower environments in Shijiazhang, China, and the SBT and virulence gene PCR results suggested that the isolates were pathogenic. Improved control and prevention strategies are urgently needed.
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Xiong L, Zhao H, Mo Z, Shi L. Prevalence of 7 virulence genes of Legionella strains isolated from environmental water sources of public facilities and sequence types diversity of L. pneumopila strains in Macau. Biosci Trends 2015; 9:214-20. [PMID: 26355222 DOI: 10.5582/bst.2015.01075] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In this study, we analyzed 7 virulence genes in 55 Legionella species (including 29 L. pneumophila and 26 non-L. pneumophila strains) which isolated from environmental water sources of the public facilities in Macau by using PCR and real-time PCR. In addition, 29 Legionella pneumophila isolates were subjected to genotyping by sequence-based typing scheme and compared with the data reported. The detection rate of flaA, pilE, asd, mip, mompS, proA and neuA genes in the L. pneumophila were 100.0%, respectively. The neuA gene was not detected in the non-L. pneumophila strains, but flaA, pilE, asd, mip, mompS, and proA genes could be amplified with a positive rate of 15.4%, 15.4%, 53.8%, 38.5%, 15.4%, and 38.5%, respectively. The results from real-time PCR were generally consistent with that of PCR. Those L. pneumophila strains were assigned into 10 sequence types (STs) and ST1 (9/29) was the dominant STs. Four new STs were found to be unique in Macau. The analysis of population structure of L. pneumophila strains which isolated from Macau, Guangzhou and Shenzhen indicated that the similar clones were existed and ST1 was the most prevalent STs. However, the distribution of the subtypes isolated from Macau was not the same extensive as those from Guangzhou and Shenzhen. The different detection rates of the 7 virulence genes in different species of Legionella might reflect their own potential for environmental adaptability and pathogenesis. And the data analyzed from STs diversity indicated the Macau L. pneumophila possessed obvious regional specificity and high genetic diversity.
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Affiliation(s)
- Lina Xiong
- School of Light Industry and Food Sciences, South China University of Technology
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van Heijnsbergen E, Schalk JAC, Euser SM, Brandsema PS, den Boer JW, de Roda Husman AM. Confirmed and Potential Sources of Legionella Reviewed. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:4797-815. [PMID: 25774976 DOI: 10.1021/acs.est.5b00142] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Legionella bacteria are ubiquitous in natural matrices and man-made systems. However, it is not always clear if these reservoirs can act as source of infection resulting in cases of Legionnaires' disease. This review provides an overview of reservoirs of Legionella reported in the literature, other than drinking water distribution systems. Levels of evidence were developed to discriminate between potential and confirmed sources of Legionella. A total of 17 systems and matrices could be classified as confirmed sources of Legionella. Many other man-made systems or natural matrices were not classified as a confirmed source, since either no patients were linked to these reservoirs or the supporting evidence was weak. However, these systems or matrices could play an important role in the transmission of infectious Legionella bacteria; they might not yet be considered in source investigations, resulting in an underestimation of their importance. To optimize source investigations it is important to have knowledge about all the (potential) sources of Legionella. Further research is needed to unravel what the contribution is of each confirmed source, and possibly also potential sources, to the LD disease burden.
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Affiliation(s)
- Eri van Heijnsbergen
- †National Institute for Public Health and the Environment, A. van Leeuwenhoeklaan 9, 3721 MA Bilthoven, The Netherlands
| | - Johanna A C Schalk
- †National Institute for Public Health and the Environment, A. van Leeuwenhoeklaan 9, 3721 MA Bilthoven, The Netherlands
| | - Sjoerd M Euser
- ‡Regional Public Health Laboratory Kennemerland, Haarlem, Boerhaavelaan 26, 2035 RC Haarlem, The Netherlands
| | - Petra S Brandsema
- †National Institute for Public Health and the Environment, A. van Leeuwenhoeklaan 9, 3721 MA Bilthoven, The Netherlands
| | - Jeroen W den Boer
- ‡Regional Public Health Laboratory Kennemerland, Haarlem, Boerhaavelaan 26, 2035 RC Haarlem, The Netherlands
| | - Ana Maria de Roda Husman
- †National Institute for Public Health and the Environment, A. van Leeuwenhoeklaan 9, 3721 MA Bilthoven, The Netherlands
- §Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands
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Sequence types diversity of Legionella pneumophila isolates from environmental water sources in Guangzhou and Jiangmen, China. INFECTION GENETICS AND EVOLUTION 2015; 29:35-41. [DOI: 10.1016/j.meegid.2014.10.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 10/17/2014] [Accepted: 10/25/2014] [Indexed: 11/18/2022]
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28
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Ditommaso S, Giacomuzzi M, Rivera SRA, Raso R, Ferrero P, Zotti CM. Virulence of Legionella pneumophila strains isolated from hospital water system and healthcare-associated Legionnaires' disease in Northern Italy between 2004 and 2009. BMC Infect Dis 2014; 14:483. [PMID: 25190206 PMCID: PMC4168204 DOI: 10.1186/1471-2334-14-483] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 09/02/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Worldwide, L. pneumophila sg 1 is the most common agent of Legionnaires' disease ( 80 to 90% of the reported cases). In contrast, L. pneumophila sg 2-14 account for only 15 to 20% of community-acquired cases, although they account for over 50% of the environmental isolates. The discrepancy between environmental isolates and clinical cases of disease suggested that there are differences in virulence.We decided to subtype the environmental Legionella strains isolated from health care facilities (HCFs) and to compare the distribution of strains with the occurrence of hospital-acquired legionellosis. METHODS Observational ecological study based on the data provided by the regional surveillance of legionellosis and on data obtained from hospitals environmental monitoring.Using the monoclonal antibody MAb 3/1 of the Dresden Panel we collected and typed environmental strains of L. pneumophila sg 1 obtained during routine testing in 56 health care facilities from 2004 to 2009.The results of the laboratory analyses of the environmental samples were compared with the number of cases that each health care facility reported during the study period. RESULTS The association between the type of colonisation (L. pneumophila sg 1 vs others serogroups) and the incidence of reported cases was statistically significant (p = 0.03 according to the χ2 test).Legionella strains with the virulence-associated epitope recognised by MAb 3/1 were isolated in 8 of the 26 HCFs colonised by L. pneumophila sg 1; 7 of the HCFs colonised by MAb 3/1-positive strains accounted for 85% of the cases of hospital-acquired legionellosis reported during the 6-year study period. There was a statistically significant association (p = 0.003) between the presence of cases and colonisation by MAb 3/1-positive Legionella strains. CONCLUSION This study suggests that hospitals colonised by more virulent strains should be aware of the increased risk and consider the opportunities of increase their monitoring efforts and implement more effective contamination control strategies.
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Affiliation(s)
- Savina Ditommaso
- />Dipartimento di Scienze della Sanità Pubblica e Pediatriche, Università degli Studi di Torino, Via Santena 5 bis, 10126 Torino, Italy
| | - Monica Giacomuzzi
- />Dipartimento di Scienze della Sanità Pubblica e Pediatriche, Università degli Studi di Torino, Via Santena 5 bis, 10126 Torino, Italy
| | - Susan R Arauco Rivera
- />Dipartimento di Scienze della Sanità Pubblica e Pediatriche, Università degli Studi di Torino, Via Santena 5 bis, 10126 Torino, Italy
| | - Roberto Raso
- />Servizio di riferimento Regionale di Epidemiologia per la sorveglianza, la prevenzione e il controllo delle Malattie Infettive, SeREMI Alessandria, Alessandria, Italy
| | - Pierangela Ferrero
- />Servizio di riferimento Regionale di Epidemiologia per la sorveglianza, la prevenzione e il controllo delle Malattie Infettive, SeREMI Alessandria, Alessandria, Italy
| | - Carla M Zotti
- />Dipartimento di Scienze della Sanità Pubblica e Pediatriche, Università degli Studi di Torino, Via Santena 5 bis, 10126 Torino, Italy
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Ditommaso S, Giacomuzzi M, Arauco Rivera SR, Zotti CM. Does better identification of the Legionella pneumophila serogroup 1 strains by Sequence-Based Typing (SBT) allow for the implementation of more effective contamination control strategies and more targeted intervention measures? Microchem J 2014. [DOI: 10.1016/j.microc.2014.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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30
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van Heijnsbergen E, de Roda Husman AM, Lodder WJ, Bouwknegt M, Docters van Leeuwen AE, Bruin JP, Euser SM, den Boer JW, Schalk JAC. Viable Legionella pneumophila bacteria in natural soil and rainwater puddles. J Appl Microbiol 2014; 117:882-90. [PMID: 24888231 DOI: 10.1111/jam.12559] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 05/28/2014] [Accepted: 05/29/2014] [Indexed: 11/30/2022]
Abstract
AIMS For the majority of sporadic Legionnaires' disease cases the source of infection remains unknown. Infection may possible result from exposure to Legionella bacteria in sources that are not yet considered in outbreak investigations. Therefore, potential sources of pathogenic Legionella bacteria--natural soil and rainwater puddles on roads--were studied in 2012. METHODS AND RESULTS Legionella bacteria were detected in 30% (6/20) of soils and 3·9% (3/77) of rainwater puddles by amoebal coculture. Legionella pneumophila was isolated from two out of six Legionella positive soil samples and two out of three Legionella positive rainwater samples. Several other species were found including the pathogenic Leg. gormanii and Leg. longbeachae. Sequence types (ST) could be assigned to two Leg. pneumophila strains isolated from soil, ST710 and ST477, and one strain isolated from rainwater, ST1064. These sequence types were previously associated with Legionnaires' disease patients. CONCLUSIONS Rainwater and soil may be alternative sources for Legionella. SIGNIFICANCE AND IMPACT OF THE STUDY The detection of clinically relevant strains indicates that rainwater and soil are potential sources of Legionella bacteria and future research should assess the public health implication of the presence of Leg. pneumophila in rainwater puddles and natural soil.
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Affiliation(s)
- E van Heijnsbergen
- National Institute for Public Health and the Environment, Bilthoven, the Netherlands
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31
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Distribution of sequence-based types of legionella pneumophila serogroup 1 strains isolated from cooling towers, hot springs, and potable water systems in China. Appl Environ Microbiol 2014; 80:2150-7. [PMID: 24463975 DOI: 10.1128/aem.03844-13] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Legionella pneumophila serogroup 1 causes Legionnaires' disease. Water systems contaminated with Legionella are the implicated sources of Legionnaires' disease. This study analyzed L. pneumophila serogroup 1 strains in China using sequence-based typing. Strains were isolated from cooling towers (n = 96), hot springs (n = 42), and potable water systems (n = 26). Isolates from cooling towers, hot springs, and potable water systems were divided into 25 sequence types (STs; index of discrimination [IOD], 0.711), 19 STs (IOD, 0.934), and 3 STs (IOD, 0.151), respectively. The genetic variation among the potable water isolates was lower than that among cooling tower and hot spring isolates. ST1 was the predominant type, accounting for 49.4% of analyzed strains (n = 81), followed by ST154. With the exception of two strains, all potable water isolates (92.3%) belonged to ST1. In contrast, 53.1% (51/96) and only 14.3% (6/42) of cooling tower and hot spring, respectively, isolates belonged to ST1. There were differences in the distributions of clone groups among the water sources. The comparisons among L. pneumophila strains isolated in China, Japan, and South Korea revealed that similar clones (ST1 complex and ST154 complex) exist in these countries. In conclusion, in China, STs had several unique allelic profiles, and ST1 was the most prevalent sequence type of environmental L. pneumophila serogroup 1 isolates, similar to its prevalence in Japan and South Korea.
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Kozak-Muiznieks NA, Lucas CE, Brown E, Pondo T, Taylor TH, Frace M, Miskowski D, Winchell JM. Prevalence of sequence types among clinical and environmental isolates of Legionella pneumophila serogroup 1 in the United States from 1982 to 2012. J Clin Microbiol 2014; 52:201-11. [PMID: 24197883 PMCID: PMC3911437 DOI: 10.1128/jcm.01973-13] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 10/28/2013] [Indexed: 11/20/2022] Open
Abstract
Since the establishment of sequence-based typing as the gold standard for DNA-based typing of Legionella pneumophila, the Legionella laboratory at the Centers for Disease Control and Prevention (CDC) has conducted routine sequence-based typing (SBT) analysis of all incoming L. pneumophila serogroup 1 (Lp1) isolates to identify potential links between cases and to better understand genetic diversity and clonal expansion among L. pneumophila bacteria. Retrospective genotyping of Lp1 isolates from sporadic cases and Legionnaires' disease (LD) outbreaks deposited into the CDC reference collection since 1982 has been completed. For this study, we compared the distribution of sequence types (STs) among Lp1 isolates implicated in 26 outbreaks in the United States, 571 clinical isolates from sporadic cases of LD in the United States, and 149 environmental isolates with no known association with LD. The Lp1 isolates under study had been deposited into our collection between 1982 and 2012. We identified 17 outbreak-associated STs, 153 sporadic STs, and 49 environmental STs. We observed that Lp1 STs from outbreaks and sporadic cases are more similar to each other than either group is to environmental STs. The most frequent ST for both sporadic and environmental isolates was ST1, accounting for 25% and 49% of the total number of isolates, respectively. The STs shared by both outbreak-associated and sporadic Lp1 included ST1, ST35, ST36, ST37, and ST222. The STs most commonly found in sporadic and outbreak-associated Lp1 populations may have an increased ability to cause disease and thus may require special attention when detected.
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Affiliation(s)
- Natalia A. Kozak-Muiznieks
- Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Claressa E. Lucas
- Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Ellen Brown
- Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Tracy Pondo
- Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Thomas H. Taylor
- Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Michael Frace
- Biotechnology Core Facility Branch, Division of Scientific Resources, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | | | - Jonas M. Winchell
- Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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Petzold M, Thürmer A, Menzel S, Mouton JW, Heuner K, Lück C. A structural comparison of lipopolysaccharide biosynthesis loci of Legionella pneumophila serogroup 1 strains. BMC Microbiol 2013; 13:198. [PMID: 24069939 PMCID: PMC3766260 DOI: 10.1186/1471-2180-13-198] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 08/31/2013] [Indexed: 01/21/2023] Open
Abstract
Background The lipopolysaccharide (LPS) is the major immuno-dominant antigen of all Legionella species including L. pneumophila. Its diversity is the basis for the classification of L. pneumophila into serogroups and monoclonal subgroups and is thought to be involved in strain specific virulence. The understanding of the genetic basis of the LPS-antigen is incomplete. Thus, we analyzed the genetic locus involved in LPS-biosynthesis of L. pneumophila serogroup 1 (Sg1) strains with the focus on strain specific gene composition. Results The LPS-biosynthesis loci of 14 L. pneumophila Sg1 strains comprise two distinct regions: A 15 kb region containing LPS-biosynthesis genes that can be found in all L. pneumophila strains and a Sg1-specific 18 kb region. The 15 kb region is highly conserved among Sg1 strains as reflected by high homologies of single ORFs and by a consistent ORF arrangement. In contrast, the Sg1 specific 18 kb region is variable and partially disrupted by phage related genes. We propose that the region spanning from ORF 6 to ORF 11 of the Sg1-specific region is likely involved in late LPS-modification. Due to the high variability of this small region and various combinations of single ORFs within this region a strain specific LPS-structure could be synthesized including modifications of legionaminic acid derivates. Conclusions Our data clearly demonstrate that the gene structure of the LPS-biosynthesis locus of L. pneumophila Sg1 strains show significant interstrain variability. These data can be used for further functional analysis of the LPS synthesis to understand pathogenesis and reactivity with monoclonal antibodies. Moreover, variable but strain specific regions can serve as basis for the development of novel genotyping assays.
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Affiliation(s)
- Markus Petzold
- Institute of Medical Microbiology and Hygiene, Faculty of Medicine 'Carl Gustav Carus', University of Technology Dresden, Fetscherstraße 74, Dresden D-01307, Germany.
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Close genetic relationship between Legionella pneumophila serogroup 1 isolates from sputum specimens and puddles on roads, as determined by sequence-based typing. Appl Environ Microbiol 2013; 79:3959-66. [PMID: 23603681 DOI: 10.1128/aem.00637-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
We investigated the prevalence of Legionella species isolated from puddles on asphalt roads. In addition, we carried out sequence-based typing (SBT) analysis on the genetic relationship between L. pneumophila serogroup 1 (SG 1) isolates from puddles and from stock strains previously obtained from sputum specimens and public baths. Sixty-nine water samples were collected from puddles on roads at 6 fixed locations. Legionella species were detected in 33 samples (47.8%) regardless of season. Among the 325 isolates from puddles, strains of L. pneumophila SG 1, a major causative agent of Legionnaires' disease, were the most frequently isolated (n = 62, 19.1%). Sixty-two isolates of L. pneumophila SG 1 from puddles were classified into 36 sequence types (STs) by SBT. ST120 and ST48 were identified as major STs. Environmental ST120 strains from puddles were found for the first time in this study. Among the 14 STs of the clinical isolates (n = 19), 4 STs (n = 6, 31.6%), including ST120, were also detected in isolates from puddles on roads, and the sources of infection in these cases remained unclear. The lag-1 gene, a tentative marker for clinical isolates, was prevalent in puddle isolates (61.3%). Our findings suggest that puddles on asphalt roads serve as potential reservoirs for L. pneumophila in the environment.
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Comparative molecular and antibody typing during the investigation of an outbreak of Legionnaires' disease. J Infect Chemother 2013; 19:896-901. [PMID: 23572275 DOI: 10.1007/s10156-013-0595-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Accepted: 03/26/2013] [Indexed: 10/27/2022]
Abstract
An outbreak of Legionnaires' disease with 113 confirmed cases was reported in the town of Mataró, Spain, in August 2002. In this study, we compared three different typing methods and characterized the clinical isolates by comparing them with other clinical isolates with the same ST from our own database to further characterize the outbreak. In the outbreak, a total of 16 clinical (nine patients) and 32 environmental (from four environmental sources) Legionella pneumophila isolates were analyzed by pulsed-field electrophoresis (PFGE), sequence-based typing (SBT), and monoclonal antibody typing (MAb). We compared the MAb and SBT profiles of the outbreak clinical isolates and other unrelated clinical isolates showing the same ST profile. We obtained seven different PFGE and SBT profiles and six MAb patterns from the outbreak isolates. PFGE and SBT showed 100% concordance during the outbreak. SBT proved to be highly discriminatory, particularly with the addition of the new neuA gene. One PFGE, SBT (ST-37), and Philadelphia profile was observed among the clinical isolates. Using PFGE, this ST37 Philadelphia profile was closely related to other unrelated clinical isolates. These findings suggest that the ST37 Philadelphia profile could be a virulence marker in our area. The combination of the three methodologies was useful to further characterize and obtain additional information on a very explosive outbreak. Despite the minor discrimination of PFGE versus SBT, the two genetic methods are recommended in outbreak investigations. Further studies are currently underway in this area to obtain more definitive conclusions.
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Kanatani JI, Isobe J, Kimata K, Shima T, Shimizu M, Kura F, Sata T, Watahiki M. Molecular epidemiology of Legionella pneumophila serogroup 1 isolates identify a prevalent sequence type, ST505, and a distinct clonal group of clinical isolates in Toyama Prefecture, Japan. J Infect Chemother 2012; 19:644-52. [PMID: 23269379 DOI: 10.1007/s10156-012-0537-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 12/06/2012] [Indexed: 10/27/2022]
Abstract
We performed comparative analyses of Legionella pneumophila serogroup (SG) 1 isolates obtained during 2005-2012 in Toyama Prefecture, Japan, by sequence-based typing (SBT) and pulsed-field gel electrophoresis (PFGE). Seventy-three isolates of L. pneumophila SG 1, including 17 isolates from patients, 51 from public baths, 4 from cooling towers, and 1 from a shower, were analyzed. The isolates were classified into 43 sequence types (STs) by SBT and 52 types by PFGE. Fourteen STs were unique to Toyama Prefecture, as determined from the SBT database of European Working Group for Legionella Infections (EWGLI), as of October 31, 2012. ST505 strain was identified in 4 isolates from patients and 5 isolates from public baths, and these isolates belonged to 2 PFGE types. These, however, were similar because of the difference with only two restriction fragments, indicating that ST505 strain was prevalent among L. pneumophila SG 1 isolates in this area. ST505 strains isolated from patients and public baths were distributed along the river in a western part of Toyama Prefecture. SBT and PFGE profiles of 3 clinical isolates were identical with those of 3 environmental isolates from the suspected origins of the infection in each case, respectively. This finding suggested that SBT and PFGE were useful for epidemiological study. Furthermore, by SBT analysis, we identified a clonal group formed only by 7 clinical isolates that are not associated with bathwater, suggesting that they were derived from unrecognized sources.
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Affiliation(s)
- Jun-Ichi Kanatani
- Department of Bacteriology, Toyama Institute of Health, 17-1 Nakataikoyama, Imizu, Toyama, 939-0363, Japan
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