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Hozalski RM, Zhao X, Kim T, LaPara TM. On-site filtration of large sample volumes improves the detection of opportunistic pathogens in drinking water distribution systems. Appl Environ Microbiol 2024; 90:e0165823. [PMID: 38236032 PMCID: PMC10880612 DOI: 10.1128/aem.01658-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 12/06/2023] [Indexed: 01/19/2024] Open
Abstract
In this study, we compared conventional vacuum filtration of small volumes through disc membranes (effective sample volumes for potable water: 0.3-1.0 L) with filtration of high volumes using ultrafiltration (UF) modules (effective sample volumes for potable water: 10.6-84.5 L) for collecting bacterial biomass from raw, finished, and tap water at seven drinking water systems. Total bacteria, Legionella spp., Legionella pneumophila, Mycobacterium spp., and Mycobacterium avium complex in these samples were enumerated using both conventional quantitative PCR (qPCR) and viability qPCR (using propidium monoazide). In addition, PCR-amplified gene fragments were sequenced for microbial community analysis. The frequency of detection (FOD) of Legionella spp. in finished and tap water samples was much greater using UF modules (83% and 77%, respectively) than disc filters (24% and 33%, respectively). The FODs for Mycobacterium spp. in raw, finished, and tap water samples were also consistently greater using UF modules than disc filters. Furthermore, the number of observed operational taxonomic units and diversity index values for finished and tap water samples were often substantially greater when using UF modules as compared to disc filters. Conventional and viability qPCR yielded similar results, suggesting that membrane-compromised cells represented a minor fraction of total bacterial biomass. In conclusion, our research demonstrates that large-volume filtration using UF modules improved the detection of opportunistic pathogens at the low concentrations typically found in public drinking water systems and that the majority of bacteria in these systems appear to be viable in spite of disinfection with free chlorine and/or chloramine.IMPORTANCEOpportunistic pathogens, such as Legionella pneumophila, are a growing public health concern. In this study, we compared sample collection and enumeration methods on raw, finished, and tap water at seven water systems throughout the State of Minnesota, USA. The results showed that on-site filtration of large water volumes (i.e., 500-1,000 L) using ultrafiltration membrane modules improved the frequency of detection of relatively rare organisms, including opportunistic pathogens, compared to the common approach of filtering about 1 L using disc membranes. Furthermore, results from viability quantitative PCR (qPCR) with propidium monoazide were similar to conventional qPCR, suggesting that membrane-compromised cells represent an insignificant fraction of microorganisms. Results from these ultrafiltration membrane modules should lead to a better understanding of the microbial ecology of drinking water distribution systems and their potential to inoculate premise plumbing systems with opportunistic pathogens where conditions are more favorable for their growth.
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Affiliation(s)
- Raymond M. Hozalski
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
- Biotechnology Institute, University of Minnesota Twin Cities, St. Paul, Minnesota, USA
| | - Xiaotian Zhao
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
| | - Taegyu Kim
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
| | - Timothy M. LaPara
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
- Biotechnology Institute, University of Minnesota Twin Cities, St. Paul, Minnesota, USA
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Palusińska-Szysz M, Simões M. Editorial: Legionella pneumophila-transmission, pathogenesis, host-pathogen interaction, prevention and treatment. Front Microbiol 2024; 15:1364620. [PMID: 38357354 PMCID: PMC10864628 DOI: 10.3389/fmicb.2024.1364620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 01/16/2024] [Indexed: 02/16/2024] Open
Affiliation(s)
| | - Manuel Simões
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Porto, Portugal
- ALiCE—Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Porto, Portugal
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Fischer FB, Bigler M, Mäusezahl D, Hattendorf J, Egli A, Julian TR, Rölli F, Gaia V, Wymann M, Fridez F, Bertschi S. Legionnaires' disease in Switzerland: rationale and study protocol of a prospective national case-control and molecular source attribution study (SwissLEGIO). Infection 2023; 51:1467-1479. [PMID: 36905400 PMCID: PMC10545568 DOI: 10.1007/s15010-023-02014-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 02/23/2023] [Indexed: 03/12/2023]
Abstract
Switzerland has one of the highest annual Legionnaires' disease (LD) notification rates in Europe (7.8 cases/100,000 population in 2021). The main sources of infection and the cause for this high rate remain largely unknown. This hampers the implementation of targeted Legionella spp. control efforts. The SwissLEGIO national case-control and molecular source attribution study investigates risk factors and infection sources for community-acquired LD in Switzerland. Over the duration of one year, the study is recruiting 205 newly diagnosed LD patients through a network of 20 university and cantonal hospitals. Healthy controls matched for age, sex, and residence at district level are recruited from the general population. Risk factors for LD are assessed in questionnaire-based interviews. Clinical and environmental Legionella spp. isolates are compared using whole genome sequencing (WGS). Direct comparison of sero- and sequence types (ST), core genome multilocus sequencing types (cgMLST), and single nucleotide polymorphisms (SNPs) between clinical and environmental isolates are used to investigate the infection sources and the prevalence and virulence of different Legionella spp. strains detected across Switzerland. The SwissLEGIO study innovates in combining case-control and molecular typing approaches for source attribution on a national level outside an outbreak setting. The study provides a unique platform for national Legionellosis and Legionella research and is conducted in an inter- and transdisciplinary, co-production approach involving various national governmental and national research stakeholders.
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Affiliation(s)
- Fabienne B Fischer
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Melina Bigler
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Daniel Mäusezahl
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland.
- University of Basel, Basel, Switzerland.
| | - Jan Hattendorf
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Adrian Egli
- Institute for Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Timothy R Julian
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Franziska Rölli
- Lucerne University of Applied Sciences and Arts, Lucerne, Switzerland
| | - Valeria Gaia
- Service of Microbiology, Institute of Laboratory Medicine, National Reference Centre for Legionella, EOC, Bellinzona, Switzerland
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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. Int J Environ Res 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Di Onofrio V, Pagano M, Santulli M, Rossi A, Liguori R, Di Dio M, Liguori G. Contamination of Hotel Water Distribution Systems by Legionella Species: Environmental Surveillance in Campania Region, South Italy. Microorganisms 2023; 11:1840. [PMID: 37513012 PMCID: PMC10385258 DOI: 10.3390/microorganisms11071840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/13/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
The COVID-19 pandemic period was marked by the absence or reduced circulation of some infectious diseases. Legionellosis may have been affected by the prevention measures adopted to counter COVID-19. Legionellosis is a form of pneumonia interstitial that is normally transmitted via aerosol-containing bacteria (genus Legionella), that could be present in contaminated water sources and is often associated with travel and with staying in hotels. In this work, the data of the environmental surveys carried out by ARPA Campania in accommodation facilities since 2019 were analyzed for a better understanding of the dispersion patterns of L. pneumophila associated with the environment and to evaluate the variation of the data during the pandemic period. The aim was to provide a better understanding of Legionella at different geographic scales and to define a predictive epidemiological method. Results: In 2019, the Legionella genus contaminated 37.7% of all tourist facilities evaluated. In 2020, the Legionella genus contaminated 44.4% of all tourist facilities evaluated. In 2021, the Legionella genus contaminated 54.2% of all tourist facilities evaluated. Conclusions: Legionella pneumophila was the most prevalent species in our community, serogroup 1 was the most frequently isolated and the most implicated risk factor of contamination was the temperature of water in circulation.
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Affiliation(s)
- Valeria Di Onofrio
- International PhD Programme/UNESCO Chair "Environment, Resources and Sustainable Development", Department of Sciences and Technologies, University of Naples "Parthenope", Business District, Block C4, 80143 Naples, Italy
| | - Mariangela Pagano
- ARPA Campania-Salerno Department-Via Lanzalone, 54/56, 84100 Salerno, Italy
| | - Marco Santulli
- School of Medicine and Health Sciences, "G. d'Annunzio" University of Chieti-Pescara, Via dei Vestini 31, 66100 Chieti, Italy
| | - Annamaria Rossi
- ARPA Campania-Salerno Department-Via Lanzalone, 54/56, 84100 Salerno, Italy
| | - Renato Liguori
- International PhD Programme/UNESCO Chair "Environment, Resources and Sustainable Development", Department of Sciences and Technologies, University of Naples "Parthenope", Business District, Block C4, 80143 Naples, Italy
| | - Mirella Di Dio
- Department of Movement Sciences and Wellbeing, University of Naples "Parthenope", Via Medina n. 40, 80133 Naples, Italy
| | - Giorgio Liguori
- Department of Movement Sciences and Wellbeing, University of Naples "Parthenope", Via Medina n. 40, 80133 Naples, Italy
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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. Med Int (Lond) 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Kim T, Zhao X, LaPara TM, Hozalski RM. Flushing Temporarily Improves Microbiological Water Quality for Buildings Supplied with Chloraminated Surface Water but Has Little Effect for Groundwater Supplies. Environ Sci Technol 2023; 57:5453-5463. [PMID: 36952669 DOI: 10.1021/acs.est.2c08123] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Microbial communities in premise plumbing systems were investigated after more than 2 months of long-term stagnation, during a subsequent flushing event, and during post-flush stagnation. Water samples were collected from showers in buildings supplied with chlorinated groundwater, untreated groundwater, and chloraminated surface water. The building supplied with chlorinated groundwater generally had the lowest bacterial concentrations across all sites (ranging from below quantification limit to 5.2 log copies/L). For buildings supplied with untreated groundwater, bacterial concentrations (5.0 to 7.6 log copies/L) and microbial community diversity index (ACE) values were consistent throughout sampling. Nontuberculous mycobacteria (NTM) and Legionella pneumophila were not detected in any groundwater-supplied buildings. Total bacteria, Legionella spp., and NTM were abundant in the surface water-supplied buildings following long-term stagnation (up to 7.6, 6.2, and 7.6 log copies/L, respectively). Flushing decreased these concentrations by ∼1 to >4 log units and reduced microbial community diversity, but the communities largely recovered within a week of post-flush stagnation. The results suggest that buildings supplied with disinfected surface water are more likely than buildings supplied with treated or untreated groundwater to experience deleterious changes in microbiological water quality during stagnation and that the water quality improvements from flushing with chloraminated water, while substantial, are short-lived.
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Affiliation(s)
- Taegyu Kim
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota Twin Cities, 500 Pillsbury Drive S.E., Minneapolis, Minnesota 55455, United States
| | - Xiaotian Zhao
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota Twin Cities, 500 Pillsbury Drive S.E., Minneapolis, Minnesota 55455, United States
| | - Timothy M LaPara
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota Twin Cities, 500 Pillsbury Drive S.E., Minneapolis, Minnesota 55455, United States
- Biotechnology Institute, University of Minnesota Twin Cities, 1479 Gortner Avenue, St. Paul, Minnesota 55108, United States
| | - Raymond M Hozalski
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota Twin Cities, 500 Pillsbury Drive S.E., Minneapolis, Minnesota 55455, United States
- Biotechnology Institute, University of Minnesota Twin Cities, 1479 Gortner Avenue, St. Paul, Minnesota 55108, United States
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Vukić Lušić D, Piškur V, Cenov A, Tomić Linšak D, Broznić D, Glad M, Linšak Ž. Surveillance of Legionella pneumophila: Detection in Public Swimming Pool Environment. Microorganisms 2022; 10:microorganisms10122429. [PMID: 36557683 PMCID: PMC9784426 DOI: 10.3390/microorganisms10122429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 11/27/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
The bacterium Legionella pneumophila is a ubiquitous microorganism naturally present in water environments. The actual presence of this opportunistic premise plumbing pathogen in recreational swimming pools and hot tubs in the northwestern part of Croatia has not been investigated. This study aimed to analyze the presence of the opportunistic pathogen L. pneumophila in public swimming pool water in Primorje-Gorski Kotar County (N = 4587) over a four-year period (2018-2021). Additionally, the second aim was to investigate the connection between the presence of L. pneumophila and pool water physicochemical parameters using mathematical predictive models. The presence of L. pneumophila was detected in six pool samples. Five positive samples were found in the water of indoor hot tubs filled with fresh water, and one positive sample in an outdoor recreational saltwater pool. A predictive mathematical model showed the simultaneous influence of chemical parameters dominated by the temperature in saltwater and freshwater pools, as well as the significant influence of free residual chlorine and trihalomethanes. Our results pointed out that keeping all physicochemical parameters in perfect harmony is necessary to reach the best disinfection procedure and to avoid the optimum conditions for L. pneumophila occurrence.
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Affiliation(s)
- Darija Vukić Lušić
- Department of Environmental Health, Faculty of Medicine, University of Rijeka, Brace Branchetta 20, 51000 Rijeka, Croatia
- Department of Environmental Health, Teaching Institute of Public Health of Primorje-Gorski Kotar County, Krešimirova 52a, 51000 Rijeka, Croatia
| | - Vanda Piškur
- Department of Environmental Health, Teaching Institute of Public Health of Primorje-Gorski Kotar County, Krešimirova 52a, 51000 Rijeka, Croatia
| | - Arijana Cenov
- Department of Environmental Health, Teaching Institute of Public Health of Primorje-Gorski Kotar County, Krešimirova 52a, 51000 Rijeka, Croatia
| | - Dijana Tomić Linšak
- Department of Environmental Health, Faculty of Medicine, University of Rijeka, Brace Branchetta 20, 51000 Rijeka, Croatia
- Department of Environmental Health, Teaching Institute of Public Health of Primorje-Gorski Kotar County, Krešimirova 52a, 51000 Rijeka, Croatia
- Correspondence: or (D.T.L.); (D.B.); Tel.: +385-51-505-920 (D.T.L.); +385-51-651-132 (D.B.)
| | - Dalibor Broznić
- Department for Medical Chemistry, Biochemistry and Clinical Chemistry, Faculty of Medicine, University of Rijeka, Brace Branchetta 20, 51000 Rijeka, Croatia
- Correspondence: or (D.T.L.); (D.B.); Tel.: +385-51-505-920 (D.T.L.); +385-51-651-132 (D.B.)
| | - Marin Glad
- Department of Environmental Health, Teaching Institute of Public Health of Primorje-Gorski Kotar County, Krešimirova 52a, 51000 Rijeka, Croatia
| | - Željko Linšak
- Department of Environmental Health, Faculty of Medicine, University of Rijeka, Brace Branchetta 20, 51000 Rijeka, Croatia
- Department of Environmental Health, Teaching Institute of Public Health of Primorje-Gorski Kotar County, Krešimirova 52a, 51000 Rijeka, Croatia
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Lu J, Yu Z, Ding P, Guo J. Triclosan Promotes Conjugative Transfer of Antibiotic Resistance Genes to Opportunistic Pathogens in Environmental Microbiome. Environ Sci Technol 2022; 56:15108-15119. [PMID: 36251935 DOI: 10.1021/acs.est.2c05537] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Although triclosan, as a widely used antiseptic chemical, is known to promote the transmission of antibiotic resistance to diverse hosts in pure culture, it is still unclear whether and how triclosan could affect the transmission of broad-host-range plasmids among complex microbial communities. Here, bacterial culturing, fluorescence-based cell sorting, and high-throughput 16S rRNA gene amplicon sequencing were combined to investigate contributions of triclosan on the transfer rate and range of an IncP-type plasmid from a proteobacterial donor to an activated sludge microbiome. Our results demonstrate that triclosan significantly enhances the conjugative transfer of the RP4 plasmid among activated sludge communities at environmentally relevant concentrations. High-throughput 16S rRNA gene sequencing on sorted transconjugants demonstrates that triclosan not only promoted the intergenera transfer but also the intragenera transfer of the RP4 plasmid among activated sludge communities. Moreover, triclosan mediated the transfer of the RP4 plasmid to opportunistic human pathogens, for example, Legionella spp. The mechanism of triclosan-mediated conjugative transfer is primarily associated with excessive oxidative stress, followed by increased membrane permeability and provoked SOS response. Our findings offer insights into the impacts of triclosan on the dissemination of antibiotic resistance in the aquatic environmental microbiome.
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Affiliation(s)
- Ji Lu
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Zhigang Yu
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Pengbo Ding
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Jianhua Guo
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St. Lucia, Queensland 4072, Australia
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10
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Viasus D, Gaia V, Manzur-Barbur C, Carratalà J. Legionnaires' Disease: Update on Diagnosis and Treatment. Infect Dis Ther 2022. [PMID: 35505000 DOI: 10.1007/s40121-022-00635-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 04/04/2022] [Indexed: 11/23/2022] Open
Abstract
Legionellosis is the infection caused by bacteria of the genus Legionella, including a non-pneumonic influenza-like syndrome, and Legionnaires’ disease is a more serious illness characterized by pneumonia. Legionellosis is becoming increasingly important as a public health problem throughout the world; although it is an underreported disease, studies have consistently documented a high incidence. In addition, health costs associated with the disease are high. Diagnosis of Legionnaires’ disease is based mainly on the detection of Legionella pneumophila serogroup 1 antigen in urine. However, there have been advances in detection tests for patients with legionellosis. New methodologies show greater sensitivity and specificity, detect more species and serogroups of Legionella spp., and have the potential for use in epidemiological studies. Testing for Legionella spp. is recommended at hospital admission for severe community-acquired pneumonia, and antibiotics directed against Legionella spp. should be included early as empirical therapy. Inadequate or delayed antibiotic treatment in Legionella pneumonia has been associated with a worse prognosis. Either a fluoroquinolone (levofloxacin or moxifloxacin) or a macrolide (azithromycin preferred) is the recommended first-line therapy for Legionnaires’ disease; however, little information is available regarding adverse events or complications, or about the duration of antibiotic therapy and its association with clinical outcomes. Most published studies evaluating antibiotic treatment for Legionnaires’ disease are observational and consequently susceptible to bias and confounding. Well-designed studies are needed to assess the usefulness of diagnostic tests regarding clinical outcomes, as well as randomized trials comparing fluoroquinolones and macrolides or combination therapy that evaluate outcomes and adverse events.
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Teira A, Sánchez J, Santiago I, Zarauza J, Nan D, Teira R. Legionella endocarditis: A case report and review. Enferm Infecc Microbiol Clin (Engl Ed) 2022; 40:190-194. [PMID: 35473990 DOI: 10.1016/j.eimce.2020.10.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 10/28/2020] [Indexed: 06/14/2023]
Abstract
BACKGROUND Legionella is a well known but infrequent cause of bacterial endocarditis. METHODS We report a case of endocarditis caused by Legionella spp. We reviewed previously reported cases in PubMed, Google Scholar and in references included in previous reports, and summarized relevant clinical data. RESULTS A 63-year-old man with a history of aortic valve replacement developed persistent fever and monoarthritis. Transesophageal echocardiography showed perivalvular abscess. He died during surgery. Blood and valve cultures were negative. Legionella spp. was demonstrated with 16S-rRNA PCR from the resected material. Twenty cases of Legionella endocarditis have been reported. Harboring a prosthetic valve was the main risk factor. Prognosis was favorable, both for patients treated with or without surgical valve replacement. Overall mortality was <10%. CONCLUSIONS Legionella is an infrequent cause of endocarditis. It frequently requires surgical treatment. Prognosis is good. Molecular techniques are likely to become the gold standard for diagnosis.
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Affiliation(s)
- Andrea Teira
- Service of Cardiology, Hospital Universitario Marqués de Valdecilla, Santander, Cantabria, Spain.
| | - Juan Sánchez
- Service of Cardiology, Hospital Universitario Marqués de Valdecilla, Santander, Cantabria, Spain
| | - Ignacio Santiago
- Service of Cardiology, Hospital Universitario Marqués de Valdecilla, Santander, Cantabria, Spain
| | - Jesús Zarauza
- Service of Cardiology, Hospital Universitario Marqués de Valdecilla, Santander, Cantabria, Spain
| | - Daniel Nan
- Service of Internal Medicine, Hospital Universitario Marqués de Valdecilla, Santander, Cantabria, Spain
| | - Ramón Teira
- Unit of Infectious Diseases, Service of Internal Medicine, Hospital de Sierrallana, Torrelavega, Cantabria, Spain
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12
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Sabatini L, Sisti M, Campana R. Isolation and identification of Legionella spp. from non-hospital facilities: a preliminary one-year surveillance study in the urban area of Pesaro-Urbino (Central Italy). Ann Ig 2022; 34:177-183. [PMID: 35088824 DOI: 10.7416/ai.2022.2477] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
BACKGROUND Legionella is considered one of the most important causes of potentially preventable morbid-ity and mortality. These microorganisms are ubiquitous, but incomplete information is available on the geographic distribution of Legionella species in our region. STUDY DESIGN For the mentioned reasons, in this work the distribution of Legionella spp. in non-hospital facilities of the urban area of Pesaro-Urbino (Central Italy), including public fountains, residential build-ings, public and private offices and retirement homes, was investigated. METHODS A total of 298 water samples were collected from the different facilities and subjected to standard Legionella isolation and identification protocols. RESULTS As reported, 17.8% of the collected water samples resulted positive for Legionella spp. (28.6% from retirement homes, 21.3% from residential buildings, 15.3% from private and public offices). The highest per-centage of positive samples (14.4%) was found in hot water from retirements homes (58.8%) and residential buildings (31.8%); the most frequent isolated serogroups were L. pneumophila 2-14 (71.7%). CONCLUSIONS This work is the first describing the distribution of Legionella spp. in non-hospital facilities in the province of Pesaro-Urbino, and highlights a condition of potential risk for susceptible categories. From our data, we can point that a regular and constant control to prevent microbiological risk from legionellosis, particularly in facilities housing the elderly, is recommended.
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Affiliation(s)
- L Sabatini
- Department of Biomolecular Sciences, Division of Pharmacology and Hygiene, "Carlo Bo" University, Urbino, Italy
| | - M Sisti
- Department of Biomolecular Sciences, Division of Pharmacology and Hygiene, "Carlo Bo" University, Urbino, Italy
| | - R Campana
- Department of Biomolecular Sciences, Division of Pharmacology and Hygiene, "Carlo Bo" University, Urbino, Italy
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Pascale MR, Salaris S, Mazzotta M, Girolamini L, Fregni Serpini G, Manni L, Grottola A, Cristino S. New Insight regarding Legionella Non- Pneumophila Species Identification: Comparison between the Traditional mip Gene Classification Scheme and a Newly Proposed Scheme Targeting the rpoB Gene. Microbiol Spectr 2021; 9:e0116121. [PMID: 34908503 PMCID: PMC8672888 DOI: 10.1128/spectrum.01161-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 11/11/2021] [Indexed: 11/23/2022] Open
Abstract
The identification of Legionella non-pneumophila species (non-Lp) in clinical and environmental samples is based on the mip gene, although several studies suggest its limitations and the need to expand the classification scheme to include other genes. In this study, the development of a new classification scheme targeting the rpoB gene is proposed to obtain a more reliable identification of 135 Legionella environmental isolates. All isolates were sequenced for the mip and rpoB genes, and the results were compared to study the discriminatory power of the proposed rpoB scheme. Complete concordance between the mip and rpoB results based on genomic percent identity was found for 121/135 (89.6%) isolates; in contrast, discordance was found for 14/135 (10.4%) isolates. Additionally, due to the lack of reference values for the rpoB gene, inter- and intraspecies variation intervals were calculated based on a pairwise identity matrix that was built using the entire rpoB gene (∼4,107 bp) and a partial region (329 bp) to better evaluate the genomic identity obtained. The interspecies variation interval found here (4.9% to 26.7%) was then proposed as a useful sequence-based classification scheme for the identification of unknown non-Lp isolates. The results suggest that using both the mip and rpoB genes makes it possible to correctly discriminate between several species, allowing possible new species to be identified, as confirmed by preliminary whole-genome sequencing analyses performed on our isolates. Therefore, starting from a valid and reliable identification approach, the simultaneous use of mip and rpoB associated with other genes, as it occurs with the sequence-based typing (SBT) scheme developed for Legionella pneumophila, could support the development of multilocus sequence typing to improve the knowledge and discovery of Legionella species subtypes. IMPORTANCELegionella spp. are a widely spread bacteria that cause a fatal form of pneumonia. While traditional laboratory techniques have provided valuable systems for Legionella pneumophila identification, the amplification of the mip gene has been recognized as the only useful tool for Legionella non-pneumophila species identification both in clinical and environmental samples. Several studies focused on the mip gene classification scheme showed its limitations and the need to improve the classification scheme, including other genes. Our study provides significant advantages on Legionella identification, providing a reproducible new rpoB gene classification scheme that seems to be more accurate than mip gene sequencing, bringing out greater genetic variation on Legionella species. In addition, the combined use of both the mip and rpoB genes allowed us to identify presumed new Legionella species, improving epidemiological investigations and acquiring new understanding on Legionella fields.
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Affiliation(s)
- Maria Rosaria Pascale
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Bologna, Italy
| | - Silvano Salaris
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Bologna, Italy
| | - Marta Mazzotta
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Bologna, Italy
| | - Luna Girolamini
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Bologna, Italy
| | - Giulia Fregni Serpini
- Regional Reference Laboratory for Clinical Diagnosis of Legionellosis, Molecular Microbiology and Virology Unit, University Hospital-Policlinico Modena, Modena, Italy
| | - Laura Manni
- Regional Reference Laboratory for Clinical Diagnosis of Legionellosis, Molecular Microbiology and Virology Unit, University Hospital-Policlinico Modena, Modena, Italy
| | - Antonella Grottola
- Regional Reference Laboratory for Clinical Diagnosis of Legionellosis, Molecular Microbiology and Virology Unit, University Hospital-Policlinico Modena, Modena, Italy
| | - Sandra Cristino
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Bologna, Italy
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Paes J, Kepler R, Gonçalves RF, Berte FK, Virginio VG, Benitez LB, Rott MB. Amoebal coculture and enrichment methods as a proposal for water quality control in Brazil. Acta Trop 2021; 223:106074. [PMID: 34358510 DOI: 10.1016/j.actatropica.2021.106074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 11/27/2022]
Abstract
Free living amoebae (FLA) can be found in different environments, where they feed on diverse microorganisms. Some bacteria preyed by FLA are called amoeba-resistant bacteria (ARB), as they can resist to lysosomal fusion and are capable of multiplying and evading FLA after internalization, propagating in the environment. Despite the health risks due to the existence of pathogenic and opportunistic species that are ARB and the pathogenicity of some FLA species, there are no water quality protocols to analyze the presence of ARB or FLA. In this sense, our study aimed to isolate FLA through amoebal enrichment and to identify ARB using amoebal coculture in water samples from a public park and two hospitals in southern Brazil. As a result, 9 different microorganisms genera have been identified through amoebal coculture, including fastidious Legionella spp. and Bosea vestrisii. From the positive samples for FLA, by amoebal enrichment, Acanthamoeba spp., Vermamoeba vermiformis and Naegleria spp. were identified in 14 amoebic isolates. The methodologies used in this work proved to be effective as simple and low-cost methods to be used in the implementation in water quality control of anthropogenic environments.
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Eble D, Gehrig V, Schubert-Ullrich P, Köppel R, Füchslin HP. Comparison of the culture method with multiplex PCR for the confirmation of Legionella spp. and Legionella pneumophila. J Appl Microbiol 2021; 131:2600-2609. [PMID: 33847421 PMCID: PMC9292777 DOI: 10.1111/jam.15103] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 04/04/2021] [Accepted: 04/09/2021] [Indexed: 11/30/2022]
Abstract
AIMS The detection and enumeration of Legionella spp. in water samples are typically performed via a cultural technique standardized in ISO 11731. This method is time-consuming (up to 15 days), and the specificity of the confirmation step is questionable. This study proposes the use of multiplex polymerase chain reaction (PCR) to confirm presumptive Legionella colonies directly from the culture plate; this shortens the response time by 2-5 days while still reporting results in colony forming units (CFU). METHODS AND RESULTS Two laboratories analysed a total of 290 colonies to compare the confirmation step of Legionella spp. and Legionella pneumophila in accordance with ISO 11731 by culture growth and agglutination vs multiplex PCR. Discordant results were resolved by the swiss national reference laboratory. The data were evaluated following ISO 16140 and showed that the PCR-technique had higher specificity. CONCLUSIONS The confirmation of Legionella spp., L. pneumophila and L. pneumophila serogroup 1 by multiplex PCR allows detection of positive colonies more rapidly and with higher specificity. SIGNIFICANCE AND IMPACT OF THE STUDY The study highlights a possibility to shorten the response time significantly during the enumeration of Legionella spp. and achieving a higher specificity while adhering to the legally recognized reporting in CFU.
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Affiliation(s)
- D Eble
- Industrielle Werke Basel, Basel, Switzerland
| | - V Gehrig
- Kantonales Labor Zürich, Zürich, Switzerland
| | | | - R Köppel
- Kantonales Labor Zürich, Zürich, Switzerland
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16
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Teira A, Sánchez J, Santiago I, Zarauza J, Nan D, Teira R. Legionella endocarditis: A case report and review. Enferm Infecc Microbiol Clin 2020; 40:S0213-005X(20)30409-2. [PMID: 33376029 DOI: 10.1016/j.eimc.2020.10.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/22/2020] [Accepted: 10/28/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND Legionella is a well known but infrequent cause of bacterial endocarditis. METHODS We report a case of endocarditis caused by Legionella spp. We reviewed previously reported cases in PubMed, Google Scholar and in references included in previous reports, and summarized relevant clinical data. RESULTS A 63-year-old man with a history of aortic valve replacement developed persistent fever and monoarthritis. Transesophageal echocardiography showed perivalvular abscess. He died during surgery. Blood and valve cultures were negative. Legionella spp. was demonstrated with 16S-rRNA PCR from the resected material. Twenty cases of Legionella endocarditis have been reported. Harboring a prosthetic valve was the main risk factor. Prognosis was favorable, both for patients treated with or without surgical valve replacement. Overall mortality was <10%. CONCLUSIONS Legionella is an infrequent cause of endocarditis. It frequently requires surgical treatment. Prognosis is good. Molecular techniques are likely to become the gold standard for diagnosis.
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Affiliation(s)
- Andrea Teira
- Service of Cardiology, Hospital Universitario Marqués de Valdecilla, Santander, Cantabria, Spain.
| | - Juan Sánchez
- Service of Cardiology, Hospital Universitario Marqués de Valdecilla, Santander, Cantabria, Spain
| | - Ignacio Santiago
- Service of Cardiology, Hospital Universitario Marqués de Valdecilla, Santander, Cantabria, Spain
| | - Jesús Zarauza
- Service of Cardiology, Hospital Universitario Marqués de Valdecilla, Santander, Cantabria, Spain
| | - Daniel Nan
- Service of Internal Medicine, Hospital Universitario Marqués de Valdecilla, Santander, Cantabria, Spain
| | - Ramón Teira
- Unit of Infectious Diseases, Service of Internal Medicine, Hospital de Sierrallana, Torrelavega, Cantabria, Spain
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Fischer FB, Schmutz C, Gaia V, Mäusezahl D. Legionnaires' Disease on the Rise in Switzerland: A Denominator-Based Analysis of National Diagnostic Data, 2007-2016. Int J Environ Res Public Health 2020; 17:ijerph17197343. [PMID: 33050023 PMCID: PMC7579383 DOI: 10.3390/ijerph17197343] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/02/2020] [Accepted: 10/03/2020] [Indexed: 12/17/2022]
Abstract
The risk of falling ill with Legionnaires' disease (LD) is suggested to increase, but the global burden of disease is unknown due to a lack of appropriate diagnosis and surveillance systems. In Switzerland, the number of LD cases, captured by the National Notification System for Infectious Diseases, has more than doubled since 2008. This study aims to investigate this increase, contextualizing disease surveillance data with denominator data, which is not routinely available, i.e., the number of tests performed for Legionella spp. We collected the testing data for Legionella spp. of 14 Swiss diagnostic laboratories and calculated the positivity, defined as the proportion of the number of positive tests to the number of tests performed. The number of positive tests increased proportionally to the number of tests performed; hence, the positivity remained stable. However, the cause of the increase in test volume is unclear and has a large impact on the interpretation of the positivity curve. Further, the test outcome was found to be dependent on regional determinants, and the diagnostic method applied. The lack of understanding if and at which stage LD is considered in current case management of pneumonia patients limits the interpretation of observed heterogeneities in incidence or underestimation of LD in Switzerland. The absence of (or non-adherence to) existing guidelines and the heterogeneity in diagnostic testing hampers the comparison of data in the Swiss public health context. Therefore, diagnostic procedures should be harmonised across Switzerland and adherence to national LD management guidelines supported.
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Affiliation(s)
- Fabienne B. Fischer
- Swiss Tropical and Public Health Institute, 4001 Basel, Switzerland; (F.B.F.); (C.S.)
- Faculty of Science, University of Basel, 4002 Basel, Switzerland
| | - Claudia Schmutz
- Swiss Tropical and Public Health Institute, 4001 Basel, Switzerland; (F.B.F.); (C.S.)
- Faculty of Science, University of Basel, 4002 Basel, Switzerland
| | - Valeria Gaia
- National Reference Center for Legionella, Service of Microbiology, Ente Ospedaliero Cantonale, 6500 Bellinzona, Switzerland;
| | - Daniel Mäusezahl
- Swiss Tropical and Public Health Institute, 4001 Basel, Switzerland; (F.B.F.); (C.S.)
- Faculty of Science, University of Basel, 4002 Basel, Switzerland
- Correspondence: ; Tel.: +41-61-284-8178
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Totaro M, Costa AL, Frendo L, Profeti S, Casini B, Gallo A, Privitera G, Baggiani A. Evaluation of Legionella spp. Colonization in Residential Buildings Having Solar Thermal System for Hot Water Production. Int J Environ Res Public Health 2020; 17:E7050. [PMID: 32993154 DOI: 10.3390/ijerph17197050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/23/2020] [Accepted: 09/24/2020] [Indexed: 11/17/2022]
Abstract
Despite an increase of literature data on Legionella spp. presence in private water systems, epidemiological reports assert a continuing high incidence of Legionnaires’ disease infection in Italy. In this study, we report a survey on Legionella spp. colonization in 58 buildings with solar thermal systems for hot water production (TB). In all buildings, Legionella spp. presence was enumerated in hot and cold water samples. Microbiological potability standards of cold water were also evaluated. Legionella spp. was detected in 40% of the buildings. Moreover, we detected correlations between the count of Legionella spp. and the presence of the optimal temperature for the microorganism growth (less than 40 °C). Our results showed that cold water was free from microbiological hazards, but Legionella spp., was detected when the mean cold water temperature was 19.1 ± 2.2 °C. This may considered close to the suboptimal value for the Legionella growth (more then 20 °C). In conclusion, we observed the presence of a Legionnaires’ disease risk and the need of some strategies aimed to reduce it, such as the application of training programs for all the workers involved in water systems maintenance.
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Ditommaso S, Giacomuzzi M, Memoli G, Garlasco J, Zotti CM. Sensitivity and Selectivity of Two Commercially Available Media for Legionella spp. Recovery from Environmental Water Samples. Pathogens 2020; 9:pathogens9070523. [PMID: 32610489 PMCID: PMC7400336 DOI: 10.3390/pathogens9070523] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 05/20/2020] [Accepted: 06/22/2020] [Indexed: 11/17/2022] Open
Abstract
The quality control of culture media used for Legionella spp. isolation and enumeration is paramount to achieve a satisfactory degree of comparability among water testing results from different laboratories. Here, we report on a comparative assessment of the sensitivity and selectivity of MWY and BCYEα media supplied by two different manufacturers (i.e., Xebios Diagnostics GmbH and Oxoid Ltd) for the detection of Legionella spp. from environmental water samples. Even though our analysis showed an excellent agreement between the recovery rates of the four media tested (90.5%), the quantitative recovery of Legionella spp. colonies using Xebios media was significantly greater than that achieved by Oxoid media (P = 0.0054). Furthermore, the sensitivity of detection was significantly higher when samples were plated on MWY Xebios agar (P = 0.0442), while the selectivity of MWY appeared to be the same regardless of the manufacturer. Furthermore, MWYXebios agar favored the growth of much larger colonies compared to those observed on MWYOxoid agar. Finally, MWYXebios medium enhanced the recovery of non-pneumophila Legionella species. Collectively, our findings demonstrate that quality control is crucial to ensure high selectivity and sensitivity of the culture media used for the detection and enumeration of Legionella spp. from environmental water resources. As water remediation measures strictly depend on Legionella spp. recovery, culture protocol standardization, as well as quality control of the culture media, is essential to achieve intra- and interlaboratory reproducibility and accuracy.
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Mazzotta M, Girolamini L, Pascale MR, Lizzadro J, Salaris S, Dormi A, Cristino S. The Role of Sensor-Activated Faucets in Surgical Handwashing Environment as a Reservoir of Legionella. Pathogens 2020; 9:pathogens9060446. [PMID: 32516992 PMCID: PMC7350366 DOI: 10.3390/pathogens9060446] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 05/21/2020] [Accepted: 06/03/2020] [Indexed: 12/18/2022] Open
Abstract
Surgical handwashing is a mandatory practice to protect both surgeons and patients in order to control Healthcare-Associated Infections (HAIs). The study is focused on Legionella and Pseudomonas aeruginosa contamination in Surgical Handwashing Outlets (SHWOs) provided by sensor-activated faucets with Thermostatic Mixer Valves (TMVs), as correlated to temperature, technologies, and disinfection used. Samples were analyzed by standard culture techniques, comparing hot- and cold-water samples. Legionella isolates were typed by an agglutination test and by mip sequencing. Legionella contamination showed the same distribution between hot and cold samples concerning positive samples and mean concentration: 44.5% and 1.94 Log10 cfu/L vs. 42.6% and 1.81 Log10 cfu/L, respectively. Regarding the distribution of isolates (Legionella pneumophila vs. Legionella non-pneumophila species), significant differences were found between hot- and cold-positive samples. The contamination found in relation to ranges of temperature showed the main positive samples (47.1%) between 45.1-49.6 °C, corresponding to high Legionella concentrations (2.17 Log10 cfu/L). In contrast, an increase of temperature (>49.6 °C) led to a decrease in positive samples (23.2%) and mean concentration (1.64 Log10 cfu/L). A low level of Pseudomonas aeruginosa was found. For SHWOs located in critical areas, lack of consideration of technologies used and uncorrected disinfection protocols may lead to the development of a high-risk environment for both patients and surgeons.
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Affiliation(s)
- Marta Mazzotta
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, via San Giacomo 12, 40126 Bologna, Italy; (M.M.); (L.G.); (M.R.P.); (J.L.); (S.S.)
| | - Luna Girolamini
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, via San Giacomo 12, 40126 Bologna, Italy; (M.M.); (L.G.); (M.R.P.); (J.L.); (S.S.)
| | - Maria Rosaria Pascale
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, via San Giacomo 12, 40126 Bologna, Italy; (M.M.); (L.G.); (M.R.P.); (J.L.); (S.S.)
| | - Jessica Lizzadro
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, via San Giacomo 12, 40126 Bologna, Italy; (M.M.); (L.G.); (M.R.P.); (J.L.); (S.S.)
| | - Silvano Salaris
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, via San Giacomo 12, 40126 Bologna, Italy; (M.M.); (L.G.); (M.R.P.); (J.L.); (S.S.)
| | - Ada Dormi
- Department of Medical and Surgical Science, University of Bologna, via San Giacomo 12, 40126 Bologna, Italy;
| | - Sandra Cristino
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, via San Giacomo 12, 40126 Bologna, Italy; (M.M.); (L.G.); (M.R.P.); (J.L.); (S.S.)
- Correspondence: ; Tel.: +39-051-209-4811; Fax: +39-051-209-4829
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Olabarria G, Eletxigerra U, Rodriguez I, Bilbao A, Berganza J, Merino S. Highly sensitive and fast Legionella spp. in situ detection based on a loop mediated isothermal amplification technique combined to an electrochemical transduction system. Talanta 2020; 217:121061. [PMID: 32498831 DOI: 10.1016/j.talanta.2020.121061] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 04/15/2020] [Accepted: 04/17/2020] [Indexed: 12/25/2022]
Abstract
A rapid highly sensitive genosensor has been developed for monitoring the presence of Legionella spp. in different water systems (domestic hot water, heating/cooling systems or cooling towers) in order to avoid its spreading from the source of contamination. The genosensor integrates a loop mediated isothermal amplification (LAMP) reaction with an electrochemical transduction signal, producing a very simple, rapid to perform and cost effective method, suitable for in situ analyses. This approach detects as low as 10 fg of Legionella nucleic acid, corresponding to only 2 number copies of the bacteria. The use of an electrochemical redox-active double stranded DNA (dsDNA) intercalating molecule, known as methylen blue (MB), allows the immediate electrochemical reading during the DNA polymerization. The sensor can obtain quantitative results in 20 min with a correlation between the electrochemical data and Legionella spp. copy number (at a logarithmic scale) of r = -0.97. In conclusion, a fast, easy to use, and accurate electrochemical genosensor, with high precision, sensitivity, and specificity has been developed for in situ detection of Legionella spp. enabling real time decision making and improving significantly the current detection methods for the prevention and screening of Legionella.
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Affiliation(s)
- Garbiñe Olabarria
- GAIKER Technology Centre, Basque Research and Technology Alliance (BRTA). Parque Tecnológico, Edificio 202. 48170, Zamudio, Spain.
| | - Unai Eletxigerra
- Surface Chemistry and Nanotechnologies Unit, Tekniker, Eibar, 20600, Spain
| | - Isabel Rodriguez
- GAIKER Technology Centre, Basque Research and Technology Alliance (BRTA). Parque Tecnológico, Edificio 202. 48170, Zamudio, Spain
| | - Ainhoa Bilbao
- GAIKER Technology Centre, Basque Research and Technology Alliance (BRTA). Parque Tecnológico, Edificio 202. 48170, Zamudio, Spain
| | - Jesus Berganza
- GAIKER Technology Centre, Basque Research and Technology Alliance (BRTA). Parque Tecnológico, Edificio 202. 48170, Zamudio, Spain
| | - Santos Merino
- Surface Chemistry and Nanotechnologies Unit, Tekniker, Eibar, 20600, Spain; Departamento de Electricidad y Electrónica, Universidad Del País Vasco UPV/EHU, 48940, Leioa, Spain
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Tuvo B, Totaro M, Cristina ML, Spagnolo AM, Di Cave D, Profeti S, Baggiani A, Privitera G, Casini B. Prevention and Control of Legionella and Pseudomonas spp. Colonization in Dental Units. Pathogens 2020; 9:E305. [PMID: 32326140 PMCID: PMC7238104 DOI: 10.3390/pathogens9040305] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/16/2020] [Accepted: 04/17/2020] [Indexed: 11/29/2022] Open
Abstract
Introduction: Dental Unit Waterlines (DUWLs) have shown to be a source of Legionella infection. We report the experience of different dental healthcare settings where a risk management plan was implemented. Materials and methods: In a Hospital Odontostomatology Clinic (HOC) and three Private Dental Clinics (PDCs) housing 13 and six dental units (DUs), respectively, an assessment checklist was applied to evaluate staff compliance with guideline recommendations. DUWLs microbial parameters were investigated before and after the application of corrective actions. Results: In the HOC a poor adherence to good practices was demonstrated, whereas protocols were carefully applied in PDCs. L. pneumophila sg 2-15 was isolated in 31% (4/13) and 33% (2/6) of DUs in HOC and PDCs, respectively, mainly from handpieces (32%, 6/19) with counts >102 colony-forming units per milliliter (CFU/L), often associated with P. aeruginosa (68%, 13/19). The shock disinfection with 3% v/v hydrogen peroxide (HP) showed a limited effect, with a recolonization period of about 4 weeks. Legionella was eradicated only after 6% v/v HP shock disinfection and filters-installation, whilst P. aeruginosa after the third shock disinfection with a solution of 4% v/v HP and biodegradable surfactants. Conclusions: Our data demonstrate the presence and persistence of microbial contamination within the DUWLs, which required strict adherence to control measures and the choice of effective disinfectants.
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Affiliation(s)
- Benedetta Tuvo
- Department of Translational Research, N.T.M.S., University of Pisa, 56123 Pisa, Italy; (B.T.); (M.T.); (S.P.); (A.B.); (G.P.)
| | - Michele Totaro
- Department of Translational Research, N.T.M.S., University of Pisa, 56123 Pisa, Italy; (B.T.); (M.T.); (S.P.); (A.B.); (G.P.)
| | - Maria Luisa Cristina
- Department of Health Sciences, University of Genova, Via Pastore 1, 16132 Genova, Italy; (M.L.C.); (A.M.S.)
| | - Anna Maria Spagnolo
- Department of Health Sciences, University of Genova, Via Pastore 1, 16132 Genova, Italy; (M.L.C.); (A.M.S.)
| | - David Di Cave
- Department of Clinical Sciences and Translational Medicine, University of Rome “Tor Vergata”, 00133 Rome, Italy;
| | - Sara Profeti
- Department of Translational Research, N.T.M.S., University of Pisa, 56123 Pisa, Italy; (B.T.); (M.T.); (S.P.); (A.B.); (G.P.)
| | - Angelo Baggiani
- Department of Translational Research, N.T.M.S., University of Pisa, 56123 Pisa, Italy; (B.T.); (M.T.); (S.P.); (A.B.); (G.P.)
| | - Gaetano Privitera
- Department of Translational Research, N.T.M.S., University of Pisa, 56123 Pisa, Italy; (B.T.); (M.T.); (S.P.); (A.B.); (G.P.)
| | - Beatrice Casini
- Department of Translational Research, N.T.M.S., University of Pisa, 56123 Pisa, Italy; (B.T.); (M.T.); (S.P.); (A.B.); (G.P.)
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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. Adv Exp Med Biol 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Molino PJ, Bentham R, Higgins MJ, Hinds J, Whiley H. Public Health Risks Associated with Heavy Metal and Microbial Contamination of Drinking Water in Australia. Int J Environ Res Public Health 2019; 16:E3982. [PMID: 31635303 DOI: 10.3390/ijerph16203982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 10/16/2019] [Accepted: 10/16/2019] [Indexed: 01/15/2023]
Abstract
Recently in Australia concerns have been raised regarding the contamination of municipal drinking water supplies with lead. This is of particular concern to children due to the impact of lead exposure on cognitive development and as such these findings have received much media attention. The response from legislators has been swift, and The Victorian School Building Authority has announced that all new schools and school upgrade works will only use lead-free tapware and piping systems. However, while the immediate replacement of lead-containing brass fittings may seem a logical and obvious response, it does not consider the potential implications on microbial contamination. This is particularly concerning given the increasing public health threat posed by opportunistic premise plumbing pathogens (OPPPs). This commentary explores this public health risk of lead exposure from plumbing materials compared to the potential public health risks from OPPPs. Non-tuberculous mycobacterium was chosen as the example OPPP, and the influence on plumbing material and its public health burden in Australia is explored. This commentary highlights the need for future research into the influence of plumbing material on OPPPs prior to any changes in legislation regarding plumbing material.
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van der Lugt W, Euser SM, Bruin JP, den Boer JW, Yzerman EPF. Wide-scale study of 206 buildings in the Netherlands from 2011 to 2015 to determine the effect of drinking water management plans on the presence of Legionella spp. Water Res 2019; 161:581-589. [PMID: 31238223 DOI: 10.1016/j.watres.2019.06.043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 06/13/2019] [Accepted: 06/16/2019] [Indexed: 05/25/2023]
Abstract
Previous analysis of the Dutch National Legionella Outbreak Detection Program 2002-2012 has shown that buildings required to maintain a Legionella control plan for their drinking water installation are more likely to test positive for Legionella spp. Than buildings without such a plan (38% versus 22% of samples). To clarify this discrepancy, we analysed the results of mandatory water sample testing conducted as part of risk assessments in 206 buildings in the Netherlands from 2011 to 2015. Of the 6171 samples analysed, 16.2% exceeded the Dutch drinking water standard for Legionella spp. of 100 CFU/litre. In buildings with ≤50 tap points, the average percentage of samples containing ≥100 CFU/litre was 28.2%, and from buildings with >50 tap points, it was 12.2%. Analysis of serial samples (taken every 6 months) from each building showed that 33.2% of all buildings tested positive for at least one sample every 6 months. The overall increase was 4.4% per year. Analysis of Legionella subgroups showed that while the majority of positive samples contained L. non-pneumophila (96.9%), some samples did contain L. pneumophila serogroup 1 (1.0%) and serogroups 2-14 (2.1%). Our data suggest that the Dutch mandatory risk assessment and drinking water management plan is not sufficiently effective in preventing the proliferation of Legionella spp. and may even contribute to proliferation. This analysis should now be expanded to include other areas of the Netherlands in order to understand the geographical differences that we observed in our results, and why smaller buildings appear to be more likely to test positive for Legionella spp.
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Affiliation(s)
| | - Sjoerd M Euser
- Regional Public Health Laboratory Kennemerland, Boerhaavelaan 26, 2035, RC, Haarlem, the Netherlands
| | - Jacob P Bruin
- Regional Public Health Laboratory Kennemerland, Boerhaavelaan 26, 2035, RC, Haarlem, the Netherlands
| | - Jeroen W den Boer
- Regional Public Health Laboratory Kennemerland, Boerhaavelaan 26, 2035, RC, Haarlem, the Netherlands
| | - Ed P F Yzerman
- Regional Public Health Laboratory Kennemerland, Boerhaavelaan 26, 2035, RC, Haarlem, the Netherlands
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26
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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. Environ Res 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Alexandropoulou I, Parasidis T, Konstantinidis T, Panopoulou M, Constantinidis TC. A Proactive Environmental Approach for Preventing Legionellosis in Infants: Water Sampling and Antibiotic Resistance Monitoring, a 3-Years Survey Program. Healthcare (Basel) 2019; 7:E39. [PMID: 30857147 DOI: 10.3390/healthcare7010039] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 03/02/2019] [Accepted: 03/06/2019] [Indexed: 11/16/2022] Open
Abstract
A proactive environmental monitoring program was conducted to determine the risk and prevent nosocomial waterborne infections of Legionella spp. in infants. Sink taps in a neonatal intensive care unit (NICU) and two obstetric clinics were monitored for Legionella spp. A total of 59 water samples were collected during a 3-year period and 20 of them were found colonized with Legionella pneumophila. Standard culture, molecular, and latex agglutination methods were used for the detection and identification of Legionella bacteria. Hospital personnel also proceeded with remedial actions (hyperchlorination and thermal shock treatment) in the event of colonization. The minimal inhibitory concentration (MIC) values of erythromycin, ciprofloxacin was determined for Legionella isolates using the e-test method. Our data indicate that the majority of neonatal sink-taps were colonized at least once during the study with Legionella spp. Among 20 isolates, 5 were considered as low-level resistant, 3 in erythromycin and 2 in ciprofloxacin, while no resistant strains were detected. Environmental surveillance in neonatal and obstetric units is suggested to prevent waterborne infections, and thus to reduce the risk of neonatal nosocomial infections.
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28
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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. Int J Environ Res 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Fleres G, Couto N, Lokate M, van der Sluis LWM, Ginevra C, Jarraud S, Deurenberg RH, Rossen JW, García-Cobos S, Friedrich AW. Detection of Legionella Anisa in Water from Hospital Dental Chair Units and Molecular Characterization by Whole-Genome Sequencing. Microorganisms 2018; 6:E71. [PMID: 30021964 DOI: 10.3390/microorganisms6030071] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 07/13/2018] [Accepted: 07/16/2018] [Indexed: 11/25/2022] Open
Abstract
This study aims to assess contamination with Legionella spp. in water from dental chair units (DCUs) of a hospital dental ward and to perform its molecular characterization by whole-genome sequencing (WGS). We collect eight water samples (250 mL) from four DCUs (sink and water-syringe). Samples are tested for the presence of Legionella spp. (CFUs/mL) by culturing according to the Nederland Norm (NEN) 6265. Three DCUs are found positive for Legionella anisa, and four isolates are cultured (sink n = 2, water-syringe n = 1; two isolates from the same chair) with 1 × 102 CFU/mL. Whole-genome multi-locus sequence typing (wgMLST) results indicate that all strains belong to the same cluster with two to four allele differences. Classical culture combined with WGS allows the identification of a unique clone of L. anisa in several DCUs in the same hospital dental ward. This may indicate a common contamination source in the dental unit waterlines, which was fixed by replacing the chairs and main pipeline of the unit. Our results reveal tap water contamination in direct contact with patients and the usefulness of WGS to investigate bacterial molecular epidemiology.
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Dobrowsky PH, Khan S, Khan W. Resistance of Legionella and Acanthamoeba mauritaniensis to heat treatment as determined by relative and quantitative polymerase chain reactions. Environ Res 2017; 158:82-93. [PMID: 28609649 DOI: 10.1016/j.envres.2017.06.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/11/2017] [Accepted: 06/04/2017] [Indexed: 06/07/2023]
Abstract
Legionella and Acanthamoeba spp. persist in harvested rainwater pasteurized at high temperatures (> 72°C) and the interaction mechanisms exhibited between these organisms need to be elucidated. The resistance of two Legionella reference strains (Legionella pneumophila ATCC 33152 and Legionella longbeachae ATCC 33462), three environmental strains [Legionella longbeachae (env.), Legionella norrlandica (env.) and Legionella rowbothamii (env.)] and Acanthamoeba mauritaniensis ATCC 50676 to heat treatment (50-90°C) was determined by monitoring culturability and viability [ethidium monoazide quantitative polymerase chain reaction (EMA-qPCR)]. The expression of metabolic and virulence genes of L. pneumophila ATCC 33152 (lolA, sidF, csrA) and L. longbeachae (env.) (lolA) in co-culture with A. mauritaniensis ATCC 50676 during heat treatment (50-90°C) was monitored using relative qPCR. While the culturability (CFU/mL) and viability (gene copies/mL) of the Legionella strains reduced significantly (p < 0.05) following heat treatment (60-90°C), L. longbeachae (env.) and L. pneumophila ATCC 33152 were culturable following heat treatment at 50-60°C. Metabolically active trophozoites and dormant cysts of A. mauritaniensis ATCC 50676 were detected at 50°C and 60-90°C, respectively. For L. pneumophila ATCC 33152, lolA expression remained constant, sidF expression increased and the expression of csrA decreased during co-culture with A. mauritaniensis ATCC 50676. For L. longbeachae (env.), while lolA was up-regulated at 50-70°C, expression was not detected at 80-90°C and in co-culture. In conclusion, while heat treatment may reduce the number of viable Legionella spp. in monoculture, results indicate that the presence of A. mauritaniensis increases the virulence of L. pneumophila during heat treatment. The virulence of Legionella spp. in co-culture with Acanthamoeba spp. should thus be monitored in water distribution systems where temperature (heat) is utilized for treatment.
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Affiliation(s)
- Penelope H Dobrowsky
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch 7602, South Africa.
| | - Sehaam Khan
- Faculty of Health and Applied Sciences, Namibia University of Science and Technology,13 Storch Street, Private Bag 13388, Windhoek, Namibia.
| | - Wesaal Khan
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch 7602, South Africa.
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Iervolino M, Mancini B, Cristino S. Industrial Cooling Tower Disinfection Treatment to Prevent Legionella spp. Int J Environ Res Public Health 2017; 14:E1125. [PMID: 28954435 PMCID: PMC5664626 DOI: 10.3390/ijerph14101125] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/19/2017] [Accepted: 09/22/2017] [Indexed: 01/22/2023]
Abstract
The contamination of industrial cooling towers has been identified as one cause of legionellosis, but the real risk has been underestimated. Two different disinfection treatments were tested on Legionella colonization in an industrial Cooling Tower System (CTS). Environmental monitoring of Legionella, P. aeruginosa, and a heterotrophic plate count (HPC) at 36 °C was performed from June to October 2016. The disinfection procedures adopted were based on hydrogen peroxide (H₂O₂) and silver salts (Ag⁺), in addition to an anti-algal treatment, then using hyperclorination as a shock, and then continuous treatment by sodium hypochlorite (NaClO). L. pneumophila serogroup 8 was found at a concentration of 5.06 Log cfu/L after the CTS filling; a shock treatment performed by H₂O₂/Ag⁺ produced a rapid increase in contamination up to 6.14 Log cfu/L. The CTS activity was stopped and two subsequent shock treatments were performed using NaClO, followed by continuous hyperclorination. These procedures showed a significant decrease (p < 0.05) in Legionella concentration (1.77 Log cfu/L). The same trend was observed for P. aeruginosa (0.55 Log cfu/100 mL) and HPC (1.95 Log cfu/mL) at 36 °C. Environmental monitoring and the adoption of maintenance procedures, including anti-scale treatment, and physical, chemical, and microbiological control, ensure the good performance of a CTS, reducing the Legionella risk for public health.
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Affiliation(s)
- Matteo Iervolino
- Department of Biological, Geological and Environmental Sciences, BiGeA, University of Bologna, via San Giacomo 12, 40126 Bologna, Italy.
| | - Benedetta Mancini
- Department of Biological, Geological and Environmental Sciences, BiGeA, University of Bologna, via San Giacomo 12, 40126 Bologna, Italy.
| | - Sandra Cristino
- Department of Biological, Geological and Environmental Sciences, BiGeA, University of Bologna, via San Giacomo 12, 40126 Bologna, Italy.
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van der Lugt W, Euser SM, Bruin JP, Den Boer JW, Walker JT, Crespi S. Growth of Legionella anisa in a model drinking water system to evaluate different shower outlets and the impact of cast iron rust. Int J Hyg Environ Health 2017; 220:1295-1308. [PMID: 28869187 DOI: 10.1016/j.ijheh.2017.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 08/11/2017] [Accepted: 08/13/2017] [Indexed: 10/19/2022]
Abstract
Legionella continues to be a problem in water systems. This study investigated the influence of different shower mixer faucets, and the influence of the presence of cast iron rust from a drinking water system on the growth of Legionella. The research is conducted using a model of a household containing four drinking water systems. All four systems, which contained standard plumbing components including copper pipes and a water heater, were filled with unchlorinated drinking water. Furthermore, all systems had three different shower faucets: (A) a stainless-steel faucet, (B) a brass-ceramic faucet, and (C) a brass thermostatic faucet. System 1 was solely filled with drinking water. System 2 was filled with drinking water, and cast iron rust. System 3 was contaminated with Legionella, and system 4 was contaminated with a Legionella, and cast iron rust. During a period of 34 months, 450 cold water samples were taken from 15 sample points of the four drinking water systems, and tested for Legionella according to the Dutch Standard (NEN 6265). In system 4, with added cast iron rust, the stainless-steel mixer faucet (A) had the highest concentration of Legionella at >4.3log10CFU/l (>20,000CFU/l) and was positive in 46.4% of samples. In contrast, the stainless-steel mixer faucet (A) of system 3 without cast iron rust showed 14.3% positive samples with a maximum concentration of 3.9log10CFU/l (7600CFU/l) Legionella. Additionally, both contaminated systems (3 and 4), with the brass thermostatic faucet (C), tested positive for Legionella. System 3 in 85.7% of the samples, with a maximum concentration of 4.38log10CFU/l (24,200CFU/l), and system 4 in 64.3% of the samples with a maximum concentration of 4.13log10CFU/l (13.400CFU/l). These results suggest that both the type of faucet used in a drinking water system and the presence or absence of cast iron rust influence the growth of Legionella.
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Affiliation(s)
| | - Sjoerd M Euser
- Regional Public Health Laboratory Kennemerland, Boerhaavelaan 26, 2035 RC, Haarlem, The Netherlands
| | - Jacob P Bruin
- Regional Public Health Laboratory Kennemerland, Boerhaavelaan 26, 2035 RC, Haarlem, The Netherlands
| | - Jeroen W Den Boer
- Regional Public Health Laboratory Kennemerland, Boerhaavelaan 26, 2035 RC, Haarlem, The Netherlands
| | - Jimmy T Walker
- Biosafety, Air and Water Microbiology Group, Public Health England, National Infection Service, Porton Down, Salisbury, England, United Kingdom
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Abstract
OBJECTIVE To determine the current presence of Legionella spp. in the output water of dental unit waterlines (DUWLs) and examine its mitigation by disinfection at the Institute of Dentistry and Oral Sciences, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc. MATERIAL AND METHODS The first stage of our survey involved collecting samples of DUWL output water from 50 dental chair units (DCUs), and 2 samples of the incoming potable water. In October 2015, a one-time disinfection (1 % Stabimed) of DUWLs was conducted. This was followed by collecting 10 control samples (survey stage 2). RESULTS From the total of 50 samples (survey stage 1), 18 samples (36.0 %) tested positive for Legionella spp. Following the disinfection, nine of the ten samples no longer showed any presence of Legionella. CONCLUSION Based on culture results, the one-time disinfection (1 % Stabimed) was effective. We are unable to comment on the duration of positive effect of disinfection on the occurrence of Legionella spp. in the outlet water. It was a one-time survey (Tab. 2, Ref. 32).
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Lösch LS, Merino LA. [Presence of Legionella spp. in household drinking water reservoirs in Resistencia, Chaco, Argentina. Preliminary report]. Rev Argent Microbiol 2016; 48:329-332. [PMID: 28029443 DOI: 10.1016/j.ram.2016.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 06/16/2016] [Accepted: 07/05/2016] [Indexed: 11/30/2022] Open
Abstract
Legionella spp. is an environmental bacterium that can survive in a wide range of physicochemical conditions and may colonize distribution systems of drinking water and storage tanks. Legionella pneumophila is the major waterborne pathogen that can cause 90% of Legionnaires' disease cases. The aim of this study was to detect the presence of Legionella spp. in household drinking water tanks in the city of Resistencia, Chaco. The detection of Legionella in water samples was performed by culture methods as set out in ISO 11731:1998. Thirty two water samples were analyzed and Legionella spp. was recovered in 12 (37.5%) of them. The monitoring of this microorganism in drinking water is the first step towards addressing the control of its spread to susceptible hosts.
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Affiliation(s)
- Liliana S Lösch
- Área de Bacteriología, Instituto de Medicina Regional, Universidad Nacional del Nordeste, Resistencia, Chaco, Argentina; Cátedra de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Universidad Nacional del Nordeste, Corrientes, Argentina.
| | - Luis A Merino
- Área de Bacteriología, Instituto de Medicina Regional, Universidad Nacional del Nordeste, Resistencia, Chaco, Argentina; Cátedra de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Universidad Nacional del Nordeste, Corrientes, Argentina
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Strauss A, Dobrowsky PH, Ndlovu T, Reyneke B, Khan W. Comparative analysis of solar pasteurization versus solar disinfection for the treatment of harvested rainwater. BMC Microbiol 2016; 16:289. [PMID: 27938342 PMCID: PMC5148859 DOI: 10.1186/s12866-016-0909-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 12/06/2016] [Indexed: 12/20/2022] Open
Abstract
Background Numerous pathogens and opportunistic pathogens have been detected in harvested rainwater. Developing countries, in particular, require time- and cost-effective treatment strategies to improve the quality of this water source. The primary aim of the current study was thus to compare solar pasteurization (SOPAS; 70 to 79 °C; 80 to 89 °C; and ≥90 °C) to solar disinfection (SODIS; 6 and 8 hrs) for their efficiency in reducing the level of microbial contamination in harvested rainwater. The chemical quality (anions and cations) of the SOPAS and SODIS treated and untreated rainwater samples were also monitored. Results While the anion concentrations in all the samples were within drinking water guidelines, the concentrations of lead (Pb) and nickel (Ni) exceeded the guidelines in all the SOPAS samples. Additionally, the iron (Fe) concentrations in both the SODIS 6 and 8 hr samples were above the drinking water guidelines. A >99% reduction in Escherichia coli and heterotrophic bacteria counts was then obtained in the SOPAS and SODIS samples. Ethidium monoazide bromide quantitative polymerase chain reaction (EMA-qPCR) analysis revealed a 94.70% reduction in viable Legionella copy numbers in the SOPAS samples, while SODIS after 6 and 8 hrs yielded a 50.60% and 75.22% decrease, respectively. Similarly, a 99.61% reduction in viable Pseudomonas copy numbers was observed after SOPAS treatment, while SODIS after 6 and 8 hrs yielded a 47.27% and 58.31% decrease, respectively. Conclusion While both the SOPAS and SODIS systems reduced the indicator counts to below the detection limit, EMA-qPCR analysis indicated that SOPAS treatment yielded a 2- and 3-log reduction in viable Legionella and Pseudomonas copy numbers, respectively. Additionally, SODIS after 8 hrs yielded a 2-log and 1-log reduction in Legionella and Pseudomonas copy numbers, respectively and could be considered as an alternative, cost-effective treatment method for harvested rainwater.
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Affiliation(s)
- André Strauss
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Penelope Heather Dobrowsky
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Thando Ndlovu
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Brandon Reyneke
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Wesaal Khan
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa.
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Wolter N, Carrim M, Cohen C, Tempia S, Walaza S, Sahr P, de Gouveia L, Treurnicht F, Hellferscee O, Cohen AL, Benitez AJ, Dawood H, Variava E, Winchell JM, von Gottberg A. Legionnaires' Disease in South Africa, 2012-2014. Emerg Infect Dis 2016; 22:131-3. [PMID: 26692504 PMCID: PMC4696697 DOI: 10.3201/eid2201.150972] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
During June 2012–September 2014, we tested patients with severe respiratory illness for Legionella spp. infection and conducted a retrospective epidemiologic investigation. Of 1,805 patients tested, Legionella was detected in samples of 21 (1.2%); most were adults who had HIV or tuberculosis infections and were inappropriately treated for Legionella.
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Caicedo C, Beutel S, Scheper T, Rosenwinkel KH, Nogueira R. Occurrence of Legionella in wastewater treatment plants linked to wastewater characteristics. Environ Sci Pollut Res Int 2016; 23:16873-16881. [PMID: 27376367 DOI: 10.1007/s11356-016-7090-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 06/13/2016] [Indexed: 06/06/2023]
Abstract
In recent years, the occurrence of Legionella in wastewater treatment plants (WWTP) has often been reported. However, until now there is limited knowledge about the factors that promote Legionella's growth in such systems. The aim of this study was to investigate the chemical wastewater parameters that might be correlated to the concentration of Legionella spp. in WWTP receiving industrial effluents. For this purpose, samples were collected at different processes in three WWTP. In 100 % of the samples taken from the activated sludge tanks Legionella spp. were detected at varying concentrations (4.8 to 5.6 log GU/mL) by the quantitative real-time polymerase chain reaction method, but not by the culture method. Statistical analysis with various parameters yielded positive correlations of Legionella spp. concentration with particulate chemical oxygen demand, Kjeldahl nitrogen and protein concentration. Amino acids were quantified in wastewater and activated sludge samples at concentrations that may not support the growth of Legionella, suggesting that in activated sludge tanks this bacterium multiplied in protozoan hosts.
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Affiliation(s)
- C Caicedo
- Institute for Sanitary Engineering and Waste Management, Leibniz University Hannover, Welfengarten 1, Hannover, 30167, Germany
| | - S Beutel
- Institute of Technical Chemistry, Leibniz University Hannover, Hannover, 30167, Germany
| | - T Scheper
- Institute of Technical Chemistry, Leibniz University Hannover, Hannover, 30167, Germany
| | - K H Rosenwinkel
- Institute for Sanitary Engineering and Waste Management, Leibniz University Hannover, Welfengarten 1, Hannover, 30167, Germany
| | - R Nogueira
- Institute for Sanitary Engineering and Waste Management, Leibniz University Hannover, Welfengarten 1, Hannover, 30167, Germany.
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Den Boer JW, Euser SM, Brandsema P, Reijnen L, Bruin JP. Results from the National Legionella Outbreak Detection Program, the Netherlands, 2002-2012. Emerg Infect Dis 2016; 21:1167-73. [PMID: 26079594 PMCID: PMC4480379 DOI: 10.3201/eid2107.141130] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
This program has provided insights into the transmission, diagnosis, source investigation, and genotypic strain characteristics of the disease. In 2002, the National Legionella Outbreak Detection Program was implemented in the Netherlands to detect and eliminate potential sources of organisms that cause Legionnaires’ disease (LD). During 2002–2012, a total of 1,991 patients with LD were reported, and 1,484 source investigations were performed. Of those sources investigated, 24.7% were positive for Legionella spp. For 266 patients with LD, 105 cluster locations were identified. A genotype match was made between a strain detected in 41 patients and a strain from a source location. Despite the systematic approach used by the program, most sources of LD infections during 2002–2012 remained undiscovered. Explorative studies are needed to identify yet undiscovered reservoirs and transmission routes for Legionella bacteria, and improved laboratory techniques are needed to detect Legionella spp. in clinical samples with a high background of microbial flora (such as soil).
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Barna Z, Kádár M, Kálmán E, Scheirich Szax A, Vargha M. Prevalence of Legionella in premise plumbing in Hungary. Water Res 2016; 90:71-78. [PMID: 26724441 DOI: 10.1016/j.watres.2015.12.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Revised: 11/30/2015] [Accepted: 12/03/2015] [Indexed: 06/05/2023]
Abstract
Legionella is one of the emerging concerns of water quality in built water environments. Premise plumbing systems are among the recognised sources of infection. In the present study, colonisation of hot water networks in health care facilities, schools, hotels, private residences, office and industrial buildings was investigated. Data was analysed in connection with building and premise plumbing characteristics. Over 60% of all buildings were colonised by Legionella; counts were over 1000 CFU/L in 49%. The most prevalent type was Legionella pneumophila serogroup 2-14, isolated from 75% of the positive samples. Centrally produced hot water was found to be a key risk factor (46% of the samples were positive vs. 16% in individual systems); within this group the type of the building was less relevant. Colonisation levels in schools were similar to hotels or hospitals, representing a previously underestimated risk setting. Systems supplied by water from deep groundwater sources were significantly less likely to be colonised than more vulnerable sources (bank-wall filtration, surface water abstraction or karstic water; 28% vs. 51% positive), regardless of the type of treatment applied, including the presence of disinfection. The aggravating effect of larger, more complex and older buildings on colonisation was also confirmed. The present study represents the first baseline analysis, pre-empting regulation or monitoring requirements for Legionella. The prevalence of legionellae and the identified risk factors are indicative for other settings lacking targeted interventions. The statistically confirmed risk factors can serve as indicators for preliminary risk assessment and the prioritisation of interventions.
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Affiliation(s)
- Zsófia Barna
- Department of Water Hygiene, National Public Health Center, Directorate of Environmental Health, Albert Flórián út 2-6, H-1097 Budapest, Hungary.
| | - Mihály Kádár
- Department of Water Hygiene, National Public Health Center, Directorate of Environmental Health, Albert Flórián út 2-6, H-1097 Budapest, Hungary.
| | - Emese Kálmán
- Department of Water Hygiene, National Public Health Center, Directorate of Environmental Health, Albert Flórián út 2-6, H-1097 Budapest, Hungary.
| | - Anita Scheirich Szax
- Department of Water Hygiene, National Public Health Center, Directorate of Environmental Health, Albert Flórián út 2-6, H-1097 Budapest, Hungary.
| | - Márta Vargha
- Department of Water Hygiene, National Public Health Center, Directorate of Environmental Health, Albert Flórián út 2-6, H-1097 Budapest, Hungary.
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Ditommaso S, Giacomuzzi M, Ricciardi E, Zotti CM. Cultural and Molecular Evidence of Legionella spp. Colonization in Dental Unit Waterlines: Which Is the Best Method for Risk Assessment? Int J Environ Res Public Health 2016; 13:211. [PMID: 26861373 DOI: 10.3390/ijerph13020211] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 02/03/2016] [Indexed: 11/17/2022]
Abstract
Legionella spp. are ubiquitous in aquatic habitats and water distribution systems, including dental unit waterlines (DUWLs). The aim of the present study was to determine the prevalence of Legionella in DUWLs and tap water samples using PMA-qPCR and standard culture methods. The total viable counts (TVCs) of aerobic heterotrophic bacteria in the samples were also determined. Legionella spp. were detected and quantified using the modified ISO 11731 culture method. Extracted genomic DNA was analysed using the iQ-Check Quanti Legionella spp. kit, and the TVCs were determined according to the ISO protocol 6222. Legionella spp. were detected in 100% of the samples using the PMA-qPCR method, whereas these bacteria were detected in only 7% of the samples using the culture method. The number of colony forming units (CFUs) of the TVCs in the DUWL and tap water samples differed, with the bacterial load being significantly lower in the tap water samples (p-value = 0). The counts obtained were within the Italian standard range established for potable water in only 5% of the DUWL water samples and in 77% of the tap water samples. Our results show that the level of Legionella spp. contamination determined using the culture method does not reflect the true scale of the problem, and consequently we recommend testing for the presence of aerobic heterotrophic bacteria based on the assumption that Legionella spp. are components of biofilms.
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41
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Rakić A, Štambuk-Giljanović N. Physical and chemical parameter correlations with technical and technological characteristics of heating systems and the presence of Legionella spp. in the hot water supply. Environ Monit Assess 2016; 188:73. [PMID: 26733467 DOI: 10.1007/s10661-015-5047-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 12/10/2015] [Indexed: 06/05/2023]
Abstract
The purpose of this study was to evaluate the prevalence of Legionella spp. and compare the quality of hot water between four facilities for accommodation located in Southern Croatia (the Split-Dalmatian County). The research included data collection on the technical and technological characteristics in the period from 2009 to 2012. The survey included a type of construction material for the distribution and internal networks, heating system water heater type, and water consumption. Changes in water quality were monitored by determination of the physical and chemical parameters (temperature, pH, free chlorine residual concentrations, iron, zinc, copper and manganese) in the samples, as well as the presence and concentration of bacteria Legionella spp. The temperature is an important factor for the development of biofilms, and it is in negative correlation with the appearance of Legionella spp. Positive correlations between the Fe and Zn concentrations and Legionella spp. were established, while the inhibitory effect of a higher Cu concentration on the Legionella spp. concentration was proven. Legionella spp. were identified in 38/126 (30.2%) of the water samples from the heating system with zinc-coated pipes, as well as in 78/299 (26.1%) of the samples from systems with plastic pipes. A similar number of Legionella spp. positive samples were established regardless of the type of the water heating system (central or independent). The study confirms the necessity of regular microbial contamination monitoring of the drinking water distribution systems (DWDSs).
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Affiliation(s)
- Anita Rakić
- Public Health Institute of Split-Dalmatian County, Vukovarska 46, 21000, Split, Croatia.
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42
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Benitez AJ, Winchell JM. Rapid detection and typing of pathogenic nonpneumophila Legionella spp. isolates using a multiplex real-time PCR assay. Diagn Microbiol Infect Dis 2016; 84:298-303. [PMID: 26867966 DOI: 10.1016/j.diagmicrobio.2016.01.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 01/05/2016] [Accepted: 01/09/2016] [Indexed: 11/26/2022]
Abstract
We developed a single tube multiplex real-time PCR assay that allows for the rapid detection and typing of 9 nonpneumophila Legionella spp. isolates that are clinically relevant. The multiplex assay is capable of simultaneously detecting and discriminating L. micdadei, L. bozemanii, L. dumoffii, L. longbeachae, L. feeleii, L. anisa, L. parisiensis, L. tucsonensis serogroup (sg) 1 and 3, and L. sainthelensis sg 1 and 2 isolates. Evaluation of the assay with nucleic acid from each of these species derived from both clinical and environmental isolates and typing strains demonstrated 100% sensitivity and 100% specificity when tested against 43 other Legionella spp. Typing of L. anisa, L. parisiensis, and L. tucsonensis sg 1 and 3 isolates was accomplished by developing a real-time PCR assay followed by high-resolution melt (HRM) analysis targeting the ssrA gene. Further typing of L. bozemanii, L. longbeachae, and L. feeleii isolates to the serogroup level was accomplished by developing a real-time PCR assay followed by HRM analysis targeting the mip gene. When used in conjunction with other currently available diagnostic tests, these assays may aid in rapidly identifying specific etiologies associated with Legionella outbreaks, clusters, sporadic cases, and potential environmental sources.
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Affiliation(s)
- Alvaro J Benitez
- Pneumonia Response and Surveillance Laboratory, Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Jonas M Winchell
- Pneumonia Response and Surveillance Laboratory, Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.
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Whiley H, Giglio S, Bentham R. Opportunistic Pathogens Mycobacterium Avium Complex (MAC) and Legionella spp. Colonise Model Shower. Pathogens 2015; 4:590-8. [PMID: 26213977 PMCID: PMC4584274 DOI: 10.3390/pathogens4030590] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 07/20/2015] [Accepted: 07/23/2015] [Indexed: 01/15/2023] Open
Abstract
Legionella spp. and Mycobacterium avium complex (MAC) are opportunistic pathogens of public health concern. Hot water systems, including showers, have been identified as a potential source of infection. This paper describes the colonization of Legionella and MAC on the flexible tubing within a model potable shower system, utilizing thermostatic mixing and a flexible shower head. A MAC qPCR method of enumeration was also developed. MAC and Legionella spp. were detected within the biofilm at maximum concentrations of 7.0 × 104 and 2.0 × 103 copies/cm2 PVC tubing respectively. No significant changes were observed between sample of the flexible shower tubing that dried between uses and those that remained filled with water. This suggested the "unhooking" showerheads and allowing them to dry is not an effective method to reduce the risk of Legionella or MAC colonisation.
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Affiliation(s)
- Harriet Whiley
- School of the Environment, Health and the Environment, Flinders University, GPO BOX 2100, Adelaide 5001, Australia.
| | - Steven Giglio
- Healthscope Pathology SA, 1 Goodwood Rd, Wayville 5034, South Australia.
| | - Richard Bentham
- School of the Environment, Health and the Environment, Flinders University, GPO BOX 2100, Adelaide 5001, Australia.
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Mirzaee SA, Nikaeen M, Hajizadeh Y, Nabavi BF, Hassanzadeh A. Detection of Legionella spp. by a nested-PCR assay in air samples of a wastewater treatment plant and downwind distances in Isfahan. Adv Biomed Res 2015; 4:48. [PMID: 25802817 PMCID: PMC4361962 DOI: 10.4103/2277-9175.151540] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 05/31/2014] [Indexed: 11/28/2022] Open
Abstract
Background: Wastewater contains a variety of pathogens and bio -aerosols generated during the wastewater treatment process, which could be a potential health risk for exposed individuals. This study was carried out to detect Legionella spp. in the bio -aerosols generated from different processes of a wastewater treatment plant (WWTP) in Isfahan, Iran, and the downwind distances. Materials and Methods: A total of 54 air samples were collected and analyzed for the presence of Legionella spp. by a nested- polymerase chain reaction (PCR) assay. A liquid impingement biosampler was used to capture bio -aerosols. The weather conditions were also recorded. Results: Legionella were detected in 6% of the samples, including air samples above the aeration tank (1/9), belt filter press (1/9), and 250 m downwind (1/9). Conclusion: The result of this study revealed the presence of Legionella spp. in air samples of a WWTP and downwind distance, which consequently represent a potential health risk to the exposed individuals.
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Affiliation(s)
- Seyyed Abbas Mirzaee
- Department of Environmental Health Engineering and Environment Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mahnaz Nikaeen
- Department of Environmental Health Engineering and Environment Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Yaghob Hajizadeh
- Department of Environmental Health Engineering and Environment Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - BiBi Fatemeh Nabavi
- Department of Environmental Health Engineering and Environment Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Akbar Hassanzadeh
- Department of Statistics and Epidemiology, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
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Kao PM, Hsu BM, Hsu TK, Ji WT, Huang PH, Hsueh CJ, Chiang CS, Huang SW, Huang YL. Application of TaqMan fluorescent probe-based quantitative real-time PCR assay for the environmental survey of Legionella spp. and Legionella pneumophila in drinking water reservoirs in Taiwan. Sci Total Environ 2014; 490:416-421. [PMID: 24867705 DOI: 10.1016/j.scitotenv.2014.04.103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 04/24/2014] [Accepted: 04/25/2014] [Indexed: 06/03/2023]
Abstract
In this study, TaqMan fluorescent quantitative real-time PCR was performed to quantify Legionella species in reservoirs. Water samples were collected from 19 main reservoirs in Taiwan, and 12 (63.2%) were found to contain Legionella spp. The identified species included uncultured Legionella spp., L. pneumophila, L. jordanis, and L. drancourtii. The concentrations of Legionella spp. and L. pneumophila in the water samples were in the range of 1.8×10(2)-2.6×10(3) and 1.6×10(2)-2.4×10(2) cells/L, respectively. The presence and absence of Legionella spp. in the reservoir differed significantly in pH values. These results highlight the importance that L. pneumophila, L. jordanis, and L. drancourtii are potential pathogens in the reservoirs. The presence of L. pneumophila in reservoirs may be a potential public health concern that must be further examined.
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Affiliation(s)
- Po-Min Kao
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, ROC
| | - Bing-Mu Hsu
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, ROC.
| | - Tsui-Kang Hsu
- Department of Ophthalmology, Cheng Hsin General Hospital, Taipei, Taiwan, ROC
| | - Wen-Tsai Ji
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, ROC
| | - Po-Hsiang Huang
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, ROC
| | - Chih-Jen Hsueh
- Department of Otorhinolaryngology, Cheng Hsin General Hospital, Taipei, Taiwan, ROC
| | - Chuen-Sheue Chiang
- Research and Diagnostic Center, Centers for Disease Control, Taiwan, ROC
| | - Shih-Wei Huang
- Center for General Education, Cheng-Shiu University, Kaohsiung, Taiwan, ROC
| | - Yu-Li Huang
- Department of Safety Health and Environmental Engineering, National Kaohsiung First University of Science and Technology, Kaohsiung, Taiwan, ROC
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Abstract
Legionella spp. are the causative agent of Legionnaire's disease and an opportunistic pathogen of significant public health concern. Identification and quantification from environmental sources is crucial for identifying outbreak origins and providing sufficient information for risk assessment and disease prevention. Currently there are a range of methods for Legionella spp. quantification from environmental sources, but the two most widely used and accepted are culture and real-time polymerase chain reaction (qPCR). This paper provides a review of these two methods and outlines their advantages and limitations. Studies from the last 10 years which have concurrently used culture and qPCR to quantify Legionella spp. from environmental sources have been compiled. 26/28 studies detected Legionella at a higher rate using qPCR compared to culture, whilst only one study detected equivalent levels of Legionella spp. using both qPCR and culture. Aggregating the environmental samples from all 28 studies, 2856/3967 (72%) tested positive for the presence of Legionella spp. using qPCR and 1331/3967 (34%) using culture. The lack of correlation between methods highlights the need to develop an acceptable standardized method for quantification that is sufficient for risk assessment and management of this human pathogen.
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Affiliation(s)
- Harriet Whiley
- a Department of Health and the Environment , Flinders University , Adelaide , Australia
| | - Michael Taylor
- a Department of Health and the Environment , Flinders University , Adelaide , Australia
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Ghotaslou R, Yeganeh Sefidan F, Akhi MT, Soroush MH, Hejazi MS. Detection of legionella contamination in tabriz hospitals by PCR assay. Adv Pharm Bull 2013; 3:131-4. [PMID: 24312825 DOI: 10.5681/apb.2013.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 11/07/2012] [Accepted: 11/07/2012] [Indexed: 11/17/2022] Open
Abstract
PURPOSE The present study was designed to evaluate the occurrence of Legionella contamination in the tap water of Tabriz hospitals, Azerbaijan, Iran. METHODS One hundred and forty water samples from diverse water supply systems of 17 hospitals were collected and analyzed for the presence of Legionella spp. by PCR assay. RESULTS In this study, 10 of 140 (7.1%) samples were positive for Legionella which L. pneumophila was detected in 4 (2.85%) water samples. CONCLUSION In conclusion, hospital potable systems are the primary reservoirs for Legionnaires' disease. This study concludes that Legionella spp. are present in aquatic hospitals environment of Tabriz. Due to the serious risk of infections, it is better to make efforts to eliminate Legionella spp. in water supplies.
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Affiliation(s)
- Reza Ghotaslou
- Tropical and Infectious Diseases Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran. ; Department of Microbiology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
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Bristela M, Skolka A, Schmid-Schwap M, Piehslinger E, Indra A, Wewalka G, Stauffer F. Testing for aerobic heterotrophic bacteria allows no prediction of contamination with potentially pathogenic bacteria in the output water of dental chair units. GMS Krankenhhyg Interdiszip 2012; 7:Doc12. [PMID: 22558046 PMCID: PMC3334951 DOI: 10.3205/dgkh000196] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Background: Currently, to our knowledge, quality of output water of dental chair units is not covered by specific regulations in the European Union, and national recommendations are heterogeneous. In Germany, water used in dental chair units must follow drinking water quality. In the United States of America, testing for aerobic heterotrophic bacteria is recommended. The present study was performed to evaluate whether the counts of aerobic heterotrophic bacteria correlate with the presence of potentially pathogenic bacteria such as Legionella spp. or Pseudomonas aeruginosa. Methods: 71 samples were collected from 26 dental chair units with integrated disinfection device and 31 samples from 15 outlets of the water distribution pipework within the department were examined. Samples were tested for aerobic heterotrophic bacteria at 35°C and 22°C using different culture media and for Legionella spp. and for Pseudomonas aeruginosa. Additionally, strains of Legionella pneumophila serogroup 1 were typed with monoclonal antibodies and representative samples of Legionella pneumophila serogroup 1 were typed by sequence based typing. Results: Our results showed a correlation between different agars for aerobic heterotrophic bacteria but no correlation for the count of aerobic heterotrophic bacteria and the presence of Legionella spp. or Pseudomonas aeruginosa. Conclusion: Testing for aerobic heterotrophic bacteria in output water or water distribution pipework within the departments alone is without any value for predicting whether the water is contaminated with potentially pathogenic bacteria like Legionella spp. or Pseudomonas aeruginosa.
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Affiliation(s)
- Margit Bristela
- Bernhard Gottlieb University Clinic of Dentistry, Department of Fixed and Removable Prosthodontics, Medical University Vienna, Austria
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