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Sauget M, Richard M, Chassagne S, Hocquet D, Bertrand X, Jeanvoine A. Validation of quantitative real-time PCR for detection of Legionella pneumophila in hospital water networks. J Hosp Infect 2023:S0195-6701(23)00195-0. [PMID: 37353007 DOI: 10.1016/j.jhin.2023.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/08/2023] [Accepted: 06/10/2023] [Indexed: 06/25/2023]
Abstract
BACKGROUND Rapid monitoring of Legionella pneumophila (Lp) is essential to reduce the risk of Legionnaires' disease in healthcare facilities. However, culture results take at least eight days, delaying the implementation of corrective measures. Here, we assessed the performance of a qPCR method and determined qPCR action thresholds for the detection of Lp in hospital hot water networks (HWNs). METHODS Hot water samples (n=459) were collected from a hospital HWNs. Lp were quantified using iQ-Check® Quanti real-time PCR Quantification kits (Bio-Rad) and the results were compared with those of culture. qPCR thresholds corresponding to the culture action thresholds of 10 and 1,000 CFU/L were determined on a training dataset and validated on an independent dataset. RESULTS Lp concentrations measured by culture and qPCR were correlated for both the training dataset (Spearman's correlation coefficient ρ = 0.687, p-value < 0.0001) and the validation dataset (ρ = 0.661, p-value < 0.0001). Lp qPCR positivity thresholds corresponding to culture action thresholds of 10 CFU/L was 91 genome units (GU) per liter (sensitivity, 86.4%; negative predictive value - NPV, 93.3%) and that corresponding to culture action thresholds of 1,000 CFU/L was 1,048 GU/L (sensitivity, 100%; NPV, 100%). CONCLUSION Detection of Lp by qPCR could be implemented with confidence in hospitals as a complement to culture in the monitoring strategy to speed up the implementation of corrective measures.
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Affiliation(s)
- Marlène Sauget
- Hygiène Hospitalière, Centre Hospitalier Universitaire de Besançon, Besançon, France; Centre de Ressources Biologiques, Centre Hospitalier Universitaire de Besançon, Besançon, France.
| | - Marion Richard
- Hygiène Hospitalière, Centre Hospitalier Universitaire de Besançon, Besançon, France; Centre de Ressources Biologiques, Centre Hospitalier Universitaire de Besançon, Besançon, France
| | - Sophie Chassagne
- Hygiène Hospitalière, Centre Hospitalier Universitaire de Besançon, Besançon, France
| | - Didier Hocquet
- Hygiène Hospitalière, Centre Hospitalier Universitaire de Besançon, Besançon, France; Chrono-environnement, Université de Franche-Comté, CNRS, Besançon, France; Centre de Ressources Biologiques, Centre Hospitalier Universitaire de Besançon, Besançon, France
| | - Xavier Bertrand
- Hygiène Hospitalière, Centre Hospitalier Universitaire de Besançon, Besançon, France; Chrono-environnement, Université de Franche-Comté, CNRS, Besançon, France
| | - Audrey Jeanvoine
- Hygiène Hospitalière, Centre Hospitalier Universitaire de Besançon, Besançon, France
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2
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Heining L, Welp L, Hugo A, Elsner M, Seidel M. Immunomagnetic separation coupled with flow cytometry for the analysis of Legionella pneumophila in aerosols. Anal Bioanal Chem 2023:10.1007/s00216-023-04738-z. [PMID: 37204446 PMCID: PMC10404198 DOI: 10.1007/s00216-023-04738-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 05/04/2023] [Accepted: 05/08/2023] [Indexed: 05/20/2023]
Abstract
Legionella pneumophila are pathogenic bacteria that can be found in high concentrations in artificial water systems like evaporative cooling towers, which have been the source of frequent outbreaks in recent years. Since inhaled L. pneumophila can lead to Legionnaires' disease, the development of suitable sampling and rapid analysis strategies for these bacteria in aerosols is therefore of great relevance. In this work, different concentrations of viable L. pneumophila Sg 1 were nebulized and sampled by the cyclone sampler Coriolis® µ under defined conditions in a bioaerosol chamber. To quantify intact Legionella cells, the collected bioaerosols were subsequently analyzed by immunomagnetic separation coupled with flow cytometry (IMS-FCM) on the platform rqmicro.COUNT. For analytical comparison, measurements with qPCR and cultivation were performed. Limits of detection (LOD) of 2.9 × 103 intact cells m-3 for IMS-FCM and 7.8 × 102 intact cells m-3 for qPCR indicating a comparable sensitivity as in culture (LOD = 1.5 × 103 culturable cells m-3). Over a working range of 103 - 106 cells mL-1, the analysis of nebulized and collected aerosol samples with IMS-FCM and qPCR provides higher recovery rates and more consistent results than by cultivation. Overall, IMS-FCM is a suitable culture-independent method for quantification of L. pneumophila in bioaerosols and is promising for field application due to its simplicity in sample preparation.
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Affiliation(s)
- Lena Heining
- Institute of Water Chemistry, Chair of Analytical Chemistry and Water Chemistry, School of Natural Sciences, Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Laura Welp
- Institut für Energie- und Umwelttechnik e.V., Bliersheimer Straße 58-60, 47229, Duisburg, Germany
| | - Achim Hugo
- Institut für Energie- und Umwelttechnik e.V., Bliersheimer Straße 58-60, 47229, Duisburg, Germany
| | - Martin Elsner
- Institute of Water Chemistry, Chair of Analytical Chemistry and Water Chemistry, School of Natural Sciences, Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Michael Seidel
- Institute of Water Chemistry, Chair of Analytical Chemistry and Water Chemistry, School of Natural Sciences, Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany.
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Chawich J, Hassen WM, Singh A, Marquez DT, DeRosa MC, Dubowski JJ. Polymer Brushes on GaAs and GaAs/AlGaAs Nanoheterostructures: A Promising Platform for Attractive Detection of Legionella pneumophila. ACS OMEGA 2022; 7:33349-33357. [PMID: 36157789 PMCID: PMC9494436 DOI: 10.1021/acsomega.2c03959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/23/2022] [Indexed: 06/16/2023]
Abstract
This work reports on the potential of polymer brushes (PBs) grown on GaAs substrates (PB-GaAs) as a promising platform for the detection of Legionella pneumophila (Lp). Three functionalization approaches of the GaAs surface were used, and their compatibility with antibodies against Lp was evaluated using Fourier transform infrared spectroscopy and fluorescence microscopy. The incorporation of PBs on GaAs has allowed a significant improvement of the antibody immobilization by increased surface coverage. Bacterial capture experiments demonstrated the promising potential for enhanced immobilization of Lp in comparison with the conventional alkanethiol self-assembled monolayer-based biosensing architectures. Consistent with an eightfold improved capture of bacteria on the surface of a PB-functionalized GaAs/AlGaAs digital photocorrosion biosensor, we report the attractive detection of Lp at 500 CFU/mL.
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Affiliation(s)
- Juliana Chawich
- Interdisciplinary
Institute for Technological Innovation (3IT), CNRS UMI-3463, Université de Sherbrooke, Sherbrooke, Québec J1K 0A5, Canada
| | - Walid M. Hassen
- Interdisciplinary
Institute for Technological Innovation (3IT), CNRS UMI-3463, Université de Sherbrooke, Sherbrooke, Québec J1K 0A5, Canada
| | - Amanpreet Singh
- Interdisciplinary
Institute for Technological Innovation (3IT), CNRS UMI-3463, Université de Sherbrooke, Sherbrooke, Québec J1K 0A5, Canada
| | - Daniela T. Marquez
- Interdisciplinary
Institute for Technological Innovation (3IT), CNRS UMI-3463, Université de Sherbrooke, Sherbrooke, Québec J1K 0A5, Canada
- Department
of Chemistry, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - Maria C. DeRosa
- Department
of Chemistry, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - Jan J. Dubowski
- Interdisciplinary
Institute for Technological Innovation (3IT), CNRS UMI-3463, Université de Sherbrooke, Sherbrooke, Québec J1K 0A5, Canada
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Evaluation of a Most Probable Number Method for Detection and Quantification of Legionella pneumophila. Pathogens 2022; 11:pathogens11070789. [PMID: 35890033 PMCID: PMC9324539 DOI: 10.3390/pathogens11070789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/02/2022] [Accepted: 07/07/2022] [Indexed: 11/17/2022] Open
Abstract
The detection and enumeration of Legionella pneumophila (L. pneumophila) in water is crucial for water quality management, human health and has been a research hotspot worldwide. Due to the time-consuming and complicated operation of the plate culture method, it is necessary to adopt a fast and effective method for application. The present study aimed to comprehensively evaluate the performance and applicability of the MPN method by comparing its qualitative and quantitative results with the GB/T 18204.5-2013 and ISO methods, respectively. The qualitative results showed that 372 samples (53%) were negative for both methods; 315 samples (45%) were positively determined by the MPN method, compared with 211 samples (30%) using GB/T 18204.5-2013. The difference in the detection rate between the two methods was statistically significant. In addition, the quantitative results showed that the concentration of L. pneumophila by the MPN method was greater than ISO 11731 and the difference was statistically significant. However, the two methods were different but highly correlated (r = 0.965, p < 0.001). The specificity and sensitivity of the MPN method were 89.85% and 95.73%, respectively. Overall, the results demonstrated that the MPN method has higher sensitivity, a simple operation process and good application prospects in the routine monitoring of L. pneumophila from water samples.
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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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Consonni M, Grassi A, Scuri S, Gori M, Tanzi E, Tesauro M. Assessing the viability of Legionella pneumophila in environmental samples: regarding the filter application of Ethidium Monoazide Bromide. ANN MICROBIOL 2021. [DOI: 10.1186/s13213-021-01653-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Purpose
Analyses of 34 water samples from 13 healthcare structures revealed how culture method and quantitative PCR (qPCR) often differ in the detection of Legionella pneumophila (Lp). With these considerations in hand, culture method, PCR and Ethidium Monoazide Bromide (EMA) qPCR have all been compared in order to detect Lp in water samples, identify a method able to speed up the procedures, detect the “viable but not cultivable” bacteria (VBNC) and exclude non-viable bacteria using a commercial kit for extraction and amplification as well as modification of the protocol.
Methods
Pure water samples artificially spiked with viable, non-viable and VBNC Lp ATCC 33152 were analyzed using a commercial kit for both qPCR and EMA-qPCR, while ISO 11731-2-2004 was used for culture method.
Results
Only 35% (12/34) of the environmental samples were positive in both culture and qPCR methods. With regard to EMA-qPCR, results showed the absence of dye toxicity on viable and VBNC strains and an incomplete effectiveness on the non-viable ones. In both viable and VBNC strains, a decrease of bacterial DNA amplification was recorded as a function of sample dilution but not of EMA concentration.
Conclusions
Discrepancies between culture method and EMA-qPCR were observed and may be due to different causes such as membrane-dye interactions, presence of interfering compounds and the sensitivity of the kit used.
Study significance and impact
In the presence of one or more suspected cases of nosocomial legionellosis, the application of a rapid molecular method able to identify only the viable and VBNC Lp would be useful in order to quickly identify the source of infection and to intervene with sanitation treatments. However, seeing that in our experience EMA pretreatment on the filter membrane did not come up with the expected results, it would be necessary to proceed with other experiments and/or different dyes.
Graphical Abstract
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Zhang C, Lu J. Legionella: A Promising Supplementary Indicator of Microbial Drinking Water Quality in Municipal Engineered Water Systems. FRONTIERS IN ENVIRONMENTAL SCIENCE 2021; 9:1-22. [PMID: 35004706 PMCID: PMC8740890 DOI: 10.3389/fenvs.2021.684319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Opportunistic pathogens (OPs) are natural inhabitants and the predominant disease causative biotic agents in municipal engineered water systems (EWSs). In EWSs, OPs occur at high frequencies and concentrations, cause drinking-water-related disease outbreaks, and are a major factor threatening public health. Therefore, the prevalence of OPs in EWSs represents microbial drinking water quality. Closely or routinely monitoring the dynamics of OPs in municipal EWSs is thus critical to ensuring drinking water quality and protecting public health. Monitoring the dynamics of conventional (fecal) indicators (e.g., total coliforms, fecal coliforms, and Escherichia coli) is the customary or even exclusive means of assessing microbial drinking water quality. However, those indicators infer only fecal contamination due to treatment (e.g., disinfection within water utilities) failure and EWS infrastructure issues (e.g., water main breaks and infiltration), whereas OPs are not contaminants in drinking water. In addition, those indicators appear in EWSs at low concentrations (often absent in well-maintained EWSs) and are uncorrelated with OPs. For instance, conventional indicators decay, while OPs regrow with increasing hydraulic residence time. As a result, conventional indicators are poor indicators of OPs (the major aspect of microbial drinking water quality) in EWSs. An additional or supplementary indicator that can well infer the prevalence of OPs in EWSs is highly needed. This systematic review argues that Legionella as a dominant OP-containing genus and natural inhabitant in EWSs is a promising candidate for such a supplementary indicator. Through comprehensively comparing the behavior (i.e., occurrence, growth and regrowth, spatiotemporal variations in concentrations, resistance to disinfectant residuals, and responses to physicochemical water quality parameters) of major OPs (e.g., Legionella especially L. pneumophila, Mycobacterium, and Pseudomonas especially P. aeruginosa), this review proves that Legionella is a promising supplementary indicator for the prevalence of OPs in EWSs while other OPs lack this indication feature. Legionella as a dominant natural inhabitant in EWSs occurs frequently, has a high concentration, and correlates with more microbial and physicochemical water quality parameters than other common OPs. Legionella and OPs in EWSs share multiple key features such as high disinfectant resistance, biofilm formation, proliferation within amoebae, and significant spatiotemporal variations in concentrations. Therefore, the presence and concentration of Legionella well indicate the presence and concentrations of OPs (especially L. pneumophila) and microbial drinking water quality in EWSs. In addition, Legionella concentration indicates the efficacies of disinfectant residuals in EWSs. Furthermore, with the development of modern Legionella quantification methods (especially quantitative polymerase chain reactions), monitoring Legionella in ESWs is becoming easier, more affordable, and less labor-intensive. Those features make Legionella a proper supplementary indicator for microbial drinking water quality (especially the prevalence of OPs) in EWSs. Water authorities may use Legionella and conventional indicators in combination to more comprehensively assess microbial drinking water quality in municipal EWSs. Future work should further explore the indication role of Legionella in EWSs and propose drinking water Legionella concentration limits that indicate serious public health effects and require enhanced treatment (e.g., booster disinfection).
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Affiliation(s)
- Chiqian Zhang
- Pegasus Technical Services, Inc., Cincinnati, OH, United States
| | - Jingrang Lu
- Office of Research and Development, United States Environmental Protection Agency, Cincinnati, OH, United States
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8
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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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Sciuto EL, Laganà P, Filice S, Scalese S, Libertino S, Corso D, Faro G, Coniglio MA. Environmental Management of Legionella in Domestic Water Systems: Consolidated and Innovative Approaches for Disinfection Methods and Risk Assessment. Microorganisms 2021; 9:577. [PMID: 33799845 PMCID: PMC8001549 DOI: 10.3390/microorganisms9030577] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/08/2021] [Accepted: 03/09/2021] [Indexed: 12/31/2022] Open
Abstract
Legionella is able to remain in water as free-living planktonic bacteria or to grow within biofilms that adhere to the pipes. It is also able to enter amoebas or to switch into a viable but not culturable (VBNC) state, which contributes to its resistance to harsh conditions and hinders its detection in water. Factors regulating Legionella growth, such as environmental conditions, type and concentration of available organic and inorganic nutrients, presence of protozoa, spatial location of microorganisms, metal plumbing components, and associated corrosion products are important for Legionella survival and growth. Finally, water treatment and distribution conditions may affect each of these factors. A deeper comprehension of Legionella interactions in water distribution systems with the environmental conditions is needed for better control of the colonization. To this purpose, the implementation of water management plans is the main prevention measure against Legionella. A water management program requires coordination among building managers, health care providers, and Public Health professionals. The review reports a comprehensive view of the state of the art and the promising perspectives of both monitoring and disinfection methods against Legionella in water, focusing on the main current challenges concerning the Public Health sector.
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Affiliation(s)
- Emanuele Luigi Sciuto
- Azienda Ospedaliero Universitaria Policlinico “G. Rodolico-San Marco”, Via Sofia 78, 95123 Catania, Italy;
| | - Pasqualina Laganà
- Regional Reference Laboratory of Clinical and Environmental Surveillance of Legionellosis, Messina, Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Torre Biologica 3p, AOU ‘G. Martino, Via C. Valeria, s.n.c., 98125 Messina, Italy;
| | - Simona Filice
- Istituto per la Microelettronica e Microsistemi–Consiglio Nazionale delle Ricerche (CNR-IMM), Ottava Strada 5, 95121 Catania, Italy; (S.F.); (S.S.); (S.L.); (D.C.)
| | - Silvia Scalese
- Istituto per la Microelettronica e Microsistemi–Consiglio Nazionale delle Ricerche (CNR-IMM), Ottava Strada 5, 95121 Catania, Italy; (S.F.); (S.S.); (S.L.); (D.C.)
| | - Sebania Libertino
- Istituto per la Microelettronica e Microsistemi–Consiglio Nazionale delle Ricerche (CNR-IMM), Ottava Strada 5, 95121 Catania, Italy; (S.F.); (S.S.); (S.L.); (D.C.)
| | - Domenico Corso
- Istituto per la Microelettronica e Microsistemi–Consiglio Nazionale delle Ricerche (CNR-IMM), Ottava Strada 5, 95121 Catania, Italy; (S.F.); (S.S.); (S.L.); (D.C.)
| | - Giuseppina Faro
- Azienda Sanitaria Provinciale di Catania, Via S. Maria La Grande 5, 95124 Catania, Italy;
| | - Maria Anna Coniglio
- Azienda Ospedaliero Universitaria Policlinico “G. Rodolico-San Marco”, Via Sofia 78, 95123 Catania, Italy;
- Regional Reference Laboratory of Clinical and Environmental Surveillance of Legionellosis, Catania, Department of Medical and Surgical Sciences and Advanced Technologies “G.F. Ingrassia”, University of Catania, Via Sofia 87, 95123 Catania, Italy
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Fricke C, Xu J, Jiang F, Liu Y, Harms H, Maskow T. Rapid culture-based detection of Legionella pneumophila using isothermal microcalorimetry with an improved evaluation method. Microb Biotechnol 2020; 13:1262-1272. [PMID: 32212253 PMCID: PMC7264898 DOI: 10.1111/1751-7915.13563] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 03/02/2020] [Indexed: 12/01/2022] Open
Abstract
The detection and quantification of Legionella pneumophila (responsible for legionnaire's disease) in water samples can be achieved by various methods. However, the culture-based ISO 11731:2017, which is based on counts of colony-forming units per ml (CFU·ml-1 ) is still the gold standard for quantification of Legionella species (spp.). As a powerful alternative, we propose real-time monitoring of the growth of L. pneumophila using an isothermal microcalorimeter (IMC). Our results demonstrate that, depending on the initial concentration of L. pneumophila, detection times of 24-48 h can be reliably achieved. IMC may, therefore, be used as an early warning system for L. pneumophila contamination. By replacing only visual detection of growth by a thermal sensor, but otherwise maintaining the standardized protocol of the ISO 11731:2017, the new procedure could easily be incorporated into existing standards. The exact determination of the beginning of metabolic heat is often very difficult because at the beginning of the calorimetric signal the thermal stabilization and the metabolic heat development overlap. Here, we propose a new data evaluation based on the first derivation of the heat flow signal. The improved evaluation method can further reduce detection times and significantly increase the reliability of the IMC approach.
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Affiliation(s)
- Christian Fricke
- Department of Environmental MicrobiologyHelmholtz‐Centre for Environmental Research – UFZLeipzigGermany
| | - Juan Xu
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education)College of Chemistry and Molecular SciencesWuhan UniversityWuhan430072China
| | - Feng‐Lei Jiang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education)College of Chemistry and Molecular SciencesWuhan UniversityWuhan430072China
| | - Yi Liu
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education)College of Chemistry and Molecular SciencesWuhan UniversityWuhan430072China
| | - Hauke Harms
- Department of Environmental MicrobiologyHelmholtz‐Centre for Environmental Research – UFZLeipzigGermany
| | - Thomas Maskow
- Department of Environmental MicrobiologyHelmholtz‐Centre for Environmental Research – UFZLeipzigGermany
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Reuter C, Slesiona N, Hentschel S, Aehlig O, Breitenstein A, Csáki A, Henkel T, Fritzsche W. Loop-mediated amplification as promising on-site detection approach for Legionella pneumophila and Legionella spp. Appl Microbiol Biotechnol 2019; 104:405-415. [PMID: 31832709 DOI: 10.1007/s00253-019-10286-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 11/08/2019] [Accepted: 11/28/2019] [Indexed: 12/16/2022]
Abstract
Recently Legionella pneumophila is the main causative waterborne organism of severe respiratory infections. Additionally, other Legionella species are documented as human pathogens. In our work, we describe a rapid detection method which combines two advantages for sensitive and specific detection of the genus Legionella: the fast isothermal amplification method "Loop-mediated isothermal AMPlification" (LAMP), and a colorimetric detection method using the metal indicator hydroxynaphtol blue (HBN) which allows to determine an optical signal with a simple readout (with the naked eye). Moreover, we present two approaches for minimizing the assay volume using a stationary microchip LAMP and droplet digital-based LAMP (ddLAMP) as promising highly sensitive setups.
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Affiliation(s)
- Cornelia Reuter
- Leibniz Institute of Photonic Technology (Leibniz IPHT) Jena, Member of the Leibniz Research Alliance-Leibniz Health Technologies, Albert-Einstein-Straße 9, 07745, Jena, Germany.
| | - Nicole Slesiona
- Leibniz Institute of Photonic Technology (Leibniz IPHT) Jena, Member of the Leibniz Research Alliance-Leibniz Health Technologies, Albert-Einstein-Straße 9, 07745, Jena, Germany
| | - Stefanie Hentschel
- Leibniz Institute of Photonic Technology (Leibniz IPHT) Jena, Member of the Leibniz Research Alliance-Leibniz Health Technologies, Albert-Einstein-Straße 9, 07745, Jena, Germany
| | - Oliver Aehlig
- Leibniz Institute of Photonic Technology (Leibniz IPHT) Jena, Member of the Leibniz Research Alliance-Leibniz Health Technologies, Albert-Einstein-Straße 9, 07745, Jena, Germany
| | | | - Andrea Csáki
- Leibniz Institute of Photonic Technology (Leibniz IPHT) Jena, Member of the Leibniz Research Alliance-Leibniz Health Technologies, Albert-Einstein-Straße 9, 07745, Jena, Germany
| | - Thomas Henkel
- Leibniz Institute of Photonic Technology (Leibniz IPHT) Jena, Member of the Leibniz Research Alliance-Leibniz Health Technologies, Albert-Einstein-Straße 9, 07745, Jena, Germany
| | - Wolfgang Fritzsche
- Leibniz Institute of Photonic Technology (Leibniz IPHT) Jena, Member of the Leibniz Research Alliance-Leibniz Health Technologies, Albert-Einstein-Straße 9, 07745, Jena, Germany
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Jiang X, Liu S, Yang M, Rasooly A. Amperometric genosensor for culture independent bacterial count. SENSORS AND ACTUATORS. B, CHEMICAL 2019; 299:10.1016/j.snb.2019.126944. [PMID: 32009738 PMCID: PMC6993526 DOI: 10.1016/j.snb.2019.126944] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Bacterial plate count for general assessment of water quality requires lengthy bacterial culturing. We report here a new DNA induced current genosensor for culture independent total bacteria determination. Since the amount of bacterial DNA is correlated to the number of bacteria, the genosensor measures the amount of bacterial DNA to determine bacterial count. The approach relies on bacteria lysis to release DNA which can react with molybdate to form redox molybdophosphate and measured electrochemically. Analysis of E. coli and S. aureus demonstrated that the DNA generated current is highly correlated with the level of bacteria lysis which was confirmed by spectrometric measurement. Culture independent measurement of S. aureus bacterial load suggests limit of detection is 21.9 CFU/mL, with linear range from 3×102 to 3×107 CFU/mL and correlation coefficient of 0.992. For E. coli analysis, the detection limit is 25.1 CFU/mL with the same linear range. The use of electrochemical microbial DNA quantitation for culture independent bacterial count is a new approach, the genosensor measurement is rapid (within 1 h) and has potential use for analysis of broad-spectrum bacteria for various applications.
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Affiliation(s)
- Xingxing Jiang
- Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, College of Chemistry and Chemical Engineering, Central South University, Changsha, China, 410083
| | - Shuping Liu
- Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, College of Chemistry and Chemical Engineering, Central South University, Changsha, China, 410083
| | - Minghui Yang
- Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, College of Chemistry and Chemical Engineering, Central South University, Changsha, China, 410083
- Corresponding Authors: (M. Yang) (A. Rasooly)
| | - Avraham Rasooly
- National Cancer Institute, National Institutes of Health, Rockville, Maryland 20850, United States
- Corresponding Authors: (M. Yang) (A. Rasooly)
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Mobed A, Hasanzadeh M, Babaie P, Agazadeh M, Mokhtarzadeh A, Rezaee MA. DNA-based bioassay of legionella pneumonia pathogen using gold nanostructure: A new platform for diagnosis of legionellosis. Int J Biol Macromol 2019; 128:692-699. [PMID: 30685302 DOI: 10.1016/j.ijbiomac.2019.01.125] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 10/27/2022]
Abstract
The specific diagnosis of hard-growing bacteria is one of the most important concerns of medical bacteriology. Legionella pneumophila is one of the most important bacteria in hard growth. In spite remarkable trends in bacteriology, now day, culture is the gold standard for detection of L. pneumophila. This work is an attempt to quantification of L. pneumophila bacteria using a bioassay. The fabrication of a new electrochemical DNA-based bioassay using gold nano architecture combined with as a transducer substrate combined with toluidine blue (TB) as a redox marker was performed successful. Also, the mixture of beta‑cyclodextrin and dopamine as Poly (dopamine‑β‑Cyclodextrin) was used to proper a biointerface for stabilization of gold nanoparticles optimum immobilize of pDNA sequence (5-SH-TCGA TAC TCT CCC CGC CCC TT T TGTATCGACG-3). So, a specific thiolated pDNA was immobilized on the transducer substrate and DNA hybridization was followed by C-DNA sequence (5-ACA AAA GGG GCG GGG AGA GTA-3) using square wave voltammetry and differential pulse voltammetry. At the optimum conditions, linear range was 1 μM to 1 ZM and low limit of quantification (LLOQ) was 1 Zepto-molar. L. pneumophila were sensitively distinguished by the planned DNA sensor. Finally, the engineered DNA based bioassay could be used for identifying the L. pneumophila samples from patients or environments.
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Affiliation(s)
- Ahmad Mobed
- Student Research Committee, Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Iran
| | - Mohammad Hasanzadeh
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Parinaz Babaie
- Pharmaceutical Analysis Research Center and Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Agazadeh
- Student Research Committee, Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Iran
| | - Ahad Mokhtarzadeh
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
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