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Lee-Masi M, Coulter C, Chow SJ, Zaitchik B, Jacangelo JG, Exum NG, Schwab KJ. Two-year evaluation of Legionella in an aging residential building: Assessment of multiple potable water remediation approaches. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 941:173710. [PMID: 38830423 DOI: 10.1016/j.scitotenv.2024.173710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 05/30/2024] [Accepted: 05/31/2024] [Indexed: 06/05/2024]
Abstract
Legionella is an opportunistic waterborne pathogen that is difficult to eradicate in colonized drinking water pipes. Legionella control is further challenged by aging water infrastructure and lack of evidence-based guidance for building treatment. This study assessed multiple premise water remediation approaches designed to reduce Legionella pneumophila within a residential building located in an aging, urban drinking water system over a two-year period. Samples (n = 745) were collected from hot and cold-water lines and quantified via most probable number culture. Building-level treatment approaches included three single heat shocks, three single chemical shocks, and continuous low-level chemical disinfection in the potable water system. The building was highly colonized with L. pneumophila with 71 % L. pneumophila positivity. Single heat shocks had a statistically significant L. pneumophila reduction one day post treatment but no significant L. pneumophila reduction at one week, two weeks, and four weeks post treatment. The first two chemical shocks resulted in statistically significant L. pneumophila reduction at two days and four weeks post treatment, but there was a significant L. pneumophila increase at four weeks following the third chemical shock. Continuous low-level chemical disinfection resulted in statistically significant L. pneumophila reduction at ten weeks post treatment implementation. This demonstrates that in a building highly colonized with L. pneumophila, sustained remediation is best achieved using continuous low-level chemical treatment.
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Affiliation(s)
- Monica Lee-Masi
- Department of Environmental Health & Engineering, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St, Baltimore, MD 21205, United States
| | - Caroline Coulter
- Department of Environmental Health & Engineering, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St, Baltimore, MD 21205, United States
| | - Steven J Chow
- Department of Environmental Health & Engineering, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St, Baltimore, MD 21205, United States
| | - Benjamin Zaitchik
- Department of Earth and Planetary Sciences, Johns Hopkins Krieger School of Arts and Sciences, 3400 N. Charles St., Baltimore, MD 21218, United States
| | - Joseph G Jacangelo
- Department of Environmental Health & Engineering, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St, Baltimore, MD 21205, United States; Stantec, 1299 Pennsylvania Ave. NW Ste 405, Washington, DC 20004, United States
| | - Natalie G Exum
- Department of Environmental Health & Engineering, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St, Baltimore, MD 21205, United States
| | - Kellogg J Schwab
- Department of Environmental Health & Engineering, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St, Baltimore, MD 21205, United States.
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Xi H, Ross KE, Hinds J, Molino PJ, Whiley H. Efficacy of chlorine-based disinfectants to control Legionella within premise plumbing systems. WATER RESEARCH 2024; 259:121794. [PMID: 38824796 DOI: 10.1016/j.watres.2024.121794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 05/14/2024] [Accepted: 05/16/2024] [Indexed: 06/04/2024]
Abstract
Legionella is an opportunistic waterborne pathogen that causes Legionnaires' disease. It poses a significant public health risk, especially to vulnerable populations in health care facilities. It is ubiquitous in manufactured water systems and is transmitted via inhalation or aspiration of aerosols/water droplets generated from water fixtures (e.g., showers and hand basins). As such, the effective management of premise plumbing systems (building water systems) in health care facilities is essential for reducing the risk of Legionnaires' disease. Chemical disinfection is a commonly used control method and chlorine-based disinfectants, including chlorine, chloramine, and chlorine dioxide, have been used for over a century. However, the effectiveness of these disinfectants in premise plumbing systems is affected by various interconnected factors that can make it challenging to maintain effective disinfection. This systematic literature review identifies all studies that have examined the factors impacting the efficacy and decay of chlorine-based disinfectant within premise plumbing systems. A total of 117 field and laboratory-based studies were identified and included in this review. A total of 20 studies directly compared the effectiveness of the different chlorine-based disinfectants. The findings from these studies ranked the typical effectiveness as follows: chloramine > chlorine dioxide > chlorine. A total of 26 factors were identified across 117 studies as influencing the efficacy and decay of disinfectants in premise plumbing systems. These factors were sorted into categories of operational factors that are changed by the operation of water devices and fixtures (such as stagnation, temperature, water velocity), evolving factors which are changed in-directly (such as disinfectant concentration, Legionella disinfectant resistance, Legionella growth, season, biofilm and microbe, protozoa, nitrification, total organic carbon(TOC), pH, dissolved oxygen(DO), hardness, ammonia, and sediment and pipe deposit) and stable factors that are not often changed(such as disinfectant type, pipe material, pipe size, pipe age, water recirculating, softener, corrosion inhibitor, automatic sensor tap, building floor, and construction activity). A factor-effect map of each of these factors and whether they have a positive or negative association with disinfection efficacy against Legionella in premise plumbing systems is presented. It was also found that evaluating the effectiveness of chlorine disinfection as a water risk management strategy is further complicated by varying disinfection resistance of Legionella species and the form of Legionella (culturable/viable but non culturable, free living/biofilm associated, intracellular replication within amoeba hosts). Future research is needed that utilises sensors and other approaches to measure these key factors (such as pH, temperature, stagnation, water age and disinfection residual) in real time throughout premise plumbing systems. This information will support the development of improved models to predict disinfection within premise plumbing systems. The findings from this study will inform the use of chlorine-based disinfection within premise plumbing systems to reduce the risk of Legionnaires disease.
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Affiliation(s)
- Hao Xi
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia; Enware Pty Ltd, Caringbah, NSW, Australia.
| | - Kirstin E Ross
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia
| | - Jason Hinds
- ARC Training Centre for Biofilm Research and Innovation, Flinders University, Bedford Park, SA, Australia; Enware Pty Ltd, Caringbah, NSW, Australia
| | | | - Harriet Whiley
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia; ARC Training Centre for Biofilm Research and Innovation, Flinders University, Bedford Park, SA, Australia
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Chochlakis D, Sandalakis V, Ntoukakis A, Daskalaki MO, Loppinet T, Thalassinaki N, Makridaki R, Panoulis C, Psaroulaki A. Multi-criterion analysis of the effect of physico-chemical microbiological agents on Legionella detection in hotel water distribution systems in Crete. Front Cell Infect Microbiol 2023; 13:1214717. [PMID: 38188625 PMCID: PMC10770838 DOI: 10.3389/fcimb.2023.1214717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 10/17/2023] [Indexed: 01/09/2024] Open
Abstract
Introduction Water distribution systems in hotels have been related to outbreaks caused by Legionella spp. Certain measures, including disinfection by chlorination, maintaining increased temperatures are usually undertaken to prevent Legionella outbreaks. However, these preventive strategies are not always effective, since there are several factors (e.g., synergistic interactions with other microbes, physico-chemical factors, biofilm formation, availability of nutrients) that promote survival and proliferation of the pathogen in water pipes., Accordingly, there is a need of a holistic approach in development of preventive models for Legionella outbreaks associated with water distribution systems. Methods Water samples were collected from hotel water systems and were tested for the presence of Legionella, E. coli, total coliforms, total mesophilic count and Pseudomonas. In each sample, temperature and chlorine were also tested. Other epidemiological factors were additionally recorded including number of rooms, stars, proximity of sampling point to the boiler, etc. Data were processed by generalized linear analysis, and modeling based on logistic regression analysis to identify independent predictive factors associated with the presence of Legionella in hotel water systems. Results According to the generalized linear model, temperature affected (p<0.05) the presence of Legionella regardless of the species or the water supply (hot or cold). Additionally, opportunistic (P. aeruginosa) or non-opportunistic (E. coli, coliforms) pathogens were significantly associated (p<0.05) with the presence of all Legionella species. Temperature also exhibited a positive effect to all pathogens tested except for Pseudomonas according to the linear model. Multivariate analysis showed that Pseudomonas, total coliforms, HPC and temperature had a statistically significant effect on the presence of Legionella. Based on a binomial model, cold water had a positive effect on Legionella. Type of sampling and proximity of the sample to the boiler seemed to pose different effect on Legionella depending on the cfu/L. The number of hotel stars and rooms did not appear to have any effect in all tested models. Discussion Collectively, these results indicate the need for development of individualized water safety plans tailored by the presence of other microbiological agents, and unique physico-chemical factors, which could facilitate the survival of Legionella.in hotel water systems.
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Affiliation(s)
- Dimosthenis Chochlakis
- Regional Laboratory of Public Health of Crete, School of Medicine, University of Crete, Heraklion, Greece
- Laboratory of Clinical Microbiology and Microbial Pathogenesis, School of Medicine, University of Crete, Heraklion, Greece
| | - Vassilios Sandalakis
- Laboratory of Clinical Microbiology and Microbial Pathogenesis, School of Medicine, University of Crete, Heraklion, Greece
| | - Apostolos Ntoukakis
- Laboratory of Clinical Microbiology and Microbial Pathogenesis, School of Medicine, University of Crete, Heraklion, Greece
| | - Maria-Olga Daskalaki
- Laboratory of Clinical Microbiology and Microbial Pathogenesis, School of Medicine, University of Crete, Heraklion, Greece
| | - Thomas Loppinet
- Laboratory of Clinical Microbiology and Microbial Pathogenesis, School of Medicine, University of Crete, Heraklion, Greece
| | - Niki Thalassinaki
- Laboratory of Clinical Microbiology and Microbial Pathogenesis, School of Medicine, University of Crete, Heraklion, Greece
| | - Rena Makridaki
- Laboratory of Clinical Microbiology and Microbial Pathogenesis, School of Medicine, University of Crete, Heraklion, Greece
| | - Christos Panoulis
- Laboratory of Clinical Microbiology and Microbial Pathogenesis, School of Medicine, University of Crete, Heraklion, Greece
| | - Anna Psaroulaki
- Regional Laboratory of Public Health of Crete, School of Medicine, University of Crete, Heraklion, Greece
- Laboratory of Clinical Microbiology and Microbial Pathogenesis, School of Medicine, University of Crete, Heraklion, Greece
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Marras L, Bertolino G, Sanna A, Carraro V, Coroneo V. Legionella spp. Monitoring in the Water Supply Systems of Accommodation Facilities in Sardinia, Italy: A Two-Year Retrospective Analysis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:6722. [PMID: 37754582 PMCID: PMC10530320 DOI: 10.3390/ijerph20186722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 08/25/2023] [Accepted: 08/30/2023] [Indexed: 09/28/2023]
Abstract
Travel-associated Legionnaires' disease is a significant public health concern worldwide. A high number of cases are reported every year among travellers who stay at guest houses, hotels, and spas. Indeed, hot water systems, showers, and air-conditioning systems can be contaminated by Legionella, which grows at 25-42 °C. Studies have shown that in Sardinia, especially during the summer months, the water circulation in the hotels' pipes is exposed to extremely high temperatures. As a result, this study was conducted to assess the colonization of hotel water systems by Legionella in Sardinia, concerning a recent EU directive 2020/2184 for drinking water with a limit of 1000 CFU /L. Methods. A total of 112 accommodation facilities were analyzed, of which 61.3% were found to be colonized with Legionella, and out of a total of 807 samples, 32.5% were positive for Legionella presence. The results showed a higher number of positive samples in the summer season. This was also associated with the higher concentration presence of >1000 CFU/L in the samples. Consequently, this study confirms that local hotel operators should improve their water safety and prevention plans, especially in spring and summer.
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Affiliation(s)
- Luisa Marras
- Department of Medical Sciences and Public Health, University of Cagliari, 09124 Cagliari, Italy
| | - Giacomo Bertolino
- Pharmaceutical Department, Azienda Ospedaliero, Universitaria di Cagliari, 09123 Cagliari, Italy;
| | - Adriana Sanna
- Department of Medical Sciences and Public Health, University of Cagliari, 09124 Cagliari, Italy
| | - Valentina Carraro
- Department of Medical Sciences and Public Health, University of Cagliari, 09124 Cagliari, Italy
| | - Valentina Coroneo
- Department of Medical Sciences and Public Health, University of Cagliari, 09124 Cagliari, Italy
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Lee-Masi M, Coulter C, Chow SJ, Zaitchik B, Jacangelo JG, Exum NG, Schwab KJ. Two-Year Evaluation of Legionella in an Aging Residential Building: Assessment of Multiple Potable Water Remediation Approaches. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.07.19.23292444. [PMID: 37502988 PMCID: PMC10371102 DOI: 10.1101/2023.07.19.23292444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Legionella is an opportunistic waterborne pathogen that is difficult to eradicate in colonized drinking water pipes. Legionella control is further challenged by aging water infrastructure and lack of evidence-based guidance for building treatment. This study assessed multiple premise water remediation approaches designed to reduce Legionella pneumophila (Lp) within a residential building located in an aging, urban drinking water system over a two-year period. Samples (n=745) were collected from hot and cold-water lines and quantified via most probable number culture. Building-level treatment approaches included three single heat shocks (HS), three single chemical shocks (CS), and continuous low-level chemical disinfection (CCD) in the potable water system. The building was highly colonized with Lp with 71% Lp positivity. Single HS had a statistically significant Lp reduction one day post treatment but no significant Lp reduction one, two, and four weeks post treatment. The first two CS resulted in statistically significant Lp reduction at two days and four weeks post treatment, but there was a significant Lp increase at four weeks following the third CS. CCD resulted in statistically significant Lp reduction ten weeks post treatment implementation. This demonstrates that in a building highly colonized with Lp, sustained remediation is best achieved using CCD.
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Affiliation(s)
- Monica Lee-Masi
- Department of Environmental Health & Engineering, Johns Hopkins Bloomberg School of Public Health, 21205, Baltimore, Maryland, United States
| | - Caroline Coulter
- Department of Environmental Health & Engineering, Johns Hopkins Bloomberg School of Public Health, 21205, Baltimore, Maryland, United States
| | - Steven J. Chow
- Department of Environmental Health & Engineering, Johns Hopkins Bloomberg School of Public Health, 21205, Baltimore, Maryland, United States
| | - Benjamin Zaitchik
- Department of Earth and Planetary Sciences, Johns Hopkins Krieger School of Arts and Sciences, 21218, Baltimore, Maryland, United States
| | - Joseph G. Jacangelo
- Department of Environmental Health & Engineering, Johns Hopkins Bloomberg School of Public Health, 21205, Baltimore, Maryland, United States
- Department of Earth and Planetary Sciences, Johns Hopkins Krieger School of Arts and Sciences, 21218, Baltimore, Maryland, United States
| | - Natalie G. Exum
- Department of Environmental Health & Engineering, Johns Hopkins Bloomberg School of Public Health, 21205, Baltimore, Maryland, United States
| | - Kellogg J. Schwab
- Department of Environmental Health & Engineering, Johns Hopkins Bloomberg School of Public Health, 21205, Baltimore, Maryland, United States
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Papadakis AA, Tsirigotakis I, Katranitsa S, Donousis C, Papalexis P, Keramydas D, Chaidoutis E, Georgakopoulou VE, Spandidos DA, Constantinidis TC. Assessing the impact of the COVID‑19 pandemic health protocols on the hygiene status of swimming pools of hotel units. MEDICINE INTERNATIONAL 2023; 3:32. [PMID: 37425352 PMCID: PMC10326652 DOI: 10.3892/mi.2023.92] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 06/21/2023] [Indexed: 07/11/2023]
Abstract
With the onset of the coronavirus disease 2019 (COVID-19) pandemic, numerous countries imposed strict lockdown measures and travel bans, resulting in the closure of hotels. Over time, the opening of hotel units was gradually allowed, and new strict regulations and protocols were issued to ensure the hygiene and safety of swimming pools in the era of COVID-19. The present study aimed to evaluate the implementation of strict health COVID-19-related protocols in hotel units during the 2020 summer tourist season concerning microbiological hygiene and physicochemical parameters of water, and to compare the data with those from the 2019 tourist season. For this reason, 591 water samples from 62 swimming pools were analyzed, of which 381 samples were for the 2019 tourist season and 210 samples were for the 2020 tourist season. To examine the presence of Legionella spp, 132 additional samples were taken from 14 pools, of which 49 in 2019 and 83 in 2020. In 2019, 2.89% (11/381) of the samples were out of legislative limits (0/250 mg/l) regarding the presence of Escherichia coli (E. coli), 9.45% (36/381) were out of acceptable limits (0/250 mg/l) regarding the presence of Pseudomonas aeruginosa (P. aeruginosa) and 8.92% (34/381) had residual chlorine levels <0.4 mg/l. In 2020, 1.43% (3/210) of the samples were out of the legislative limits as regards the presence of E. coli, 7.14% (15/210) were out of acceptable limits regarding the presence of P. aeruginosa and 3.33% (7/210) of the samples measured residual chlorine levels <0.4 mg/l. The risk ratio (RR) in relation to the presence of E. coli due to incorrect compliance with the requirements for residual chlorine was calculated for 2019 at 8.50, while in 2020 it was calculated at 14.50 (P=0.008). The RR of the presence of P. aeruginosa due to inappropriate residual chlorine requirements was calculated in 2019 at 2.04 (P=0.0814), while in 2020 it was calculated at 2.07 (P=0.44). According to the microbiological hygiene and physicochemical parameters of the water samples studied, there was a significant improvement due to the strict protocols for the swimming pools in the summer season of 2020 compared to the tourist season of 2019, namely 72.72% (E. coli), 58.33% (P. aeruginosa), 79.41% (of residual chlorine <0.4 mg/l) in the three main parameters studied. Finally, an increased colonization by Legionella spp. detected in the internal networks of the hotels due to the non-operation of the hotels during the lockdown, the improper disinfection and stagnant water in the internal water supply networks. Specifically, in 2019, 95.92% (47/49) of the samples tested negative and 4.08% (2/49) tested positive (≥50 CFU/l) for Legionella spp., compared to 2020 where 91.57% (76/83) of the samples tested negative and 8.43% (7/83) tested positive.
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Affiliation(s)
- Antonios A. Papadakis
- Laboratory of Hygiene and Environmental Protection, Faculty of Medicine, Democritus University of Thrace, 68100 Alexandroupolis, Greece
- Department of Clinical Microbiology and Microbial Pathogenesis, School of Medicine, University of Crete, 71110 Heraklion, Greece
- Institute of Agri-Food and Life Sciences, University Research Centre, Hellenic Mediterranean University, 71410 Heraklion, Greece
| | | | | | | | - Petros Papalexis
- Unit of Endocrinology, First Department of Internal Medicine, Laiko General Hospital, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
- Department of Biomedical Sciences, University of West Attica, 12243 Athens, Greece
| | - Dimitrios Keramydas
- First Department of Pathology, School of Medicine, National and Kapodistrian University of Athens, Greece
| | - Elias Chaidoutis
- First Department of Pathology, School of Medicine, National and Kapodistrian University of Athens, Greece
| | - Vasiliki Epameinondas Georgakopoulou
- Department of Infectious Diseases and COVID-19 Unit, Laiko General Hospital, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Demetrios A. Spandidos
- Laboratory of Clinical Virology, School of Medicine, University of Crete, 71003, Heraklion, Greece
| | - Theodoros C. Constantinidis
- Laboratory of Hygiene and Environmental Protection, Faculty of Medicine, Democritus University of Thrace, 68100 Alexandroupolis, Greece
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Lombardi A, Borriello T, De Rosa E, Di Duca F, Sorrentino M, Torre I, Montuori P, Trama U, Pennino F. Environmental Monitoring of Legionella in Hospitals in the Campania Region: A 5-Year Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:ijerph20085526. [PMID: 37107807 PMCID: PMC10138562 DOI: 10.3390/ijerph20085526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/06/2023] [Accepted: 04/13/2023] [Indexed: 05/11/2023]
Abstract
Legionella is a pathogen that colonizes soils, freshwater, and building water systems. People who are most affected are those with immunodeficiencies, so it is necessary to monitor its presence in hospitals. The purpose of this study was to evaluate the presence of Legionella in water samples collected from hospitals in the Campania region, Southern Italy. A total of 3365 water samples were collected from January 2018 to December 2022 twice a year in hospital wards from taps and showers, tank bottoms, and air-treatment units. Microbiological analysis was conducted in accordance with the UNI EN ISO 11731:2017, and the correlations between the presence of Legionella and water temperature and residual chlorine were investigated. In total, 708 samples (21.0%) tested positive. The most represented species was L. pneumophila 2-14 (70.9%). The serogroups isolated were 1 (27.7%), 6 (24.5%), 8 (23.3%), 3 (18.9%), 5 (3.1%), and 10 (1.1%). Non-pneumophila Legionella spp. represented 1.4% of the total. Regarding temperature, the majority of Legionella positive samples were found in the temperature range of 26.0-40.9 °C. An influence of residual chlorine on the presence of the bacterium was observed, confirming that chlorine disinfection is effective for controlling contamination. The positivity for serogroups other than serogroup 1 suggested the need to continue environmental monitoring of Legionella and to focus on the clinical diagnosis of other serogroups.
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Affiliation(s)
- Annalisa Lombardi
- Department of Public Health, University “Federico II”, Via Sergio Pansini N° 5, 80131 Naples, Italy
| | - Tonia Borriello
- Department of Public Health, University “Federico II”, Via Sergio Pansini N° 5, 80131 Naples, Italy
| | - Elvira De Rosa
- Department of Public Health, University “Federico II”, Via Sergio Pansini N° 5, 80131 Naples, Italy
| | - Fabiana Di Duca
- Department of Public Health, University “Federico II”, Via Sergio Pansini N° 5, 80131 Naples, Italy
| | - Michele Sorrentino
- Department of Public Health, University “Federico II”, Via Sergio Pansini N° 5, 80131 Naples, Italy
| | - Ida Torre
- Department of Public Health, University “Federico II”, Via Sergio Pansini N° 5, 80131 Naples, Italy
| | - Paolo Montuori
- Department of Public Health, University “Federico II”, Via Sergio Pansini N° 5, 80131 Naples, Italy
| | - Ugo Trama
- General Directorate of Health, Campania Region, Centro Direzionale C3, 80143 Naples, Italy
| | - Francesca Pennino
- Department of Public Health, University “Federico II”, Via Sergio Pansini N° 5, 80131 Naples, Italy
- Correspondence:
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Campaña M, Del Hoyo R, Monleón-Getino A, Checa J. Predicting Legionella contamination in cooling towers and evaporative condensers from microbiological and physicochemical parameters. Int J Hyg Environ Health 2023; 248:114117. [PMID: 36708652 DOI: 10.1016/j.ijheh.2023.114117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 12/30/2022] [Accepted: 01/22/2023] [Indexed: 01/27/2023]
Abstract
BACKGROUND Inhalation of Legionella-containing aerosols generated by cooling towers (CT) and evaporative condensers (EC) where water risk management is not performed correctly has been linked to a high percentage of community outbreaks of Legionnaires' disease (LD). Likewise, microbiological and physicochemical characteristics of the water in these facilities have been associated with this bacterium. The main aim of this study was to assess the risk of Legionella colonization in CT and EC based on the data for microbiological and physicochemical water quality provided by the Environmental Health Department and Laboratory of the City Council of L'Hospitalet de Llobregat (Barcelona, Spain). METHODS Legionella was analysed in 789 samples collected from 127 CT and EC in 46 companies in Catalonia from 2002 to 2019. A two-step logistic regression analysis was carried out to assess the risk of colonization by Legionella in the studied facilities according to the microbiological (aerobic heterotrophic bacteria) and physicochemical (pH, alkalinity, hardness, turbidity, conductivity, total iron and Langelier Index) water parameters. The optimal cut-off points for the water parameters predictive of Legionella contamination were defined as the values on the receiver operating characteristic (ROC) curve where sensitivity and specificity were jointly maximized. RESULTS Legionella was isolated in 8.49% of the 789 analysed samples, 22.39% of which were heavily contaminated (with counts higher than 1.0 × 104 CFU/l). L. pneumophila was isolated in 82.09% of the samples, with 41.82% belonging to serogroup 1. Logistic regression analysis revealed that aerobic heterotrophic bacteria concentrations ≥6.90 × 102 CFU/ml [Odds ratios (OR) (95% CI) = 3.56 (1.39-9.43), p = 0.01], a pH ≥ 8.70 [OR (95% CI) = 3.60 (1.34-10.09), p = 0.01], and water hardness ≥5.72 × 102 mg/l [OR (95% CI) = 6.30 (2.34-18.56), p < 0.001] were each independently associated with a higher risk of CT and EC colonization by Legionella. CONCLUSIONS The present study shows the importance of risk assessment for improving the control measures aimed at preventing or reducing Legionella populations in CT and EC, thus minimizing potential dangers for public health.
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Affiliation(s)
- María Campaña
- BIOST(3). GRBIO. Department of Genetics, Microbiology and Statistics (Section of Statistics), Faculty of Biology, University of Barcelona, Diagonal 645, 08028, Barcelona, Spain.
| | - Rafael Del Hoyo
- Environmental Health Department and Laboratory, City Council of L'Hospitalet de Llobregat, Cobalt Building. Cobalt Street, 57-59, 2nd Floor, 08907, L'Hospitalet de Llobregat, Barcelona, Spain.
| | - Antonio Monleón-Getino
- BIOST(3). GRBIO. Department of Genetics, Microbiology and Statistics (Section of Statistics), Faculty of Biology, University of Barcelona, Diagonal 645, 08028, Barcelona, Spain.
| | - Javier Checa
- Environmental Health Department and Laboratory, City Council of L'Hospitalet de Llobregat, Cobalt Building. Cobalt Street, 57-59, 2nd Floor, 08907, L'Hospitalet de Llobregat, Barcelona, Spain.
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Capuano R, Mansi A, Paba E, Marcelloni AM, Chiominto A, Proietto AR, Gordiani A, Catini A, Paolesse R, Tranfo G, Di Natale C. A Pilot Study for Legionella pneumophila Volatilome Characterization Using a Gas Sensor Array and GC/MS Techniques. SENSORS (BASEL, SWITZERLAND) 2023; 23:1401. [PMID: 36772440 PMCID: PMC9920052 DOI: 10.3390/s23031401] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/13/2023] [Accepted: 01/19/2023] [Indexed: 06/18/2023]
Abstract
Legionellosis is a generic term describing the pneumonic (Legionnaires' disease, LD) and non-pneumonic (Pontiac fever, PF) forms of infection with bacteria belonging to the genus Legionella. Currently, the techniques used to detect Legionella spp. in water samples have certain limitations and drawbacks, and thus, there is a need to identify new tools to carry out low-cost and rapid analysis. In this regard, several studies demonstrated that a volatolomics approach rapidly detects and discriminates different species of microorganisms via their volatile signature. In this paper, the volatile organic compounds (VOCs) pattern emitted in vitro by Legionella pneumophila cultures is characterized and compared to those produced by other Legionella species and by Pseudomonas aeruginosa, using a gas sensor array and gas chromatograph mass spectrometer (GC-MS). Bacterial cultures were measured at the 3rd and 7th day after the incubation. Sensor array data analyzed via the K-nearest neighbours (k-NN) algorithm showed a sensitivity to Legionella pneumophila identification at around 89%. On the other hand, GC-MS identified a bouquet of VOCs, mainly alcohols and ketones, that enable the differentiation of Legionella pneumophila in respect to other waterborne microorganisms.
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Affiliation(s)
- Rosamaria Capuano
- Department of Electronic Engineering, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome, Italy
- Interdepartmental Centre for Volatilomics ‘A. D’Amico’, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome, Italy
| | - Antonella Mansi
- Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Italian Workers’ Compensation Authority (INAIL), Via Fontana Candida 1, Monte Porzio Catone, 00078 Rome, Italy
| | - Emilia Paba
- Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Italian Workers’ Compensation Authority (INAIL), Via Fontana Candida 1, Monte Porzio Catone, 00078 Rome, Italy
| | - Anna Maria Marcelloni
- Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Italian Workers’ Compensation Authority (INAIL), Via Fontana Candida 1, Monte Porzio Catone, 00078 Rome, Italy
| | - Alessandra Chiominto
- Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Italian Workers’ Compensation Authority (INAIL), Via Fontana Candida 1, Monte Porzio Catone, 00078 Rome, Italy
| | - Anna Rita Proietto
- Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Italian Workers’ Compensation Authority (INAIL), Via Fontana Candida 1, Monte Porzio Catone, 00078 Rome, Italy
| | - Andrea Gordiani
- Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Italian Workers’ Compensation Authority (INAIL), Via Fontana Candida 1, Monte Porzio Catone, 00078 Rome, Italy
| | - Alexandro Catini
- Department of Electronic Engineering, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome, Italy
- Interdepartmental Centre for Volatilomics ‘A. D’Amico’, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome, Italy
| | - Roberto Paolesse
- Interdepartmental Centre for Volatilomics ‘A. D’Amico’, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome, Italy
- Department of Chemical Science and Technology, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy
| | - Giovanna Tranfo
- Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Italian Workers’ Compensation Authority (INAIL), Via Fontana Candida 1, Monte Porzio Catone, 00078 Rome, Italy
| | - Corrado Di Natale
- Department of Electronic Engineering, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome, Italy
- Interdepartmental Centre for Volatilomics ‘A. D’Amico’, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome, Italy
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Molina JJ, Bennassar M, Palacio E, Crespi S. Impact of prolonged hotel closures during the COVID-19 pandemic on Legionella infection risks. Front Microbiol 2023; 14:1136668. [PMID: 36910223 PMCID: PMC9998907 DOI: 10.3389/fmicb.2023.1136668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 02/10/2023] [Indexed: 03/14/2023] Open
Abstract
In general, it is accepted that water stagnation and lack or poor maintenance in buildings are risk factors for Legionella growth. Then, in theory, the prolonged hotel closures due to the COVID-19 pandemic may have increased the risk of Legionella infections. However, there are very few field studies comparing the level of Legionella colonization in buildings before the pandemic and the new situation created after the lockdown. The objective of this study was to analyze these differences in a group of hotels that experienced prolonged closures in 2020 due to the COVID-19 pandemic. We have studied the Legionella spp. results, analyzed by standard culture, from the domestic water distribution systems of 73 hotels that experienced closures (from 1 to >4 months) during 2020, immediately after the reopening. The results were compared with those obtained in similar samplings of 2019. For the comparative analysis, we divided the hotels in two groups: Group A that have suffered closures for ≤3 months and Group B that remained closed for more than 3 months, both in relation to the opening period of 2019. In the Group B (36 sites), the frequency of positive samples in the hot water system increased from 6.7% in 2019 to 14.0% in 2020 (p < 0.05). In the Group A (37 sites), no significant differences were observed. No statistically significant differences were observed in terms of positive sites (defined as hotels with at least 1 positive sample), Legionella spp. concentrations and prevalence of Legionella pneumophila sg1 between the samplings of the two periods studied. The results suggest that hotels that suffered the longest prolonged closures (> 3 months) could have carried a higher risk of exposure to Legionella in the domestic hot water system. These findings highlight the importance of adequate preopening cleaning and disinfection procedures for hotel water systems, and the convenience of considering the most effective disinfection methods especially for hot water systems and after prolonged closure periods.
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Affiliation(s)
- Jhon J Molina
- Environmental Health and Laboratory Services, Biolinea Int., Palma, Spain.,Environmental Analytical Chemistry Laboratory, Department of Chemistry, University of the Balearic Islands, Palma, Spain
| | | | - Edwin Palacio
- Environmental Analytical Chemistry Laboratory, Department of Chemistry, University of the Balearic Islands, Palma, Spain
| | - Sebastian Crespi
- Environmental Health and Laboratory Services, Biolinea Int., Palma, Spain
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11
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Doménech-Sánchez A, Laso E, Berrocal CI, Albertí S. Environmental surveillance of Legionella in tourist facilities of the Balearic Islands, Spain, 2006 to 2010 and 2015 to 2018. Euro Surveill 2022; 27:2100769. [PMID: 35621000 PMCID: PMC9137269 DOI: 10.2807/1560-7917.es.2022.27.21.2100769] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 12/20/2021] [Indexed: 06/15/2023] Open
Abstract
BackgroundLegionnaires' disease is a respiratory illness often associated with hotels and travel. Spain is a major tourist destination and one of the European countries with most cases of Legionnaires' disease , both community- and travel-associated. However, the prevalence of Legionella in tourist facilities is unknown.AimThe present investigation aimed to survey the tourist facilities in the Balearic Islands, Spain, for Legionella prevalence.MethodsWe visited tourist facilities in the Balearic Islands in two different periods (2006-2010 and 2015-2018) and took water samples following national and international guidelines. Legionella was investigated by culture methods following international standards (ISO 11731:1998).ResultsWe evaluated 13,472 samples from 465 facilities. Bacteria of the Legionella genus were detected in 65.4% of the surveyed facilities. Contamination of the facilities was significantly higher during the second decade (54.5 vs 78.6%). The most frequent colonisers were L. pneumophila serogroup 2-14. We detected the pathogen in 15.9% and 6.9% of hot and cold water distribution systems samples, respectively. The Legionella contamination rate in cold water systems samples was higher when free chlorine levels were < 0.2 mg/L and at > 25 °C temperatures, while in the hot water systems samples, the contamination rate was higher at < 50 °C. Of the samples from hot tubs, 10.9% were contaminated.ConclusionLegionella prevalence in hotels in the Balearic Islands was high but the contamination rates depended on the installations. Corrective measures are still needed to improve Legionella control.
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Affiliation(s)
- Antonio Doménech-Sánchez
- Saniconsult Ibérica SL, Palma de Mallorca, Spain
- Instituto Universitario de Investigación en Ciencias de la Salud (IUNICS), Universidad de las Islas Baleares, Palma de Mallorca, Spain
- Instituto de Investigación Sanitaria de les Illes Balears (IdIsBa), Palma de Mallorca, Spain
| | - Elena Laso
- Saniconsult Ibérica SL, Palma de Mallorca, Spain
| | | | - Sebastián Albertí
- Instituto Universitario de Investigación en Ciencias de la Salud (IUNICS), Universidad de las Islas Baleares, Palma de Mallorca, Spain
- Instituto de Investigación Sanitaria de les Illes Balears (IdIsBa), Palma de Mallorca, Spain
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12
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Variable Legionella Response to Building Occupancy Patterns and Precautionary Flushing. Microorganisms 2022; 10:microorganisms10030555. [PMID: 35336130 PMCID: PMC8950775 DOI: 10.3390/microorganisms10030555] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 02/21/2022] [Accepted: 02/26/2022] [Indexed: 02/04/2023] Open
Abstract
When stay-at-home orders were issued to slow the spread of COVID-19, building occupancy (and water demand) was drastically decreased in many buildings. There was concern that widespread low water demand may cause unprecedented Legionella occurrence and Legionnaires’ disease incidence. In lieu of evidenced-based guidance, many people flushed their water systems as a preventative measure, using highly variable practices. Here, we present field-scale research from a building before, during, and after periods of low occupancy, and controlled stagnation experiments. We document no change, a > 4-log increase, and a > 1.5-log decrease of L. pneumophila during 3- to 7-week periods of low water demand. L. pneumophila increased by > 1-log after precautionary flushing prior to reoccupancy, which was repeated in controlled boiler flushing experiments. These results demonstrate that the impact of low water demand (colloquially called stagnation) is not as straight forward as is generally assumed, and that some flushing practices have potential unintended consequences. In particular, stagnation must be considered in context with other Legionella growth factors like temperature and flow profiles. Boiler flushing practices that dramatically increase the flow rate and rapidly deplete boiler temperature may mobilize Legionella present in biofilms and sediment.
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13
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Doménech-Sánchez A, Laso E, Albertí S. Determination of Legionella spp. prevalence in Spanish hotels in five years. Are tourists really at risk? Travel Med Infect Dis 2022; 46:102269. [DOI: 10.1016/j.tmaid.2022.102269] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 01/26/2022] [Indexed: 11/17/2022]
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14
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Prevalence of opportunistic pathogens in a school building plumbing during periods of low water use and a transition to normal use. Int J Hyg Environ Health 2022; 241:113945. [PMID: 35182850 DOI: 10.1016/j.ijheh.2022.113945] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/28/2022] [Accepted: 02/10/2022] [Indexed: 11/23/2022]
Abstract
The spread of opportunistic pathogens via building water supply and plumbing is of public health concern. This study was conducted to better understand microbial water quality changes in a LEED-certified school building during low water use (Summer) and normal water use (Autumn). The copper plumbed building contained water saving devices, a hot water recirculation system, and received chloraminated drinking water from a public water system. Three separate sampling events were conducted during the summer break inside the building and another three sampling events were conducted after the school returned to session. Using quantitative PCR, Legionella spp. were detected in all water samples, followed by Mycobacterium spp. (99%). Mycobacterium avium (75%) and Acanthamoeba spp. (17.5%) throughout the building water system. Legionella pneumophila and Naegleria fowleri were not detected in any of the samples. The mean concentrations of Legionella spp., Mycobacterium spp., Mycobacterium avium, and Acanthamoeba spp. detected in water samples were 3.9, 5.7, 4.7, and 2.8 log10 gene copies per 100 ml, respectively. There was a statistically significantly difference in the mean concentrations of Legionella spp., Mycobacterium spp. and M. avium gene markers in water samples between school breaks and when school was in session. Cultivable Legionella were also detected in water samples collected during periods of low water use. This study highlights the need for routine proactive water quality testing in school buildings to determine the extent of drinking water quality problems associated with plumbing and direct action to remediate microbial colonization.
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15
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Molina JJ, Bennassar M, Palacio E, Crespi S. Low Efficacy of Periodical Thermal Shock for Long-Term Control of Legionella spp. in Hot Water System of Hotels. Pathogens 2022; 11:pathogens11020152. [PMID: 35215095 PMCID: PMC8875211 DOI: 10.3390/pathogens11020152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/21/2022] [Accepted: 01/21/2022] [Indexed: 02/04/2023] Open
Abstract
Different guidelines and regulations for the prevention of legionellosis in public facilities include the recommendation of a periodical thermal shock in the hot water system. The purpose of this study was to assess the efficacy of periodical thermal shocks along a 1-year period on the presence of Legionella spp. in the domestic hot water system of hotels. The Legionella testing results from the period January–December 2019 coming from a group of 77 hotel facilities in the Balearic Islands (Spain) conducting periodical thermal shocks were analyzed. A second group of 44 hotels operating without periodical thermal shocks was used for a comparative analysis. In the facilities where the periodical thermal shock was performed, 16.0% of the results (429 hot water samples collected) were positive for Legionella spp., compared to 21.1% (298 samples), where periodical thermal shock was not performed. Overall, in the thermal shock group, 32.5% of the sites presented at least 1 positive sample along the period of study versus 45.5% in the control group. None of these differences was statistically significant (p-value > 0.05). These findings suggest that the efficacy of regular thermal shock for long-term control of Legionella spp. in domestic hot water systems of hotels is low.
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Affiliation(s)
- Jhon J. Molina
- Biolinea Int., 07007 Palma, Spain; (J.J.M.); (M.B.)
- Environmental Analytical Chemistry Group, University of the Balearic Islands, 07122 Palma, Spain;
| | | | - Edwin Palacio
- Environmental Analytical Chemistry Group, University of the Balearic Islands, 07122 Palma, Spain;
| | - Sebastian Crespi
- Biolinea Int., 07007 Palma, Spain; (J.J.M.); (M.B.)
- Correspondence: ; Tel.: +34-971724701
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Zhang C, Lu J. Legionella: A Promising Supplementary Indicator of Microbial Drinking Water Quality in Municipal Engineered Water Systems. FRONTIERS IN ENVIRONMENTAL SCIENCE 2021; 9:1-22. [PMID: 35004706 PMCID: PMC8740890 DOI: 10.3389/fenvs.2021.684319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Opportunistic pathogens (OPs) are natural inhabitants and the predominant disease causative biotic agents in municipal engineered water systems (EWSs). In EWSs, OPs occur at high frequencies and concentrations, cause drinking-water-related disease outbreaks, and are a major factor threatening public health. Therefore, the prevalence of OPs in EWSs represents microbial drinking water quality. Closely or routinely monitoring the dynamics of OPs in municipal EWSs is thus critical to ensuring drinking water quality and protecting public health. Monitoring the dynamics of conventional (fecal) indicators (e.g., total coliforms, fecal coliforms, and Escherichia coli) is the customary or even exclusive means of assessing microbial drinking water quality. However, those indicators infer only fecal contamination due to treatment (e.g., disinfection within water utilities) failure and EWS infrastructure issues (e.g., water main breaks and infiltration), whereas OPs are not contaminants in drinking water. In addition, those indicators appear in EWSs at low concentrations (often absent in well-maintained EWSs) and are uncorrelated with OPs. For instance, conventional indicators decay, while OPs regrow with increasing hydraulic residence time. As a result, conventional indicators are poor indicators of OPs (the major aspect of microbial drinking water quality) in EWSs. An additional or supplementary indicator that can well infer the prevalence of OPs in EWSs is highly needed. This systematic review argues that Legionella as a dominant OP-containing genus and natural inhabitant in EWSs is a promising candidate for such a supplementary indicator. Through comprehensively comparing the behavior (i.e., occurrence, growth and regrowth, spatiotemporal variations in concentrations, resistance to disinfectant residuals, and responses to physicochemical water quality parameters) of major OPs (e.g., Legionella especially L. pneumophila, Mycobacterium, and Pseudomonas especially P. aeruginosa), this review proves that Legionella is a promising supplementary indicator for the prevalence of OPs in EWSs while other OPs lack this indication feature. Legionella as a dominant natural inhabitant in EWSs occurs frequently, has a high concentration, and correlates with more microbial and physicochemical water quality parameters than other common OPs. Legionella and OPs in EWSs share multiple key features such as high disinfectant resistance, biofilm formation, proliferation within amoebae, and significant spatiotemporal variations in concentrations. Therefore, the presence and concentration of Legionella well indicate the presence and concentrations of OPs (especially L. pneumophila) and microbial drinking water quality in EWSs. In addition, Legionella concentration indicates the efficacies of disinfectant residuals in EWSs. Furthermore, with the development of modern Legionella quantification methods (especially quantitative polymerase chain reactions), monitoring Legionella in ESWs is becoming easier, more affordable, and less labor-intensive. Those features make Legionella a proper supplementary indicator for microbial drinking water quality (especially the prevalence of OPs) in EWSs. Water authorities may use Legionella and conventional indicators in combination to more comprehensively assess microbial drinking water quality in municipal EWSs. Future work should further explore the indication role of Legionella in EWSs and propose drinking water Legionella concentration limits that indicate serious public health effects and require enhanced treatment (e.g., booster disinfection).
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Affiliation(s)
- Chiqian Zhang
- Pegasus Technical Services, Inc., Cincinnati, OH, United States
| | - Jingrang Lu
- Office of Research and Development, United States Environmental Protection Agency, Cincinnati, OH, United States
- Correspondence: Jingrang Lu,
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De Giglio O, Napoli C, Diella G, Fasano F, Lopuzzo M, Apollonio F, D'Ambrosio M, Campanale C, Triggiano F, Caggiano G, Montagna MT. Integrated approach for legionellosis risk analysis in touristic-recreational facilities. ENVIRONMENTAL RESEARCH 2021; 202:111649. [PMID: 34252427 DOI: 10.1016/j.envres.2021.111649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/30/2021] [Accepted: 07/02/2021] [Indexed: 06/13/2023]
Abstract
Legionellosis is a severe pneumonia caused by the inhalation of aerosols containing Legionella, Gram-negative bacteria present in the water systems of touristic-recreational facilities. The purpose of this study was to develop a scoring tool to predict the risk of both environmental contamination and Legionnaires' disease cases in such facilities in the Apulia region of southern Italy. We analyzed 47 structural and management parameters/risk factors related to the buildings, water systems, and air conditioning at the facilities. A Poisson regression model was used to compute an overall risk score for each facility with respect to three outcomes: water samples positive for Legionella (risk score range: 7-54), water samples positive for Legionella with an average load exceeding 1000 colony-forming units per liter (CFU/L) (risk score range: 22-179,871), and clinical cases of Legionnaire's disease (risk score range: 6-31). The cut-off values for three outcomes were determined by receiver operating characteristic curves (first outcome, samples positive for Legionella in a touristic-recreational facility: 19; second outcome, samples positive for Legionella in a touristic-recreational facility with an average load exceeding 1000 CFU/L: 2062; third outcome, clinical cases of Legionnaire's disease in a touristic-recreational facility: 22). Above these values, there was a significant probability of observing the outcome. We constructed this predictive model using 70% of a large dataset (18 years of clinical and environmental surveillance) and tested the model on the remaining 30% of the dataset to demonstrate its reliability. Our model enables the assessment of risk for a touristic facility and the creation of a conceptual framework to link the risk analysis with prevention measures.
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Affiliation(s)
- Osvalda De Giglio
- Regional Reference Laboratory of Clinical and Environmental Surveillance of Legionellosis, Department of Biomedical Science and Human Oncology, University of Bari Aldo Moro, Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Christian Napoli
- Department of Medical Surgical Sciences and Translational Medicine, "Sapienza" University of Rome, Via di Grottarossa 1035/1039, 00189, Rome, Italy.
| | - Giusy Diella
- Regional Reference Laboratory of Clinical and Environmental Surveillance of Legionellosis, Department of Biomedical Science and Human Oncology, University of Bari Aldo Moro, Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Fabrizio Fasano
- Regional Reference Laboratory of Clinical and Environmental Surveillance of Legionellosis, Department of Biomedical Science and Human Oncology, University of Bari Aldo Moro, Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Marco Lopuzzo
- Regional Reference Laboratory of Clinical and Environmental Surveillance of Legionellosis, Department of Biomedical Science and Human Oncology, University of Bari Aldo Moro, Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Francesca Apollonio
- Regional Reference Laboratory of Clinical and Environmental Surveillance of Legionellosis, Department of Biomedical Science and Human Oncology, University of Bari Aldo Moro, Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Marilena D'Ambrosio
- Regional Reference Laboratory of Clinical and Environmental Surveillance of Legionellosis, Department of Biomedical Science and Human Oncology, University of Bari Aldo Moro, Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Carmen Campanale
- Regional Reference Laboratory of Clinical and Environmental Surveillance of Legionellosis, Department of Biomedical Science and Human Oncology, University of Bari Aldo Moro, Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Francesco Triggiano
- Regional Reference Laboratory of Clinical and Environmental Surveillance of Legionellosis, Department of Biomedical Science and Human Oncology, University of Bari Aldo Moro, Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Giuseppina Caggiano
- Regional Reference Laboratory of Clinical and Environmental Surveillance of Legionellosis, Department of Biomedical Science and Human Oncology, University of Bari Aldo Moro, Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Maria Teresa Montagna
- Regional Reference Laboratory of Clinical and Environmental Surveillance of Legionellosis, Department of Biomedical Science and Human Oncology, University of Bari Aldo Moro, Piazza G. Cesare 11, 70124, Bari, Italy.
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Toplitsch D, Platzer S, Zehner R, Maitz S, Mascher F, Kittinger C. Comparison of Updated Methods for Legionella Detection in Environmental Water Samples. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18105436. [PMID: 34069615 PMCID: PMC8161308 DOI: 10.3390/ijerph18105436] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 05/11/2021] [Accepted: 05/14/2021] [Indexed: 12/04/2022]
Abstract
The difficulty of cultivation of Legionella spp. from water samples remains a strenuous task even for experienced laboratories. The long incubation periods for Legionellae make isolation difficult. In addition, the water samples themselves are often contaminated with accompanying microbial flora, and therefore require complex cultivation methods from diagnostic laboratories. In addition to the recent update of the standard culture method ISO 11731:2017, new strategies such as quantitative PCR (qPCR) are often discussed as alternatives or additions to conventional Legionella culture approaches. In this study, we compared ISO 11731:2017 with qPCR assays targeting Legionella spp., Legionella pneumophila, and Legionella pneumophila serogroup 1. In samples with a high burden of accompanying microbial flora, qPCR shows an excellent negative predictive value for Legionella pneumophila, thus making qPCR an excellent tool for pre-selection of negative samples prior to work-intensive culture methods. This and its low limit of detection make qPCR a diagnostic asset in Legionellosis outbreak investigations, where quick-risk assessments are essential, and are a useful method for monitoring risk sites.
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Masaka E, Reed S, Davidson M, Oosthuizen J. Opportunistic Premise Plumbing Pathogens. A Potential Health Risk in Water Mist Systems Used as a Cooling Intervention. Pathogens 2021; 10:pathogens10040462. [PMID: 33921277 PMCID: PMC8068904 DOI: 10.3390/pathogens10040462] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/29/2021] [Accepted: 04/07/2021] [Indexed: 11/16/2022] Open
Abstract
Water mist systems (WMS) are used for evaporative cooling in public areas. The health risks associated with their colonization by opportunistic premise plumbing pathogens (OPPPs) is not well understood. To advance the understanding of the potential health risk of OPPPs in WMS, biofilm, water and bioaerosol samples (n = 90) from ten (10) WMS in Australia were collected and analyzed by culture and polymerase chain reaction (PCR) methods to detect the occurrence of five representative OPPPs: Legionella pneumophila, Pseudomonas aeruginosa, Mycobacterium avium, Naegleria fowleri and Acanthamoeba. P. aeruginosa (44%, n = 90) occurred more frequently in samples, followed by L. pneumophila serogroup (Sg) 2–14 (18%, n = 90) and L. pneumophila Sg 1 (6%, n = 90). A negative correlation between OPPP occurrence and residual free chlorine was observed except with Acanthamoeba, rs (30) = 0.067, p > 0.05. All detected OPPPs were positively correlated with total dissolved solids (TDS) except with Acanthamoeba. Biofilms contained higher concentrations of L. pneumophila Sg 2–14 (1000–3000 CFU/mL) than water samples (0–100 CFU/mL). This study suggests that WMS can be colonized by OPPPs and are a potential health risk if OPPP contaminated aerosols get released into ambient atmospheres.
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Leftwich B, Opoku ST, Yin J, Adhikari A. Assessing Hotel Employee Knowledge on Risk Factors and Risk Management Procedures for Microbial Contamination of Hotel Water Distribution Systems. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:3539. [PMID: 33805459 PMCID: PMC8037688 DOI: 10.3390/ijerph18073539] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/13/2021] [Accepted: 03/25/2021] [Indexed: 11/16/2022]
Abstract
Water management plans (WMPs), sometimes referred to as risk management plans (RMPs) or water safety plans (WSPs), are not mandatory for hotels in many countries of the world, including the US. As such, many hotel personnel are uninformed of WMPs and the precautions to take if their hotel water system is compromised. The purpose of this study was to identify hotel personnel's knowledge and practices of WMPs through a survey incorporating the Health Belief Model (HBM). Data were collected from 59 hotels within Fulton County, Georgia, USA, through a questionnaire, and questions were developed tailored to the HBM. Significant associations were found between the perceived susceptibility of contracting a waterborne illness and WMP for hotel personnel as well as between cues to action and having a WMP in general linear models (p ≤ 0.05). The study concludes that many key personnel are not aware of WMPs. Many hotel facilities do not have a plan in place, and some facilities are unaware of a current plan is in place. The study findings provide insight into the importance of WMPs and the risk factors associated with microbial contamination in a hotel building's plumbing system. Future research and potential law change should be emphasized to increase hotel employees' and owner's WMP knowledge.
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Affiliation(s)
- Brandon Leftwich
- Department of Health Policy and Community Health, Jiann-Ping Hsu College of Public Health, Georgia Southern University, Statesboro, GA 30460, USA; (B.L.); (S.T.O.)
| | - Samuel T. Opoku
- Department of Health Policy and Community Health, Jiann-Ping Hsu College of Public Health, Georgia Southern University, Statesboro, GA 30460, USA; (B.L.); (S.T.O.)
| | - Jingjing Yin
- Department of Biostatistics, Epidemiology, and Environmental Health Sciences, Jiann-Ping Hsu College of Public Health, Georgia Southern University, Statesboro, GA 30460, USA;
| | - Atin Adhikari
- Department of Biostatistics, Epidemiology, and Environmental Health Sciences, Jiann-Ping Hsu College of Public Health, Georgia Southern University, Statesboro, GA 30460, USA;
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Abstract
Legionellosis is a serious bacterial infection characterized by atypical pneumonia primarily due to infection with Legionella pneumophila, and bathing can be a potential cause of this infection. Legionellosis was first identified in 1977, and it is caused by Gram-negative bacteria belonging to the genus Legionella. Legionellosis remains an important public health threat, particularly in Japan, where the population is rapidly aging, thereby becoming more at risk of developing severe disease and accompanying life-threatening pneumonia. The bacteria are most commonly transmitted via the inhalation of contaminated aerosols produced and broadcast via water sprays, jets or mists. Infection can also occur via the aspiration of contaminated water or ice, or through inhalation of contaminated dust. Because the signs and symptoms of Legionnaires' disease (LD), as well as radiographic imaging are similar to pneumonia caused by other pathogens, a specific diagnostic test is required, such as a urine antigen detection test. Six clinical and laboratory parameters, a high body temperature, a non-productive cough, low serum sodium and platelet counts, and high lactate dehydrogenase (LDH) and c-reactive protein concentrations can be used to reliably predict the likelihood of LD. The first choices for chemotherapy are fluoroquinolone and macrolide antibiotic drugs. The main goals of LD prevention measures are 1) the prevention of microbial growth and biofilm formation, 2) the removal of all biofilm formed on equipment and in facilities, 3) minimizing aerosol splash and spread, and 4) minimizing bacterial contamination from external sources. It is apparent that, in Japan, where hot spring (onsen) bathing is common among aged people, strict regulations need to be in place - and enforced - to ensure that all Japanese onsens and spas provide a safe environment and undertake regular, effective infection control practices.
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Falkinham JO. Living with Legionella and Other Waterborne Pathogens. Microorganisms 2020; 8:E2026. [PMID: 33352932 PMCID: PMC7766883 DOI: 10.3390/microorganisms8122026] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 12/04/2020] [Accepted: 12/16/2020] [Indexed: 02/06/2023] Open
Abstract
Legionella spp. and other opportunistic premise plumbing pathogens (OPPPs), including Pseudomonas aeruginosa, Mycobacterium avium, Stenotrophomonas maltophilia, and Acinetobacter baumannii, are normal inhabitants of natural waters, drinking water distribution systems and premise plumbing. Thus, humans are regularly exposed to these pathogens. Unfortunately, Legionella spp. and the other OPPPs share a number of features that allow them to grow and persist in premise plumbing. They form biofilms and are also relatively disinfectant-resistant, able to grow at low organic matter concentrations, and able to grow under stagnant conditions. Infections have been traced to exposure to premise plumbing or aerosols generated in showers. A number of measures can lead to reduction in OPPP numbers in premise plumbing, including elevation of water heater temperatures.
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Affiliation(s)
- Joseph O Falkinham
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
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Zayed AR, Butmeh S, Pecellin M, Salah A, Alalam H, Steinert M, Höfle MG, Bitar DM, Brettar I. Biogeography and Environmental Drivers of Legionella pneumophila Abundance and Genotype Composition Across the West Bank: Relevance of a Genotype-Based Ecology for Understanding Legionella Occurrence. Pathogens 2020; 9:pathogens9121012. [PMID: 33271905 PMCID: PMC7761038 DOI: 10.3390/pathogens9121012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/27/2020] [Accepted: 11/27/2020] [Indexed: 12/20/2022] Open
Abstract
The West Bank can be considered as a high-risk area for Legionella prevalence in drinking water due to high ambient temperature, intermittent water supply, frequent pressure loss, and storage of drinking water in roof containers. To assess occurrence of Legionella species, especially L. pneumophila, in the drinking water of the West Bank, the drinking water distribution systems of eight hospitals were sampled over a period of 2.3 years covering the seasonal cycle and the major geographic regions. To gain insight into potential environmental drivers, a set of physico-chemical and microbiological parameters was recorded. Sampling included drinking water and biofilm analyzed by culture and PCR-based methods. Cultivation led to the isolation of 180 strains of L. pneumophila that were genotyped by Multi-Locus Variable Number of Tandem Repeat Analysis (MLVA). Surprisingly, the abundance of culturable L. pneumophila was low in drinking water of the sampling sites, with only three out of eight sites where Legionella was observed at all (range: 30–500 CFU/Liter). By contrast, biofilm and PCR-based analyses showed a higher prevalence. Statistical analyses with physico-chemical parameters revealed a decrease of L. pneumophila abundance for water and biofilm with increasing magnesium concentrations (>30 mg/L). MLVA-genotype analysis of the L. pneumophila isolates and their spatial distribution indicated three niches characterized by distinct physico-chemical parameters and inhabited by specific consortia of genotypes. This study provides novel insights into mechanisms shaping L. pneumophila populations and triggering their abundance leading to an understanding of their genotype-specific niches and ecology in support of improved prevention measures.
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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.); (M.G.H.)
- Department of Microbiology and Immunology, Al-Quds University, Abu-Dis, University Street, Jerusalem 19356, Palestine; (S.B.); (A.S.); (H.A.); (D.M.B.)
| | - Suha Butmeh
- Department of Microbiology and Immunology, Al-Quds University, Abu-Dis, University Street, Jerusalem 19356, Palestine; (S.B.); (A.S.); (H.A.); (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.); (M.G.H.)
| | - Alaa Salah
- Department of Microbiology and Immunology, Al-Quds University, Abu-Dis, University Street, Jerusalem 19356, Palestine; (S.B.); (A.S.); (H.A.); (D.M.B.)
| | - Hanna Alalam
- Department of Microbiology and Immunology, Al-Quds University, Abu-Dis, University Street, Jerusalem 19356, Palestine; (S.B.); (A.S.); (H.A.); (D.M.B.)
| | - Michael Steinert
- Department of Life Sciences, Institute of Microbiology, Technical University of Braunschweig, Universitätsplatz 2, 38106 Braunschweig, Germany;
| | - 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.); (M.G.H.)
| | - Dina M. Bitar
- Department of Microbiology and Immunology, Al-Quds University, Abu-Dis, University Street, Jerusalem 19356, Palestine; (S.B.); (A.S.); (H.A.); (D.M.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.); (M.G.H.)
- Correspondence:
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24
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Cullom AC, Martin RL, Song Y, Williams K, Williams A, Pruden A, Edwards MA. Critical Review: Propensity of Premise Plumbing Pipe Materials to Enhance or Diminish Growth of Legionella and Other Opportunistic Pathogens. Pathogens 2020; 9:E957. [PMID: 33212943 PMCID: PMC7698398 DOI: 10.3390/pathogens9110957] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 12/20/2022] Open
Abstract
Growth of Legionella pneumophila and other opportunistic pathogens (OPs) in drinking water premise plumbing poses an increasing public health concern. Premise plumbing is constructed of a variety of materials, creating complex environments that vary chemically, microbiologically, spatially, and temporally in a manner likely to influence survival and growth of OPs. Here we systematically review the literature to critically examine the varied effects of common metallic (copper, iron) and plastic (PVC, cross-linked polyethylene (PEX)) pipe materials on factors influencing OP growth in drinking water, including nutrient availability, disinfectant levels, and the composition of the broader microbiome. Plastic pipes can leach organic carbon, but demonstrate a lower disinfectant demand and fewer water chemistry interactions. Iron pipes may provide OPs with nutrients directly or indirectly, exhibiting a high disinfectant demand and potential to form scales with high surface areas suitable for biofilm colonization. While copper pipes are known for their antimicrobial properties, evidence of their efficacy for OP control is inconsistent. Under some circumstances, copper's interactions with premise plumbing water chemistry and resident microbes can encourage growth of OPs. Plumbing design, configuration, and operation can be manipulated to control such interactions and health outcomes. Influences of pipe materials on OP physiology should also be considered, including the possibility of influencing virulence and antibiotic resistance. In conclusion, all known pipe materials have a potential to either stimulate or inhibit OP growth, depending on the circumstances. This review delineates some of these circumstances and informs future research and guidance towards effective deployment of pipe materials for control of OPs.
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Affiliation(s)
- Abraham C. Cullom
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
| | - Rebekah L. Martin
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
- Civil and Environmental Engineering, Virginia Military Institute, Lexington, VA 24450, USA
| | - Yang Song
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
| | | | - Amanda Williams
- c/o Marc Edwards, Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA;
| | - Amy Pruden
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
| | - Marc A. Edwards
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
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25
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Li S, Yang Z, Hu D, Cao L, He Q. Understanding building-occupant-microbiome interactions toward healthy built environments: A review. FRONTIERS OF ENVIRONMENTAL SCIENCE & ENGINEERING 2020; 15:65. [PMID: 33145119 PMCID: PMC7596174 DOI: 10.1007/s11783-020-1357-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 08/30/2020] [Accepted: 09/16/2020] [Indexed: 06/11/2023]
Abstract
Built environments, occupants, and microbiomes constitute a system of ecosystems with extensive interactions that impact one another. Understanding the interactions between these systems is essential to develop strategies for effective management of the built environment and its inhabitants to enhance public health and well-being. Numerous studies have been conducted to characterize the microbiomes of the built environment. This review summarizes current progress in understanding the interactions between attributes of built environments and occupant behaviors that shape the structure and dynamics of indoor microbial communities. In addition, this review also discusses the challenges and future research needs in the field of microbiomes of the built environment that necessitate research beyond the basic characterization of microbiomes in order to gain an understanding of the causal mechanisms between the built environment, occupants, and microbiomes, which will provide a knowledge base for the development of transformative intervention strategies toward healthy built environments. The pressing need to control the transmission of SARS-CoV-2 in indoor environments highlights the urgency and significance of understanding the complex interactions between the built environment, occupants, and microbiomes, which is the focus of this review.
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Affiliation(s)
- Shuai Li
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996 USA
| | - Zhiyao Yang
- Lyles School of Civil Engineering, Purdue University, West Lafayette, IN 47907 USA
| | - Da Hu
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996 USA
| | - Liu Cao
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996 USA
| | - Qiang He
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996 USA
- Institute for a Secure & Sustainable Environment, University of Tennessee, Knoxville, TN 37996 USA
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26
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Rasheduzzaman M, Singh R, Haas CN, Gurian PL. Required water temperature in hotel plumbing to control Legionella growth. WATER RESEARCH 2020; 182:115943. [PMID: 32590203 DOI: 10.1016/j.watres.2020.115943] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 05/12/2020] [Accepted: 05/13/2020] [Indexed: 05/07/2023]
Abstract
Legionella spp. occurring in hotel hot water systems, in particular Legionella pneumophila, are causing serious pneumonic infections, and water temperature is a key factor to control their occurrence in plumbing systems. We performed a systematic review and meta-analyses of the available evidence on the association between water temperature and Legionella colonization to identify the water temperature in hotel hot water systems required for control of Legionella. Qualitative synthesis and quantitative analysis were performed on 13 studies that met our inclusion criteria to identify the effect of temperature. The Receiver Operating Characteristic (ROC) curve identified 55 °C as a cutoff point for hotel hot water temperature with an Area Under the Curve (AUC) value of 0.914. The odds ratios (OR) for detecting Legionella at temperatures >55 °C compared to lower temperatures from a meta-analysis of three studies was 0.17 [95% CI: 0.11, 0.25], which indicates a strong negative association between temperature and Legionella colonization. A logistic regression on results from multiple studies using both molecular and culture methods found a temperature of 59 °C associated with an 8% probability of detectable Legionella. Only two studies reported sufficiently detailed data to allow a model of concentration vs. temperature to be fit, and this model was not statistically significant. Additional research or more detailed reporting of existing datasets is required to assess if Legionella growth can be limited below particular concentration targets at different temperatures.
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Affiliation(s)
- Md Rasheduzzaman
- Department of Civil, Architectural and Environmental Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA, 19104, USA.
| | - Rajveer Singh
- Department of Civil, Architectural and Environmental Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA, 19104, USA
| | - Charles N Haas
- Department of Civil, Architectural and Environmental Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA, 19104, USA
| | - Patrick L Gurian
- Department of Civil, Architectural and Environmental Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA, 19104, USA
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27
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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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28
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Paniagua AT, Paranjape K, Hu M, Bédard E, Faucher SP. Impact of temperature on Legionella pneumophila, its protozoan host cells, and the microbial diversity of the biofilm community of a pilot cooling tower. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 712:136131. [PMID: 31931228 DOI: 10.1016/j.scitotenv.2019.136131] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 12/13/2019] [Accepted: 12/13/2019] [Indexed: 06/10/2023]
Abstract
Legionella pneumophila is a waterborne bacterium known for causing Legionnaires' Disease, a severe pneumonia. Cooling towers are a major source of outbreaks, since they provide ideal conditions for L. pneumophila growth and produce aerosols. In such systems, L. pneumophila typically grow inside protozoan hosts. Several abiotic factors such as water temperature, pipe material and disinfection regime affect the colonization of cooling towers by L. pneumophila. The local physical and biological factors promoting the growth of L. pneumophila in water systems and its spatial distribution are not well understood. Therefore, we built a lab-scale cooling tower to study the dynamics of L. pneumophila colonization in relationship to the resident microbiota and spatial distribution. The pilot was filled with water from an operating cooling tower harboring low levels of L. pneumophila. It was seeded with Vermamoeba vermiformis, a natural host of L. pneumophila, and then inoculated with L. pneumophila. After 92 days of operation, the pilot was disassembled, the water was collected, and biofilm was extracted from the pipes. The microbiome was studied using 16S rRNA and 18S rRNA genes amplicon sequencing. The communities of the water and of the biofilm were highly dissimilar. The relative abundance of Legionella in water samples reached up to 11% whereas abundance in the biofilm was extremely low (≤0.5%). In contrast, the host cells were mainly present in the biofilm. This suggests that L. pneumophila grows in host cells associated with biofilm and is then released back into the water following host cell lysis. In addition, water temperature shaped the bacterial and eukaryotic community of the biofilm, indicating that different parts of the systems may have different effects on Legionella growth.
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Affiliation(s)
- Adriana Torres Paniagua
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Drive, Ste-Anne-de-Bellevue, Quebec, H9X 3V9, Canada
| | - Kiran Paranjape
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Drive, Ste-Anne-de-Bellevue, Quebec, H9X 3V9, Canada
| | - Mengqi Hu
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Drive, Ste-Anne-de-Bellevue, Quebec, H9X 3V9, Canada
| | - Emilie Bédard
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Drive, Ste-Anne-de-Bellevue, Quebec, H9X 3V9, Canada; Department of Civil Engineering, Polytechnique Montreal, P.O. Box 6079, Station Centre-Ville, Montreal, Quebec H3C 3A7, Canada.
| | - Sébastien P Faucher
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Drive, Ste-Anne-de-Bellevue, Quebec, H9X 3V9, Canada.
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29
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Huang C, Shen Y, Smith RL, Dong S, Nguyen TH. Effect of disinfectant residuals on infection risks from Legionella pneumophila released by biofilms grown under simulated premise plumbing conditions. ENVIRONMENT INTERNATIONAL 2020; 137:105561. [PMID: 32088542 DOI: 10.1016/j.envint.2020.105561] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 02/05/2020] [Accepted: 02/06/2020] [Indexed: 06/10/2023]
Abstract
The ubiquitous presence of biofilms in premise plumbing and stagnation, which commonly occurs in premise plumbing, can exacerbate the decay of chlorine residual in drinking water. Using biofilms grown in a simulated premise plumbing setup fed directly with freshly treated water at two full-scale water treatment plants, we previously determined the mass transfer coefficients for chlorine decay in premise plumbing. These coefficients coupled with inactivation kinetics of L. pneumophila released from biofilms reported previously were integrated into a Monte Carlo framework to estimate the infection risk of biofilm-derived L. pneumophila from 1 to 48 h of stagnation. The annual infection risk was significantly higher when water stayed stagnant for up to 48 h in pipes covered internally with biofilms, compared to clean pipes without biofilms. The decay of residual chlorine due to biofilms during 48-hour stagnation led to up to 6 times increase in the annual infection risk compared to the case where biofilms was absent. Global sensitivity analysis revealed that the rate of L. pneumophila detachment from biofilms and the decay of chlorine residual during stagnation are the two most important factors influencing the infection risks. Stagnation caused by water use patterns and water-saving devices in the premise plumbing can lead to increased infection risk by biofilm-derived L. pneumophila. Overall, this study's findings suggested that biofilms could induce chlorine decay and consequently increase L. pneumophila infection risk. Thus, reducing stagnation, maintaining residual chlorine, and suppressing biofilm growth could contribute to better management of L. pneumophila infection risk.
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Affiliation(s)
- Conghui Huang
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | - Yun Shen
- Department of Chemical and Environmental Engineering, The University of California, Riverside, Riverside, CA 92521, United States
| | - Rebecca L Smith
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | - Shengkun Dong
- Guangdong Engineering Technology Research Center of Water Security Regulation and Control for Southern China, Key Laboratory of Water Cycle and Water Security in Southern China of Guangdong Higher Education Institute, School of Civil Engineering, Sun Yat-sen University, Guangzhou, Guangdong 510275, China.
| | - Thanh H Nguyen
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
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Bertolino G, Marras L, Sanna C, Carrucciu G, Schintu M, Coroneo V. Ten-Year Retrospective Analysis of Legionella Diffusion in Hospital Water Systems and Its Serogroup Seasonal Variation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1282:93-103. [PMID: 32030638 DOI: 10.1007/5584_2020_484] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
INTRODUCTION Legionella spp. are ubiquitous aquatic organisms found to be associated with community-acquired pneumoniae (CAP) as well as hospital-acquired pneumonia (HAP). Direct inhalation of aerosols from environmental colonisation is typically the source of infection. The aim of this study was to determine the level of colonisation in hospital water supply systems in order to assess the criticality of the water distribution network and strengthen preventive measures. METHODS From 2009 to 2018, 769 water samples were collected and then analysed according to the standard methods indicated in ISO11731-2:2004 and ISO11731:2017 for Legionella detection. RESULTS The samples were positive in 37.1% cases (n. 285) and negative in 62.9% cases (n. 484). The threshold of 10,000 CFU/L was exceeded in 15.1% cases and led to decolonisation as indicated by Italian and European ECDC guidelines. In the autumn-winter period SG1 showed a positivity of 41.2% (n. 40) with a decrease in the spring-summer period with 9.6% (n. 18) of positivity. In contrast, SG2-15 showed a positivity of 30.9% (n. 30) in autumn-winter, which tends to increase to 56.9% (n. 112) in spring-summer (p < 0.001). CONCLUSION Surprisingly, besides showing a seasonal trend already described previously in the literature, the positivity of our sample was not balanced even for serogroups in the two periods. This could be due to genetic differences and ecological niches to be further investigated that could also have links with the greater pathogenicity of SG1. Environmental microbiological surveillance and risk assessment should be performed more frequently and disinfection must be carried out, especially in health facilities where people are more susceptible to infections.
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Affiliation(s)
- Giacomo Bertolino
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy. .,Pharmaceutical Department, ATS Sardegna, ASSL Cagliari, Cagliari, Italy.
| | - Luisa Marras
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Clara Sanna
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Gerolamo Carrucciu
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Marco Schintu
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Valentina Coroneo
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
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31
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De Giglio O, Fasano F, Diella G, Lopuzzo M, Napoli C, Apollonio F, Brigida S, Calia C, Campanale C, Marzella A, Pousis C, Rutigliano S, Triggiano F, Caggiano G, Montagna MT. Legionella and legionellosis in touristic-recreational facilities: Influence of climate factors and geostatistical analysis in Southern Italy (2001-2017). ENVIRONMENTAL RESEARCH 2019; 178:108721. [PMID: 31541805 DOI: 10.1016/j.envres.2019.108721] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 09/02/2019] [Accepted: 09/03/2019] [Indexed: 06/10/2023]
Abstract
Legionella is the causative agent of Legionnaires' disease, a flu-like illness normally acquired following inhalation or aspiration of contaminated water aerosols. Our recent studies revealed that climatic parameters can increase the number of reported cases of community-acquired Legionnaires' disease. Here, we evaluated the presence of Legionella in water networks and the distribution of Legionnaires' disease cases associated with touristic-recreational facilities in the Apulia region (southern Italy) during the period 2001-2017 using geostatistical and climatic analyses. Geostatistical analysis data revealed that the area with the highest concentration of Legionella in water systems also had the greatest number of cases of Legionnaires' disease associated with touristic-recreational facilities. Climatic analysis showed that higher daily temperature excursion (difference between maximum and minimum temperature) on the day of sampling was more often associated with Legionella-positive samples than Legionella-negative samples. In addition, our data highlighted an increased risk of Legionnaires' disease with increases in precipitation and average temperature and with decreases in daily temperature excursion (difference between maximum and minimum temperature over the course of 24 h in the days of incubation period of disease) and minimum temperature. Healthcare professionals should be aware of this phenomenon and be particularly vigilant for cases of community-acquired pneumonia during such climatic conditions and among the tourist population. The innovative geo-statistical approach used in this study could be applied in other contexts when evaluating the effects of climatic conditions on the incidence of Legionella infections.
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Affiliation(s)
- Osvalda De Giglio
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Fabrizio Fasano
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Giusy Diella
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Marco Lopuzzo
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Christian Napoli
- Department of Medical Surgical Sciences and Translational Medicine, "Sapienza" University of Rome, Via di Grottarossa 1035/1039, 00189, Rome, Italy.
| | - Francesca Apollonio
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Silvia Brigida
- Water Research Institute-Italian National Research Council, Bari, Italy.
| | - Carla Calia
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Carmen Campanale
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Angelo Marzella
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Chrysovalentinos Pousis
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Serafina Rutigliano
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Francesco Triggiano
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Giuseppina Caggiano
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Maria Teresa Montagna
- Department of Biomedical Science and Human Oncology, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124, Bari, Italy.
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Moreno Y, Moreno-Mesonero L, García-Hernández J. DVC-FISH to identify potentially pathogenic Legionella inside free-living amoebae from water sources. ENVIRONMENTAL RESEARCH 2019; 176:108521. [PMID: 31195295 DOI: 10.1016/j.envres.2019.06.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 04/11/2019] [Accepted: 06/01/2019] [Indexed: 06/09/2023]
Abstract
Despite all safety efforts, drinking and wastewater can still be contaminated by Legionella and free-living amoebae (FLA) since these microorganisms are capable of resisting disinfection treatments. An amoebae cyst harboring pathogenic Legionella spp. can be a transporter of this organism, protecting it and enhancing its infection abilities. Therefore, the aim of this work is to identify by DVC-FISH viable Legionella spp and Legionella pneumophila cells inside FLA from water sources in a specific and rapid way with the aim of assessing the real risk of these waters. A total of 55 water samples were processed, 30 reclaimed wastewater and 25 drinking water. FLA presence was detected in 52.7% of the total processed water samples. When DVC-FISH technique was applied, the presence of viable internalized Legionella spp. cells was identified in 69.0% of the total FLA-positive samples, concretely in 70.0% and 66.7% of wastewater and drinking water samples, respectively. L. pneumophila was simultaneously identified in 48.3% of the total FLA-positive samples, specifically in 50.0% and 44.4% of wastewater and drinking water samples, respectively. By culture, potentially pathogenic Legionella cells were recovered in 27.6% of the total FLA-positive bacteria, particularly in 35.0% and 11.1% of wastewater and drinking water samples, respectively. These findings demonstrate that FLA may promote resistance of bacteria to the performed disinfection treatments for drinking as well as for wastewater. So, in addition to the risk for the presence of pathogenic FLA in water it is necessary to take into account that these can be transporters of the pathogenic bacteria Legionella, which are able to survive inside them. The DVC-FISH method described here has been proved to be a rapid and specific tool to identify pathogenic Legionella spp. and L. penumophila viable cells harboured by FLA in these water sources, posing particular public health concern.
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Affiliation(s)
- Y Moreno
- Research Institute of Water and Environmental Ingeneering (IIAMA), Universitat Politècnica de València, 46022 Valencia, Spain.
| | - L Moreno-Mesonero
- Research Institute of Water and Environmental Ingeneering (IIAMA), Universitat Politècnica de València, 46022 Valencia, Spain
| | - J García-Hernández
- Biotechnology Department, Universitat Politècnica de València, 46022 Valencia, Spain
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Environmental surveillance and spatio-temporal analysis of Legionella spp. in a region of northeastern Italy (2002-2017). PLoS One 2019; 14:e0218687. [PMID: 31287819 PMCID: PMC6615612 DOI: 10.1371/journal.pone.0218687] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 06/06/2019] [Indexed: 01/01/2023] Open
Abstract
Legionella spp. are considered an important cause of potentially preventable morbidity and mortality, making environmental surveillance a crucial component of risk assessment plans. In this work, 20,319 water samples were collected in 3,983 environmental surveys during a 16-year period by ARPA, the Regional Agency for Environmental Protection, Friuli Venezia Giulia, and the results were studied to better understand the diffusion mechanisms of Legionella. The data showed a strong seasonal signal, a prevalence of L. pneumophila serogroup 2–15 in most environments (63% of positive samples), a prevalence of L. pneumophila serogroup 1 in swimming pool-associated environments (82% of positive samples), a persistent presence of Legionella in hospitals and a recurrent presence of Legionella in other facilities such as hotels, possibly years after interventions, highlighting the difficulty of eradicating the bacteria. Retrospective spatio-temporal analyses on geocoded historical data were carried out with SaTScan using an ordinal model with risk as a covariate to identify potential clusters with an excess of cases in the higher-risk categories. Although no outbreaks occurred during the period of study, such analyses identified spatially restricted zones with unusual contamination, which sometimes were also areas in which several surveys triggered by notifications of clinical cases were performed. Simulations of periodic prospective analyses permitted the assessment of the efficacy of the method in early detection of such clusters. The proposed method may be a useful tool in environmental surveillance, prevention and control of Legionella.
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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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De Filippis P, Mozzetti C, Messina A, D'Alò GL. Prevalence of Legionella in retirement homes and group homes water distribution systems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 643:715-724. [PMID: 29957436 DOI: 10.1016/j.scitotenv.2018.06.216] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 05/25/2018] [Accepted: 06/17/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Although historically the focus has been placed above all on hospital infections and travel-associated outbreaks, most of the cases of Legionella infection are sporadic and occur in community-dwellers. OBJECTIVES To evaluate the presence and load of Legionella in hot water systems of non-healthcare facilities that host closed communities. Furthermore, we tried to verify the association between Heterotrophic Plate Counts (HPCs) and presence of Legionella. METHODS We collected hot water and biofilm samples from the showerheads of retirement homes and group homes. Samples were tested by culture method for the presence of Legionella. Confirmation and identification were carried out through Latex test and PCR. We determined the HPCs at 22 and 37 °C by the pour plate method. Statistics performed through STATA. RESULTS We collected 140 hot water and biofilm samples, 95 from 26 retirement homes and 35 from 9 group homes. Legionella was found in 36.8% samples collected from retirement homes and only in 10.3% group homes' samples (p = 0.01). Legionella was identified more frequently in water than in biofilm (29.8% vs 16.9%); just in one case the pathogen was found in the biofilm only. L. pneumophila sg 1 was the pathogen more frequently isolated (65.8%), with an average load of 2720 CFU/L (SD = 8393 CFU/L). We have often noticed a high microbial contamination (67% of HPCs >200 CFU/mL) and identified a higher prevalence of Legionella for intermediate values of HPC 22 °C (p = 0.011). 32% of people hosted in retirement homes were exposed to Legionella. CONCLUSIONS Colonization of water-systems of retirement homes and group homes is anything but occasional, and in our survey it mainly affects the former, moreover often due to L. pneumophila sg 1. The search for the pathogen in the biofilm has proved to be of little use. The relationship between HPC and Legionella deserves further studies.
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Affiliation(s)
- Patrizia De Filippis
- Section of Hygiene, Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Via Montpellier 1, 00133 Rome, Italy.
| | - Cinzia Mozzetti
- Section of Hygiene, Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Via Montpellier 1, 00133 Rome, Italy.
| | - Alessandra Messina
- Section of Hygiene, Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Via Montpellier 1, 00133 Rome, Italy.
| | - Gian Loreto D'Alò
- Section of Hygiene, Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Via Montpellier 1, 00133 Rome, Italy.
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Kyritsi MA, Mouchtouri VA, Katsioulis A, Kostara E, Nakoulas V, Hatzinikou M, Hadjichristodoulou C. Legionella Colonization of Hotel Water Systems in Touristic Places of Greece: Association with System Characteristics and Physicochemical Parameters. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:E2707. [PMID: 30513698 PMCID: PMC6313630 DOI: 10.3390/ijerph15122707] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 11/21/2018] [Accepted: 11/25/2018] [Indexed: 11/17/2022]
Abstract
This study aimed to assess the colonization of hotel water systems in central Greece and Corfu by Legionella, and to investigate the association between physicochemical parameters and Legionella colonization. Standardized hygiene inspection was conducted in 51 hotels, and 556 water samples were analyzed for Legionella spp. Free chlorine concentration, pH, hardness, conductivity, and trace metals were defined in cold water samples. The results of inspections and chemical analyses were associated with the microbiological results using univariate and logistic regression analysis. According to the score of the checklist used for the inspections, 17.6% of the hotels were classified as satisfactory, 15.7% as adequate, and 66.7% as unsatisfactory. Moreover, 74.5% of the hotels were colonized by Legionella spp. and 31.4% required remedial measures according to the European guidelines. Legionella spp. were isolated in 28% of the samples. Unsatisfactory results of inspections were associated with Legionella presence (relative risk (RR) = 7.67, p-value = 0.043). In hot-water systems, <50 °C temperatures increased the risk of Legionella colonization (RR = 5.36, p-value < 0.001). In cold-water systems, free chlorine concentration <0.375 mg/L (odds ratio (OR) = 9.76, p-value = 0.001), pH ≥ 7.45 (OR = 4.05, p-value = 0.007), and hardness ≥321 mgCaCO₃/L (OR = 5.63, p-value = 0.003) increased the risk, whereas copper pipes demonstrated a protective role (OR = 0.29, p-value = 0.0024). The majority of the hotels inspected were colonized with Legionella. Supplementary monitoring of the risk factors that were identified should be considered.
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Affiliation(s)
- Maria A Kyritsi
- Department of Hygiene and Epidemiology, Medical School, University of Thessaly, 41222 Larissa, Greece.
| | - Varvara A Mouchtouri
- Department of Hygiene and Epidemiology, Medical School, University of Thessaly, 41222 Larissa, Greece.
| | - Antonis Katsioulis
- Department of Hygiene and Epidemiology, Medical School, University of Thessaly, 41222 Larissa, Greece.
- Regional Public Health Laboratory of Thessaly, 41222 Larissa, Greece.
| | - Elina Kostara
- Department of Hygiene and Epidemiology, Medical School, University of Thessaly, 41222 Larissa, Greece.
| | - Vasileios Nakoulas
- Department of Hygiene and Epidemiology, Medical School, University of Thessaly, 41222 Larissa, Greece.
| | - Marina Hatzinikou
- Department of Hygiene and Epidemiology, Medical School, University of Thessaly, 41222 Larissa, Greece.
- Regional Public Health Laboratory of Thessaly, 41222 Larissa, Greece.
| | - Christos Hadjichristodoulou
- Department of Hygiene and Epidemiology, Medical School, University of Thessaly, 41222 Larissa, Greece.
- Regional Public Health Laboratory of Thessaly, 41222 Larissa, Greece.
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Leoni E, Catalani F, Marini S, Dallolio L. Legionellosis Associated with Recreational Waters: A Systematic Review of Cases and Outbreaks in Swimming Pools, Spa Pools, and Similar Environments. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:E1612. [PMID: 30061526 PMCID: PMC6121464 DOI: 10.3390/ijerph15081612] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 07/20/2018] [Accepted: 07/25/2018] [Indexed: 12/24/2022]
Abstract
Legionella spp. is widespread in many natural and artificial water systems, such as hot water distribution networks, cooling towers, and spas. A particular risk factor has been identified in the use of whirlpools and hot tubs in spa facilities and public baths. However, there has been no systematic synthesis of the published literature reporting legionellosis cases or outbreaks related to swimming/spa pools or similar environments used for recreational purposes (hot springs, hot tubs, whirlpools, natural spas). This study presents the results of a systematic review of the literature on cases and outbreaks associated with these environments. Data were extracted from 47 articles, including 42 events (17 sporadic cases and 25 outbreaks) and 1079 cases, 57.5% of which were diagnosed as Pontiac fever, without any deaths, and 42.5% were of Legionnaires' disease, with a fatality rate of 6.3%. The results are presented in relation to the distribution of Legionella species involved in the events, clinical manifestations and diagnosis, predisposing conditions in the patients, favourable environmental factors, and quality of the epidemiological investigation, as well as in relation to the different types of recreational water sources involved. Based on the epidemiological and microbiological criteria, the strength of evidence linking a case/outbreak of legionellosis with a recreational water system was classified as strong, probable, and possible; in more than half of the events the resulting association was strong.
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Affiliation(s)
- Erica Leoni
- Unit of Hygiene, Public Health and Medical Statistics, Department of Biomedical and Neuromotor Sciences, University of Bologna, via S. Giacomo 12, 40126 Bologna, Italy.
| | - Federica Catalani
- School of Hygiene and Preventive Medicine, Department of Biomedical and Neuromotor Sciences, University of Bologna, via S. Giacomo 12, 40126 Bologna, Italy.
| | - Sofia Marini
- Department of Life Quality Studies, University of Bologna, Campus of Rimini; Corso d'Augusto 237, 47921 Rimini, Italy.
| | - Laura Dallolio
- Unit of Hygiene, Public Health and Medical Statistics, Department of Biomedical and Neuromotor Sciences, University of Bologna, via S. Giacomo 12, 40126 Bologna, Italy.
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Legionella contamination in warm water systems: A species-level survey. Int J Hyg Environ Health 2018; 221:199-210. [DOI: 10.1016/j.ijheh.2017.10.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/23/2017] [Accepted: 10/24/2017] [Indexed: 02/08/2023]
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van der Kooij D, Veenendaal HR, van der Mark EJ, Dignum M. Assessment of the microbial growth potential of slow sand filtrate with the biomass production potential test in comparison with the assimilable organic carbon method. WATER RESEARCH 2017; 125:270-279. [PMID: 28865376 DOI: 10.1016/j.watres.2017.06.086] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 06/26/2017] [Accepted: 06/30/2017] [Indexed: 06/07/2023]
Abstract
Slow sand filtration is the final treatment step at four surface-water supplies in the Netherlands. The microbial growth potential (MGP) of the finished water was measured with the assimilable organic carbon (AOC) method using pure cultures and the biomass production potential (BPP) test. In the BPP test, water samples were incubated untreated at 25 °C and the active-biomass concentration was measured by adenosine tri-phosphate (ATP) analysis. Addition of a river-water inoculum improved the test performance and characteristic growth and maintenance profiles of the water were obtained. The maximum ATP concentration attained within seven days and the cumulative biomass production after 14 days of incubation (BPC14, d ng ATP L-1) showed highly significant and strong linear relationships with the AOC in the slow sand filtrates. The lowest AOC and BPC14 levels were observed in the supplies applying dune filtration without ozonation in post treatment, with AOC/TOC = 1.7 ± 0.3 μg acetate-C equivalents mg-1 C and BPC14/TOC = 16.3 ± 2.2 d ng ATP mg-1 C, corresponding with 1.2 ± 0.19 ng ATP mg-1 C. These characteristics may represent the lowest specific MGP of natural organic matter achievable by biofiltration at temperatures ≤20 °C. The AOC and BPC14 concentrations in the slow sand filtrate of the supply treating lake water by ozonation with granular-activated-carbon filtration and slow sand filtration as post treatment increased with decreasing temperature. The BPP test revealed that this slow sand filtrate sampled at 2 °C contained growth-promoting compounds that were not detected with the AOC test. These observations demonstrate the utility of the BPP test for assessing the MGP of drinking water and show the performance limits of biofiltration for MGP reduction.
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Affiliation(s)
- Dick van der Kooij
- KWR Watercycle Research Institute, PO Box 1072, 3430 BB Nieuwegein, The Netherlands.
| | - Harm R Veenendaal
- KWR Watercycle Research Institute, PO Box 1072, 3430 BB Nieuwegein, The Netherlands.
| | | | - Marco Dignum
- Waternet, PO Box 94370, 1090 GJ Amsterdam, The Netherlands.
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Whiley H, Bentham R, Brown MH. Legionella Persistence in Manufactured Water Systems: Pasteurization Potentially Selecting for Thermal Tolerance. Front Microbiol 2017; 8:1330. [PMID: 28769899 PMCID: PMC5515819 DOI: 10.3389/fmicb.2017.01330] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 06/30/2017] [Indexed: 01/13/2023] Open
Abstract
Legionella is an opportunistic waterborne pathogen of increasing public health significance. Pasteurization, otherwise known as super-heat and flush (increasing water temperature to above 70°C and flushing all outlets), has been identified as an important mechanism for the disinfection of Legionella in manufactured water systems. However, several studies have reported that this procedure was ineffective at remediating water distribution systems as Legionella was able to maintain long term persistent contamination. Up to 25% of L. pneumophila cells survived heat treatment of 70°C, but all of these were in a viable but non-culturable state. This demonstrates the limitations of the culture method of Legionella detection currently used to evaluate disinfection protocols. In addition, it has been demonstrated that pasteurization and nutrient starvation can select for thermal tolerant strains, where L. pneumophila was consistently identified as having greater thermal tolerance compared to other Legionella species. This review demonstrates that further research is needed to investigate the effectiveness of pasteurization as a disinfection method. In particular, it focuses on the potential for pasteurization to select for thermal tolerant L. pneumophila strains which, as the primary causative agent of Legionnaires disease, have greater public health significance compared to other Legionella species.
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Affiliation(s)
- Harriet Whiley
- College of Science and Engineering, Flinders University, Bedford ParkSA, Australia
| | - Richard Bentham
- College of Science and Engineering, Flinders University, Bedford ParkSA, Australia
| | - Melissa H Brown
- College of Science and Engineering, Flinders University, Bedford ParkSA, Australia
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Rhoads WJ, Pruden A, Edwards MA. Interactive Effects of Corrosion, Copper, and Chloramines on Legionella and Mycobacteria in Hot Water Plumbing. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:7065-7075. [PMID: 28513143 DOI: 10.1021/acs.est.6b05616] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Complexities associated with drinking water plumbing systems can result in undesirable interactions among plumbing components that undermine engineering controls for opportunistic pathogens (OPs). In this study, we examine the effects of plumbing system materials and two commonly applied disinfectants, copper and chloramines, on water chemistry and the growth of Legionella and mycobacteria across a transect of bench- and pilot-scale hot water experiments carried out with the same municipal water supply. We discovered that copper released from corrosion of plumbing materials can initiate evolution of >1100 times more hydrogen (H2) from water heater sacrificial anode rods than does presence of copper dosed as soluble cupric ions. H2 is a favorable electron donor for autotrophs and causes fixation of organic carbon that could serve as a nutrient for OPs. Dosed cupric ions acted as a disinfectant in stratified stagnant pipes, inhibiting culturable Legionella and biofilm formation, but promoted Legionella growth in pipes subject to convective mixing. This difference was presumably due to continuous delivery of nutrients to biofilm on the pipes under convective mixing conditions. Chloramines eliminated culturable Legionella and prevented L. pneumophila from recolonizing biofilms, but M. avium gene numbers increased by 0.14-0.76 logs in the bulk water and were unaffected in the biofilm. This study provides practical confirmation of past discrepancies in the literature regarding the variable effects of copper on Legionella growth, and confirms prior reports of trade-offs between Legionella and mycobacteria if chloramines are applied as secondary disinfectant residual.
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Affiliation(s)
- William J Rhoads
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University , 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Amy Pruden
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University , 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Marc A Edwards
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University , 418 Durham Hall, Blacksburg, Virginia 24061, United States
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Wang H, Bédard E, Prévost M, Camper AK, Hill VR, Pruden A. Methodological approaches for monitoring opportunistic pathogens in premise plumbing: A review. WATER RESEARCH 2017; 117:68-86. [PMID: 28390237 PMCID: PMC5693313 DOI: 10.1016/j.watres.2017.03.046] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/19/2017] [Accepted: 03/22/2017] [Indexed: 05/06/2023]
Abstract
Opportunistic premise (i.e., building) plumbing pathogens (OPPPs, e.g., Legionella pneumophila, Mycobacterium avium complex, Pseudomonas aeruginosa, Acanthamoeba, and Naegleria fowleri) are a significant and growing source of disease. Because OPPPs establish and grow as part of the native drinking water microbiota, they do not correspond to fecal indicators, presenting a major challenge to standard drinking water monitoring practices. Further, different OPPPs present distinct requirements for sampling, preservation, and analysis, creating an impediment to their parallel detection. The aim of this critical review is to evaluate the state of the science of monitoring OPPPs and identify a path forward for their parallel detection and quantification in a manner commensurate with the need for reliable data that is informative to risk assessment and mitigation. Water and biofilm sampling procedures, as well as factors influencing sample representativeness and detection sensitivity, are critically evaluated with respect to the five representative bacterial and amoebal OPPPs noted above. Available culturing and molecular approaches are discussed in terms of their advantages, limitations, and applicability. Knowledge gaps and research needs towards standardized approaches are identified.
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Affiliation(s)
- Hong Wang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
| | - Emilie Bédard
- Department of Civil Engineering, Polytechnique Montreal, Montreal, QC, Canada
| | - Michèle Prévost
- Department of Civil Engineering, Polytechnique Montreal, Montreal, QC, Canada
| | - Anne K Camper
- Center for Biofilm Engineering and Department of Civil Engineering, Montana State University, Bozeman, MT 59717, USA
| | - Vincent R Hill
- Waterborne Disease Prevention Branch, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA 30329, USA
| | - Amy Pruden
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061, USA
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De Filippis P, Mozzetti C, Amicosante M, D'Alò GL, Messina A, Varrenti D, Giammattei R, Di Giorgio F, Corradi S, D'Auria A, Fraietta R, Gabrieli R. Occurrence of Legionella in showers at recreational facilities. JOURNAL OF WATER AND HEALTH 2017; 15:402-409. [PMID: 28598344 DOI: 10.2166/wh.2017.296] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Critical environments, including water systems in recreational settings, represent an important source of Legionella pneumophila infection in humans. In order to assess the potential risk for legionellosis, we analyzed Legionella contamination of water distribution systems in 36 recreational facilities equipped with swimming pools. One hundred and sixty water samples were analyzed from shower heads or taps located in locker rooms or in bathrooms. By culture method and polymerase chain reaction, 41/160 samples were positive for Legionella from 12/36 recreational centers. Hotels (57.1%) and sports centers (41.2%) were the most contaminated. L. pneumophila serotypes 2-14 (25/41) were more frequently found than serotype 1 (10/41). Samples at temperature ≥30 °C were more frequently positive than samples at temperature <30 °C (n = 39 vs n = 2, p < 0.00001). The presence of L. pneumophila was investigated by comparison with heterotrophic plate count (HPC), an indicator of water quality. The presence of L. pneumophila was associated more frequently with high and intermediate HPC load at 37 °C, therefore should be considered a potential source when HPC at 37 °C is >10 CFU/mL. Maintenance, good hygiene practices, interventions on the hydraulic system and regular controls must be implemented to minimize exposure to L. pneumophila infection risk.
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Affiliation(s)
- Patrizia De Filippis
- Section of Hygiene, Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Via Montpellier 1, Rome 00133, Italy E-mail:
| | - Cinzia Mozzetti
- Section of Hygiene, Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Via Montpellier 1, Rome 00133, Italy E-mail:
| | - Massimo Amicosante
- Section of Hygiene, Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Via Montpellier 1, Rome 00133, Italy E-mail:
| | - Gian Loreto D'Alò
- Section of Hygiene, Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Via Montpellier 1, Rome 00133, Italy E-mail:
| | - Alessandra Messina
- Section of Hygiene, Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Via Montpellier 1, Rome 00133, Italy E-mail:
| | - Donatella Varrenti
- Service of Hygiene and Public Health, ASL Roma 6 ex H, Borgo Garibaldi 12, Albano Laziale, Rome 00041, Italy
| | - Roberto Giammattei
- Service of Hygiene and Public Health, ASL Roma 6 ex H, Borgo Garibaldi 12, Albano Laziale, Rome 00041, Italy
| | - Floriana Di Giorgio
- Service of Hygiene and Public Health, ASL Roma 6 ex H, Borgo Garibaldi 12, Albano Laziale, Rome 00041, Italy
| | - Stefania Corradi
- Service of Hygiene and Public Health, ASL Roma 6 ex H, Borgo Garibaldi 12, Albano Laziale, Rome 00041, Italy
| | - Alberto D'Auria
- Service of Hygiene and Public Health, ASL Roma 6 ex H, Borgo Garibaldi 12, Albano Laziale, Rome 00041, Italy
| | - Roberta Fraietta
- Service of Hygiene and Public Health, ASL Roma 6 ex H, Borgo Garibaldi 12, Albano Laziale, Rome 00041, Italy
| | - Rosanna Gabrieli
- Section of Hygiene, Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Via Montpellier 1, Rome 00133, Italy E-mail:
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Sepin Özen N, Tuğlu Ataman Ş, Emek M. Exploring the Legionella pneumophila positivity rate in hotel water samples from Antalya, Turkey. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:12238-12242. [PMID: 28353109 DOI: 10.1007/s11356-017-8864-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 03/17/2017] [Indexed: 06/06/2023]
Abstract
The genus Legionella is a fastidious Gram-negative bacteria widely distributed in natural waters and man made water supply systems. Legionella pneumophila is the aetiological agent of approximately 90% of reported Legionellosis cases, and serogroup 1 is the most frequent cause of infections. Legionnaires' disease is often associated with travel and continues to be a public health concern at present. The correct water management quality practices and rapid methods for analyzing Legionella species in environmental water is a key point for the prevention of Legionnaires' disease outbreaks. This study aimed to evaluate the positivity rates and serotyping of Legionella species from water samples in the region of Antalya, Turkey, which is an important tourism center. During January-December 2010, a total of 1403 samples of water that were collected from various hotels (n = 56) located in Antalya were investigated for Legionella pneumophila. All samples were screened for L. pneumophila by culture method according to "ISO 11731-2" criteria. The culture positive Legionella strains were serologically identified by latex agglutination test. A total of 142 Legionella pneumophila isolates were recovered from 21 (37.5%) of 56 hotels. The total frequency of L. pneumophila isolation from water samples was found as 10.1%. Serological typing of 142 Legionella isolates by latex agglutination test revealed that strains belonging to L. pneumophila serogroups 2-14 predominated in the examined samples (85%), while strains of L. pneumophila serogroup 1 were less numerous (15%). According to our knowledge, our study with the greatest number of water samples from Turkey demonstrates that L. pneumophila serogroups 2-14 is the most common isolate. Rapid isolation of L. pneumophila from environmental water samples is essential for the investigation of travel related outbreaks and the possible resources. Further studies are needed to have epidemiological data and to determine the types of L. pneumophila isolates from Turkey.
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Affiliation(s)
| | | | - Mestan Emek
- Epidemiology, Public Health Laboratory, Antalya, Turkey
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van der Kooij D, Bakker GL, Italiaander R, Veenendaal HR, Wullings BA. Biofilm Composition and Threshold Concentration for Growth of Legionella pneumophila on Surfaces Exposed to Flowing Warm Tap Water without Disinfectant. Appl Environ Microbiol 2017; 83:e02737-16. [PMID: 28062459 PMCID: PMC5311405 DOI: 10.1128/aem.02737-16] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 12/13/2016] [Indexed: 02/07/2023] Open
Abstract
Legionella pneumophila in potable water installations poses a potential health risk, but quantitative information about its replication in biofilms in relation to water quality is scarce. Therefore, biofilm formation on the surfaces of glass and chlorinated polyvinyl chloride (CPVC) in contact with tap water at 34 to 39°C was investigated under controlled hydraulic conditions in a model system inoculated with biofilm-grown L. pneumophila The biofilm on glass (average steady-state concentration, 23 ± 9 pg ATP cm-2) exposed to treated aerobic groundwater (0.3 mg C liter-1; 1 μg assimilable organic carbon [AOC] liter-1) did not support growth of the organism, which also disappeared from the biofilm on CPVC (49 ± 9 pg ATP cm-2) after initial growth. L. pneumophila attained a level of 4.3 log CFU cm-2 in the biofilms on glass (1,055 ± 225 pg ATP cm-2) and CPVC (2,755 ± 460 pg ATP cm-2) exposed to treated anaerobic groundwater (7.9 mg C liter-1; 10 μg AOC liter-1). An elevated biofilm concentration and growth of L. pneumophila were also observed with tap water from the laboratory. The Betaproteobacteria Piscinibacter and Methyloversatilis and amoeba-resisting Alphaproteobacteria predominated in the clones and isolates retrieved from the biofilms. In the biofilms, the Legionella colony count correlated significantly with the total cell count (TCC), heterotrophic plate count, ATP concentration, and presence of Vermamoeba vermiformis This amoeba was rarely detected at biofilm concentrations of <100 pg ATP cm-2 A threshold concentration of approximately 50 pg ATP cm-2 (TCC = 1 × 106 to 2 × 106 cells cm-2) was derived for growth of L. pneumophila in biofilms.IMPORTANCELegionella pneumophila is the etiologic agent in more than 10,000 cases of Legionnaires' disease that are reported annually worldwide and in most of the drinking water-associated disease outbreaks reported in the United States. The organism proliferates in biofilms on surfaces exposed to warm water in engineered freshwater installations. An investigation with a test system supplied with different types of warm drinking water without disinfectant under controlled hydraulic conditions showed that treated aerobic groundwater (0.3 mg liter-1 of organic carbon) induced a low biofilm concentration that supported no or very limited growth of L. pneumophila Elevated biofilm concentrations and L. pneumophila colony counts were observed on surfaces exposed to two types of extensively treated groundwater, containing 1.8 and 7.9 mg C liter-1 and complying with the microbial water quality criteria during distribution. Control measures in warm tap water installations are therefore essential for preventing growth of L. pneumophila.
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Affiliation(s)
| | | | | | | | - Bart A Wullings
- KWR Watercycle Research Institute, Nieuwegein, the Netherlands
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Springston JP, Yocavitch L. Existence and control of Legionella bacteria in building water systems: A review. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2017; 14:124-134. [PMID: 27624495 DOI: 10.1080/15459624.2016.1229481] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Legionellae are waterborne bacteria which are capable of causing potentially fatal Legionnaires' disease (LD), as well as Pontiac Fever. Public concern about Legionella exploded following the 1976 outbreak at the American Legion conference in Philadelphia, where 221 attendees contracted pneumonia and 34 died. Since that time, a variety of different control methods and strategies have been developed and implemented in an effort to eradicate Legionella from building water systems. Despite these efforts, the incidence of LD has been steadily increasing in the U.S. for more than a decade. Public health and occupational hygiene professionals have maintained an active debate regarding best practices for management and control of Legionella. Professional opinion remains divided with respect to the relative merits of performing routine sampling for Legionella, vs. the passive, reactive approach that has been largely embraced by public health officials and facility owners. Given the potential risks and ramifications associated with waiting to assess systems for Legionella until after disease has been identified and confirmed, a proactive approach of periodic testing for Legionella, along with proper water treatment, is the best approach to avoiding large-scale disease outbreaks.
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47
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Control of Legionella Contamination and Risk of Corrosion in Hospital Water Networks following Various Disinfection Procedures. Appl Environ Microbiol 2016; 82:2959-2965. [PMID: 26969696 DOI: 10.1128/aem.03873-15] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 03/03/2016] [Indexed: 12/13/2022] Open
Abstract
Physical and chemical disinfection methods have been proposed with the aim of controlling Legionella water contamination. To date, the most effective procedures for reducing bacterial contamination have not yet been defined. The aim of this study was to assess the long-term effectiveness of various disinfection procedures in order to reduce both culturable and nonculturable (NC) legionellae in different hospital water networks treated with heat, chlorine dioxide, monochloramine, and hydrogen peroxide. The temperature levels and biocide concentrations that proved to give reliable results were analyzed. In order to study the possible effects on the water pipes, we verified the extent of corrosion on experimental coupons after applying each method for 6 months. The percentage of positive points was at its lowest after treatment with monochloramine, followed by chlorine dioxide, hydrogen peroxide, and hyperthermia. Different selections of Legionella spp. were observed, as networks treated with chlorine-based disinfectants were contaminated mainly by Legionella pneumophila serogroup 1, hyperthermia was associated with serogroups 2 to 14, and hydrogen peroxide treatment was associated mainly with non-pneumophila species. NC cells were detected only in heat-treated waters, and also when the temperature was approximately 60°C. The corrosion rates of the coupons were within a satisfactory limit for water networks, but the morphologies differed. We confirm here that chemical disinfection controls Legionella colonization more effectively than hyperthermia does. Monochloramine was the most effective treatment, while hydrogen peroxide may be a promising alternative to chlorine-based disinfectants due to its ability to select for other, less virulent or nonpathogenic species.
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48
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Kocazeybek BS, Yuksel P, Keskin D, Sheikh S, Habip Z, Yavuzer SS, Caliskan R, Altun YM, Kuskucu M, Cengiz M, Dinc HO, Karakullukcu A, Ergin S, Saribas S, Yilmaz N, Tokman HB. Travel-associated infections caused by unusual serogroups of Legionella pneumophila identified using Legionella BIOCHIP slides in Turkey and Iraq. Travel Med Infect Dis 2016; 14:248-54. [DOI: 10.1016/j.tmaid.2016.04.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 03/31/2016] [Accepted: 04/05/2016] [Indexed: 11/28/2022]
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49
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Lesnik R, Brettar I, Höfle MG. Legionella species diversity and dynamics from surface reservoir to tap water: from cold adaptation to thermophily. THE ISME JOURNAL 2016; 10:1064-80. [PMID: 26528838 PMCID: PMC5029207 DOI: 10.1038/ismej.2015.199] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 08/12/2015] [Accepted: 09/22/2015] [Indexed: 12/20/2022]
Abstract
Water samples of the Drinking Water Supply System (DWSS) of the city of Braunschweig were analysed for its Legionella species composition using genus-specific PCR amplicons and single-strand conformation polymorphism (SSCP) fingerprint analyses based on 16S rRNA genes. These analyses comprised the whole supply chain including raw water, treatment process and large-scale storage, and a seasonal study of finished drinking water sampled monthly from cold and hot tap water. Treatment of raw water had a major impact on Legionella species by reducing their diversity and abundances. The Legionella species composition of the tap water was highly distinct from that of both source waters. In cold water, 8-14 different phylotypes of Legionella (PTLs) were observed per sample with relative abundances ranging from >1% to 53%. In hot water, L. pneumophila was present during all seasons at high relative abundances (8-40%) accompanied by 5-14 other PTLs of which 6 PTLs were in common with cold water. This thermophilic Legionella community, including L. pneumophila, was able to grow in the hot water above 50 °C. Such thermophilic Legionella populations are of general relevance for drinking water management and public health, but also for the ecology and evolution of the genus Legionella.
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Affiliation(s)
- René Lesnik
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ingrid Brettar
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Manfred G Höfle
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research, Braunschweig, Germany
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50
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Rhoads WJ, Pruden A, Edwards MA. Convective Mixing in Distal Pipes Exacerbates Legionella pneumophila Growth in Hot Water Plumbing. Pathogens 2016; 5:E29. [PMID: 26985908 PMCID: PMC4810150 DOI: 10.3390/pathogens5010029] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 02/15/2016] [Accepted: 03/01/2016] [Indexed: 11/17/2022] Open
Abstract
Legionella pneumophila is known to proliferate in hot water plumbing systems, but little is known about the specific physicochemical factors that contribute to its regrowth. Here, L. pneumophila trends were examined in controlled, replicated pilot-scale hot water systems with continuous recirculation lines subject to two water heater settings (40 °C and 58 °C) and three distal tap water use frequencies (high, medium, and low) with two pipe configurations (oriented upward to promote convective mixing with the recirculating line and downward to prevent it). Water heater temperature setting determined where L. pneumophila regrowth occurred in each system, with an increase of up to 4.4 log gene copies/mL in the 40 °C system tank and recirculating line relative to influent water compared to only 2.5 log gene copies/mL regrowth in the 58 °C system. Distal pipes without convective mixing cooled to room temperature (23-24 °C) during periods of no water use, but pipes with convective mixing equilibrated to 30.5 °C in the 40 °C system and 38.8 °C in the 58 °C system. Corresponding with known temperature effects on L. pneumophila growth and enhanced delivery of nutrients, distal pipes with convective mixing had on average 0.2 log more gene copies/mL in the 40 °C system and 0.8 log more gene copies/mL in the 58 °C system. Importantly, this work demonstrated the potential for thermal control strategies to be undermined by distal taps in general, and convective mixing in particular.
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Affiliation(s)
- William J Rhoads
- Via Department of Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 401 Durham Hall, Blacksburg, VA 24061, USA.
| | - Amy Pruden
- Via Department of Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 401 Durham Hall, Blacksburg, VA 24061, USA.
| | - Marc A Edwards
- Via Department of Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 401 Durham Hall, Blacksburg, VA 24061, USA.
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