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Zacharias N, Waßer F, Freier L, Spies K, Koch C, Pleischl S, Mutters NT, Kistemann T. Legionella in drinking water: the detection method matters. JOURNAL OF WATER AND HEALTH 2023; 21:884-894. [PMID: 37515560 PMCID: wh_2023_035 DOI: 10.2166/wh.2023.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/31/2023]
Abstract
Legionella concentrations in drinking water have been regulated for decades and are evaluated with regard to their concentrations in drinking water plumbing systems (DWPS). The respective action levels differ at the international level. In Germany, the Federal Environment Agency (UBA) specifies the application of ISO 11731 for the detection of legionella in drinking water and gives a binding recommendation for the methods to be used for culturing and evaluation. Effective from 01 March 2019, the UBA recommendation was revised. The utilized culture media in the culture approach were altered, consequently affecting the spectrum of legionella colonies detected in drinking water. Using data from a routine legionella monitoring of a large laboratory, over a period of 6 years and 17,270 individual drinking water samples, allowed us to assess the impact of the alteration on the assessment of DWPS. By comparing the amount of action level exceedances before and after the method change, it could be demonstrated that exceedances are reported significantly more often under the new method. Consequently, the corresponding action level for evaluation of legionella contamination and the resulting risk to human health needs to be revised to avoid the misleading impression of increased health risk.
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Affiliation(s)
- Nicole Zacharias
- Institute for Hygiene and Public Health, University Hospital Bonn, Venusberg-Campus 1, Bonn 53127, Germany E-mail:
| | - Felix Waßer
- Institute for Hygiene and Public Health, University Hospital Bonn, Venusberg-Campus 1, Bonn 53127, Germany
| | - Lia Freier
- Institute for Hygiene and Public Health, University Hospital Bonn, Venusberg-Campus 1, Bonn 53127, Germany
| | - Kirsten Spies
- Institute for Hygiene and Public Health, University Hospital Bonn, Venusberg-Campus 1, Bonn 53127, Germany
| | - Christoph Koch
- Institute for Hygiene and Public Health, University Hospital Bonn, Venusberg-Campus 1, Bonn 53127, Germany
| | - Stefan Pleischl
- Institute for Hygiene and Public Health, University Hospital Bonn, Venusberg-Campus 1, Bonn 53127, Germany
| | - Nico T Mutters
- Institute for Hygiene and Public Health, University Hospital Bonn, Venusberg-Campus 1, Bonn 53127, Germany
| | - Thomas Kistemann
- Institute for Hygiene and Public Health, University Hospital Bonn, Venusberg-Campus 1, Bonn 53127, Germany; Department of Geography, University of Bonn, Meckenheimer Allee 166, Bonn 53115, Germany; Centre for Development Research, University of Bonn, Genscherallee 3, Bonn 53113, Germany
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Karimiravesh R, Mohabati Mobarez A, Behmanesh M, Nikkhah M, Talebi Bezmin Abadi A, Esmaeilli S. Design of an optical nanobiosensor for detection of Legionella pneumophila in water samples. IRANIAN JOURNAL OF MICROBIOLOGY 2022; 14:802-812. [PMID: 36721447 PMCID: PMC9867621 DOI: 10.18502/ijm.v14i6.11254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Background and Objectives Legionella spp. is a causative agent of Legionnaires' disease that creates public health problems. Isolation of these bacteria from water sources is essential to identify outbreak origins and prevent disease. Diagnostic biosensors for water quality control to protect consumers from water-borne infections can predict many outbreaks. Gold nanoparticles conjugated probes are a new generation of diagnostic tools. In this study, an optical nano biosensor was designed and characterized to detect Legionella pneumophila in water samples rapidly. Materials and Methods Thiolated probes designed for the mip gene were attached to gold nanoparticles and then water samples containing Legionella pneumophila were examined. Results The limit of detection for PCR and biosensor was 104 and 103 copy numbers/μl, respectively. Biosensor sensitivity and PCR were reported to be 90% (18 out of 20) and 85% (17 out of 20), respectively. Specificity 100% has been reported for both methods. Conclusion According to the obtained results, this method has the potential to diagnose L. pneumophila with high sensitivity and specificity. This system can be employed as a practical tool for rapid, accurate, high-sensitivity, and acceptable detection of Legionella pneumophila in contaminated water, which is cost-effective in terms of cost and time.
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Affiliation(s)
- Raheleh Karimiravesh
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Ashraf Mohabati Mobarez
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran,Corresponding author: Ashraf Mohabati Mobarez, Ph.D, Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran. Tel: +98-21-82883862 Fax: +98-21-82884555
| | - Mehrdad Behmanesh
- Department of Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Maryam Nikkhah
- Department of Nanobiotechnology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Amin Talebi Bezmin Abadi
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Saber Esmaeilli
- National Reference Laboratory for Plague, Tularemia and Q fever, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Akanlu, Kabudar Ahang, Hamadan, Iran,Department of Epidemiology and Biostatistics, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Tehran, Iran
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Du J, Ma B, Li J, Wang Y, Dou T, Xu S, Zhang M. Rapid Detection and Differentiation of Legionella pneumophila and Non-Legionella pneumophila Species by Using Recombinase Polymerase Amplification Combined With EuNPs-Based Lateral Flow Immunochromatography. Front Chem 2022; 9:815189. [PMID: 35198541 PMCID: PMC8859533 DOI: 10.3389/fchem.2021.815189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 12/28/2021] [Indexed: 11/13/2022] Open
Abstract
Legionella, a waterborne pathogen, is the main cause of Legionnaires’ disease. Therefore, timely and accurate detection and differentiation of Legionella pneumophila and non-Legionella pneumophila species is crucial. In this study, we develop an easy and rapid recombinase polymerase amplification assay combined with EuNPs-based lateral flow immunochromatography (EuNPs-LFIC-RPA) to specifically distinguish Legionella pneumophila and non-Legionella pneumophila. We designed primers based on the mip gene of Legionella pneumophila and the 5S rRNA gene of non-Legionella pneumophila. The recombinase polymerase amplification reaction could go to completion in 10 min at 37°C, and the amplification products could be detected within 5 min with EuNPs-LFIC strips. Using a florescent test strip reader, the quantitative results were achieved by reading the colored signal intensities on the strips. The sensitivity was 1.6 × 101 CFU/ml, and a linear standard linear curve plotted from the test strip reader had a correlation coefficient for the determination of Legionella pneumophila (R2 = 0.9516). Completed concordance for the presence or absence of Legionella pneumophila by EuNPs-LFIC-RPA and qPCR was 97.32% (κ = 0.79, 95% CI), according to an analysis of practical water samples (n = 112). In short, this work shows the feasibility of EuNPs-LFIC-RPA for efficient and rapid monitoring of Legionella pneumophila and non-Legionella pneumophila in water samples.
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Sevillano M, Vosloo S, Cotto I, Dai Z, Jiang T, Santiago Santana JM, Padilla IY, Rosario-Pabon Z, Velez Vega C, Cordero JF, Alshawabkeh A, Gu A, Pinto AJ. Spatial-temporal targeted and non-targeted surveys to assess microbiological composition of drinking water in Puerto Rico following Hurricane Maria. WATER RESEARCH X 2021; 13:100123. [PMID: 34704006 PMCID: PMC8524244 DOI: 10.1016/j.wroa.2021.100123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 09/28/2021] [Accepted: 09/30/2021] [Indexed: 05/05/2023]
Abstract
Loss of basic utilities, such as drinking water and electricity distribution, were sustained for months in the aftermath of Hurricane Maria's (HM) landfall in Puerto Rico (PR) in September 2017. The goal of this study was to assess if there was deterioration in biological quality of drinking water due to these disruptions. This study characterized the microbial composition of drinking water following HM across nine drinking water systems (DWSs) in PR and utilized an extended temporal sampling campaign to determine if changes in the drinking water microbiome were indicative of HM associated disturbance followed by recovery. In addition to monitoring water chemistry, the samples were subjected to culture independent targeted and non-targeted microbial analysis including quantitative PCR (qPCR) and genome-resolved metagenomics. The qPCR results showed that residual disinfectant was the major driver of bacterial concentrations in tap water with marked decrease in concentrations from early to late sampling timepoints. While Mycobacterium avium and Pseudomonas aeruginosa were not detected in any sampling locations and timepoints, genetic material from Leptospira and Legionella pneumophila were transiently detected in a few sampling locations. The majority of metagenome assembled genomes (MAGs) recovered from these samples were not associated with pathogens and were consistent with bacterial community members routinely detected in DWSs. Further, whole metagenome-level comparisons between drinking water samples collected in this study with samples from other full-scale DWS indicated no significant deviation from expected community membership of the drinking water microbiome. Overall, our results suggest that disruptions due to HM did not result in significant and sustained deterioration of biological quality of drinking water at our study sites.
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Affiliation(s)
- Maria Sevillano
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, United States of America
| | - Solize Vosloo
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Irmarie Cotto
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, United States of America
| | - Zihan Dai
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Tao Jiang
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, United States of America
| | - Jose M. Santiago Santana
- Department of Natural Sciences, University of Puerto Rico, Carolina, PR, United States of America
| | - Ingrid Y. Padilla
- Department of Civil Engineering and Surveying, University of Puerto Rico, Mayagüez, PR, United States of America
| | - Zaira Rosario-Pabon
- University of Puerto Rico—Medical Sciences Campus, San Juan, PR, United States of America
| | - Carmen Velez Vega
- University of Puerto Rico—Medical Sciences Campus, San Juan, PR, United States of America
| | - José F. Cordero
- Department of Epidemiology and Biostatistics, University of Georgia, Athens, Georgia, United States of America
| | - Akram Alshawabkeh
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, United States of America
| | - April Gu
- School of Civil and Environmental Engineering, Cornell University, Ithaca, NY, United States of America
| | - Ameet J. Pinto
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, United States of America
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5
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Donohue MJ. Quantification of Legionella pneumophila by qPCR and culture in tap water with different concentrations of residual disinfectants and heterotrophic bacteria. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 774:145142. [PMID: 33610980 PMCID: PMC8358786 DOI: 10.1016/j.scitotenv.2021.145142] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 01/07/2021] [Accepted: 01/08/2021] [Indexed: 05/21/2023]
Abstract
Legionellosis prevalence is increasing in the United States. This disease is caused primarily by the bacterium Legionella pneumophila found in water and transmitted by aerosol inhalation. This pathogen has a slow growth rate and can "hide" in amoeba, making it difficult to monitor by the traditional culture method on selective media. Tap water samples (n = 358) collected across the United States were tested for L. pneumophila by both culture and quantitative Polymerase Chain Reaction (qPCR). The presence of other bacteria was quantified by heterotrophic plate counts (HPC). Residual disinfectant concentrations (free chlorine or monochloramine) were measured in all samples. Legionella pneumophila had the highest prevalence and concentration in the chlorinated water samples that had a free‑chlorine value of less than 0.2 mg Cl2/L. In total, 24% (87/358) of the samples were positive for L. pneumophila either by qPCR or 3% (11/358) were positive by culture. In chloramine-treated samples, L. pneumophila was detected by qPCR in 21% (31/148) and 1% (2/148) by culture, despite a high monochloramine residual >1 mg Cl2/L. Despite the presence of a high disinfectant residual (>1 mg Cl2/L), HPC counts were substantial. This study indicates that both culture and qPCR methods have limitations when predicting a potential risk for disease associated with L. pneumophila in tap water. Measuring disinfectant residuals and quantifying HPC in water samples may be useful adjunct parameters for reducing Legionellosis' risk from public water supplies at high-risk locations.
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Affiliation(s)
- Maura J Donohue
- United States Environmental Protection Agency, Office Research and Development, Center for Environmental Solutions and Emergency Response, Cincinnati, OH 45268, United States of America.
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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] [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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Gomes TS, Vaccaro L, Magnet A, Izquierdo F, Ollero D, Martínez-Fernández C, Mayo L, Moran M, Pozuelo MJ, Fenoy S, Hurtado C, Del Águila C. Presence and interaction of free-living amoebae and amoeba-resisting bacteria in water from drinking water treatment plants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 719:137080. [PMID: 32114219 DOI: 10.1016/j.scitotenv.2020.137080] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 12/19/2019] [Accepted: 01/31/2020] [Indexed: 06/10/2023]
Abstract
Free-living amoebae (FLA) are ubiquitous and many isolates have been shown to be infected with amoeba-resisting bacteria, as the example of Acanthamoeba and Legionella interaction. Due to the high environmental prevalence of Acanthamoeba. in the Castilian Plateau (Spain), the aims of this work were to investigate the occurrence of Acanthamoeba and other FLA in water from several sampling points from four Drinking Water Treatment Plants (DWTP) and to investigate the presence of Legionella spp. and other amoeba-resisting bacteria in biofilms in raw and finished water, taking into account that no legislation exists for this protozoa control. Acanthamoeba was detected at different sampling points, and sand filters seemed to contribute to amoebic enrichment. After ozonation, a temporary decrease in viable amoebae was observed. The genotypes detected were T3, T4, and T5, revealing the first report of genotype T5 in waters from this region. Moreover, Balamuthia mandrillaris, Vermamoeba vermiformis and Paravahlkampfia sp. were detected. Regarding Legionella, PCR detection in raw and finished water was higher than by agar culture, but even higher after Acanthamoeba co-culture. Also, Legionella's presence was higher in raw water than in finished water. The decrease of free Legionella observed from raw (27.5%, by PCR) to finished water (3.4% by PCR) contrasted with the increase of Legionella-infected FLA from raw (30.7%) to finished water (52%). At biofilm, free Legionella was not detected, and the percentage of infected FLA was low (3.8%). Legionella species identified in these samples were L. drozanskii, L. donaldsonii and L. feeleii. Additionally, Acanthamoeba co-culture led to the isolation of Pseudomonas aeruginosa, P. stutzeri, P. fluorecens, Achromobacter xylosoxidans and Stenotrophomonas maltophilia. The highly disseminated presence of Acanthamoeba and the detection of amoeba-resisting bacteria inside amoebae highlight the importance of developing methods for controlling FLA in order to limit human pathogenic amoeba-resisting bacteria survival to the water purification processes.
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Affiliation(s)
- Thiago Santos Gomes
- University San Pablo CEU, Faculty of Pharmacy, Urbanización Monteprincipe s/n, 28925 Alcorcón, Madrid, Spain; CAPES Foundation, Ministry of Education of Brazil, Brasília, DF 70040-020, Brazil
| | - Lucianna Vaccaro
- University San Pablo CEU, Faculty of Pharmacy, Urbanización Monteprincipe s/n, 28925 Alcorcón, Madrid, Spain
| | - Angela Magnet
- University San Pablo CEU, Faculty of Pharmacy, Urbanización Monteprincipe s/n, 28925 Alcorcón, Madrid, Spain
| | - Fernando Izquierdo
- University San Pablo CEU, Faculty of Pharmacy, Urbanización Monteprincipe s/n, 28925 Alcorcón, Madrid, Spain
| | - Dolores Ollero
- University San Pablo CEU, Faculty of Pharmacy, Urbanización Monteprincipe s/n, 28925 Alcorcón, Madrid, Spain
| | - Carmen Martínez-Fernández
- University San Pablo CEU, Faculty of Pharmacy, Urbanización Monteprincipe s/n, 28925 Alcorcón, Madrid, Spain
| | - Laura Mayo
- University San Pablo CEU, Faculty of Pharmacy, Urbanización Monteprincipe s/n, 28925 Alcorcón, Madrid, Spain
| | - María Moran
- University San Pablo CEU, Faculty of Pharmacy, Urbanización Monteprincipe s/n, 28925 Alcorcón, Madrid, Spain
| | - María José Pozuelo
- University San Pablo CEU, Faculty of Pharmacy, Urbanización Monteprincipe s/n, 28925 Alcorcón, Madrid, Spain
| | - Soledad Fenoy
- University San Pablo CEU, Faculty of Pharmacy, Urbanización Monteprincipe s/n, 28925 Alcorcón, Madrid, Spain
| | - Carolina Hurtado
- University San Pablo CEU, Faculty of Pharmacy, Urbanización Monteprincipe s/n, 28925 Alcorcón, Madrid, Spain
| | - Carmen Del Águila
- University San Pablo CEU, Faculty of Pharmacy, Urbanización Monteprincipe s/n, 28925 Alcorcón, Madrid, Spain.
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Bayle S, Martinez-Arribas B, Jarraud S, Giannoni P, Garrelly L, Roig B, Cadière A. Development of a DGGE method to explore Legionella communities. Heliyon 2020; 6:e03149. [PMID: 31922052 PMCID: PMC6948247 DOI: 10.1016/j.heliyon.2019.e03149] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 03/18/2019] [Accepted: 12/30/2019] [Indexed: 11/26/2022] Open
Abstract
Legionella risk assessment is nowadays based on the presence and concentration of either Legionella pneumophila or Legionella spp. Many species of Legionella can cause Legionnaires' disease, indeed about half of the known species have been associated with infection. The aim of this work was to develop a method to assess the composition of the Legionella species community in an environmental sample in order to have a better understanding of the contamination of the ecosystem by pathogenic strains. The method is based on the comparison of PCR-DGGE profile of DNA sample with a database consisting in DGGE profiles of Legionella species. Such a database includes all pathogenic Legionella strains. In order to homogenize and normalize the different DGGE fingerprint, a reference marker has been built and added during DGGE gel analysis. This study gives a valuable advance in the methods available for the understanding of Legionella contamination of water environments.
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Affiliation(s)
- S Bayle
- Laboratoire Génie de l'Environnement Industriel, IMT- Mines Alès, Université de Montpellier, Alès, 30100, France
| | - B Martinez-Arribas
- EA7352 CHROME, Rue du Dr G. Salan, University of Nîmes, 30021 Nîmes cedex 1, France
| | - S Jarraud
- Hospices Civils de Lyon, Groupement Hospitalier Nord, Institut des Agents Infectieux, France
| | - P Giannoni
- EA7352 CHROME, Rue du Dr G. Salan, University of Nîmes, 30021 Nîmes cedex 1, France
| | - L Garrelly
- GL Biocontrol, 9, avenue de l'Europe, Cap Alpha, 34830, Clapiers, France
| | - B Roig
- EA7352 CHROME, Rue du Dr G. Salan, University of Nîmes, 30021 Nîmes cedex 1, France
| | - A Cadière
- EA7352 CHROME, Rue du Dr G. Salan, University of Nîmes, 30021 Nîmes cedex 1, France
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Martynenko IV, Kusić D, Weigert F, Stafford S, Donnelly FC, Evstigneev R, Gromova Y, Baranov AV, Rühle B, Kunte HJ, Gun’ko YK, Resch-Genger U. Magneto-Fluorescent Microbeads for Bacteria Detection Constructed from Superparamagnetic Fe3O4 Nanoparticles and AIS/ZnS Quantum Dots. Anal Chem 2019; 91:12661-12669. [DOI: 10.1021/acs.analchem.9b01812] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Irina V. Martynenko
- Federal Institute for Materials Research and Testing (BAM), Division Biophotonics, Richard-Willstaetter Strasse 11, D-12489 Berlin, Germany
| | - Dragana Kusić
- Federal Institute for Materials Research and Testing (BAM), Division Biophotonics, Richard-Willstaetter Strasse 11, D-12489 Berlin, Germany
- Federal Institute for Materials Research and Testing (BAM), Division Biodeterioration and Reference Organisms, Unter den Eichen 87, D-12205 Berlin, Germany
| | - Florian Weigert
- Federal Institute for Materials Research and Testing (BAM), Division Biophotonics, Richard-Willstaetter Strasse 11, D-12489 Berlin, Germany
| | | | | | - Roman Evstigneev
- ITMO University, 49 Kronverksky Prospekt, St. Petersburg 197101, Russia
| | - Yulia Gromova
- School of Chemistry, Trinity College Dublin, Dublin 2, Ireland
| | | | - Bastian Rühle
- Federal Institute for Materials Research and Testing (BAM), Division Biophotonics, Richard-Willstaetter Strasse 11, D-12489 Berlin, Germany
| | - Hans-Jörg Kunte
- Federal Institute for Materials Research and Testing (BAM), Division Biodeterioration and Reference Organisms, Unter den Eichen 87, D-12205 Berlin, Germany
| | - Yurii K. Gun’ko
- School of Chemistry, Trinity College Dublin, Dublin 2, Ireland
- ITMO University, 49 Kronverksky Prospekt, St. Petersburg 197101, Russia
| | - Ute Resch-Genger
- Federal Institute for Materials Research and Testing (BAM), Division Biophotonics, Richard-Willstaetter Strasse 11, D-12489 Berlin, Germany
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Caicedo C, Rosenwinkel KH, Exner M, Verstraete W, Suchenwirth R, Hartemann P, Nogueira R. Legionella occurrence in municipal and industrial wastewater treatment plants and risks of reclaimed wastewater reuse: Review. WATER RESEARCH 2019; 149:21-34. [PMID: 30445393 DOI: 10.1016/j.watres.2018.10.080] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/26/2018] [Accepted: 10/27/2018] [Indexed: 05/22/2023]
Abstract
Wastewater treatment plants (WWTPs) have been identified as confirmed but until today underestimated sources of Legionella, playing an important role in local and community cases and outbreaks of Legionnaires' disease. In general, aerobic biological systems provide an optimum environment for the growth of Legionella due to high organic nitrogen and oxygen concentrations, ideal temperatures and the presence of protozoa. However, few studies have investigated the occurrence of Legionella in WWTPs, and many questions in regards to the interacting factors that promote the proliferation and persistence of Legionella in these treatment systems are still unanswered. This critical review summarizes the current knowledge about Legionella in municipal and industrial WWTPs, the conditions that might support their growth, as well as control strategies that have been applied. Furthermore, an overview of current quantification methods, guidelines and health risks associated with Legionella in reclaimed wastewater is also discussed in depth. A better understanding of the conditions promoting the occurrence of Legionella in WWTPs will contribute to the development of improved wastewater treatment technologies and/or innovative mitigation approaches to minimize future Legionella outbreaks.
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Affiliation(s)
- C Caicedo
- Leibniz University Hannover, Institute for Sanitary Engineering and Waste Management, Hannover, 30167, Germany.
| | - K-H Rosenwinkel
- Leibniz University Hannover, Institute for Sanitary Engineering and Waste Management, Hannover, 30167, Germany
| | - M Exner
- University of Bonn, Institute for Hygiene and Public Health, Bonn, Germany
| | - W Verstraete
- Ghent University, CMET, Ghent, and Avecom, Wondelgem, Belgium
| | - R Suchenwirth
- Public Health Office of Lower Saxony, Hannover, Germany
| | - P Hartemann
- Faculty of Medicine, Department of Environment and Public Health, Nancy University-CHU Nancy, Vandoeuvre Les Nancy, France
| | - R Nogueira
- Leibniz University Hannover, Institute for Sanitary Engineering and Waste Management, Hannover, 30167, Germany.
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Schrammel B, Petzold M, Cervero-Aragó S, Sommer R, Lück C, Kirschner A. Persistent presence of outer membrane epitopes during short- and long-term starvation of five Legionella pneumophila strains. BMC Microbiol 2018; 18:75. [PMID: 30016940 PMCID: PMC6050704 DOI: 10.1186/s12866-018-1220-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 06/29/2018] [Indexed: 11/25/2022] Open
Abstract
Background Legionella pneumophila, the causative agent of Legionnaire’s disease, may enter a viable but non-culturable (VBNC) state triggered by environmental stress conditions. Specific outer-membrane epitopes of L. pneumophila are used in many diagnostic applications and some of them are linked to important virulence-related factors or endotoxins. However, it is not clear how the presence and status of these epitopes are influenced by environmental stress conditions. In this study, changes of outer membrane epitopes for monoclonal antibodies (mAb) from the Dresden panel and the major outer membrane protein MOMP were analysed for five L. pneumophila strains during short- and long-term starvation in ultrapure water. Results With ELISA and single cell immuno-fluorescence analysis, we could show that for most of the investigated mAb-strain combinations the total number of mAb-stained Legionella cells stayed constant for up to 400 days. Especially the epitopes of mAb 3/1, 8/5, 26/1 and 20/1, which are specific for L. pneumophila serogroup 1 subtypes, and the mAb 9/1, specific for serogroup 6, showed long-term persistence. For most mAb- stained cells, a high percentage of viable cells was observed at least until 118 days of starvation. At the same time, we observed a reduction of the fluorescence intensity of the stained cells during starvation indicating a loss of epitopes from the cell surface. However, most of the epitopes, including the virulence-associated mAb 3/1 epitope were still present with high fluorescence intensity after 400 days of starvation in up to 50% of the starved L. pneumophila population. Conclusions The results demonstrate the continuous presence of outer membrane epitopes of L. pneumophila during short-term and long-term starvation. Thus, culture-independent mAb-based diagnostic and detection tools, such as immuno-magnetic separation and microarray techniques are applicable for both L. pneumophila in the culturable and the VBNC state even after long-term starvation but nevertheless require careful testing before application. However, the mere presence of those epitopes is not necessarily an indication of viability or infectivity. Electronic supplementary material The online version of this article (10.1186/s12866-018-1220-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Barbara Schrammel
- Institute for Hygiene and Applied Immunology - Water Hygiene, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Kinderspitalgasse 15, A-1090, Vienna, Austria
| | - Markus Petzold
- Institute for Medical Microbiology and Hygiene, Medical Faculty "Carl Gustav Carus", University of Technology Dresden, Dresden, Germany
| | - Sílvia Cervero-Aragó
- Institute for Hygiene and Applied Immunology - Water Hygiene, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Kinderspitalgasse 15, A-1090, Vienna, Austria.,Interuniversity Cooperation Centre for Water and Health, Vienna, Austria
| | - Regina Sommer
- Institute for Hygiene and Applied Immunology - Water Hygiene, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Kinderspitalgasse 15, A-1090, Vienna, Austria.,Interuniversity Cooperation Centre for Water and Health, Vienna, Austria
| | - Christian Lück
- Institute for Medical Microbiology and Hygiene, Medical Faculty "Carl Gustav Carus", University of Technology Dresden, Dresden, Germany
| | - Alexander Kirschner
- Institute for Hygiene and Applied Immunology - Water Hygiene, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Kinderspitalgasse 15, A-1090, Vienna, Austria. .,Interuniversity Cooperation Centre for Water and Health, Vienna, Austria.
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12
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New system for the detection of Legionella pneumophila in water samples. Talanta 2018; 189:324-331. [PMID: 30086926 DOI: 10.1016/j.talanta.2018.07.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 07/04/2018] [Accepted: 07/06/2018] [Indexed: 11/21/2022]
Abstract
Waterborne pathogens are a global concern for public health worldwide. Despite continuing efforts to maintain water safety, water quality is still affected by deterioration and pollution. Legionella pneumophila colonizes man-made water systems and can infect humans causing Legionnaire's disease (LD), pneumonia. The prevention of LD is a public health issue and requires specific systems to control and detect these microorganisms. Culture plate is the only technique currently approved, but requires more than 10 days to obtain results. A rapid test that inform in hours about the presence of Legionella pneumophila in water samples will improve the control of this pathogen colonization. In order to control colonization by L. pneumophila we developed a membrane filter method to capture and immunodetect this microorganism in water samples. This membrane filter is used to retain the bacteria using a nitrocellulose disc inside a home-made cartridge. Subsequently we perform the immunodetection of the bacteria retained in the nitrocellulose (blocking, antibody incubation, washings and developing). On comparing our test with the gold-standard, the most important finding is the considerably reduction in time maintaining the same detection limit. This rapid test is easily automated for L. pneumophila detection allowing a comprehensive surveillance of L. pneumophila in water facilities and reducing the variability in the analyses due to the low need for manipulation. Moreover, corrective measures may be applied the same day of the analysis. This method considerably reduces the detection time compared with the conventional, gold-standard detection culture method that requires more than 10 days, being decisive to prevent outbreaks.
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13
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Borthong J, Omori R, Sugimoto C, Suthienkul O, Nakao R, Ito K. Comparison of Database Search Methods for the Detection of Legionella pneumophila in Water Samples Using Metagenomic Analysis. Front Microbiol 2018; 9:1272. [PMID: 29971047 PMCID: PMC6018159 DOI: 10.3389/fmicb.2018.01272] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Accepted: 05/24/2018] [Indexed: 12/12/2022] Open
Abstract
Metagenomic analysis has become a powerful tool to analyze bacterial communities in environmental samples. However, the detection of a specific bacterial species using metagenomic analysis remains difficult due to false positive detections of sequences shared between different bacterial species. In this study, 16S rRNA amplicon and shotgun metagenomic analyses were conducted on samples collected along a stream and ponds in the campus of Hokkaido University. We compared different database search methods for bacterial detection by focusing on Legionella pneumophila. In this study, we used L. pneumophila-specific nested PCR as a gold standard to evaluate the results of the metagenomic analysis. Comparison with the results from L. pneumophila-specific nested PCR indicated that a blastn search of shotgun reads against the NCBI-NT database led to false positive results and had problems with specificity. We also found that a blastn search of shotgun reads against a database of the catalase-peroxidase (katB) gene detected L. pneumophila with the highest area under the receiver operating characteristic curve among the tested search methods; indicating that a blastn search against the katB gene database had better diagnostic ability than searches against other databases. Our results suggest that sequence searches targeting long genes specifically associated with the bacterial species of interest is a prerequisite to detecting the bacterial species in environmental samples using metagenomic analyses.
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Affiliation(s)
- Jednipit Borthong
- Division of Bioinformatics, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Ryosuke Omori
- Division of Bioinformatics, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan.,Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan
| | - Chihiro Sugimoto
- Division of Collaboration and Education, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan.,Global Institute for Collaborative Research and Education, Hokkaido University, Sapporo, Japan
| | - Orasa Suthienkul
- Faculty of Public Health, Thammasat University, Rangsit Campus, Pathumthani, Thailand
| | - Ryo Nakao
- Laboratory of Parasitology, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Kimihito Ito
- Division of Bioinformatics, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan.,Global Institute for Collaborative Research and Education, Hokkaido University, Sapporo, Japan.,Faculty of Public Health, Thammasat University, Rangsit Campus, Pathumthani, Thailand
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14
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Properties of bacterial communities attached to artificial substrates in a hypereutrophic urban river. AMB Express 2018; 8:22. [PMID: 29453676 PMCID: PMC5815975 DOI: 10.1186/s13568-018-0545-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 01/27/2018] [Indexed: 11/10/2022] Open
Abstract
Bacterial communities of biofilms growing on artificial substrates were examined at two time periods (7 and 14 days) and two locations (lentic and lotic areas) in a hypereutrophic urban river of eastern China. Previous studies in this river network indicated that variations of microbial communities were the major factor affecting the distribution of antibiotic resistant genes highlighting the importance of understanding controls of microbial communities. Bacterial communities associated with biofilms were determined using epifluorescence microscopy and high-throughput sequencing. Results showed that sampling time and site had significant effects on the abundances of surface-associated bacteria. No significant differences were found in the number of surface-associated bacteria between two substrate types (filament vs. slide). Sequencing revealed microbial communities attached to artificial substrates in a hypereutrophic urban river were composed of 80,375 OTUs, and distributed in 47 phyla. Proteobacteria and Cyanobacteria/Chloroplast were the two dominant phyla, followed by Planctomycetes, Actinobacteria, Verrucomicrobia, Firmicutes and Bacteroidetes. Taxonomic composition showed ammonia-oxidizing microorganisms, fecal indicator bacteria and pathogens enriched in attached microbial communities, especially the ammonia-oxidizing Nitrosomonas bacteria. These results indicated that there were significant temporal and intra-river heterogeneity of attached microbial community structure, but no significant difference in community composition was detected between the two substrate types.
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15
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Antibody test for Legionella pneumophila detection. Diagn Microbiol Infect Dis 2018; 90:85-89. [DOI: 10.1016/j.diagmicrobio.2017.11.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 11/03/2017] [Accepted: 11/04/2017] [Indexed: 11/21/2022]
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16
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Peter A, Thompson KC, Routledge EJ. Barriers to effectiveLegionellacontrol in a changing world: a practitioner’s view. ACTA ACUST UNITED AC 2017. [DOI: 10.1080/21622515.2017.1335352] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Aji Peter
- Institute of Environment, Health and Societies, Brunel University London, Uxbridge, UK
| | | | - Edwin John Routledge
- Institute of Environment, Health and Societies, Brunel University London, Uxbridge, UK
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17
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Collins S, Stevenson D, Walker J, Bennett A. Evaluation ofLegionellareal-time PCR against traditional culture for routine and public health testing of water samples. J Appl Microbiol 2017; 122:1692-1703. [DOI: 10.1111/jam.13461] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/25/2017] [Accepted: 03/27/2017] [Indexed: 11/29/2022]
Affiliation(s)
- S. Collins
- Biosafety Air and Water Microbiology Group; Public Health England; Porton Down Salisbury UK
| | - D. Stevenson
- Biosafety Air and Water Microbiology Group; Public Health England; Porton Down Salisbury UK
| | - J. Walker
- Biosafety Air and Water Microbiology Group; Public Health England; Porton Down Salisbury UK
| | - A. Bennett
- Biosafety Air and Water Microbiology Group; Public Health England; Porton Down Salisbury UK
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18
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Zhang L, Li Y, Wang X, Shangguan Z, Zhou H, Wu Y, Wang L, Ren H, Hu Y, Lin M, Qin T. High Prevalence and Genetic Polymorphisms of Legionella in Natural and Man-Made Aquatic Environments in Wenzhou, China. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:ijerph14030222. [PMID: 28245548 PMCID: PMC5369058 DOI: 10.3390/ijerph14030222] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 02/14/2017] [Accepted: 02/16/2017] [Indexed: 12/28/2022]
Abstract
Natural and engineered water systems are the main sources of Legionnaires’ disease. It is essential from a public health perspective to survey water environments for the existence of Legionella. To analyze the main serogroups, genotypes and pathogenicity of the pathogen, a stratified sampling method was adopted to collect water samples randomly from shower water, cooling tower water, and local public hot springs in Wenzhou, China. Suspected strains were isolated from concentrated water samples. Serum agglutination assay and real-time PCR (Polymerase chain reaction) were used to identify L. pneumophila. Sequence-based typing (SBT) and pulsed-field gel electrophoresis (PFGE) were used to elucidate the genetic polymorphisms in the collected isolates. The intracellular growth ability of the isolates was determined through their interaction with J774 cells and plating them onto BCYE (Buffered Charcoal Yeast Extract) agar plates. Overall, 25.56% (46/180) of water samples were Legionella-positive; fifty-two strains were isolated and two kinds of serogroups were co-detected from six water samples from 2015 to 2016. Bacterial concentrations ranged from 20 CFU/100 mL to 10,720 CFU/100 mL. In detail, the Legionella-positive rates of shower water, cooling tower water and hot springs water were 15.45%, 13.33%, and 62.5%, respectively. The main serogroups were LP1 (30.69%) and LP3 (28.85%) and all strains carried the dot gene. Among them, 52 isolates and another 10 former isolates were analyzed by PFGE. Nineteen distinct patterns were observed in 52 strains isolated from 2015 to 2016 with three patterns being observed in 10 strains isolated from 2009 to 2014. Seventy-three strains containing 52 from this study and 21 former isolates were selected for SBT analysis and divided into 25 different sequence types in 4 main clonal groups belonging to 4 homomorphic types. Ten strains were chosen to show their abilities to grow and multiply in J744 cells. Taken together, our results demonstrate a high prevalence and genetic polymorphism of Legionella in Wenzhou’s environmental water system. The investigated environmental water sources pose a potential threat to the public where intervention could help to prevent the occurrence of Legionnaires’ disease.
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Affiliation(s)
- Leyi Zhang
- Wenzhou Center for Disease Control and Prevention, Wenzhou 325000, China.
| | - Yi Li
- Wenzhou Center for Disease Control and Prevention, Wenzhou 325000, China.
| | - Xin Wang
- Qingjiangpu District Center for Disease Control and Prevention, Huai'an 223001, China.
| | - Zhihui Shangguan
- Wenzhou Center for Disease Control and Prevention, Wenzhou 325000, China.
| | - Haijian Zhou
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Centre for Disease Control and Prevention, Beijing 102206, China.
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China.
| | - Yuejin Wu
- Wenzhou Center for Disease Control and Prevention, Wenzhou 325000, China.
| | - Lianghuai Wang
- Wenzhou Center for Disease Control and Prevention, Wenzhou 325000, China.
| | - Hongyu Ren
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Centre for Disease Control and Prevention, Beijing 102206, China.
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China.
| | - Yun Hu
- Wenzhou Center for Disease Control and Prevention, Wenzhou 325000, China.
| | - Meifen Lin
- Wenzhou Center for Disease Control and Prevention, Wenzhou 325000, China.
| | - Tian Qin
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Centre for Disease Control and Prevention, Beijing 102206, China.
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China.
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19
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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. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 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] [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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20
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Kusić D, Rösch P, Popp J. Fast label-free detection of Legionella spp. in biofilms by applying immunomagnetic beads and Raman spectroscopy. Syst Appl Microbiol 2016; 39:132-40. [DOI: 10.1016/j.syapm.2016.01.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 01/18/2016] [Accepted: 01/21/2016] [Indexed: 11/29/2022]
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21
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Combined use of real-time PCR and nested sequence-based typing in survey of human Legionella infection. Epidemiol Infect 2016; 144:2006-10. [PMID: 26790498 DOI: 10.1017/s0950268815003301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Legionnaires' disease (LD) is a globally distributed systemic infectious disease. The burden of LD in many regions is still unclear, especially in Asian countries including China. A survey of Legionella infection using real-time PCR and nested sequence-based typing (SBT) was performed in two hospitals in Shanghai, China. A total of 265 bronchoalveolar lavage fluid (BALF) specimens were collected from hospital A between January 2012 and December 2013, and 359 sputum specimens were collected from hospital B throughout 2012. A total of 71 specimens were positive for Legionella according to real-time PCR focusing on the 5S rRNA gene. Seventy of these specimens were identified as Legionella pneumophila as a result of real-time PCR amplification of the dotA gene. Results of nested SBT revealed high genetic polymorphism in these L. pneumophila and ST1 was the predominant sequence type. These data revealed that the burden of LD in China is much greater than that recognized previously, and real-time PCR may be a suitable monitoring technology for LD in large sample surveys in regions lacking the economic and technical resources to perform other methods, such as urinary antigen tests and culture methods.
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22
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Wu TY, Su YY, Shu WH, Mercado AT, Wang SK, Hsu LY, Tsai YF, Chen CY. A novel sensitive pathogen detection system based on Microbead Quantum Dot System. Biosens Bioelectron 2015; 78:37-44. [PMID: 26590701 DOI: 10.1016/j.bios.2015.11.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 11/04/2015] [Accepted: 11/06/2015] [Indexed: 10/22/2022]
Abstract
A fast and accurate detection system for pathogens can provide immediate measurements for the identification of infectious agents. Therefore, the Microbead Quantum-dots Detection System (MQDS) was developed to identify and measure target DNAs of pathogenic microorganisms and eliminated the need of PCR amplifications. This nanomaterial-based technique can detect different microorganisms by flow cytometry measurements. In MQDS, pathogen specific DNA probes were designed to form a hairpin structure and conjugated on microbeads. In the presence of the complementary target DNA sequence, the probes will compete for binding with the reporter probes but will not interfere with the binding between the probe and internal control DNA. To monitor the binding process by flow cytometry, both the reporter probes and internal control probes were conjugated with Quantum dots that fluoresce at different emission wavelengths using the click reaction. When MQDS was used to detect the pathogens in environmental samples, a high correlation coefficient (R=0.994) for Legionella spp., with a detection limit of 0.1 ng of the extracted DNAs and 10 CFU/test, can be achieved. Thus, this newly developed technique can also be applied to detect other pathogens, particularly viruses and other genetic diseases.
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Affiliation(s)
- Tzong-Yuan Wu
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li 320, Taiwan; Center for Nanotechnology and Center for Biomedical Technology, Chung Yuan Christian University, Chung-Li 320, Taiwan; R&D Center of Membrane Technology, Chung Yuan Christian University, Chung-Li 320, Taiwan
| | - Yi-Yu Su
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li 320, Taiwan
| | - Wei-Hsien Shu
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li 320, Taiwan
| | - Augustus T Mercado
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li 320, Taiwan; Department of Chemistry, Chung Yuan Christian University, Chung-Li 320, Taiwan
| | - Shi-Kwun Wang
- Environmental Analysis Laboratory, Environmental Protection Administration, Chung-Li 320, Taiwan
| | - Ling-Yi Hsu
- Environmental Analysis Laboratory, Environmental Protection Administration, Chung-Li 320, Taiwan
| | - Yow-Fu Tsai
- Department of Chemistry, Chung Yuan Christian University, Chung-Li 320, Taiwan
| | - Chung-Yung Chen
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li 320, Taiwan; Center for Nanotechnology and Center for Biomedical Technology, Chung Yuan Christian University, Chung-Li 320, Taiwan.
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23
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Janczarek M, Palusińska-Szysz M. PCR method for the rapid detection and discrimination of Legionella spp. based on the amplification of pcs, pmtA, and 16S rRNA genes. J Appl Genet 2015; 57:251-61. [PMID: 26423783 DOI: 10.1007/s13353-015-0317-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 08/18/2015] [Accepted: 09/14/2015] [Indexed: 10/23/2022]
Abstract
Legionella bacteria are organisms of public health interest due to their ability to cause pneumonia (Legionnaires' disease) in susceptible humans and their ubiquitous presence in water supply systems. Rapid diagnosis of Legionnaires' disease allows the use of therapy specific for the disease. L. pneumophila serogroup 1 is the most common cause of infection acquired in community and hospital environments. The non-L. pneumophila infections are likely under-detected because of a lack of effective diagnosis. In this work, simplex and duplex PCR assays with the use of new molecular markers pcs and pmtA involved in phosphatidylcholine synthesis were specified for rapid and cost-efficient identification and distinguishing Legionella species. The sets of primers developed were found to be sensitive and specific for reliable detection of Legionella belonging to the eight most clinically relevant species. Among these, four primer sets I, II, VI, and VII used for duplex-PCRs proved to have the highest identification power and reliability in the detection of the bacteria. Application of this PCR-based method should improve detection of Legionella spp. in both clinical and environmental settings and facilitate molecular typing of these organisms.
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Affiliation(s)
- Monika Janczarek
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Maria Curie-Sklodowska University, Akademicka St. 19, 20-033, Lublin, Poland
| | - Marta Palusińska-Szysz
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Maria Curie-Sklodowska University, Akademicka St. 19, 20-033, Lublin, Poland.
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24
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Hsu TK, Wu SF, Hsu BM, Kao PM, Tao CW, Shen SM, Ji WT, Huang WC, Fan CW. Surveillance of parasitic Legionella in surface waters by using immunomagnetic separation and amoebae enrichment. Pathog Glob Health 2015; 109:328-35. [PMID: 26373823 DOI: 10.1179/2047773215y.0000000034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Free-living amoebae (FLA) are potential reservoirs of Legionella in aquatic environments. However, the parasitic relationship between various Legionella and amoebae remains unclear. In this study, surface water samples were gathered from two rivers for evaluating parasitic Legionella. Warmer water temperature is critical to the existence of Legionella. This result suggests that amoebae may be helpful in maintaining Legionella in natural environments because warmer temperatures could enhance parasitisation of Legionella in amoebae. We next used immunomagnetic separation (IMS) to identify extracellular Legionella and remove most free Legionella before detecting the parasitic ones in selectively enriched amoebae. Legionella pneumophila was detected in all the approaches, confirming that the pathogen is a facultative amoebae parasite. By contrast, two obligate amoebae parasites, Legionella-like amoebal pathogens (LLAPs) 8 and 9, were detected only in enriched amoebae. However, several uncultured Legionella were detected only in the extracellular samples. Because the presence of potential hosts, namely Vermamoeba vermiformis, Acanthamoeba spp. and Naegleria gruberi, was confirmed in the samples that contained intracellular Legionella, uncultured Legionella may survive independently of amoebae. Immunomagnetic separation and amoebae enrichment may have referential value for detecting parasitic Legionella in surface waters.
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Affiliation(s)
- Tsui-Kang Hsu
- Department of Ophthalmology, Cheng Hsin General Hospital , Taipei, Taiwan, Republic of China
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25
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Collins S, Jorgensen F, Willis C, Walker J. Real-time PCR to supplement gold-standard culture-based detection of Legionella
in environmental samples. J Appl Microbiol 2015. [DOI: 10.1111/jam.12911] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S. Collins
- Public Health England; Biosafety Investigation Unit; Salisbury UK
- Public Health England; Food, Water and Environmental Microbiology Laboratory; Salisbury UK
| | - F. Jorgensen
- Public Health England; Food, Water and Environmental Microbiology Laboratory; Salisbury UK
| | - C. Willis
- Public Health England; Food, Water and Environmental Microbiology Laboratory; Salisbury UK
| | - J. Walker
- Public Health England; Biosafety Investigation Unit; Salisbury UK
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26
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Improved PCR assay for the species-specific identification and quantitation of Legionella pneumophila in water. Appl Microbiol Biotechnol 2015; 99:9227-36. [PMID: 26142386 DOI: 10.1007/s00253-015-6759-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 06/02/2015] [Accepted: 06/05/2015] [Indexed: 10/23/2022]
Abstract
Legionellosis outbreak is a major global health care problem. However, current Legionella risk assessments may be compromised by uncertainties in Legionella detection methods, infectious dose, and strain infectivity. These limitations may place public health at significant risk, leading to significant monetary losses in health care. However, there are still unmet needs for its rapid identification and monitoring of legionellae in water systems. Therefore, in the present study, a primer set was designed based on a LysR-type transcriptional regulator (LTTR) family protein gene of Legionella pneumophila subsp. pneumophila str. Philadelphia 1 because it was found that this gene is structurally diverse among species through BLAST searches. The specificity of the primer set was evaluated using genomic DNA from 6 strains of L. pneumophila, 5 type strains of other related Legionella species, and other 29 reference pathogenic bacteria. The primer set used in the PCR assay amplified a 264-bp product for only targeted six strains of L. pneumophila. The assay was also able to detect at least 1.39 × 10(3) copies/μl of cloned amplified target DNA using purified DNA or 7.4 × 10(0) colony-forming unit per reaction when using calibrated cell suspension. In addition, the sensitivity and specificity of this assay were confirmed by successful detection of Legionella pneumophila in environmental water samples.
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Kao PM, Hsu BM, Chang TY, Hsu TK, Tzeng KJ, Huang YL. Seasonal variation of Legionella in Taiwan's reservoir and its relationships with environmental factors. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:6104-6111. [PMID: 25391236 DOI: 10.1007/s11356-014-3819-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 11/03/2014] [Indexed: 06/04/2023]
Abstract
In this study, the presence of Legionella in major water reservoirs of Taiwan was examined with respect to seasonal variation, geographical variation, and water quality parameters using TaqMan real-time qPCR. Water samples were collected quarterly at 19 reservoirs in Taiwan between November 2012 and August 2013. The detection rate for Legionella was 35.5% (27/76), and Legionella was detected in all seasons. The Legionella concentration was relatively high in spring and summer, reaching 3.86 × 10(8) and 7.35 × 10(8) cells/L, respectively. By sampling the area, Legionella was detected at a higher proportion in reservoirs in the northern and southern areas, and the difference was consistent in all seasons. Significant association was found between detection of Legionella and various water quality parameters, including conductivity, chlorophyll a, and dissolved oxygen (Mann-Whitney U test, P < 0.05). Results of Spearman rank test showed negative correlation for Legionella detection with pH (P = 0.030, R = -0.497) and dissolved oxygen (P = 0.007, R = -0.596) in fall and positive correlation with Carlson's trophic state index (P = 0.049, R = 0.457) in spring. The identified species included Legionella pneumophila and Legionella drancourtii. The detection of Legionella in reservoirs was indicative of a potential public health risk and should be further evaluated.
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Affiliation(s)
- Po-Min Kao
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, Republic of China
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Antibody-modified iron oxide nanoparticles for efficient magnetic isolation and flow cytometric determination of L. pneumophila. Mikrochim Acta 2015. [DOI: 10.1007/s00604-015-1466-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Sánchez-Busó L, Olmos MP, Camaró ML, Adrián F, Calafat JM, González-Candelas F. Phylogenetic analysis of environmental Legionella pneumophila isolates from an endemic area (Alcoy, Spain). INFECTION GENETICS AND EVOLUTION 2015; 30:45-54. [DOI: 10.1016/j.meegid.2014.12.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 12/02/2014] [Accepted: 12/06/2014] [Indexed: 12/20/2022]
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Mercante JW, Winchell JM. Current and emerging Legionella diagnostics for laboratory and outbreak investigations. Clin Microbiol Rev 2015; 28:95-133. [PMID: 25567224 PMCID: PMC4284297 DOI: 10.1128/cmr.00029-14] [Citation(s) in RCA: 213] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Legionnaires' disease (LD) is an often severe and potentially fatal form of bacterial pneumonia caused by an extensive list of Legionella species. These ubiquitous freshwater and soil inhabitants cause human respiratory disease when amplified in man-made water or cooling systems and their aerosols expose a susceptible population. Treatment of sporadic cases and rapid control of LD outbreaks benefit from swift diagnosis in concert with discriminatory bacterial typing for immediate epidemiological responses. Traditional culture and serology were instrumental in describing disease incidence early in its history; currently, diagnosis of LD relies almost solely on the urinary antigen test, which captures only the dominant species and serogroup, Legionella pneumophila serogroup 1 (Lp1). This has created a diagnostic "blind spot" for LD caused by non-Lp1 strains. This review focuses on historic, current, and emerging technologies that hold promise for increasing LD diagnostic efficiency and detection rates as part of a coherent testing regimen. The importance of cooperation between epidemiologists and laboratorians for a rapid outbreak response is also illustrated in field investigations conducted by the CDC with state and local authorities. Finally, challenges facing health care professionals, building managers, and the public health community in combating LD are highlighted, and potential solutions are discussed.
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Affiliation(s)
- Jeffrey W Mercante
- Pneumonia Response and Surveillance Laboratory, Respiratory Diseases Branch, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Jonas M Winchell
- Pneumonia Response and Surveillance Laboratory, Respiratory Diseases Branch, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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Hsu CY, Hsu BM, Chang TY, Hsu TK, Shen SM, Chiu YC, Wang HJ, Ji WT, Fan CW, Chen JL. Evaluation of immunomagnetic separation for the detection of Salmonella in surface waters by polymerase chain reaction. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2014; 11:9811-21. [PMID: 25243887 PMCID: PMC4199051 DOI: 10.3390/ijerph110909811] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 09/10/2014] [Accepted: 09/12/2014] [Indexed: 11/17/2022]
Abstract
Salmonella spp. is associated with fecal pollution and capable of surviving for long periods in aquatic environments. Instead of the traditional, time-consuming biochemical detection, polymerase chain reaction (PCR) allows rapid identification of Salmonella directly concentrated from water samples. However, prevalence of Salmonella may be underestimated because of the vulnerability of PCR to various environmental chemicals like humic acid, compounded by the fact that various DNA polymerases have different susceptibility to humic acid. Because immunomagnetic separation (IMS) theoretically could isolate Salmonella from other microbes and facilitate removal of aquatic PCR inhibitors of different sizes, this study aims to compare the efficiency of conventional PCR combined with immunomagnetic separation (IMS) for Salmonella detection within a moderately polluted watershed. In our study, the positive rate was increased from 17.6% to 47% with nearly ten-fold improvement in the detection limit. These results suggest the sensitivity of Salmonella detection could be enhanced by IMS, particularly in low quality surface waters. Due to its effects on clearance of aquatic pollutants, IMS may be suitable for most DNA polymerases for Salmonella detection.
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Affiliation(s)
- Chao-Yu Hsu
- Division of Urology, Department of Surgery, Tungs' Taichung MetroHarbor Hospital, Taichung 435, Taiwan.
| | - Bing-Mu Hsu
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi 621, Taiwan.
| | - Tien-Yu Chang
- Department of Radiology, Cheng Hsin General Hospital, Taipei 112, Taiwan.
| | - Tsui-Kang Hsu
- Department of Ophthalmology, Cheng Hsin General Hospital, Taipei 112, Taiwan.
| | - Shu-Min Shen
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi 621, Taiwan.
| | - Yi-Chou Chiu
- General Surgery, Surgical Department, Cheng Hsin General Hospital, Taipei 112, Taiwan.
| | - Hung-Jen Wang
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi 621, Taiwan.
| | - Wen-Tsai Ji
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi 621, Taiwan.
| | - Cheng-Wei Fan
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi 621, Taiwan.
| | - Jyh-Larng Chen
- Department of Environmental Engineering and Health, Yuan-Pei University, Hsinchu 300, Taiwan.
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Ditommaso S, Ricciardi E, Giacomuzzi M, Arauco Rivera SR, Ceccarelli A, Zotti CM. Overestimation of the Legionella spp. load in environmental samples by quantitative real-time PCR: pretreatment with propidium monoazide as a tool for the assessment of an association between Legionella concentration and sanitary risk. Diagn Microbiol Infect Dis 2014; 80:260-6. [PMID: 25284373 DOI: 10.1016/j.diagmicrobio.2014.09.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 09/08/2014] [Accepted: 09/08/2014] [Indexed: 11/29/2022]
Abstract
Quantitative polymerase chain reaction (qPCR) offers rapid, sensitive, and specific detection of Legionella in environmental water samples. In this study, qPCR and qPCR combined with propidium monoazide (PMA-qPCR) were both applied to hot-water system samples and compared to traditional culture techniques. In addition, we evaluated the ability of PMA-qPCR to monitor the efficacy of different disinfection strategies. Comparison between the quantification obtained by culture and by qPCR or PMA-qPCR on environmental water samples confirms that the concentration of Legionella estimated by GU/L is generally higher than that estimated in CFU/L. Our results on 57 hot-water-system samples collected from 3 different sites show that: i) qPCR results were on average 178-fold higher than the culture results (Δ log10=2.25), ii) PMA-qPCR results were on average 27-fold higher than the culture results (Δ log10=1.43), iii) propidium monoazide-induced signal reduction in qPCR were nearly 10-fold (Δ log10=0.95), and that iv) different degrees of correlations between the 3 methods might be explained by different matrix properties, but also by different disinfection methods affecting cultivability of Legionella. In our study, we calculated the logarithmic differences between the results obtained by PMA-qPCR and those obtained by culture, and we suggested an algorithm for the interpretation of PMA-qPCR results for the routine monitoring of healthcare water systems using a commercial qPCR system (iQ-check real-time PCR kit; Bio-Rad, Marnes-la-Coquette, France).
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Affiliation(s)
- Savina Ditommaso
- Department of Public Health and Pediatrics, University of Turin, Italy.
| | - Elisa Ricciardi
- Department of Public Health and Pediatrics, University of Turin, Italy
| | - Monica Giacomuzzi
- Department of Public Health and Pediatrics, University of Turin, Italy
| | | | - Adriano Ceccarelli
- Department of Clinical and Biological Sciences, University of Turin, Italy
| | - Carla M Zotti
- Department of Public Health and Pediatrics, University of Turin, Italy
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Taylor MJ, Bentham RH, Ross KE. Limitations of Using Propidium Monoazide with qPCR to Discriminate between Live and Dead Legionella in Biofilm Samples. Microbiol Insights 2014; 7:15-24. [PMID: 25288885 PMCID: PMC4167484 DOI: 10.4137/mbi.s17723] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 06/30/2014] [Accepted: 07/08/2014] [Indexed: 01/17/2023] Open
Abstract
Accurately quantifying Legionella for regulatory purposes to protect public health is essential. Real-time PCR (qPCR) has been proposed as a better method for detecting and enumerating Legionella in samples than conventional culture method. However, since qPCR amplifies any target DNA in the sample, the technique’s inability to discriminate between live and dead cells means that counts are generally significantly overestimated. Propidium monoazide (PMA) has been used successfully in qPCR to aid live/dead discrimination. We tested PMA use as a method to count only live Legionella cells in samples collected from a modified chemostat that generates environmentally comparable samples. Counts from PMA-treated samples that were pretreated with either heat or three types of disinfectants (to kill the cells) were highly variable, with the only consistent trend being the relationship between biofilm mass and numbers of Legionella cells. Two possibilities explain this result: 1. PMA treatment worked and the subsequent muted response of Legionella to disinfection treatment is a factor of biofilm/microbiological effects; although this does not account for the relationship between the amount of biofilm sampled and the viable Legionella count as determined by PMA-qPCR; or 2. PMA treatment did not work, and any measured decrease or increase in detectable Legionella is because of other factors affecting the method. This is the most likely explanation for our results, suggesting that higher concentrations of PMA might be needed to compensate for the presence of other compounds in an environmental sample or that lower amounts of biofilm need to be sampled. As PMA becomes increasingly toxic at higher concentrations and is very expensive, augmenting the method to include higher PMA concentrations is both counterproductive and cost prohibitive. Conversely, if smaller volumes of biofilm are used, the reproducibility of the method is reduced. Our results suggest that using PMA is not an appropriate method for discriminating between live and dead cells to enumerate Legionella for regulatory purposes.
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Affiliation(s)
- Michael J Taylor
- Health and Environment, School of the Environment, Flinders University, Adelaide, Australia
| | - Richard H Bentham
- Health and Environment, School of the Environment, Flinders University, Adelaide, Australia
| | - Kirstin E Ross
- Health and Environment, School of the Environment, Flinders University, Adelaide, Australia
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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. THE SCIENCE OF THE TOTAL ENVIRONMENT 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] [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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Donohue MJ, O'Connell K, Vesper SJ, Mistry JH, King D, Kostich M, Pfaller S. Widespread molecular detection of Legionella pneumophila Serogroup 1 in cold water taps across the United States. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:3145-3152. [PMID: 24548208 DOI: 10.1021/es4055115] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In the United States, 6,868 cases of legionellosis were reported to the Center for Disease Control and Prevention in 2009-2010. Of these reports, it is estimated that 84% are caused by the microorganism Legionella pneumophila Serogroup (Sg) 1. Legionella spp. have been isolated and recovered from a variety of natural freshwater environments. Human exposure to L. pneumophila Sg1 may occur from aerosolization and subsequent inhalation of household and facility water. In this study, two primer/probe sets (one able to detect L. pneumophila and the other L. pneumophila Sg1) were determined to be highly sensitive and selective for their respective targets. Over 272 water samples, collected in 2009 and 2010 from 68 public and private water taps across the United States, were analyzed using the two qPCR assays to evaluate the incidence of L. pneumophila Sg1. Nearly half of the taps showed the presence of L. pneumophila Sg1 in one sampling event, and 16% of taps were positive in more than one sampling event. This study is the first United States survey to document the occurrence and colonization of L. pneumophila Sg1 in cold water delivered from point of use taps.
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Affiliation(s)
- Maura J Donohue
- Office of Research and Development, National Exposure Research Laboratory, United States Environmental Protection Agency , 26 West Martin Luther King Drive, Mail Stop 593, Cincinnati, Ohio 45268, United States
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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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Avendaño-Herrera R, Maldonado JP, Tapia-Cammas D, Feijóo CG, Calleja F, Toranzo AE. PCR protocol for detection of Vibrio ordalii by amplification of the vohB (hemolysin) gene. DISEASES OF AQUATIC ORGANISMS 2014; 107:223-234. [PMID: 24429473 DOI: 10.3354/dao02684] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Vibrio ordalii is the causative agent of atypical vibriosis and has the potential to cause severe losses in salmonid aquaculture. To prevent and control outbreaks, a rapid, reproducible, sensitive, and effective diagnostic method is needed. We evaluated a new conventional polymerase chain reaction (PCR) and real-time PCR (qPCR) protocol using a primer set (VohB_Fw-VohB_Rv) designed to amplify a 112 bp fragment flanking the vohB gene (coding for hemolysin production), against 24 V. ordalii strains isolated from different fish species, the V. ordalii type strain, and 42 representative related and unrelated bacterial species. The primer set was species-specific, recognizing all V. ordalii strains evaluated, with no cross-reaction with the other bacterial species. A sensitivity of 103 copies of the vohB gene was obtained with a standard curve. When the VohB_Fw-VohB_Rv qPCR protocol was applied to Atlantic salmon seeded tissues (kidney, liver, spleen, and muscle), the detection limit ranged from 5.27 × 102 to 4.13 × 103 V. ordalii CFU ml-1, i.e. 62 to 145 copies of the vohB gene, using the previously calculated standard curve. The conventional PCR also detected V. ordalii, but the total reaction time was 1 h longer. When the qPCR protocol was applied to naturally infected cage-cultured Atlantic salmon samples, 5 of 8 fish tested positive for V. ordalii, but only one of them was diagnosed as positive by direct cultivation on agar. We conclude that the PCR protocol evaluated is fast, specific, and sensitive enough to detect V. ordalii in infected tissues and is an important tool for secure diagnosis of atypical vibriosis, and is therefore helpful for the control of the disease through the prompt detection within fish populations.
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Affiliation(s)
- R Avendaño-Herrera
- Laboratorio de Patología de Organismos Acuáticos y Biotecnología Acuícola, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Viña del Mar, Chile
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Grúas C, Llambi S, Arruga MV. Detection of Legionella spp. and Legionella pneumophila in water samples of Spain by specific real-time PCR. Arch Microbiol 2013; 196:63-71. [DOI: 10.1007/s00203-013-0934-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 10/08/2013] [Accepted: 10/13/2013] [Indexed: 10/26/2022]
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Bedrina B, Macián S, Solís I, Fernández-Lafuente R, Baldrich E, Rodríguez G. Fast immunosensing technique to detect Legionella pneumophila in different natural and anthropogenic environments: comparative and collaborative trials. BMC Microbiol 2013; 13:88. [PMID: 23601924 PMCID: PMC3637370 DOI: 10.1186/1471-2180-13-88] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 04/16/2013] [Indexed: 12/05/2022] Open
Abstract
Background Legionellosis is an uncommon form of pneumonia. After a clinical encounter, the necessary antibiotic treatment is available if the diagnosis is made early in the illness. Before the clinical encounter, early detection of the main pathogen involved, Legionella pneumophila, in hazardous environments is important in preventing infectious levels of this bacterium. In this study a qualitative test based on combined magnetic immunocapture and enzyme-immunoassay for the fast detection of Legionella pneumophila in water samples was compared with the standard method, in both comparative and collaborative trials. The test was based on the use of anti-Legionella pneumophila antibodies immobilized on magnetic microspheres. The final protocol included concentration by filtration, resuspension and immunomagnetic capture. The whole assay took less than 1 hour to complete. Results A comparative trial was performed against the standard culture method (ISO 11731) on both artificially and naturally contaminated water samples, for two matrices: chlorinated tap water and cooling tower water. Performance characteristics of the test used as screening with culture confirmation resulted in sensitivity, specificity, false positive, false negative, and efficiency of 96.6%, 100%, 0%, 3.4%, and 97.8%, respectively. The detection limit at the level under which the false negative rate increases to 50% (LOD50) was 93 colony forming units (CFU) in the volume examined for both tested matrices. The collaborative trial included twelve laboratories. Water samples spiked with certified reference materials were tested. In this study the coincidence level between the two methods was 95.8%. Conclusion Results demonstrate the applicability of this immunosensing technique to the rapid, simple, and efficient detection of Legionella pneumophila in water samples. This test is not based on microbial growth, so it could be used as a rapid screening technique for the detection of L. pneumophila in waters, maintaining the performance of conventional culture for isolation of the pathogen and related studies.
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Affiliation(s)
- Begoña Bedrina
- Biótica, Bioquímica Analítica, S.L, Science and Technology Park of Jaume I University, Campus Riu Sec - Espaitec 2, planta baja, E12071, Castellón de la Plana, Spain
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Pathogen-free screening of bacteria-specific hybridomas for selecting high-quality monoclonal antibodies against pathogen bacteria as illustrated for Legionella pneumophila. J Immunol Methods 2013; 391:81-94. [PMID: 23454033 DOI: 10.1016/j.jim.2013.02.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 02/19/2013] [Accepted: 02/21/2013] [Indexed: 11/20/2022]
Abstract
Antibodies are potent biological tools increasingly used as detection, diagnostic and therapeutic reagents. Many technological advances have optimized and facilitated production and screening of monoclonal antibodies. We report here an original method to screen for antibodies targeting biosafety level 2 or 3 pathogens without the fastidious handling inherent to pathogen use. A double ELISA screening was performed using as coated antigen transformed Escherichia coli expressing at its surface a protein specific to the pathogenic bacteria versus control untransformed E. coli. This method was applied to Legionella, using the surface-exposed Mip protein (macrophage infectivity potentiator). This screening proved to be an excellent means of selecting mAbs that bind Legionella pneumophila 1 surface-exposed Mip protein. This method also appears more biologically relevant than screening using the recombinant Mip protein alone and less tedious than a test performed directly on Legionella bacteria. We obtained 21 mAbs that bind strongly to L. pneumophila serogroups 1 to 13, and we validated their use in a rapid ELISA (performed in 4.5 h) and an immunochromatographic test (20 min).
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Calvo L, Gregorio I, García A, Fernández MT, Goñi P, Clavel A, Peleato ML, Fillat MF. A new pentaplex-nested PCR to detect five pathogenic bacteria in free living amoebae. WATER RESEARCH 2013; 47:493-502. [PMID: 23168310 DOI: 10.1016/j.watres.2012.09.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 09/19/2012] [Accepted: 09/21/2012] [Indexed: 06/01/2023]
Abstract
Changes in water use and anthropogenic activity have major impacts on the quality of natural aquatic ecosystems, water distribution and wastewater plants. One of the main problems is the presence of some pathogenic microorganisms that are resistant to disinfection procedures when they are hosted by free living amoeba and that in many cases are hardly detectable by culture-based procedures. In this work we report a sensitive, low-cost procedure consisting of a pentaplex-nested PCR that allows simultaneous detection of Legionella pneumophila, Mycobacterium spp., Pseudomonas spp., Vibrio cholerae and the microcystin-producing cyanobacteria Microcystis aeruginosa. The method has been used to detect the presence of these pathogenic bacteria in water and inside free living amoeba. Its validation in 72 samples obtained from different water sources from Aragon (Spain) evidences that Mycobacterium and Pseudomonas spp are prevailing as amoeba-resistant bacteria.
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Affiliation(s)
- L Calvo
- Department of Biochemistry and Molecular and Cell Biology, Faculty of Sciences, University of Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
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Leclerc O, Fraisse PO, Labarraque G, Oster C, Pichaut JP, Baume M, Jarraud S, Fisicaro P, Vaslin-Reimann S. Method development for genomic Legionella pneumophila DNA quantification by inductively coupled plasma mass spectrometry. Anal Biochem 2013; 435:153-8. [PMID: 23333226 DOI: 10.1016/j.ab.2012.12.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Revised: 12/17/2012] [Accepted: 12/19/2012] [Indexed: 11/13/2022]
Abstract
The development of a method for the quantification of Legionella pneumophila genomic deoxyribonucleic acid is considered. The method is based on the quantification by inductively coupled plasma mass spectrometry (ICP-MS) of the mass fraction of phosphorus, stoichiometrically presented in the DNA molecules. Through the DNA sequencing data, it was possible to convert the ICP-MS analysis results into DNA genome units. L. pneumophila DNA samples were analyzed using ICP-sector field MS and ICP-quadrupole MS with a collision/reaction cell. Spectrophotometric measurements of the absorbance at 260nm and real-time PCR techniques were used to independently confirm the ICP-MS results. The comparison of the methods showed that the ICP-MS method provides better accuracy with respect to currently applied analytical techniques such as UV spectrophotometry, fluorescent dye methods, and real-time PCR. Moreover, with the use of calibration standards whose values are traceable to the International System of Units and the possibility of evaluating the contribution to the overall uncertainty of each step of the measurement procedure, the method enables long-term comparability of the measurement results. These advantages make the ICP-MS method suitable for nucleic acid investigation, from nucleotides to genomic DNA, as well as for the certification of the reference materials containing nucleic acids.
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Affiliation(s)
- Olga Leclerc
- Department of Medical and Inorganic Chemistry, Laboratoire National de Métrologie et d'Essais, Paris, France.
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Knez K, Janssen KPF, Spasic D, Declerck P, Vanysacker L, Denis C, Tran DT, Lammertyn J. Spherical Nucleic Acid Enhanced FO-SPR DNA Melting for Detection of Mutations in Legionella pneumophila. Anal Chem 2013; 85:1734-42. [DOI: 10.1021/ac303008f] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Karel Knez
- BIOSYST—MeBioS, KU Leuven—University of Leuven, Willem De Croylaan
42, P.O. Box 2428, B-3001 Leuven, Belgium
| | - Kris P. F. Janssen
- BIOSYST—MeBioS, KU Leuven—University of Leuven, Willem De Croylaan
42, P.O. Box 2428, B-3001 Leuven, Belgium
| | - Dragana Spasic
- BIOSYST—MeBioS, KU Leuven—University of Leuven, Willem De Croylaan
42, P.O. Box 2428, B-3001 Leuven, Belgium
| | - Priscilla Declerck
- Laboratorium for Aquatic Ecology
en Evolutionary Biology, KU Leuven—University of Leuven, Charles Deberiotstraat 32, P.O. Box 2439,
B-3000 Leuven, Belgium
| | - Louise Vanysacker
- Centre for Surface Chemistry
and Catalysis, KU Leuven—University of Leuven, Kasteelpark Arenberg 23, P.O. Box 2461, B-3001 Heverlee, Belgium
| | - Carla Denis
- Laboratorium for Aquatic Ecology
en Evolutionary Biology, KU Leuven—University of Leuven, Charles Deberiotstraat 32, P.O. Box 2439,
B-3000 Leuven, Belgium
| | - Dinh T. Tran
- Department of Food Processing,
Faculty of Food Science and Technology, Hanoi University of Agriculture, 10000 Hanoi, Vietnam
| | - Jeroen Lammertyn
- BIOSYST—MeBioS, KU Leuven—University of Leuven, Willem De Croylaan
42, P.O. Box 2428, B-3001 Leuven, Belgium
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Keserue H, Baumgartner A, Felleisen R, Egli T. Rapid detection of total and viable Legionella pneumophila in tap water by immunomagnetic separation, double fluorescent staining and flow cytometry. Microb Biotechnol 2012; 5:753-63. [PMID: 23062200 PMCID: PMC3815896 DOI: 10.1111/j.1751-7915.2012.00366.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
We developed a rapid detection method for Legionella pneumophila (Lp) by filtration, immunomagnetic separation, double fluorescent staining, and flow cytometry (IMS-FCM method). The method requires 120 min and can discriminate 'viable' and 'membrane-damaged' cells. The recovery is over 85% of spiked Lp SG 1 cells in 1 l of tap water and detection limits are around 50 and 15 cells per litre for total and viable Lp, respectively. The method was compared using water samples from house installations in a blind study with three environmental laboratories performing the ISO 11731 plating method. In 53% of the water samples from different taps and showers significantly higher concentrations of Lp were detected by flow cytometry. No correlation to the plate culture method was found. Since also 'viable but not culturable' (VNBC) cells are detected by our method, this result was expected. The IMS-FCM method is limited by the specificity of the used antibodies; in the presented case they target Lp serogroups 1-12. This and the fact that no Lp-containing amoebae are detected may explain why in 21% of all samples higher counts were observed using the plate culture method. Though the IMS-FCM method is not yet fit to completely displace the established plating method (ISO 11731) for routine Lp monitoring, it has major advantages to plating and can quickly provide important insights into the ecology of this pathogen in water distribution systems.
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Affiliation(s)
- Hans‐Anton Keserue
- Swiss Federal Institute for Aquatic Science and Technology (Eawag)Überlandstrasse 133, PO Box 611, CH‐8600, Dübendorf, Switzerland
- Federal Office of Public Health (FOPH)Schwarzenburgstrasse 165, CH‐3003, Bern, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH ZurichUniversitätsstrasse 16, 8092, Zurich, Switzerland
| | - Andreas Baumgartner
- Federal Office of Public Health (FOPH)Schwarzenburgstrasse 165, CH‐3003, Bern, Switzerland
| | - Richard Felleisen
- Federal Office of Public Health (FOPH)Schwarzenburgstrasse 165, CH‐3003, Bern, Switzerland
| | - Thomas Egli
- Swiss Federal Institute for Aquatic Science and Technology (Eawag)Überlandstrasse 133, PO Box 611, CH‐8600, Dübendorf, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH ZurichUniversitätsstrasse 16, 8092, Zurich, Switzerland
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Zbikowska E, Walczak M, Krawiec A. Distribution of Legionella pneumophila bacteria and Naegleria and Hartmannella amoebae in thermal saline baths used in balneotherapy. Parasitol Res 2012; 112:77-83. [PMID: 23052757 PMCID: PMC3536949 DOI: 10.1007/s00436-012-3106-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 08/24/2012] [Indexed: 11/29/2022]
Abstract
The present study was aimed at investigating the coexistence and interactions between free living amoebae of Naegleria and Hartmannella genera and pathogenic Legionella pneumophila bacteria in thermal saline baths used in balneotherapy in central Poland. Water samples were collected from November 2010 to May 2011 at intervals longer than 1 month. The microorganisms were detected with the use of a very sensitive fluorescence in situ hybridisation method. In addition, the morphology of the amoebae was studied. Despite relatively high salinity level, ranging from 1.5 to 5.0 %, L. pneumophila were found in all investigated baths, although their number never exceeded 106 cells dm−3. Hartmannella were not detected, while Naegleria fowleri were found in one bath. The observation that N. fowleri and L. pneumophila may coexist in thermal saline baths is the first observation emphasising potential threat from these microorganisms in balneotherapy.
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Affiliation(s)
- Elżbieta Zbikowska
- Department of Invertebrate Zoology, Faculty of Biology and Earth Sciences, Nicolaus Copernicus University, Toruń, Poland.
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Janssen KPF, Knez K, Vanysacker L, Schrooten J, Spasic D, Lammertyn J. Enabling fiber optic serotyping of pathogenic bacteria through improved anti-fouling functional surfaces. NANOTECHNOLOGY 2012; 23:235503. [PMID: 22609831 DOI: 10.1088/0957-4484/23/23/235503] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Significant research efforts are continually being directed towards the development of sensitive and accurate surface plasmon resonance biosensors for sequence specific DNA detection. These sensors hold great potential for applications in healthcare and diagnostics. However, the performance of these sensors in practical usage scenarios is often limited due to interference from the sample matrix. This work shows how the co-immobilization of glycol(PEG) diluents or 'back filling' of the DNA sensing layer can successfully address these problems. A novel SPR based melting assay is used for the analysis of a synthetic oligomer target as well as PCR amplified genomic DNA extracted from Legionella pneumophila. The benefits of sensing layer back filling on the assay performance are first demonstrated through melting analysis of the oligomer target and it is shown how back filling enables accurate discrimination of Legionella pneumophila serogroups directly from the PCR reaction product with complete suppression of sensor fouling.
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Affiliation(s)
- K P F Janssen
- BIOSYST-MeBioS, KU Leuven, Willem De Croylaan 42, Leuven, Belgium
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Magnetic techniques for the detection and determination of xenobiotics and cells in water. Anal Bioanal Chem 2012; 404:1257-73. [DOI: 10.1007/s00216-012-6056-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 04/15/2012] [Accepted: 04/16/2012] [Indexed: 10/28/2022]
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Buse HY, Schoen ME, Ashbolt NJ. Legionellae in engineered systems and use of quantitative microbial risk assessment to predict exposure. WATER RESEARCH 2012; 46:921-33. [PMID: 22209280 DOI: 10.1016/j.watres.2011.12.022] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 11/07/2011] [Accepted: 12/08/2011] [Indexed: 05/22/2023]
Abstract
While it is well-established that Legionella are able to colonize engineered water systems, the number of interacting factors contributing to their occurrence, proliferation, and persistence are unclear. This review summarizes current methods used to detect and quantify legionellae as well as the current knowledge of engineered water system characteristics that both favour and promote legionellae growth. Furthermore, the use of quantitative microbial risk assessment (QMRA) models to predict potentially critical human exposures to legionellae are also discussed. Understanding the conditions favouring Legionella occurrence in engineered systems and their overall ecology (growth in these systems/biofilms, biotic interactions and release) will aid in developing new treatment technologies and/or systems that minimize or eliminate human exposure to potentially pathogenic legionellae.
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Affiliation(s)
- Helen Y Buse
- National Exposure Research Laboratory, US Environmental Protection Agency, 26 W Martin Luther King Dr, MS 579, Cincinnati, OH 45268, USA.
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Krøjgaard LH, Krogfelt KA, Albrechtsen HJ, Uldum SA. Detection of Legionella by quantitative-polymerase chain reaction (qPCR) for monitoring and risk assessment. BMC Microbiol 2011; 11:254. [PMID: 22103438 PMCID: PMC3268758 DOI: 10.1186/1471-2180-11-254] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Accepted: 11/21/2011] [Indexed: 11/19/2022] Open
Abstract
Background Culture and quantitative polymerase chain reaction (qPCR) assays for the detection of Legionella were compared on samples from a residential area before and after two interventions. A total of 84 samples were collected from shower hoses and taps as first flush samples and at constant temperature. Samples were grouped according to the origin of the sample, a) circulation water b) water from empty apartments c) water from shower hoses. The aims were to investigate the usefulness of qPCR compared to culture for monitoring remedial actions for elimination of Legionella bacteria and as a tool for risk assessment. Results In water collected from the apartments Legionella spp were detected by qPCR in the concentration range from LOQ to 9.6*105GU/L while L. pneumophila were detected in a range from LOQ to 6.8*105 GU/L. By culturing, the legionellae were detected in the range from below detection limit (> 10 CFU/L) to 1.6*106 CFU/L. In circulating water and in first flush water from shower hoses, culture and qPCR showed the same tendencies. The overall correlation between the bacteria number detected by culture and the two developed qPCR assays (L. spp and L. pneumophila) was relatively poor (r2 = 0.31 for culture and Legionella spp. assay, r2 = 0.20 for culture and L. pneumophila assay). Conclusion Detection by qPCR was suitable for monitoring changes in the concentration of Legionella but the precise determination of bacteria is difficult. Risk assessment by qPCR only on samples without any background information regarding treatment, timing, etc is dubious. However, the rapid detection by qPCR of high concentrations of Legionella - especially Legionella pneumophila - is valuable as an indicator of risk, although it may be false positive compared to culture results. On the other hand, the detection of a low number of bacteria by qPCR is a strong indication for the absence of risk.
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Affiliation(s)
- Louise H Krøjgaard
- Dept. of Microbiological Surveillance and Research, Statens Serum Institut, Ørestads Boulevard 5, Copenhagen S, Denmark.
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50
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Lu X, Mo ZY, Zhao HB, Yan H, Shi L. LAMP-based method for a rapid identification of Legionella spp. and Legionella pneumophila. Appl Microbiol Biotechnol 2011; 92:179-87. [PMID: 21847513 DOI: 10.1007/s00253-011-3496-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 07/08/2011] [Accepted: 07/18/2011] [Indexed: 11/25/2022]
Abstract
Legionella pneumophila is accounted for more than 80% of Legionella infection. However it is difficult to discriminate between the L. pneumophila and non-L. pneumophila species rapidly. In order to detect the Legionella spp. and distinguish L. pneumophila from Legionella spp., a real-time loop-mediated isothermal amplification (LAMP) platform that targets a specific sequence of the 16S rRNA gene was developed. LS-LAMP amplifies the fragment of the 16S rRNA gene to detect all species of Legionella genus. A specific sequence appears at the 16S rRNA gene of L. pneumophila, while non-L. pneumophila strains have a variable sequence in this site, which can be recognized by the primer of LP-LAMP. In the present study, 61 reference strains were used for the method verification. We found that the specificity was 100% for both LS-LAMP and LP-LAMP, and the sensitivity of LAMP assay for L. pneumophila detection was between 52 and 5.2 copies per reaction. In the environmental water samples detection, a total of 107 water samples were identified by the method. The culture and serological test were used as reference methods. The specificity of LS-LAMP and LP-LAMP for the samples detection were 91.59% (98/107) and 93.33% (56/60), respectively. The sensitivity of LS-LAMP and LP-LAMP were 100% (51/51) and 100% (18/18). The results suggest that real-time LAMP, as a new assay, provides a specific and sensitive method for rapid detection and differentiation of Legionella spp. and L. pneumophila and should be utilized to test environmental water samples for increased rates of detection.
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Affiliation(s)
- Xi Lu
- College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, China
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