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Checa J, Carbonell I, Manero N, Martí I. Comparative study of Legiolert with ISO 11731-1998 standard method-conclusions from a Public Health Laboratory. J Microbiol Methods 2021; 186:106242. [PMID: 34019935 DOI: 10.1016/j.mimet.2021.106242] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/16/2021] [Accepted: 05/16/2021] [Indexed: 11/18/2022]
Abstract
BACKGROUND Legionella pneumophila (L. pneumophila) is responsible for 96% of Legionnaires' disease (LD) and 10% of all worldwide pneumonia cases. Legiolert™, a liquid culture method for most probable number (MPN) enumeration of L. pneumophila, was developed by IDEXX Laboratories. The method detects all serogroups of L. pneumophila in potable and non-potable water samples. OBJECTIVE The goal of this study is to establish that Legiolert is a suitable alternative method to meet testing requirements in Spain for the enumeration of Legionella in water samples. METHODOLOGY The laboratory analyzed 118 environmental water samples from the Barcelona region (56 potable and 62 non-potable) in parallel by the Standard method for detection and enumeration of Legionella (ISO 11731:1998) and by Legiolert. Comparison of the recovery of the alternative method (Legiolert) and the Standard was made using ISO 17994:2014 and McNemar's binomial test statistical methods. RESULTS 44 samples were positive for Legionella (36 potable and 8 non-potable). Legiolert and the Standard method detected a similar percentage of positive samples, with Legiolert being slightly higher (31 vs 30%) and detecting higher concentrations of Legionella within the samples. ISO 17994:2014 analysis of the potable water samples found Legiolert was more sensitive than the Standard at detecting Legionella, even when complete Legionella species (L. spp.) results were considered for both methods. The two methods also demonstrated equivalent detection of L. spp. according to the McNemar's test. The comparison is significantly more in favor of Legiolert when only L. pneumophila results are considered. Each confirmation run with material extracted from positive Legiolert wells contained L. pneumophila, giving the method a specificity of 100%. Although statistical results for non-potable waters are not included because of the low number of samples, the two methods trended towards equivalence. CONCLUSIONS Relative to the Standard method, Legiolert has a greater sensitivity and selectivity, and appears to have higher recovery for L. pneumophila, and equivalent recovery when L. spp. is included in the comparison. Legiolert also has high specificity. The procedural advantages of Legiolert allow laboratories to save on resources, costs, and time and consequently to test more frequently. In conclusion, the study finds IDEXX Legiolert a suitable alternative to ISO 11731:1998.
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Affiliation(s)
- Javier Checa
- Public Health Laboratory of L'Hospitalet. Health Service, L'Hospitalet City Council, Cobalt Building. Cobalt street, 57-59, 2nd floor, 08907 L'Hospitalet de Llobregat, Barcelona, Spain.
| | - Iago Carbonell
- Public Health Laboratory of L'Hospitalet. Health Service, L'Hospitalet City Council, Cobalt Building. Cobalt street, 57-59, 2nd floor, 08907 L'Hospitalet de Llobregat, Barcelona, Spain.
| | - Neus Manero
- Public Health Laboratory of L'Hospitalet. Health Service, L'Hospitalet City Council, Cobalt Building. Cobalt street, 57-59, 2nd floor, 08907 L'Hospitalet de Llobregat, Barcelona, Spain.
| | - Inés Martí
- Public Health Laboratory of L'Hospitalet. Health Service, L'Hospitalet City Council, Cobalt Building. Cobalt street, 57-59, 2nd floor, 08907 L'Hospitalet de Llobregat, Barcelona, Spain.
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Quero S, Párraga-Niño N, Garcia-Núñez M, Pedro-Botet ML, Gavaldà L, Mateu L, Sabrià M, Mòdol JM. The impact of pipeline changes and temperature increase in a hospital historically colonised with Legionella. Sci Rep 2021; 11:1916. [PMID: 33479467 PMCID: PMC7820426 DOI: 10.1038/s41598-021-81625-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 01/01/2021] [Indexed: 01/25/2023] Open
Abstract
Healthcare-related Legionnaires’ disease has a devastating impact on high risk patients, with a case fatality rate of 30–50%. Legionella prevention and control in hospitals is therefore crucial. To control Legionella water colonisation in a hospital setting we evaluated the effect of pipeline improvements and temperature increase, analysing 237 samples over a 2-year period (first year: 129, second year: 108). In the first year, 25.58% of samples were positive for Legionella and 16.67% for amoeba. Assessing the distance of the points analysed from the hot water tank, the most distal points presented higher proportion of Legionella colonisation and lower temperatures (nearest points: 6.4% colonised, and temperature 61.4 °C; most distal points: 50% and temperature 59.1 °C). After the first year, the hot water system was repaired and the temperature stabilised. This led to a dramatic reduction in Legionella colonisation, which was negative in all the samples analysed; however, amoeba colonisation remained stable. This study shows the importance of keeping the temperature stable throughout the circuit, at around 60 °C. Special attention should be paid to the most distal points of the circuit; a fall in temperature at these weak points would favour the colonisation and spread of Legionella, because amoeba (the main Legionella reservoir) are not affected by temperature.
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Affiliation(s)
- S Quero
- Infectious Diseases Unit, Fundació Institut d'Investigació Germans Trias I Pujol, Carretera de Can Ruti, Camí de les Escoles s/n, 08916, Badalona, Barcelona, Spain. .,CIBER de Enfermedades Respiratorias, CIBERES, Av. de Monforte de Lemos, 3-5, 28029, Madrid, Spain. .,Institut d'Investigació i Innovació Parc Taulí, I3PT, Parc Taulí, 1, 08208, Sabadell, Barcelona, Spain.
| | - N Párraga-Niño
- Infectious Diseases Unit, Fundació Institut d'Investigació Germans Trias I Pujol, Carretera de Can Ruti, Camí de les Escoles s/n, 08916, Badalona, Barcelona, Spain
| | - M Garcia-Núñez
- Infectious Diseases Unit, Fundació Institut d'Investigació Germans Trias I Pujol, Carretera de Can Ruti, Camí de les Escoles s/n, 08916, Badalona, Barcelona, Spain.,CIBER de Enfermedades Respiratorias, CIBERES, Av. de Monforte de Lemos, 3-5, 28029, Madrid, Spain.,Institut d'Investigació i Innovació Parc Taulí, I3PT, Parc Taulí, 1, 08208, Sabadell, Barcelona, Spain
| | - M L Pedro-Botet
- CIBER de Enfermedades Respiratorias, CIBERES, Av. de Monforte de Lemos, 3-5, 28029, Madrid, Spain.,Hospital Universitari Germans Trias i Pujol, Carretera de Canyet, s/n, 08916, Badalona, Barcelona, Spain
| | - L Gavaldà
- Hospital Universitari de Bellvitge-IDIBELL, Feixa Llarga, s/n., 08907, L'Hospitalet de Llobregat, Barcelona, Spain
| | - L Mateu
- Hospital Universitari Germans Trias i Pujol, Carretera de Canyet, s/n, 08916, Badalona, Barcelona, Spain
| | - M Sabrià
- CIBER de Enfermedades Respiratorias, CIBERES, Av. de Monforte de Lemos, 3-5, 28029, Madrid, Spain.,Hospital Universitari Germans Trias i Pujol, Carretera de Canyet, s/n, 08916, Badalona, Barcelona, Spain
| | - J M Mòdol
- Hospital Universitari Germans Trias i Pujol, Carretera de Canyet, s/n, 08916, Badalona, Barcelona, Spain
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Ginevra C, Chastang J, David S, Mentasti M, Yakunin E, Chalker VJ, Chalifa-Caspi V, Valinsky L, Jarraud S, Moran-Gilad J. A real-time PCR for specific detection of the Legionella pneumophila serogroup 1 ST1 complex. Clin Microbiol Infect 2019; 26:514.e1-514.e6. [PMID: 31525518 DOI: 10.1016/j.cmi.2019.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 08/28/2019] [Accepted: 09/01/2019] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Legionella pneumophila serogroup 1 (Lp1) sequence type (ST) 1 is globally widespread in the environment and accounts for a significant proportion of Legionella infections, including nosocomial Legionnaires' disease (LD). This study aimed to design a sensitive and specific detection method for Lp ST1 that will underpin epidemiological investigations and risk assessment. METHODS A total of 628 Lp genomes (126 ST1s) were analyzed by comparative genomics. Interrogation of more than 900 accessory genes revealed seven candidate targets for specific ST1 detection and specific primers and hydrolysis probes were designed and evaluated. The analytical sensitivity and specificity of the seven primer and probe sets were evaluated on serially diluted DNA extracted from the reference strain CIP107629 and via qPCR applied on 200 characterized isolates. The diagnostic performance of the assay was evaluated on 142 culture-proven clinical samples from LD cases and a real-life investigation of a case cluster. RESULTS Of seven qPCR assays that underwent analytical validation, one PCR target (lpp1868) showed higher sensitivity and specificity for ST1 and ST1-like strains. The diagnostic performance of the assay using respiratory samples corresponded to a sensitivity of 95% (19/20) (95% CI (75.1-99.9)) and specificity of 100% (122/122) (95% CI (97-100)). The ST1 PCR assay could link two out of three culture-negative hospitalized LD cases to ST1 during a real-time investigation. CONCLUSION Using whole genome sequencing (WGS) data, we developed and validated a sensitive and specific qPCR assay for the detection of Lp1 belonging to the ST1 clonal complex by amplification of the lpp1868 gene. The ST1 qPCR is expected to deliver an added value for Lp control and prevention, in conjunction with other recently developed molecular assays.
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Affiliation(s)
- C Ginevra
- CIRI, Centre International de Recherche en Infectiologie, Legionella Pathogenesis Team, Univ Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, F-69007, Lyon, France; National Reference Centre of Legionella, Institute of Infectious Agents, Hospices Civils de Lyon, Lyon, France; ESCMID Study Group for Legionella Infections (ESGLI), Basel, Switzerland
| | - J Chastang
- National Reference Centre of Legionella, Institute of Infectious Agents, Hospices Civils de Lyon, Lyon, France
| | - S David
- ESCMID Study Group for Legionella Infections (ESGLI), Basel, Switzerland; Pathogen Genomics, Welcome Trust Sanger Institute, Cambridge, UK; Respiratory and Vaccine Preventable Bacteria Reference Unit, Public Health England, London, UK
| | - M Mentasti
- ESCMID Study Group for Legionella Infections (ESGLI), Basel, Switzerland; Respiratory and Vaccine Preventable Bacteria Reference Unit, Public Health England, London, UK
| | - E Yakunin
- ESCMID Study Group for Legionella Infections (ESGLI), Basel, Switzerland; Central Laboratories, Public Health Services, Ministry of Health, Jerusalem, Israel
| | - V J Chalker
- ESCMID Study Group for Legionella Infections (ESGLI), Basel, Switzerland; Respiratory and Vaccine Preventable Bacteria Reference Unit, Public Health England, London, UK
| | - V Chalifa-Caspi
- National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - L Valinsky
- Central Laboratories, Public Health Services, Ministry of Health, Jerusalem, Israel
| | - S Jarraud
- CIRI, Centre International de Recherche en Infectiologie, Legionella Pathogenesis Team, Univ Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, F-69007, Lyon, France; National Reference Centre of Legionella, Institute of Infectious Agents, Hospices Civils de Lyon, Lyon, France; ESCMID Study Group for Legionella Infections (ESGLI), Basel, Switzerland
| | - J Moran-Gilad
- ESCMID Study Group for Legionella Infections (ESGLI), Basel, Switzerland; School of Public Health, Faculty of Health Sciences, Ben-Gurion University of the Negev. Beer-Sheva, Israel; Public Health Services, Ministry of Health, Jerusalem, Israel.
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Population structure of Environmental and Clinical Legionella pneumophila isolates in Catalonia. Sci Rep 2018; 8:6241. [PMID: 29674708 PMCID: PMC5908911 DOI: 10.1038/s41598-018-24708-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 04/09/2018] [Indexed: 11/13/2022] Open
Abstract
Legionella is the causative agent of Legionnaires’ disease (LD). In Spain, Catalonia is the region with the highest incidence of LD cases. The characterisation of clinical and environmental isolates using molecular epidemiology techniques provides epidemiological data for a specific geographic region and makes it possible to carry out phylogenetic and population-based analyses. The aim of this study was to describe and compare environmental and clinical isolates of Legionella pneumophila in Catalonia using sequence-based typing and monoclonal antibody subgrouping. A total of 528 isolates were characterised. For data analysis, the isolates were filtered to reduce redundancies, and 266 isolates (109 clinical and 157 environmental) were finally included. Thirty-two per cent of the clinical isolates were ST23, ST37 and ST1 while 40% of the environmental isolates were ST284 and ST1. Although the index of diversity was higher in clinical than in environmental ST isolates, we observed that clinical STs were similar to those recorded in other regions but that environmental STs were more confined to particular study areas. This observation supports the idea that only certain STs trigger cases or outbreaks in humans. Therefore, comparison of the genomes of clinical and environmental isolates could provide important information about the traits that favour infection or environmental persistence.
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