Gezondheidsaspecten van Legionella in water

NARCIS (Netherlands)

Schets FM; de Roda Husman AM; MGB

2004-01-01

Legionella pneumophila is een veroorzaker van ernstige longontsteking bij mensen. Legionella bacterien blijken overal in waterige milieus aanwezig te zijn. Met name in kunstmatige waterige milieus kunnen mensen blootgesteld worden aan aerosolen waarin Legionella aanwezig is. Dit beknopte

Clinical Application of a Multiplex Real-Time PCR Assay for Simultaneous Detection of Legionella Species, Legionella pneumophila, and Legionella pneumophila Serogroup 1

OpenAIRE

Benitez, Alvaro J.; Winchell, Jonas M.

2014-01-01

We developed a single-tube multiplex real-time PCR assay capable of simultaneously detecting and discriminating Legionella spp., Legionella pneumophila, and Legionella pneumophila serogroup 1 in primary specimens. Evaluation of 21 clinical specimens and 115 clinical isolates demonstrated this assay to be a rapid, high-throughput diagnostic test with 100% specificity that may aid during legionellosis outbreaks and epidemiologic investigations.

Legionella in habitations

DEFF Research Database (Denmark)

Krøjgaard, Louise Hjelmar

. Other have shown that more permanent, long-term water treatments, such as copper-silver ionisation, addition of chlorine dioxide or monochloramine to the portable water can be effective against Legionella colonisation, though none of the methods completely eradicated Legionella in all treatet water...

Technologies for Legionella Control

Science.gov (United States)

Presentation includes a review of new Office of Water document entitled "Technologies for Legionella Control in Premise Plumbing Systems", and discussion on ORD research projects involving Legionella and disinfection.

Prevention of legionella. Special issue; Legionellapreventie. Themanummer

Energy Technology Data Exchange (ETDEWEB)

Van Wolferen, H. [TNO, Apeldoorn (Netherlands); Eland, A.; Meijer, J. [Procas, Rotterdam (Netherlands); Van den Brink, J. [Econosto Nederland, Capelle aan den IJssel (Netherlands); Tiedink, H. [Wilo Nederland, Beverwijk (Netherlands); Nuijten, O.W.W. [ISSO, Rotterdam (Netherlands); Brands, R. [Cumulus Nederland, Cuijk (Netherlands); Reijman, D.

2008-09-15

In seven articles attention is paid to several aspects with regard to the prevention of legionella in water heating systems: (1) an interview with an expert in this field (Will Scheffer); (2) regulations for alternative techniques; (3) experiences with collective water heaters; (4) the effect of pressure on legionella risk; (5) the prevention of legionella in cooling towers; (6) legionella safe adiabatic humidification of ambient air; (7) reducing the risk of legionella by maintenance and control. [Dutch] In 7 artikelen wordt aandacht besteed aan verschillende aspecten m.b.t. de voorkoming van legionella in verwarmingssystemen: (1) een interview met een expert op dit gebied (Will Scheffer); (2) beoordelingsrichtlijnen voor alternatieve technieken; (3) praktijkervaringen met collectieve leidingwaterinstallaties; (4) de invloed van drukverhoging op het risico van legionella; (5) legionellapreventie in koeltorens; (6) legionellaveilige adiabatische luchtbevochtiging; en (7) het beperken van het risico op legionella door onderhoud en beheer.

Legionella safety in cooling towers; Legionellaveiligheid in koeltorens

Energy Technology Data Exchange (ETDEWEB)

Kordes, B. [Kordes Advies, (Netherlands); De Bok, F. [KBBL Wijhe, (Netherlands); De Zeeuw, L. [Holland Environment Group, (Netherlands); Settels, P. [Safety, Health Services and Ergonomics, ING, (Netherlands); Oesterholt, F.; Wullings, B. [KWR Watercycle Research Institute, (Netherlands); Guiot, P. [Tevan, Gorinchem (Netherlands); Brands, R. [Cumulus Nederland, Cuijk (Netherlands); Nuijten, O. [Kennisinstituut ISSO, Rotterdam (Netherlands); Wijne, R. [Beer advocaten, Amsterdam (Netherlands)

2010-04-15

In 9 articles attention is paid to several aspects with regard to Legionella in cooling towers: representative sampling, the use of copper and silver ionization or hydrogen peroxide to prevent Legionella growth and biofilms, the use of a zero-tolerance model to control a cooling tower installation, detection of DNA of Legionella Pneumophila, legionella safety in air conditioners, the model Legionella risk analysis and control of cooling tower installations, legislation and regulations for the control of cooling tower installations with regard to the Dutch Occupational Health and Safety Act ('Arbo-wet'), and an article about a lawsuit for victims of a Legionella outbreak, caused by careless owners of a cooling tower in Amsterdam, Netherlands. [Dutch] In 9 artikelen wordt in deze aflevering aandacht besteed aan verschillende aspecten m.b.t. Legionella in koeltorens: representatieve monstername, de toepassing van koper en zilver-ionisatie of waterstofperoxide om de groei van Legionella en biofilms te voorkomen, het gebruik van een zero-tolerance model om een koeltoren installatie te controleren, detectie van DNA van Legionella Pneumophila, Legionella veiligheid in luchtbehandelingsinstallaties, het model Legionella risicoanalyse en beheersplan voor koeltoreninstallaties, de rol van de Arbo-wet, en een artikel over een rechtszaak voor slachtoffers van Legionella door onzorgvuldig beheer van een koeltoren in Amsterdam.

'Gatekeeper' unit defeats legionella.

Science.gov (United States)

Wolters, Jo

2007-03-01

Legionella presents an ongoing cause for concern in any sector where duty of care responsibilities prevail. Jo Wolters, microbiologist and sector head of TA-Aqua+ at Tour & Andersson, describes a recently developed method of legionella prevention and control.

Research on Legionella pneumophila in hospital supply networks - DOI: 10.3395/reciis.v1i2.85en

Directory of Open Access Journals (Sweden)

Aldo Pacheco Ferreira

2007-12-01

Full Text Available The species of Legionella (gram-negative aerobic bacillus are widely distributed in water environments. The Legionellaceae family comprises a group of fastidious bacteria that requires special isolation techniques, and of which the Legionella pneumophila is the member which is most commonly identified as the cause of human diseases or of the worsening of health conditions. The purpose of this work is to verify conditions in randomly chosen hospitals from the public system for the development of Legionella pneumophila, and, thus, contribute to the debate on legislation and technical standardization in the network, with the purpose of controlling and preventing the presence of this bacillus in the Brazilian hospital system. At the same time, some physicochemical and colimetric parameters (total and thermo-tolerant coliforms were evaluated aiming at defining the total quality of water used. The results show the presence of coliforms and Legionella sp in the water used in the monitored hospitals. In this way, it is shown that the maintenance of the quality of water used in hospitals is fundamental, as well as the carrying out of biological tests for the detection of Legionella pneumophila so that the necessary safety of the hospital environment can be achieved.

Betekenis van Legionella-soorten voor preventiebeleid van leidingwaterinstallaties

NARCIS (Netherlands)

Versteegh JFM; Brandsema PS; Lodder WJ; de Roda Husman AM; Schalk JAC; van der Aa NGFM; IMG; LZO; EPI

2009-01-01

Het RIVM adviseert om de huidige normstelling voor het preventiebeleid van Legionella te handhaven en niet uitsluitend op Legionella pneumophila te richten. Als andere Legionella-soorten worden aangetroffen kan er ook groei van Legionella pneumophila optreden. Als er dan geen maatregelen worden

Combined pericarditis and pneumonia caused by Legionella infection

DEFF Research Database (Denmark)

Svendsen, Jesper Hastrup; Jønsson, V; Niebuhr, U

1987-01-01

During a one year period acute pericarditis was diagnosed in 16 consecutive patients without acute infarction or malignancy. In two of these patients with both pericarditis and pneumonia Legionella infection was present. One case was caused by Legionella longbeachae and the other by both Legionella...... longbeachae and Legionella jordanis. When pericarditis is associated with pneumonia Legionella infection should be sought so that effective treatment with erythromycin may be started early....

Occurrence of Legionella in UK household showers.

Science.gov (United States)

Collins, Samuel; Stevenson, David; Bennett, Allan; Walker, Jimmy

2017-04-01

Household water systems have been proposed as a source of sporadic, community acquired Legionnaires' disease. Showers represent a frequently used aerosol generating device in the domestic setting yet little is known about the occurrence of Legionella spp. in these systems. This study has investigated the prevalence of Legionella spp. by culture and qPCR in UK household showers. Ninety nine showers from 82 separate properties in the South of England were sampled. Clinically relevant Legionella spp. were isolated by culture in 8% of shower water samples representing 6% of households. Legionella pneumophila sg1 ST59 was isolated from two showers in one property and air sampling demonstrated its presence in the aerosol state. A further 31% of showers were positive by Legionella spp. qPCR. By multi-variable binomial regression modelling Legionella spp. qPCR positivity was associated with the age of the property (p=0.02), the age of the shower (p=0.01) and the frequency of use (p=0.09). The concentration of Legionella spp. detected by qPCR was shown to decrease with increased frequency of use (p=0.04) and more frequent showerhead cleaning (p=0.05). There was no association between Legionella spp. qPCR positivity and the cold water supply or the showerhead material (p=0.65 and p=0.71, respectively). Household showers may be important reservoirs of clinically significant Legionella and should be considered in source investigations. Simple public health advice may help to mitigate the risk of Legionella exposure in the domestic shower environment. Crown Copyright © 2016. Published by Elsevier GmbH. All rights reserved.

A new Legionella species, Legionella feeleii species nova, causes Pontiac fever in an automobile plant.

Science.gov (United States)

Herwaldt, L A; Gorman, G W; McGrath, T; Toma, S; Brake, B; Hightower, A W; Jones, J; Reingold, A L; Boxer, P A; Tang, P W

1984-03-01

From 15 to 21 August 1981, Pontiac fever affected 317 automobile assembly plant workers. Results of serologic tests were negative for Mycoplasma, Chlamydia, respiratory tract viruses, and previously described legionellae. A gram-negative, rod-shaped organism (WO-44C) that did not grow on blood agar, required L-cysteine for growth, and contained large amounts of branched-chain fatty acids was isolated from a water-based coolant. The organism did not react with antisera against other legionellae, and on DNA hybridization the organism was less than 10% related to other Legionella species. Geometric mean titers found by indirect fluorescent antibody testing to WO-44C were significantly higher in ill employees than in controls (p = 0.0001). Attack rates by department decreased linearly with the department's distance from the implicated coolant system. The etiologic agent apparently was a new Legionella species; we propose the name Legionella feeleii species nova (AATC 35072). This is the first outbreak of nonpneumonic legionellosis in which the etiologic agent is not L. pneumophila, serogroup 1.

[Legionella pneumonia after the use of CPAP equipment].

Science.gov (United States)

Stolk, Jaap M; Russcher, Anne; van Elzakker, Erika P M; Schippers, Emile F

2016-01-01

Continuous positive airway pressure (CPAP) equipment can be colonised by Legionellae and might cause Legionella pneumonia in the user. However, there is no reported case of Legionella pneumonia related to CPAP equipment in which an identical Legionella was found in both the patient and the CPAP equipment. A 51-year-old man came to the Emergency Department with fever, confusion and dyspnoea that had been present for 3 days. His medical history included obstructive sleep apnoea, for which he had been using CPAP therapy at home for 10 weeks. The CPAP equipment showed signs of poor maintenance. Chest X-ray revealed a pulmonary consolidation. Laboratory investigation resulted in a positive urine antigen test for Legionella. Water from the CPAP equipment and sputum from the patient revealed Legionella pneumophila. Serotyping and sequence-based typing showed an identical L. pneumophila serotype 1 ST37. It is important to be aware that CPAP equipment can be colonised with Legionellae and might cause Legionella pneumonia. It is therefore necessary to ask about CPAP therapy in a patient with community-acquired pneumonia.

Survey of Legionella spp. in Mud Spring Recreation Area

Science.gov (United States)

Hsu, B.-M.; Ma, P.-H.; Su, I.-Z.; Chen, N.-S.

2009-04-01

Legionella genera are parasites of FLA, and intracellular bacterial replication within the FLA plays a major role in the transmission of disease. At least 13 FLA species—including Acanthamoeba spp., Naegleria spp., and Hartmannella spp.—support intracellular bacterial replication. In the study, Legionellae were detected with microbial culture or by direct DNA extraction and analysis from concentrated water samples or cultured free-living amoebae, combined with molecular methods that allow the taxonomic identification of these pathogens. The water samples were taken from a mud spring recreation area located in a mud-rock-formation area in southern Taiwan. Legionella were detected in 15 of the 34 samples (44.1%). Four of the 34 samples analyzed by Legionella culture were positive for Legionella, five of 34 were positive for Legionella when analyzed by direct DNA extraction and analysis, and 11 of 34 were positive for amoebae-resistant Legionella when analyzed by FLA culture. Ten samples were shown to be positive for Legionella by one analysis method and five samples were shown to be positive by two analysis methods. However, Legionella was detected in no sample by all three analysis methods. This suggests that the three analysis methods should be used together to detect Legionella in aquatic environments. In this study, L. pneumophila serotype 6 coexisted with A. polyphaga, and two uncultured Legionella spp. coexisted with either H. vermiformis or N. australiensis. Of the unnamed Legionella genotypes detected in six FLA culture samples, three were closely related to L. waltersii and the other three were closely related to L. pneumophila serotype 6. Legionella pneumophila serotype 6, L. drancourtii, and L. waltersii are noted endosymbionts of FLA and are categorized as pathogenic bacteria. This is significant for human health because these Legionella exist within FLA and thus come into contact with typically immunocompromised people.

Multiplex real-time PCR assay for Legionella species.

Science.gov (United States)

Kim, Seung Min; Jeong, Yoojung; Sohn, Jang Wook; Kim, Min Ja

2015-12-01

Legionella pneumophila serogroup 1 (sg1) accounts for the majority of infections in humans, but other Legionella species are also associated with human disease. In this study, a new SYBR Green I-based multiplex real-time PCR assay in a single reaction was developed to allow the rapid detection and differentiation of Legionella species by targeting specific gene sequences. Candidate target genes were selected, and primer sets were designed by referring to comparative genomic hybridization data of Legionella species. The Legionella species-specific groES primer set successfully detected all 30 Legionella strains tested. The xcpX and rfbA primers specifically detected L. pneumophila sg1-15 and L. pneumophila sg1, respectively. In addition, this assay was validated by testing clinical samples and isolates. In conclusion, this novel multiplex real-time PCR assay might be a useful diagnostic tool for the rapid detection and differentiation of Legionella species in both clinical and epidemiological studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nucleotide sequence analysis of the Legionella micdadei mip gene, encoding a 30-kilodalton analog of the Legionella pneumophila Mip protein

DEFF Research Database (Denmark)

Bangsborg, Jette Marie; Cianciotto, N P; Hindersson, P

1991-01-01

After the demonstration of analogs of the Legionella pneumophila macrophage infectivity potentiator (Mip) protein in other Legionella species, the Legionella micdadei mip gene was cloned and expressed in Escherichia coli. DNA sequence analysis of the L. micdadei mip gene contained in the plasmid p...... homology with the mip-like genes of several Legionella species. Furthermore, amino acid sequence comparisons revealed significant homology to two eukaryotic proteins with isomerase activity (FK506-binding proteins)....

Alternative sources of Legionella bacteria

NARCIS (Netherlands)

van Heijnsbergen, H.H.L.

2017-01-01

Legionella bacteria can cause Legionnaires’ disease (LD) in humans. Symptoms of LD can range from mild disease to severe pneumonia with sometimes fatal outcome. In the Netherlands, the most important infective agent is Legionella pneumophila. L. pneumophila infection is associated with aquatic

Legionella confirmation in cooling tower water

Science.gov (United States)

Farhat, Maha; Shaheed, Raja A.; Al-Ali, Haidar H.; Al-Ghamdi, Abdullah S.; Al-Hamaqi, Ghadeer M.; Maan, Hawraa S.; Al-Mahfoodh, Zainab A.; Al-Seba, Hussain Z.

2018-01-01

Objectives: To investigate the presence of Legionella spp in cooling tower water. Legionella proliferation in cooling tower water has serious public health implications as it can be transmitted to humans via aerosols and cause Legionnaires’ disease. Methods: Samples of cooling tower water were collected from King Fahd Hospital of the University (KFHU) (Imam Abdulrahman Bin Faisal University, 2015/2016). The water samples were analyzed by a standard Legionella culture method, real-time polymerase chain reaction (RT-PCR), and 16S rRNA next-generation sequencing. In addition, the bacterial community composition was evaluated. Results: All samples were negative by conventional Legionella culture. In contrast, all water samples yielded positive results by real-time PCR (105 to 106 GU/L). The results of 16S rRNA next generation sequencing showed high similarity and reproducibility among the water samples. The majority of sequences were Alpha-, Beta-, and Gamma-proteobacteria, and Legionella was the predominant genus. The hydrogen-oxidizing gram-negative bacterium Hydrogenophaga was present at high abundance, indicating high metabolic activity. Sphingopyxis, which is known for its resistance to antimicrobials and as a pioneer in biofilm formation, was also detected. Conclusion: Our findings indicate that monitoring of Legionella in cooling tower water would be enhanced by use of both conventional culturing and molecular methods. PMID:29436561

Legionella prevalence and risk of legionellosis in Japanese households.

Science.gov (United States)

Kuroki, T; Watanabe, Y; Teranishi, H; Izumiyama, S; Amemura-Maekawa, J; Kura, F

2017-05-01

This study determined the occurrence of legionellae in private houses for which there were no available data on aquatic environments other than the water supply system. From June 2013 to November 2014, we collected 138 water and 90 swab samples from aquatic environments in 19 houses. Legionella DNA was detected via a loop-mediated isothermal amplification assay in 66 (47·8%) water and 17 (18·9%) swab samples. High Legionella DNA detection rates were observed in water samples from washing machines and aquariums. Legionella spp. was isolated from 9 (6·5%) water and 3 (3·3%) swab samples. Legionella pneumophila SG 1 was detected from the outlet water of a bathtub spout and a bath sponge. Use of amoebic co-culture effectively increased legionellae and Legionella DNA detection rates from all sample types. A logistic regression analysis revealed that the heterotrophic plate count was significantly related to Legionella contamination. Our findings indicate that there is a risk of legionellosis from exposure to Legionella spp. in a variety of aquatic environments in residential houses. Control measures for legionellae in houses should include frequent cleaning and disinfecting to reduce heterotrophic bacteria in water and, where possible, preventing aerosolization from aquatic environments.

May car washing represent a risk for Legionella infection?

Science.gov (United States)

Baldovin, T; Pierobon, A; Bertoncello, C; Destefani, E; Gennari, M; Stano, A; Baldo, V

2018-01-01

Legionella is a ubiquitous Gram-negative bacterium naturally found in aquatic environments. It can pose a health problem when it grows and spreads in man-made water systems. Legionella pneumophila is the most common cause of Legionnaires' disease nowadays, a community-acquired pneumonia with pulmonary symptoms and chest radiography no different from any other form of infectious pneumonia. Legionella monitoring is important for public health reasons, including the identification of unusual environmental sources of Legionella. We report two cases of Legionnaires' disease associated with two different car wash installations in the province of Vicenza, in the Veneto region, northeastern Italy. Patients were not employees of the car wash installations, but users of the service. In both cases, Legionella antigen was detected in urine using the Alere BinaxNOW® Legionella Urinary Antigen, and Legionella antibodies were detected in serum using SERION ELISA classic Legionella pneumophila 1-7 IgG and IgM. Water samples were also analyzed as part of the surveillance program for Legionella prevention and control in compliance with the Italian guidelines. Both patients had clinical symptoms and chest radiography compatible with pneumonia, and only one of them had diabetes as a risk factor. Legionella urinary antigen and serological test on serum samples were positive for Legionella in both patients, even if much slighter in the case A due to the retrospective serological investigation performed a year later the episode and after the second clinical case occurred in the same district. The environmental investigations highlighted two different car wash plants as potential source of infection. A certified company using shock hyperchlorination was asked to disinfect the two plants and, subsequently, control samples resulted negative for Legionella pneumophila. Any water source producing aerosols should be considered at risk for the transmission of Legionella bacteria, including car

Characterization of Legionella Species from Watersheds in British Columbia, Canada

Science.gov (United States)

Peabody, Michael A.; Caravas, Jason A.; Morrison, Shatavia S.; Mercante, Jeffrey W.; Prystajecky, Natalie A.; Raphael, Brian H.

2017-01-01

ABSTRACT Legionella spp. present in some human-made water systems can cause Legionnaires’ disease in susceptible individuals. Although legionellae have been isolated from the natural environment, variations in the organism’s abundance over time and its relationship to aquatic microbiota are poorly understood. Here, we investigated the presence and diversity of legionellae through 16S rRNA gene amplicon and metagenomic sequencing of DNA from isolates collected from seven sites in three watersheds with varied land uses over a period of 1 year. Legionella spp. were found in all watersheds and sampling sites, comprising up to 2.1% of the bacterial community composition. The relative abundance of Legionella tended to be higher in pristine sites than in sites affected by agricultural activity. The relative abundance levels of Amoebozoa, some of which are natural hosts of legionellae, were similarly higher in pristine sites. Compared to other bacterial genera detected, Legionella had both the highest richness and highest alpha diversity. Our findings indicate that a highly diverse population of legionellae may be found in a variety of natural aquatic sources. Further characterization of these diverse natural populations of Legionella will help inform prevention and control efforts aimed at reducing the risk of Legionella colonization of built environments, which could ultimately decrease the risk of human disease. IMPORTANCE Many species of Legionella can cause Legionnaires’ disease, a significant cause of bacterial pneumonia. Legionella in human-made water systems such as cooling towers and building plumbing systems are the primary sources of Legionnaires’ disease outbreaks. In this temporal study of natural aquatic environments, Legionella relative abundance was shown to vary in watersheds associated with different land uses. Analysis of the Legionella sequences detected at these sites revealed highly diverse populations that included potentially novel

[The clinical value of urinary antigen detection of Legionella pneumonia].

Science.gov (United States)

Jiang, Luxi; Chen, Yu; Xia, Shuyue; Ma, Jiangwei; Zhao, Hongwen; Lu, Ye; Tao, Sixu; Zhao, Li

2015-01-01

To investigate the clinical value of urinary antigen detection of Legionella, and to describe the clinical characteristics of Legionella pneumonia. Patients with suspected Legionella pneumonia were enrolled from the Respiratory departments of 3 tertiary hospitals in Shenyang during May 2011 to November 2013. Urinary Legionella antigen was detected for all the enrolled patients. Bacterial culture, polymerase chain reaction (PCR) for Legionella, and double Legionella antibody detection in sera were performed for each patient whose urinary antigen was positive. Patients confirmed to have Legionella pneumonia were pooled and analyzed. Totally 13 cases presenting with pneumonia were positive for Legionella by the urinary antigen method, and in one of them Legionella strain was isolated from the secretion of lower respiratory tract. PCR detection was performed in 8 patients, and 4 of them were positive. Legionella antibody detection was performed in 12 patients, and 7 of them were positive. Nine patients had a history of exposure to Legionella high-risk environments. The characteristics of the cases with Legionella pneumonia were as follows: characteristic orange sputum in 4 patients, digestive symptoms in 6, neurologic disorders in 8, hyponatremia in 10, hypoxia with oxygenation index 130) in 8 patients . Chest CT scan showed bilateral involvement in 6, ground-glass opacity combined with consolidation in 11, and moderate pleural effusion in 11 patients. Cavity and reversed halo sign were found in one case, respectively. All of the patients received fluoroquinolone treatment, and 11 patients recovered completely while 2 died of multiple organ dysfunction syndrome, one of them was complicated with secondary infection. Detection of urinary antigen of Legionella is very useful in the diagnosis of Legionella pneumonia. Attention should be paid to exposure history to the high-risk environments and multiple organ impairment when Legionella infection is suspected. Orange sputum

Detectiemethoden voor legionella in water

NARCIS (Netherlands)

Schalk M; de Roda Husman AM; LZO; cib

2011-01-01

Het RIVM heeft een overzicht gemaakt van bestaande en nieuwe methoden om legionella in water aan te tonen. Dit is gemaakt in opdracht van de VROM Inspectie, die inzicht wil hebben in de kenmerken en toepassingsmogelijkheden van bestaande en nieuwe methoden.
Legionella komt overal in het milieu

First Case of Legionnaire's Disease Caused by Legionella anisa in Spain and the Limitations on the Diagnosis of Legionella non-pneumophila Infections.

Science.gov (United States)

Vaccaro, Lucianna; Izquierdo, Fernando; Magnet, Angela; Hurtado, Carolina; Salinas, Mireya B; Gomes, Thiago Santos; Angulo, Santiago; Salso, Santiago; Pelaez, Jesús; Tejeda, Maria Isabel; Alhambra, Almudena; Gómez, Carmen; Enríquez, Ana; Estirado, Eva; Fenoy, Soledad; Del Aguila, Carmen

2016-01-01

Legionnaires' disease is a severe form of pneumonia, with worldwide relevance, caused by Legionella spp. Approximately 90% of all cases of legionellosis are caused by Legionella pneumophila, but other species can also be responsible for this infection. These bacteria are transmitted by inhalation of aerosols or aspiration of contaminated water. In Spain, environmental studies have demonstrated the presence of Legionella non-pneumophila species in drinking water treatment plants and water distribution networks. Aware that this evidence indicates a risk factor and the lack of routine assays designed to detect simultaneously diverse Legionella species, we analyzed 210 urine samples from patients presenting clinical manifestations of pneumonia using a semi-nested PCR for partial amplification of the 16S rDNA gene of Legionella and a diagnostic method used in hospitals for Legionella antigen detection. In this study, we detected a total of 15 cases of legionellosis (7.1%) and the first case of Legionnaires' disease caused by L. anisa in Spain. While the conventional method used in hospitals could only detect four cases (1.9%) produced by L. pneumophila serogroup 1, using PCR, the following species were identified: Legionella spp. (10/15), L. pneumophila (4/15) and L. anisa (1/15). These results suggest the need to change hospital diagnostic strategies regarding the identification of Legionella species associated with this disease. Therefore, the detection of Legionella DNA by PCR in urine samples seems to be a suitable alternative method for a sensitive, accurate and rapid diagnosis of Legionella pneumonia, caused by L. pneumophila and also for L. non-pneumophila species.

Aerobiology of the built environment: Synergy between Legionella and fungi.

Science.gov (United States)

Alum, Absar; Isaacs, Galahad Zachariah

2016-09-02

The modern built environment (BE) design creates unique ecological niches ideal for the survival and mutual interaction of microbial communities. This investigation focused on the synergistic relations between Legionella and the fungal species commonly found in BEs and the impact of these synergistic relationships on the survival and transmission of Legionella. A field study was conducted to identify the types and concentrations of fungi in BEs. The fungal isolates purified from BEs were cocultured with Legionella to study their synergistic association. Cocultured Legionella cells were aerosolized in an air-tight chamber to evaluate the efficacy of ultraviolet (UV) to inactivate these cells. Aspergillus, Alternaria, and Cladosporium were the most common fungi detected in samples that tested positive for Legionella. After coculturing, Legionella cells were detected inside fungal hyphae. The microscopic observations of Legionella internalization in fungal hyphae were confirmed by molecular analyses. UV disinfection of the aerosolized Legionella cells that were cocultured with fungi indicated that fungal spores and propagules act as a shield against UV radiation. The shield effect of fungal spores on Legionella cells was quantified at >2.5 log10. This study provides the first evidence, to our knowledge, of Legionella cell presence inside fungi detected in an indoor environment. This symbiotic relationship with fungi results in longer survival of Legionella under ambient conditions and provides protection against UV rays. Copyright © 2016. Published by Elsevier Inc.

Growth regulation of Legionella Pneumophila in biofilms and amoebae; Wachstumsregulation von Legionella Pneumophila in Biofilmen und Amoeben

Energy Technology Data Exchange (ETDEWEB)

Hilbi, H.

2006-07-01

This final report for the Swiss Federal Office of Energy (SFOE) presents the results of studies made on the regulation of the growth of Legionella Pneumophila bacteria in biofilms and amoebae. In a first project, the formation of biofilms by Legionella Pneumophila bacteria was analysed in static and dynamic systems using a complex growth medium. Under static and dynamic clinical and environmental conditions, the adherence of the biofilms on polystyrene tissue was studied. This was also examined under dynamic flow conditions. In a second part of the project, the regulation of growth of Legionella Pneumophila in amoebae was examined in that changes were made to the genome of the bacteria. The importance of the work for the de-activation of Legionella Pneumophila bacteria in biofilms is noted in the conclusions of the report.

In Vitro Activity of ABT-773 against Legionella pneumophila, Its Pharmacokinetics in Guinea Pigs, and Its Use to Treat Guinea Pigs with L. pneumophila Pneumonia

OpenAIRE

Edelstein, Paul H.; Higa, F.; Edelstein, Martha A. C.

2001-01-01

The activity of ABT-773 was studied against extracellular and intracellular Legionella pneumophila and for the treatment of guinea pigs with L. pneumophila pneumonia. The ABT-773 MIC at which 50% of isolates are inhibited (MIC50) for 20 different Legionella sp. strains was 0.016 μg/ml, whereas the MIC50s of clarithromycin and erythromycin were 0.032 and 0.125 μg/ml, respectively. ABT-773 (1 μg/ml) was bactericidal for two L. pneumophila strains grown in guinea pig alveolar macrophages. In con...

Legionella (Legionnaires' Disease and Pontiac Fever): Causes and Transmission

Science.gov (United States)

... are not a risk for Legionella growth. How Legionella Affects Building Water Systems and People Learn four key steps that can lead to Legionella growing in building water systems and spreading to ...

Legionella (Legionnaires' Disease and Pontiac Fever): Diagnosis

Science.gov (United States)

... Search Form Controls Cancel Submit Search The CDC Legionella (Legionnaires' Disease and Pontiac Fever) Note: Javascript is ... message, please visit this page: About CDC.gov . Legionella Home About the Disease Causes, How it Spreads, & ...

Trend of Legionella colonization in hospital water supply.

Science.gov (United States)

D'Alessandro, D; Fabiani, M; Cerquetani, F; Orsi, G B

2015-01-01

In many nosocomial Legionella outbreaks water distribution systems are the most frequent source of infection. Considering the hospital waterline old age, an investigation on colonization by Legionella spp was carried out in order to evaluate the pipeline system weaknesses and to implement environmental preventive measures. From 2004 to 2010, overall 97 samples from the water line were collected. The samples were analyzed according to the italian Legionella spp standard methods; water temperature, pH and residual free chlorine were determined at the time of collection. X2 test, exact-test and t-test were used to compare proportions and means. Overall 28 samples (23.7%) were positive for Legionella spp, and five of them (17.9%) exceeded the threshold level >104 cfu/L. The number of positive samples varied along the years, showing a significant increasing trend (X2 for trend = 11.5; pLegionella spp by comparison to negative ones showed a lower free chlorine concentration (0.08 mg/L vs 0.15 mg/L) and a higher water temperature (46.1° vs 42.7°). Actually the percentage of positive samples decreased significantly with the increasing in free chlorine in the water (X2 for trend = 8.53; pLegionella. All hospital buildings were colonized by Legionella spp, although 80% of samples >104 cfu/L occurred in the C-building. No cases of nosocomial legionellosis were reported during the study period. Hospital water system showed a diffuse colonization by Legionella spp, although the degree of contamination reached the threshold level (>104 cfu/L) only in a small percentage of samples, showing a substantial effectiveness of the control measures applied.

Effect of UV irradiation (253.7 nm) on free Legionella and Legionella associated with its amoebae hosts.

Science.gov (United States)

Cervero-Aragó, Sílvia; Sommer, Regina; Araujo, Rosa M

2014-12-15

Water systems are the primary reservoir for Legionella spp., where the bacteria live in association with other microorganisms, such as free-living amoebae. A wide range of disinfection treatments have been studied to control and prevent Legionella colonization but few of them were performed considering its relation with protozoa. In this study, the effectiveness of UV irradiation (253.7 nm) using low-pressure lamps was investigated as a disinfection method for Legionella and amoebae under controlled laboratory conditions. UV treatments were applied to 5 strains of Legionella spp., 4 strains of free-living amoeba of the genera Acanthamoeba and Vermamoeba, treating separately trophozoites and cysts, and to two different co-cultures of Legionella pneumophila with the Acanthamoeba strains. No significant differences in the UV inactivation behavior were observed among Legionella strains tested which were 3 logs reduced for fluences around 45 J/m(2). UV irradiation was less effective against free-living amoebae; which in some cases required up to 990 J/m(2) to obtain the same population reduction. UV treatment was more effective against trophozoites compared to cysts; moreover, inactivation patterns were clearly different between the genus Acanthamoeba and Vermamoeba. For the first time data about Vermamoeba vermiformis UV inactivation has been reported in a study. Finally, the results showed that the association of L. pneumophila with free-living amoebae decreases the effectiveness of UV irradiation against the bacteria in a range of 1.5-2 fold. That fact demonstrates that the relations established between different microorganisms in the water systems can modify the effectiveness of the UV treatments applied. Copyright © 2014 Elsevier Ltd. All rights reserved.

Legionella spp. in dental unit waterlines.

Science.gov (United States)

Sedlata Juraskova, E; Sedlackova, H; Janska, J; Holy, O; Lalova, I; Matouskova, I

2017-01-01

To determine the current presence of Legionella spp. in the output water of dental unit waterlines (DUWLs) and examine its mitigation by disinfection at the Institute of Dentistry and Oral Sciences, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc. The first stage of our survey involved collecting samples of DUWL output water from 50 dental chair units (DCUs), and 2 samples of the incoming potable water. In October 2015, a one-time disinfection (1 % Stabimed) of DUWLs was conducted. This was followed by collecting 10 control samples (survey stage 2). From the total of 50 samples (survey stage 1), 18 samples (36.0 %) tested positive for Legionella spp. Following the disinfection, nine of the ten samples no longer showed any presence of Legionella. Based on culture results, the one-time disinfection (1 % Stabimed) was effective. We are unable to comment on the duration of positive effect of disinfection on the occurrence of Legionella spp. in the outlet water. It was a one-time survey (Tab. 2, Ref. 32).

Isolation of Legionella pneumophila from hotels of Greece.

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Alexiou, S D; Antoniadis, A; Papapaganagiotou, J; Stefanou, T

1989-03-01

Twenty water samples collected from 6 hotels situated in various areas of Greece were examined for the presence of Legionella pneumophila and Legionella-like organisms. Five of the six hotels included in this investigation were associated with cases of legionellosis. Legionella pneumophila serogroups 1 and 8 were isolated from four of six hotels, mainly from the hot water supply system. This is the first isolation and identification of L. pneumophila in Greece.

Surveillance of parasitic Legionella in surface waters by using immunomagnetic separation and amoebae enrichment.

Science.gov (United States)

Hsu, Tsui-Kang; Wu, Shu-Fen; Hsu, Bing-Mu; Kao, Po-Min; Tao, Chi-Wei; Shen, Shu-Min; Ji, Wen-Tsai; Huang, Wen-Chien; Fan, Cheng-Wei

2015-01-01

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.

Characterization of a Legionella micdadei mip mutant

DEFF Research Database (Denmark)

O'Connell, W A; Bangsborg, Jette Marie; Cianciotto, N P

1995-01-01

The pathogenesis of Legionella micdadei is dependent upon its ability to infect alveolar phagocytes. To better understand the basis of intracellular infection by this organism, we examined the importance of its Mip surface protein. In Legionella pneumophila, Mip promotes infection of both human...

Vectorial role of Acanthamoeba in Legionella propagation in water for human use.

Science.gov (United States)

Magnet, A; Peralta, R H S; Gomes, T S; Izquierdo, F; Fernandez-Vadillo, C; Galvan, A L; Pozuelo, M J; Pelaz, C; Fenoy, S; Del Águila, C

2015-02-01

Legionella spp. is the causative agent of Legionnaires' disease and is transmitted through aerosols emanating from man-made water systems. Legionella resistance to water treatments has been related to its association with environmental amoebae such as Acanthamoeba. Due to the high presence of this protozoon in Spain and the high rate of notification of Legionnaires' disease of this country, the aims of this work were to study the coexistence of these bacteria and protozoa in water as well as their interaction. The usefulness of Acanthamoeba co-culture for the isolation of environmental Legionella was also studied. For this purpose, 70 water samples were collected in 2011 from three Drinking Water Treatment Plants, three Wastewater Treatment Plants and five Natural Pools in Spain. Acanthamoeba was found by PCR in 87.1% (61/70) samples and, by culture in 85.7% (60/70) samples. Legionella was detected by PCR in 58.6% (41/70) of water samples, in 5.7% (4/70) by agar culture and 75.7% (53/70) by Acanthamoeba co-culture. From the 54 Acanthamoeba water isolates, Legionella was detected in 43 of them independently of Acanthamoeba's genotype (T3, T4 and T11). Legionella feeleii, Legionella birminghamiensis, Legionella gresilensis/berliardensis, Legionella fairfieldensis, Legionella drozanski and Legionella falloni were identified. In conclusion, our results showed that environmental Acanthamoeba is infected by Legionella to a high percentage, and due to its ubiquity, high resistance and its pathogenic potential per se, new methods for its elimination should be studied. Also, the high effectivity of Acanthamoeba co-culture for Legionella detection has been shown. Copyright © 2014 Elsevier B.V. All rights reserved.

The Legionella micdadei flagellin

DEFF Research Database (Denmark)

Bangsborg, Jette Marie; Hindersson, P; Shand, G

1995-01-01

To study the structure and function of the Legionella flagellum, we screened a genomic L. micdadei library in Escherichia coli for expression of the flagellin (Fla) subunit. One recombinant clone, JM105 (pHI5588), producing a truncated Fla protein of 40.5 kDa was identified. The plasmid pHI5588...... shared a high degree of homology with other flagellin genes in the amino- and carboxy termini, whereas the central region was found to be nonconserved. The fla sequence will facilitate the cloning of Fla proteins from other Legionella species and the study of flagella in the pathogenesis of Legionnaires...

Legionella-uitbraak in Amsterdam: koeltoren als bron

NARCIS (Netherlands)

Hoek, J A R van den; IJzerman, E P F; Coutinho, Roel A

2006-01-01

During the period 6-28 July 2006, 30 confirmed cases of Legionella infection were identified in Amsterdam, 2 of which were fatal. All had a positive urinary antigen test, by which Legionella pneumophila serogroup I could be demonstrated. Consultations between the parties involved in the control of

Confirmed and Potential Sources of Legionella Reviewed

NARCIS (Netherlands)

van Heijnsbergen, Eri; Schalk, Johanna A C; Euser, Sjoerd M; Brandsema, Petra S; den Boer, Jeroen W; de Roda Husman, Ana Maria|info:eu-repo/dai/nl/139498281

2015-01-01

Legionella bacteria are ubiquitous in natural matrices and man-made systems. However, it is not always clear if these reservoirs can act as source of infection resulting in cases of Legionnaires' disease. This review provides an overview of reservoirs of Legionella reported in the literature, other

Eliminating Legionella by inhibiting BCL-XL to induce macrophage apoptosis.

Science.gov (United States)

Speir, Mary; Lawlor, Kate E; Glaser, Stefan P; Abraham, Gilu; Chow, Seong; Vogrin, Adam; Schulze, Keith E; Schuelein, Ralf; O'Reilly, Lorraine A; Mason, Kylie; Hartland, Elizabeth L; Lithgow, Trevor; Strasser, Andreas; Lessene, Guillaume; Huang, David C S; Vince, James E; Naderer, Thomas

2016-02-24

Human pathogenic Legionella replicate in alveolar macrophages and cause a potentially lethal form of pneumonia known as Legionnaires' disease(1). Here, we have identified a host-directed therapeutic approach to eliminate intracellular Legionella infections. We demonstrate that the genetic deletion, or pharmacological inhibition, of the host cell pro-survival protein BCL-XL induces intrinsic apoptosis of macrophages infected with virulent Legionella strains, thereby abrogating Legionella replication. BCL-XL is essential for the survival of Legionella-infected macrophages due to bacterial inhibition of host-cell protein synthesis, resulting in reduced levels of the short-lived, related BCL-2 pro-survival family member, MCL-1. Consequently, a single dose of a BCL-XL-targeted BH3-mimetic therapy, or myeloid cell-restricted deletion of BCL-XL, limits Legionella replication and prevents lethal lung infections in mice. These results indicate that repurposing BH3-mimetic compounds, originally developed to induce cancer cell apoptosis, may have efficacy in treating Legionnaires' and other diseases caused by intracellular microbes.

Legionella risk assessment in cruise ships and ferries.

Science.gov (United States)

Laganà, Pasqualina; Gambuzza, Maria Elsa; Delia, Santi

2017-06-12

Introduction. The increasing development of marine traffic has led to a rise in the incidence of legionellosis among travellers. It occurs in similar environments, especially closed and crowded, and aboard ships Legionella survives and multiplies easily in water pipes, spreading into the environment through air conditioning systems and water distribution points. Although in recent years in the construction of cruise ships preventive measures aimed at curbing the proliferation of Legionella (design, materials, focus on the operation and maintenance of the water system), have been taken account, little or no attention has been paid to small ships which, in many cases, are old and not well maintained. Objective. The aim of the study was to evaluate the frequency and severity of Legionella contamination in ferries and cruise ships in order to adopt more specific control measures. Materials and method. A prevalence study was carried out on 10 ferries and 6 cruise ships docking or in transit across the port of Messina (Sicily, Italy). Water and air samples collected from many critical points were tested for qualitative and quantitative identification of Legionella. Results and conclusions. Legionella pneumophila sg 1 was isolated from the samples of shower and tap water in 7 (70%) of the 10 ferries examined, and in 3 (33%) of the 6 cruise ships examined, and L. pneumophila sg 2-14 in 8 (80%) and 1 (16.7%) of these ships, respectively. No Legionella contamination was found in whirlpool baths, air and ice samples. In conclusion, the data obtained confirm higher levels of Legionella contamination in local ferries and cruise ships, underlining the need to adopt corrective actions more specific for these smaller vessels.

Population structure of Legionella spp. from environmental samples in Gabon, 2013.

Science.gov (United States)

Ehrhardt, Jonas; Alabi, Abraham S; Kuczius, Thorsten; Tsombeng, Francis Foguim; Becker, Karsten; Kremsner, Peter G; Schaumburg, Frieder; Esen, Meral

2015-07-01

Aquatic environments are the most important source for Legionella spp. infections such as Legionnaires' disease and Pontiac fever. The reservoirs of Legionella spp. are mostly unclear in sub-Saharan Africa. The aim of this study, conducted in 2013, was to identify geographical areas of an increased risk for exposure to Legionella spp., and to describe the population structure of Legionella spp. from different water sources in a cross-sectional study in Gabon. Fresh water samples (n = 200) were cultured on Legionella selective agar; species were confirmed by MALDI-TOF, a Legionella pneumophila specific real-time PCR and 16S RNA gene sequencing. Serogroups were identified by agglutination test. The population structure was assessed by multilocus sequence typing (MLST). Legionella spp. isolates (n = 29) were frequently found in the hospital setting particularly in hot water systems. Open water bodies (i.e. rivers, lakes) were not contaminated with Legionella spp. Isolated L. pneumophila mainly belonged to serogroups 2-14 (n = 19) and MLST sequence type ST1, ST75 (and related STs) and ST1911. In conclusion, hospitalized patients might have an increased risk to become infected with Legionella spp. in the studied areas in Gabon, particularly if they have risk factors such as comorbidities. Both broadly extended (ST1, ST75) and local lineages (ST1911) were present in our setting. Copyright © 2015 Elsevier B.V. All rights reserved.

Legionella (Legionnaires' Disease and Pontiac Fever): Fast Facts

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... Search Form Controls Cancel Submit Search The CDC Legionella (Legionnaires' Disease and Pontiac Fever) Note: Javascript is ... message, please visit this page: About CDC.gov . Legionella Home About the Disease Causes, How it Spreads, & ...

Survey of Legionella Species Found in Thai Soil

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Tatiana C. Travis

2012-01-01

Full Text Available Members of the Gram-negative genus Legionella are typically found in freshwater environments, with the exception of L. longbeachae, which is present in composts and potting mixes. When contaminated aerosols are inhaled, legionellosis may result, typically as either the more serious pneumonia Legionnaires’ disease or the less severe flu-like illness Pontiac fever. It is presumed that all species of the genus Legionella are capable of causing disease in humans. As a followup to a prior clinical study of legionellosis in rural Thailand, indigenous soil samples were collected proximal to cases’ homes and workplaces and tested for the presence of legionellae by culture. We obtained 115 isolates from 22/39 soil samples and used sequence-based methods to identify 12 known species of Legionella represented by 87 isolates.

Rainfall is a risk factor for sporadic cases of Legionella pneumophila pneumonia.

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Carolina Garcia-Vidal

Full Text Available It is not known whether rainfall increases the risk of sporadic cases of Legionella pneumonia. We sought to test this hypothesis in a prospective observational cohort study of non-immunosuppressed adults hospitalized for community-acquired pneumonia (1995-2011. Cases with Legionella pneumonia were compared with those with non-Legionella pneumonia. Using daily rainfall data obtained from the regional meteorological service we examined patterns of rainfall over the days prior to admission in each study group. Of 4168 patients, 231 (5.5% had Legionella pneumonia. The diagnosis was based on one or more of the following: sputum (41 cases, antigenuria (206 and serology (98. Daily rainfall average was 0.556 liters/m(2 in the Legionella pneumonia group vs. 0.328 liters/m(2 for non-Legionella pneumonia cases (p = 0.04. A ROC curve was plotted to compare the incidence of Legionella pneumonia and the weighted median rainfall. The cut-off point was 0.42 (AUC 0.54. Patients who were admitted to hospital with a prior weighted median rainfall higher than 0.42 were more likely to have Legionella pneumonia (OR 1.35; 95% CI 1.02-1.78; p = .03. Spearman Rho correlations revealed a relationship between Legionella pneumonia and rainfall average during each two-week reporting period (0.14; p = 0.003. No relationship was found between rainfall average and non-Legionella pneumonia cases (-0.06; p = 0.24. As a conclusion, rainfall is a significant risk factor for sporadic Legionella pneumonia. Physicians should carefully consider Legionella pneumonia when selecting diagnostic tests and antimicrobial therapy for patients presenting with CAP after periods of rainfall.

Legionella prevalence and risk of legionellosis in Hungarian hospitals.

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Barna, Zsófia; Kádár, Mihály; Kálmán, Emese; Róka, Eszter; Szax, Anita Sch; Vargha, Márta

2015-12-01

Nosocomial legionellosis is a growing concern worldwide. In Hungary, about 20% of the reported cases are health-care associated, but in the absence of legal regulation, environmental monitoring of Legionella is not routinely performed in hospitals. In the present study, 23 hospitals were investigated. The hot water distribution system was colonized by Legionella in over 90%; counts generally exceeded the public health limit value. Hot water temperature was critically low in all systems (Legionella prevalence (OR = 28.0, 27.3, 27.7, respectively). Risk management interventions (including thermal or chemical disinfection) were only efficient if the system operation was optimized. Though the risk factors were similar, in those hospitals where nosocomial legionellosis was reported, Legionella counts and the proportion of L. pneumophila sg 1 isolates were significantly higher. The results of environmental prevalence of legionellae in hospitals suggest that the incidence of nosocomial legionellosis is likely to be underreported. The observed colonization rates call for the introduction of a mandatory environmental monitoring scheme.

Spatial distribution of Legionella pneumophila MLVA-genotypes in a drinking water system.

Science.gov (United States)

Rodríguez-Martínez, Sarah; Sharaby, Yehonatan; Pecellín, Marina; Brettar, Ingrid; Höfle, Manfred; Halpern, Malka

2015-06-15

Bacteria of the genus Legionella cause water-based infections, resulting in severe pneumonia. To improve our knowledge about Legionella spp. ecology, its prevalence and its relationships with environmental factors were studied. Seasonal samples were taken from both water and biofilm at seven sampling points of a small drinking water distribution system in Israel. Representative isolates were obtained from each sample and identified to the species level. Legionella pneumophila was further determined to the serotype and genotype level. High resolution genotyping of L. pneumophila isolates was achieved by Multiple-Locus Variable number of tandem repeat Analysis (MLVA). Within the studied water system, Legionella plate counts were higher in summer and highly variable even between adjacent sampling points. Legionella was present in six out of the seven selected sampling points, with counts ranging from 1.0 × 10(1) to 5.8 × 10(3) cfu/l. Water counts were significantly higher in points where Legionella was present in biofilms. The main fraction of the isolated Legionella was L. pneumophila serogroup 1. Serogroup 3 and Legionella sainthelensis were also isolated. Legionella counts were positively correlated with heterotrophic plate counts at 37 °C and negatively correlated with chlorine. Five MLVA-genotypes of L. pneumophila were identified at different buildings of the sampled area. The presence of a specific genotype, "MLVA-genotype 4", consistently co-occurred with high Legionella counts and seemed to "trigger" high Legionella counts in cold water. Our hypothesis is that both the presence of L. pneumophila in biofilm and the presence of specific genotypes, may indicate and/or even lead to high Legionella concentration in water. This observation deserves further studies in a broad range of drinking water systems to assess its potential for general use in drinking water monitoring and management. Copyright © 2015 Elsevier Ltd. All rights reserved.

Legionella risk assessment in cruise ships and ferries

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Pasqualina Laganà

2017-06-01

Legionella pneumophila sg 1 was isolated from the samples of shower and tap water in 7 (70% of the 10 ferries examined, and in 3 (33% of the 6 cruise ships examined, and L. pneumophila sg 2–14 in 8 (80% and 1 (16.7% of these ships, respectively. No Legionella contamination was found in whirlpool baths, air and ice samples. In conclusion, the data obtained confirm higher levels of Legionella contamination in local ferries and cruise ships, underlining the need to adopt corrective actions more specific for these smaller vessels.

Relationships between free-living protozoa, cultivable Legionella spp., and water quality characteristics in three drinking water supplies in the Caribbean.

Science.gov (United States)

Valster, Rinske M; Wullings, Bart A; van den Berg, Riemsdijk; van der Kooij, Dick

2011-10-01

The study whose results are presented here aimed at identifying free-living protozoa (FLP) and conditions favoring the growth of these organisms and cultivable Legionella spp. in drinking water supplies in a tropical region. Treated and distributed water (±30°C) of the water supplies of three Caribbean islands were sampled and investigated with molecular techniques, based on the 18S rRNA gene. The protozoan host Hartmannella vermiformis and cultivable Legionella pneumophila were observed in all three supplies. Operational taxonomic units (OTUs) with the highest similarity to the potential or candidate hosts Acanthamoeba spp., Echinamoeba exundans, E. thermarum, and an Neoparamoeba sp. were detected as well. In total, 59 OTUs of FLP were identified. The estimated protozoan richness did not differ significantly between the three supplies. In supply CA-1, the concentration of H. vermiformis correlated with the concentration of Legionella spp. and clones related to Amoebozoa predominated (82%) in the protozoan community. These observations, the low turbidity (water. The absence of H. vermiformis in most samples from supply CA-3 suggests that growth of this protozoan is limited at ATP concentrations of <1 ng liter(-1).

Presence of Legionella and Free-Living Amoebae in Composts and Bioaerosols from Composting Facilities

Science.gov (United States)

Conza, Lisa; Pagani, Simona Casati; Gaia, Valeria

2013-01-01

Several species of Legionella cause Legionnaires’ disease (LD). Infection may occur through inhalation of Legionella or amoebal vesicles. The reservoirs of Legionella are water, soil, potting soil and compost. Some species of free-living amoebae (FLA) that are naturally present in water and soil were described as hosts for Legionella. This study aimed to understand whether or not the composting facilities could be sources of community-acquired Legionella infections after development of bioaerosols containing Legionella or FLA. We looked for the presence of Legionella (by co-culture) and FLA (by culture) in composts and bioaerosols collected at four composting facilities located in southern Switzerland. We investigated the association between the presence of Legionella and compost and air parameters and presence of FLA. Legionella spp. (including L. pneumophila) were detected in 69.3% (61/88) of the composts and FLA (mainly Acanthamoeba, Vermamoeba, Naegleria and Stenamoeba) in 92.0% (81/88). L. pneumophila and L. bozemanii were most frequently isolated. FLA as potential host for Legionella spp. were isolated from 40.9% (36/88) of the composts in all facilities. In Legionella-positive samples the temperature of compost was significantly lower (P = 0.012) than in Legionella-negative samples. Of 47 bioaerosol samples, 19.1% (9/47) were positive for FLA and 10.6% (5/47) for L. pneumophila. Composts (62.8%) were positive for Legionella and FLA contemporaneously, but both microorganisms were never detected simultaneously in bioaerosols. Compost can release bioaerosol containing FLA or Legionella and could represent a source of infection of community-acquired Legionella infections for workers and nearby residents. PMID:23844174

Presence of Legionella and free-living Amoebae in composts and bioaerosols from composting facilities.

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Lisa Conza

Full Text Available Several species of Legionella cause Legionnaires' disease (LD. Infection may occur through inhalation of Legionella or amoebal vesicles. The reservoirs of Legionella are water, soil, potting soil and compost. Some species of free-living amoebae (FLA that are naturally present in water and soil were described as hosts for Legionella. This study aimed to understand whether or not the composting facilities could be sources of community-acquired Legionella infections after development of bioaerosols containing Legionella or FLA. We looked for the presence of Legionella (by co-culture and FLA (by culture in composts and bioaerosols collected at four composting facilities located in southern Switzerland. We investigated the association between the presence of Legionella and compost and air parameters and presence of FLA. Legionella spp. (including L. pneumophila were detected in 69.3% (61/88 of the composts and FLA (mainly Acanthamoeba, Vermamoeba, Naegleria and Stenamoeba in 92.0% (81/88. L. pneumophila and L. bozemanii were most frequently isolated. FLA as potential host for Legionella spp. were isolated from 40.9% (36/88 of the composts in all facilities. In Legionella-positive samples the temperature of compost was significantly lower (P = 0.012 than in Legionella-negative samples. Of 47 bioaerosol samples, 19.1% (9/47 were positive for FLA and 10.6% (5/47 for L. pneumophila. Composts (62.8% were positive for Legionella and FLA contemporaneously, but both microorganisms were never detected simultaneously in bioaerosols. Compost can release bioaerosol containing FLA or Legionella and could represent a source of infection of community-acquired Legionella infections for workers and nearby residents.

Hydrodynamic cavitation to prevent legionella and scaling; Hydrodynamische cavitatie voorkomt legionella en kalk

Energy Technology Data Exchange (ETDEWEB)

Van Baarle, D. (ed.)

2006-03-15

To prevent biofouling, legionella, scaling and corrosion in heat exchangers or cooling systems chemicals are added to the process and the cooling water. An alternative is the use of so-called hydrodynamic cavitation. [Dutch] Om biofouling, kalkaanslag en corrosie tegen te gaan, worden chemicalien aan proces en koelwater toegevoegd. Er is nu ook een chemicalienvrij mechanisch alternatief om legionellavorming, corrosie en kalkafzet tegen te gaan: hydrodynamische cavitatie. Door water in een vortex-stroom te leiden ontstaan er cavitatiekrachten die (legionella)bacterieen doden en CaCO{sub 3} omvormen tot filtreerbare colloiden. Doordat het in het water aanwezige kalk niet neerslaat, verbeter de prestatie van de warmtewisselaars.

Legionella contamination in hot water of Italian hotels.

Science.gov (United States)

Borella, Paola; Montagna, Maria Teresa; Stampi, Serena; Stancanelli, Giovanna; Romano-Spica, Vincenzo; Triassi, Maria; Marchesi, Isabella; Bargellini, Annalisa; Tatò, Daniela; Napoli, Christian; Zanetti, Franca; Leoni, Erica; Moro, Matteo; Scaltriti, Stefania; Ribera D'Alcalà, Gabriella; Santarpia, Rosalba; Boccia, Stefania

2005-10-01

A cross-sectional multicenter survey of Italian hotels was conducted to investigate Legionella spp. contamination of hot water. Chemical parameters (hardness, free chlorine concentration, and trace element concentrations), water systems, and building characteristics were evaluated to study risk factors for colonization. The hot water systems of Italian hotels were strongly colonized by Legionella; 75% of the buildings examined and 60% of the water samples were contaminated, mainly at levels of > or =10(3) CFU liter(-1), and Legionella pneumophila was the most frequently isolated species (87%). L. pneumophila serogroup 1 was isolated from 45.8% of the contaminated sites and from 32.5% of the hotels examined. When a multivariate logistic model was used, only hotel age was associated with contamination, but the risk factors differed depending on the contaminating species and serogroup. Soft water with higher chlorine levels and higher temperatures were associated with L. pneumophila serogroup 1 colonization, whereas the opposite was observed for serogroups 2 to 14. In conclusion, Italian hotels, particularly those located in old buildings, represent a major source of risk for Legionnaires' disease due to the high frequency of Legionella contamination, high germ concentration, and major L. pneumophila serogroup 1 colonization. The possible role of chlorine in favoring the survival of Legionella species is discussed.

Clinical predictors for Legionella in patients presenting with community-acquired pneumonia to the emergency department

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Frei Reno

2009-01-01

Full Text Available Abstract Background Legionella species cause severe forms of pneumonia with high mortality and complication rates. Accurate clinical predictors to assess the likelihood of Legionella community-acquired pneumonia (CAP in patients presenting to the emergency department are lacking. Methods We retrospectively compared clinical and laboratory data of 82 consecutive patients with Legionella CAP with 368 consecutive patients with non-Legionella CAP included in two studies at the same institution. Results In multivariate logistic regression analysis we identified six parameters, namely high body temperature (OR 1.67, p Legionella CAP. Using optimal cut off values of these six parameters, we calculated a diagnostic score for Legionella CAP. The median score was significantly higher in Legionella CAP as compared to patients without Legionella (4 (IQR 3–4 vs 2 (IQR 1–2, p Legionella pneumonia. Conversely, of the 73 patients (16% with ≥4 points, 66% of patients had Legionella CAP. Conclusion Six clinical and laboratory parameters embedded in a simple diagnostic score accurately identified patients with Legionella CAP. If validated in future studies, this score might aid in the management of suspected Legionella CAP.

Minimum inhibitory concentration distribution in environmental Legionella spp. isolates.

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Sandalakis, Vassilios; Chochlakis, Dimosthenis; Goniotakis, Ioannis; Tselentis, Yannis; Psaroulaki, Anna

2014-12-01

In Greece standard tests are performed in the watering and cooling systems of hotels' units either as part of the surveillance scheme or following human infection. The purpose of this study was to establish the minimum inhibitory concentration (MIC) distributions of environmental Legionella isolates for six antimicrobials commonly used for the treatment of Legionella infections, by MIC-test methodology. Water samples were collected from 2004 to 2011 from 124 hotels from the four prefectures of Crete (Greece). Sixty-eight (68) Legionella isolates, comprising L. pneumophila serogroups 1, 2, 3, 5, 6, 8, 12, 13, 15, L. anisa, L. rubrilucens, L. maceachernii, L. quinlivanii, L. oakridgensis, and L. taurinensis, were included in the study. MIC-tests were performed on buffered charcoal yeast extract with α-ketoglutarate, L-cysteine, and ferric pyrophosphate. The MICs were read after 2 days of incubation at 36 ± 1 °C at 2.5% CO2. A large distribution in MICs was recorded for each species and each antibiotic tested. Rifampicin proved to be the most potent antibiotic regardless of the Legionella spp.; tetracycline appeared to have the least activity on our environmental isolates. The MIC-test approach is an easy, although not so cost-effective, way to determine MICs in Legionella spp. These data should be kept in mind especially since these Legionella species may cause human disease.

Relationships between Free-Living Protozoa, Cultivable Legionella spp., and Water Quality Characteristics in Three Drinking Water Supplies in the Caribbean▿†

Science.gov (United States)

Valster, Rinske M.; Wullings, Bart A.; van den Berg, Riemsdijk; van der Kooij, Dick

2011-01-01

The study whose results are presented here aimed at identifying free-living protozoa (FLP) and conditions favoring the growth of these organisms and cultivable Legionella spp. in drinking water supplies in a tropical region. Treated and distributed water (±30°C) of the water supplies of three Caribbean islands were sampled and investigated with molecular techniques, based on the 18S rRNA gene. The protozoan host Hartmannella vermiformis and cultivable Legionella pneumophila were observed in all three supplies. Operational taxonomic units (OTUs) with the highest similarity to the potential or candidate hosts Acanthamoeba spp., Echinamoeba exundans, E. thermarum, and an Neoparamoeba sp. were detected as well. In total, 59 OTUs of FLP were identified. The estimated protozoan richness did not differ significantly between the three supplies. In supply CA-1, the concentration of H. vermiformis correlated with the concentration of Legionella spp. and clones related to Amoebozoa predominated (82%) in the protozoan community. These observations, the low turbidity (water. The absence of H. vermiformis in most samples from supply CA-3 suggests that growth of this protozoan is limited at ATP concentrations of <1 ng liter−1. PMID:21873489

Seasonal variation of Legionella in Taiwan's reservoir and its relationships with environmental factors.

Science.gov (United States)

Kao, Po-Min; Hsu, Bing-Mu; Chang, Tien-Yu; Hsu, Tsui-Kang; Tzeng, Kai-Jiun; Huang, Yu-Li

2015-04-01

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 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.

Legionella (Legionnaires' Disease and Pontiac Fever): Signs and Symptoms

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... Search Form Controls Cancel Submit Search The CDC Legionella (Legionnaires' Disease and Pontiac Fever) Note: Javascript is ... message, please visit this page: About CDC.gov . Legionella Home About the Disease Causes, How it Spreads, & ...

Legionella spp. in UK composts--a potential public health issue?

Science.gov (United States)

Currie, S L; Beattie, T K; Knapp, C W; Lindsay, D S J

2014-04-01

Over the past 5 years, a number of cases of legionellosis in Scotland have been associated with compost use; however, studies investigating sources of infection other than water systems remain limited. This study delivers the first comprehensive survey of composts commonly available in the UK for the presence of Legionella species. Twenty-two store-bought composts, one green-waste compost and one home-made compost were tested for Legionella by culture methods on BCYE-α medium, and the findings were confirmed by macrophage infectivity potentiator (mip) speciation. Twenty-two of the samples were retested after an enrichment period of 8 weeks. In total, 15 of 24 composts tested positive for Legionella species, a higher level of contamination than previously seen in Europe. Two isolates of Legionella pneumophila were identified, and Legionella longbeachae serogroup 1 was found to be one of the most commonly isolated species. L. longbeachae infection would not be detected by routine Legionella urinary antigen assay, so such testing should not be used as the sole diagnostic technique in atypical pneumonia cases, particularly where there is an association with compost use. The occurrence of Legionella in over half of the samples tested indicates that compost could pose a public health risk. The addition of general hygiene warnings to compost packages may be beneficial in protecting public health. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.

Distribution of Legionella and bacterial community composition among regionally diverse US cooling towers.

Science.gov (United States)

Llewellyn, Anna C; Lucas, Claressa E; Roberts, Sarah E; Brown, Ellen W; Nayak, Bina S; Raphael, Brian H; Winchell, Jonas M

2017-01-01

Cooling towers (CTs) are a leading source of outbreaks of Legionnaires' disease (LD), a severe form of pneumonia caused by inhalation of aerosols containing Legionella bacteria. Accordingly, proper maintenance of CTs is vital for the prevention of LD. The aim of this study was to determine the distribution of Legionella in a subset of regionally diverse US CTs and characterize the associated microbial communities. Between July and September of 2016, we obtained aliquots from water samples collected for routine Legionella testing from 196 CTs located in eight of the nine continental US climate regions. After screening for Legionella by PCR, positive samples were cultured and the resulting Legionella isolates were further characterized. Overall, 84% (164) were PCR-positive, including samples from every region studied. Of the PCR-positive samples, Legionella spp were isolated from 47% (78), L. pneumophila was isolated from 32% (53), and L. pneumophila serogroup 1 (Lp1) was isolated from 24% (40). Overall, 144 unique Legionella isolates were identified; 53% (76) of these were Legionella pneumophila. Of the 76 L. pneumophila isolates, 51% (39) were Lp1. Legionella were isolated from CTs in seven of the eight US regions examined. 16S rRNA amplicon sequencing was used to compare the bacterial communities of CT waters with and without detectable Legionella as well as the microbiomes of waters from different climate regions. Interestingly, the microbial communities were homogenous across climate regions. When a subset of seven CTs sampled in April and July were compared, there was no association with changes in corresponding CT microbiomes over time in the samples that became culture-positive for Legionella. Legionella species and Lp1 were detected frequently among the samples examined in this first large-scale study of Legionella in US CTs. Our findings highlight that, under the right conditions, there is the potential for CT-related LD outbreaks to occur throughout the US.

Factors Stimulating Propagation of Legionellae in Cooling Tower Water

OpenAIRE

Yamamoto, Hiroyuki; Sugiura, Minoru; Kusunoki, Shinji; Ezaki, Takayuki; Ikedo, Masanari; Yabuuchi, Eiko

1992-01-01

Our survey of cooling tower water demonstrated that the highest density of legionellae, ≥104 CFU/100 ml, appeared in water containing protozoa, ≥102 MPN/100 ml, and heterotrophic bacteria, ≥106 CFU/100 ml, at water temperatures between 25 and 35°C. Viable counts of legionellae were detected even in the winter samples, and propagation, up to 105 CFU/100 ml, occurs in summer. The counts of legionellae correlated positively with increases in water temperature, pH, and protozoan counts, but not w...

Occurrence of Legionella in wastewater treatment plants linked to wastewater characteristics.

Science.gov (United States)

Caicedo, C; Beutel, S; Scheper, T; Rosenwinkel, K H; Nogueira, R

2016-08-01

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.

Legionella pneumophila: From potable water to treated greywater; quantification and removal during treatment.

Science.gov (United States)

Blanky, Marina; Rodríguez-Martínez, Sara; Halpern, Malka; Friedler, Eran

2015-11-15

Greywater is an alternative water source that can help alleviate stress on depleted water resources. The main options for greywater reuse are toilet flushing and garden irrigation, both producing aerosols. For that reason transmission of inhalable pathogens like Legionella present a potential risk. To improve the understanding about Legionella in greywater, we traced the pathogen seasonally from the potable water system to the final steps of the greywater treatment in four houses in northern Israel. Physicochemical and microbiological parameters were analyzed in order to assess background greywater quality and to establish possible associations with Legionella. The mean concentrations of Legionella pneumophila isolated from the potable water system were 6.4×10(2) and 5.9×10(3) cfu/l in cold and hot water respectively. By amending the ISO protocol for Legionella isolation from drinking water, we succeeded in quantifying Legionella in greywater. The mean Legionella concentrations that were found in raw, treated and treated chlorinated greywater were 1.2×10(5), 2.4×10(4) and 5.7×10(3) cfu/l respectively. While Legionella counts in potable water presented a seasonal pattern with high concentrations in summer, its counts in greywater presented an almost inversed pattern. Greywater treatment resulted in 95% decrease in Legionella counts. No significant difference was found between Legionella concentrations in potable water and the treated chlorinated greywater. These findings indicate that regarding Legionella, reusing treated chlorinated greywater would exhibit a risk that is very similar to the risk associated with using potable water for the same non-potable uses. Copyright © 2015 Elsevier B.V. All rights reserved.

Strategies for the reduction of Legionella in biological treatment systems.

Science.gov (United States)

Nogueira, R; Utecht, K-U; Exner, M; Verstraete, W; Rosenwinkel, K-H

A community-wide outbreak of Legionnaire's disease occurred in Warstein, Germany, in August 2013. The epidemic strain, Legionella pneumophila Serogruppe 1, was isolated from an industrial wastewater stream entering the municipal wastewater treatment plant (WWTP) in Wartein, the WWTP itself, the river Wäster and air/water samples from an industrial cooling system 3 km downstream of the WWTP. The present study investigated the effect of physical-chemical disinfection methods on the reduction of the concentration of Legionella in the biological treatment and in the treated effluent entering the river Wäster. Additionally, to gain insight into the factors that promote the growth of Legionella in biological systems, growth experiments were made with different substrates and temperatures. The dosage rates of silver micro-particles, hydrogen peroxide, chlorine dioxide and ozone and pH stress to the activated sludge were not able to decrease the number of culturable Legionella spp. in the effluent. Nevertheless, the UV treatment of secondary treated effluent reduced Legionella spp. on average by 1.6-3.4 log units. Laboratory-scale experiments and full-scale measurements suggested that the aerobic treatment of warm wastewater (30-35 °C) rich in organic nitrogen (protein) is a possible source of Legionella infection.

Fatal pneumonia by Legionella in a farmer with hypersensitivity pneumonitis Neumonía por Legionella con desenlace fatal en un granjero con neumonitis por hipersensibilidad

Directory of Open Access Journals (Sweden)

Vega García López

2009-12-01

Full Text Available Background: The retrospective investigation of a fatal sporadic Legionnaires' disease identified an unknown case of occupational hypersensitivity pneumonitis in a swine breeder. Methods: Chest high-resolution computed tomography, bronchoalveolar lavage, lung biopsy, arterial gasometry, pulmonary function tests and autopsy were performed. It was studied the presence of Legionella by serology and risk water samples were analyzed to identify the Legionella's source. Results: HP and Legionella pneumophila pneumonia diagnostics were confirmed. Lung fibrosis, a restrictive functional pattern, decreased diffusion, hypoxemia and bronchoalveolar lavage lymphocytosis were evidenced. Legionella´s source was detected in a shower and a positive serology in the patient. Autopsy verified pulmonary fibrosis and the septic shock leaded to Legionella causing the death. Conclusions: Chronic cough and pulmonary infiltrates in a farmer should suspect the presence of hypersensitivity pneumonitis. Later diagnosis carries a worse prognosis, the offending antigens exposure can't be avoided and fibrotic stage enhanced opportunity infection disease.Introducción: La investigación retrospectiva sobre un fallecimiento aislado por Legionelosis, hizo aflorar un caso de neumonitis por hipersensibilidad en un granjero cuidador de cerdos. Métodos: Se realizaron las siguientes pruebas: tomografía axial computerizada de alta resolución, lavado broncoalveolar, biopsia pulmonar, gasometría arterial, pruebas de función respiratoria y autopsia. Se estudió la presencia de Legionella por serología y se analizaron las muestras de fuentes de riesgo para identificar el foco de Legionella. Resultados: El estudio confirmó los diagnósticos de neumonitis por hipersensibilidad y neumonía por Legionella pneumophila. Las pruebas realizadas objetivaron la fibrosis pulmonar, un patrón respiratorio funcional restrictivo, un descenso de la difusión pulmonar, hipoxemia y la presencia de

Existence and control of Legionella bacteria in building water systems: A review.

Science.gov (United States)

Springston, John P; Yocavitch, Liana

2017-02-01

Legionellae are waterborne bacteria which are capable of causing potentially fatal Legionnaires' disease (LD), as well as Pontiac Fever. Public concern about Legionella exploded following the 1976 outbreak at the American Legion conference in Philadelphia, where 221 attendees contracted pneumonia and 34 died. Since that time, a variety of different control methods and strategies have been developed and implemented in an effort to eradicate Legionella from building water systems. Despite these efforts, the incidence of LD has been steadily increasing in the U.S. for more than a decade. Public health and occupational hygiene professionals have maintained an active debate regarding best practices for management and control of Legionella. Professional opinion remains divided with respect to the relative merits of performing routine sampling for Legionella, vs. the passive, reactive approach that has been largely embraced by public health officials and facility owners. Given the potential risks and ramifications associated with waiting to assess systems for Legionella until after disease has been identified and confirmed, a proactive approach of periodic testing for Legionella, along with proper water treatment, is the best approach to avoiding large-scale disease outbreaks.

Be prepared should Legionella strike.

Science.gov (United States)

Steel, Andrew

2013-03-01

When measures to prevent Legionella fail, and a positive result is returned from the laboratory, there is an imperative to act fast to stamp infection out, but taking the right action requires a rigorous approach. So says Andrew Steel, managing director of Airmec, a provider of essential air and water services solutions. Here he explains the legal and other obligations of health estates managers in taking all possible steps to prevent a Legionella outbreak, and, when they do face one, sets out the key remedial steps, and outlines what regulators or HSE personnel will expect to see as 'evidence' that sufficient 'duty of care' has been taken.

Molecular Evolution of the dotA Gene in Legionella pneumophila

OpenAIRE

Ko, Kwan Soo; Hong, Seong Karp; Lee, Hae Kyung; Park, Mi-Yeoun; Kook, Yoon-Hoh

2003-01-01

The molecular evolution of dotA, which is related to the virulence of Legionella pneumophila, was investigated by comparing the sequences of 15 reference strains (serogroups 1 to 15). It was found that dotA has a complex mosaic structure. The whole dotA gene of Legionella pneumophila subsp. pneumophila serogroups 2, 6, and 12 has been transferred from Legionella pneumophila subsp. fraseri. A discrepancy was found between the trees inferred from the nucleotide and deduced amino acid sequences ...

Legionella-protozoa-nematode interactions in aquatic biofilms and influence of Mip on Caenorhabditis elegans colonization.

Science.gov (United States)

Rasch, Janine; Krüger, Stefanie; Fontvieille, Dominique; Ünal, Can M; Michel, Rolf; Labrosse, Aurélie; Steinert, Michael

2016-09-01

Legionella pneumophila, the causative agent of Legionnaireś disease, is naturally found in aquatic habitats. The intracellular life cycle within protozoa pre-adapted the "accidental" human pathogen to also infect human professional phagocytes like alveolar macrophages. Previous studies employing the model organism Caenorhabditis elegans suggest that also nematodes might serve as a natural host for L. pneumophila. Here, we report for the first time from a natural co-habitation of L. pneumophila and environmental nematode species within biofilms of a warm water spring. In addition, we identified the protozoan species Oxytricha bifaria, Stylonychia mytilus, Ciliophrya sp. which have never been described as potential interaction partners of L. pneumophila before. Modeling and dissection of the Legionella-protozoa-nematode interaction revealed that C. elegans ruptures Legionella-infected amoebal cells and by this means incorporate the pathogen. Further infection studies revealed that the macrophage infectivity potentiator (Mip) protein of L. pneumophila, which is known to bind collagen IV during human lung infection, promotes the colonization of the intestinal tract of L4 larvae of C. elegans and negatively influences the life span of the worms. The Mip-negative L. pneumophila mutant exhibited a 32-fold reduced colonization rate of the nematodes after 48h when compared to the wild-type strain. Taken together, these studies suggest that nematodes may serve as natural hosts for L. pneumophila, promote their persistence and dissemination in the environment, and co-evolutionarily pre-adapt the pathogen for interactions with extracellular constituents of human lung tissue. Copyright © 2016 Elsevier GmbH. All rights reserved.

High prevalence of Legionella in non-passenger merchant vessels.

Science.gov (United States)

Collins, S L; Stevenson, D; Mentasti, M; Shaw, A; Johnson, A; Crossley, L; Willis, C

2017-03-01

There is a paucity of information on the risk from potable water in non-passenger merchant vessels (NPMVs) particularly with regard to Legionella and other bacteria. This retrospective study examined water samples from 550 NPMVs docked in eight UK ports. A total of 1027 samples from 412 NPMVs were examined for total aerobic colony counts (ACC), coliforms, Escherichia coli and enterococci; 41% of samples yielded ACC above the action level (>1 × 103 c.f.u./ml) and 4·5% contained actionable levels (>1 c.f.u./100 ml) of faecal indicator bacteria. Eight hundred and three samples from 360 NPMVs were cultured specifically for Legionella and 58% of vessels proved positive for these organisms with 27% of samples showing levels greater than the UK upper action limit of 1 × 103 c.f.u./l. Cabin showers (49%) and hospital shower (45%) were frequently positive. A subset of 106 samples was analysed by quantitative polymerase chain reaction for Legionella and identified a further 11 Legionella-positive NPMVs, returning a negative predictive value of 100%. There was no correlation between NPMV age or size and any microbial parameters (P > 0·05). Legionella pneumophila serogroup 1 was isolated from 46% of NPMVs and sequence-based typing of 17 isolates revealed four sequence types (STs) previously associated with human disease. These data raise significant concerns regarding the management of microbial and Legionella risks on board NPMVs and suggest that better guidance and compliance are required to improve control.

Legionella detection by culture and qPCR: Comparing apples and oranges.

Science.gov (United States)

Whiley, Harriet; Taylor, Michael

2016-01-01

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.

Multiplication of Legionella spp. in tap water containing Hartmannella vermiformis.

Science.gov (United States)

Wadowsky, R M; Wilson, T M; Kapp, N J; West, A J; Kuchta, J M; States, S J; Dowling, J N; Yee, R B

1991-07-01

A model was developed to study the multiplication of various Legionella spp. in tap water containing Hartmannella vermiformis. Tap water cultures prepared with the following components were suitable for the multiplication studies: Legionella spp., 10(3) CFU/ml; H. vermiformis, 10(4.4) cysts per ml; and killed Pseudomonas paucimobilis, 10(9) cells per ml. Cocultures were incubated at 37 degrees C for at least 1 week. The following legionellae multiplied in tap water cocultures in each replicate experiment: L. bozemanii (WIGA strain), L. dumoffii (NY-23 and TX-KL strains), L. micdadei (two environmental strains), and L. pneumophila (six environmental strains and one clinical isolate). Growth yield values for these strains were 0.6 to 3.5 log CFU/ml. Legionellae which did not multiply in replicate cocultures included L. anisa (one strain), L. bozemanii (MI-15 strain), L. micdadei (a clinical isolate), L. longbeachae, (one strain), and L. pneumophila (Philadelphia 1 strain). L. gormanii and an environmental isolate of L. pneumophila multiplied in only one of three experiments. None of the legionellae multiplied in tap water containing only killed P. paucimobilis. The mean growth yield (+/- standard deviation) of H. vermiformis in the cocultures was 1.2 +/- 0.1 log units/ml. H. vermiformis supports multiplication of only particular strains of legionellae, some of which are from diverse origins.

Legionella pollution in cooling tower water of air-conditioning systems in Shanghai, China.

Science.gov (United States)

Lin, H; Xu, B; Chen, Y; Wang, W

2009-02-01

To determine Legionella pollution prevalence, describe the amount of Legionellae with respect to temperature in Shanghai cooling tower water (CTWs) in various types of public sites. Six urban districts were selected as the study fields, adopting multiple-phase sampling methods. Routine culture was used to identify Legionellae. Of the samples, 58.9% (189/321) were observed to be positive, 19.9% were isolated over 100 CFU ml(-1). Legionella pneumophila serogroup 1 was the most frequently isolated species (155/189, 82.0%), followed by Leg. micdadei that was at the second place (44/189, 23.3%). The mean CFU ml(-1) of Legionellae in CTWs reached its peak from July to September. Over all 15.4% of the samples exceeding 100 CFU ml(-1) were observed in a hospital setting. The prevalence of Legionella pollution in CTWs, especially in CTWs of subway stations and hospitals, is worrying, and the positive rate and CFU ml(-1) of Legionellae in CTWs have a close relationship with air temperature. The study demonstrates pollution prevalence rates in different types of sites and various seasons, and provides a proportion of different serogroups of Legionellae. It illuminates an urgent need for dealing with the potential risk of legionellosis in Shanghai, through improved control and prevention strategies.

Legionella (Legionnaires' Disease and Pontiac Fever): History and Disease Patterns

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... Search Form Controls Cancel Submit Search The CDC Legionella (Legionnaires' Disease and Pontiac Fever) Note: Javascript is ... message, please visit this page: About CDC.gov . Legionella Home About the Disease Causes, How it Spreads, & ...

Legionella Antibodies in a Danish Hospital Staff with Known Occupational Exposure

International Nuclear Information System (INIS)

Rudbeck, M.; Uldum, S.A.; Rudbeck, M.; Viskum, S.; Molbak, K.

2010-01-01

Although legionnaires' disease frequently is acquired in health care institutions, little is known about the occupational risk of Legionella infection among health care workers. The aim of the present cross-sectional study was to analyse antibody levels among exposed hospital workers and to determine the correlation between antibodies to Legionella and self-reported symptoms. The study included 258 hospital employees and a reference group of 708 healthy blood donors. Hospital workers had a higher prevalence of Legionella antibody titres (=1 : 128) than blood donors (odds ratio 3.4; 95% CI 2.4-4.8). Antibody levels were not higher among staff members at risk of frequent aerosol exposure than among less exposed employees. There was no consistent association between a history of influenza-like symptom complex and the presence of antibodies. The results indicate that hospital workers have a higher risk of Legionella infections than the general population. However, since no excess morbidity was associated with sero positivity, most Legionella infections may be asymptomatic.

Legionella pneumophila lung abscess associated with immune suppression.

Science.gov (United States)

Guy, S D; Worth, L J; Thursky, K A; Francis, P A; Slavin, M A

2011-10-01

Legionella species are a common cause of community-acquired pneumonia, infrequently complicated by cavitary disease. We describe Legionella pneumophila pneumonia and abscess formation in an immunosuppressed patient receiving corticosteroid therapy for metastatic breast carcinoma. The predisposing role of corticosteroids is discussed and the management of this complication is reviewed. © 2011 The Authors. Internal Medicine Journal © 2011 Royal Australasian College of Physicians.

Detection of Legionella pneumophila by real-time PCR for the mip gene.

Science.gov (United States)

Wilson, Deborah A; Yen-Lieberman, Belinda; Reischl, Udo; Gordon, Steve M; Procop, Gary W

2003-07-01

A real-time PCR assay for the mip gene of Legionella pneumophila was tested with 27 isolates of L. pneumophila, 20 isolates of 14 other Legionella species, and 103 non-Legionella bacteria. Eight culture-positive and 40 culture-negative clinical specimens were tested. This assay was 100% sensitive and 100% specific for L. pneumophila.

Automobile windshield washer fluid: A potential source of transmission for Legionella

International Nuclear Information System (INIS)

Schwake, David Otto; Alum, Absar; Abbaszadegan, Morteza

2015-01-01

Epidemiological evidence suggesting driving cars to be a risk factor for legionellosis has prompted public health studies to investigate vehicle windshield washer fluid as a novel transmission source of this disease. The goal of the current study was to investigate whether or not windshield washer fluid could serve as a potential source of transmission for Legionella. A wide variation in the survival of L. pneumophila was observed when incubated in different washer fluids at 25 and 37 °C, however, one brand tested supported Legionella survival similar to or greater than sterilized deionized water. In addition, 1 L of tap water contained in a washer fluid reservoir was able to support population growth and survival of Legionella for several months. In a field study examining the windshield washer fluid of 12 elementary school buses, Legionella were detected from 84% of samples at a high concentration of 8.1 × 10 4 CFU/mL. Culturable cells were also detected in aerosolized washer fluid during washer fluid spray. By demonstrating survival in certain windshield washer fluids, growth within washer fluid reservoirs, and the presence of viable cells in bus washer fluid spray, we have provided evidence suggesting the potential for a novel route of Legionella exposure. - Highlights: • L. pneumophila survival in one brand of washer fluid and sterilized deionized water were similar. • Legionella population was maintained in tap water for several months. • Culturable Legionella were detected in 10 of 12 school bus washer fluid reservoirs sampled. • Legionella concentrations up to 8.1 × 104 CFU/mL were detected in school bus washer fluid. • L. pneumophila was detected in washer fluid reservoirs and aerosolized washer fluid

Automobile windshield washer fluid: A potential source of transmission for Legionella

Energy Technology Data Exchange (ETDEWEB)

Schwake, David Otto [School of Life Sciences, Arizona State University, P.O. Box 875306, Tempe, AZ 85287 (United States); Alum, Absar [School of Sustainable Engineering and the Built Environment, Arizona State University, P.O. Box 875306, Tempe, AZ 85287 (United States); Abbaszadegan, Morteza, E-mail: abbaszadegan@asu.edu [School of Sustainable Engineering and the Built Environment, Arizona State University, P.O. Box 875306, Tempe, AZ 85287 (United States)

2015-09-01

Epidemiological evidence suggesting driving cars to be a risk factor for legionellosis has prompted public health studies to investigate vehicle windshield washer fluid as a novel transmission source of this disease. The goal of the current study was to investigate whether or not windshield washer fluid could serve as a potential source of transmission for Legionella. A wide variation in the survival of L. pneumophila was observed when incubated in different washer fluids at 25 and 37 °C, however, one brand tested supported Legionella survival similar to or greater than sterilized deionized water. In addition, 1 L of tap water contained in a washer fluid reservoir was able to support population growth and survival of Legionella for several months. In a field study examining the windshield washer fluid of 12 elementary school buses, Legionella were detected from 84% of samples at a high concentration of 8.1 × 10{sup 4} CFU/mL. Culturable cells were also detected in aerosolized washer fluid during washer fluid spray. By demonstrating survival in certain windshield washer fluids, growth within washer fluid reservoirs, and the presence of viable cells in bus washer fluid spray, we have provided evidence suggesting the potential for a novel route of Legionella exposure. - Highlights: • L. pneumophila survival in one brand of washer fluid and sterilized deionized water were similar. • Legionella population was maintained in tap water for several months. • Culturable Legionella were detected in 10 of 12 school bus washer fluid reservoirs sampled. • Legionella concentrations up to 8.1 × 104 CFU/mL were detected in school bus washer fluid. • L. pneumophila was detected in washer fluid reservoirs and aerosolized washer fluid.

Detection of Legionella spp. from Domestic Water in the Prefecture of Arta, Greece

Directory of Open Access Journals (Sweden)

Dimitra Dimitriadi

2014-01-01

Full Text Available The aim of this research was the isolation of Legionella spp. from domestic water supply networks in the Prefecture of Arta. A total of 100 water samples, from 25 houses, were collected. Half of the samples concerned the cold water and half the hot water supply. Purpose was to detect colonization of the water networks with Legionella spp. >500 cfu/L by using the method of filtration (ISO 11731. Out of 100 samples, 6 samples from 3 houses were positive for Legionella spp. Legionella pneumophila serogroup 2–14 was isolated in 5 of 6 samples, whereas in the sixth sample Legionella anisa was identified. Only three of the samples had residual chloride over 0.2 mg/L, rate which is necessary for potable water, according to the Greek hygienic practice. Concerning the temperature of hot water, the mean temperature of the negative for Legionella samples was higher compared to the mean temperature of the positive for Legionella samples (49.9°C versus 45.5°C. It is estimated that there is risk of infection through the use of showers. The low concentration of chloride and the temperature, which was found within the limits favorable to developing Legionella spp. (20–45°C, provide fertile ground for proliferation of the bacteria.

Prevalence of Legionella in premise plumbing in Hungary.

Science.gov (United States)

Barna, Zsófia; Kádár, Mihály; Kálmán, Emese; Scheirich Szax, Anita; Vargha, Márta

2016-03-01

Legionella is one of the emerging concerns of water quality in built water environments. Premise plumbing systems are among the recognised sources of infection. In the present study, colonisation of hot water networks in health care facilities, schools, hotels, private residences, office and industrial buildings was investigated. Data was analysed in connection with building and premise plumbing characteristics. Over 60% of all buildings were colonised by Legionella; counts were over 1000 CFU/L in 49%. The most prevalent type was Legionella pneumophila serogroup 2-14, isolated from 75% of the positive samples. Centrally produced hot water was found to be a key risk factor (46% of the samples were positive vs. 16% in individual systems); within this group the type of the building was less relevant. Colonisation levels in schools were similar to hotels or hospitals, representing a previously underestimated risk setting. Systems supplied by water from deep groundwater sources were significantly less likely to be colonised than more vulnerable sources (bank-wall filtration, surface water abstraction or karstic water; 28% vs. 51% positive), regardless of the type of treatment applied, including the presence of disinfection. The aggravating effect of larger, more complex and older buildings on colonisation was also confirmed. The present study represents the first baseline analysis, pre-empting regulation or monitoring requirements for Legionella. The prevalence of legionellae and the identified risk factors are indicative for other settings lacking targeted interventions. The statistically confirmed risk factors can serve as indicators for preliminary risk assessment and the prioritisation of interventions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Survival and multiplication of Legionella pneumophila in municipal drinking water systems.

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States, S J; Conley, L F; Kuchta, J M; Oleck, B M; Lipovich, M J; Wolford, R S; Wadowsky, R M; McNamara, A M; Sykora, J L; Keleti, G

1987-05-01

Studies were conducted to investigate the survival and multiplication of Legionella spp. in public drinking water supplies. An attempt was made, over a period of several years, to isolate legionellae from a municipal system. Sampling sites included the river water supply, treatment plant, finished water reservoir system, mains, and distribution taps. Despite the use of several isolation techniques, Legionella spp. could not be detected in any of the samples other than those collected from the river. It was hypothesized that this was due to the maintenance of a chlorine residual throughout the system. To investigate the potential for Legionella growth, additional water samples, collected from throughout the system, were dechlorinated, pasteurized, and inoculated with Legionella pneumophila. Subsequent growth indicated that many of these samples, especially those collected from areas affected by an accumulation of algal materials, exhibited a much greater ability to support Legionella multiplication than did river water prior to treatment. Chemical analyses were also performed on these samples. Correlation of chemical data and experimental growth results indicated that the chemical environment significantly affects the ability of the water to support multiplication, with turbidity, organic carbon, and certain metals being of particular importance. These studies indicate that the potential exists for Legionella growth within municipal systems and support the hypothesis that public water supplies may contaminate the plumbing systems of hospitals and other large buildings. The results also suggest that useful methods to control this contamination include adequate treatment plant filtration, maintenance of a chlorine residual throughout the treatment and distribution network, and effective covering of open reservoirs.

A comparison of assays measuring the viability of Legionella ...

Science.gov (United States)

Background: The relatively high prevalence of Legionella pneumophila in premise plumbing systems has been widely reported. Published reports indicate Legionella has a comparatively high resistance to chlorine and moreover has the ability to grow in phagocytic amoeba which could provide additional protection in chlorinated drinking water distribution systems. Copper-Silver (Cu-Ag) ionization treatment systems are commercially available for use in large building water systems to help control the risks from Legionella bacteria. The objectives of this study were to develop and optimize Legionella viability assays and use them to investigate the viability of Legionella bacteria after exposure to water treated with coppper and silver ions. Methods: Log phase L. pneumophila cells were used in all experiments and were generated by incubation at 35C for 48 hours in buffered yeast extract broth. Viability assays used included plating on buffered charcoal yeast extract agar to determine the number of culturable cells and treating cells with propidium monoazide (PMA) or ethidium monoazide (EMA) followed by quantitative PCR targeting mip gene of L. pneumophila. The qPCR viability assays were optimized using L. pneumophila inactivated by heat treatment at 65C for 60 min. The effectiveness of Cu-Ag ionization treatment was studied by inoculating L. pneumonia at 105 CFU/mL in water collected directly from a building water system that employed this technology and incubat

Viable Legionella pneumophila bacteria in natural soil and rainwater puddles

NARCIS (Netherlands)

van Heijnsbergen, E.; de Roda Husman, A. M.; Lodder, W. J.; Bouwknegt, M.; Docters van Leeuwen, A. E.; Bruin, J. P.; Euser, S. M.; den Boer, J. W.; Schalk, J. A C

Aims: For the majority of sporadic Legionnaires' disease cases the source of infection remains unknown. Infection may possible result from exposure to Legionella bacteria in sources that are not yet considered in outbreak investigations. Therefore, potential sources of pathogenic Legionella

An in-premise model for Legionella exposure during showering events

Science.gov (United States)

An exposure model was constructed to predict the critical Legionella densities in an engineered water system that might result in infection from inhalation of aerosols containing the pathogen while showering. The model predicted the Legionella densities in the shower air, water ...

Cross-reactive Legionella antigens and the antibody response during infection

DEFF Research Database (Denmark)

Bangsborg, Jette Marie; Shand, G; Pearlman, E

1991-01-01

In order to define cross-reactive Legionella antigens suitable for diagnostic purposes, we investigated sonicate antigens from two Legionella species, including two serogroups of L. pneumophila. The antigens were reacted with heterologous and homologous rabbit antisera in Western blot. Sera from ...

Legionella in industrial cooling towers: monitoring and control strategies.

Science.gov (United States)

Carducci, A; Verani, M; Battistini, R

2010-01-01

Legionella contamination of industrial cooling towers has been identified as the cause of sporadic cases and outbreaks of legionellosis among people living nearby. To evaluate and control Legionella contamination in industrial cooling tower water, microbiological monitoring was carried out to determine the effectiveness of the following different disinfection treatments: (i) continuous chlorine concentration of 0.01 ppm and monthly chlorine shock dosing (5 ppm) on a single cooling tower; (ii) continuous chlorine concentration of 0.4 ppm and monthly shock of biocide P3 FERROCID 8580 (BKG Water Solution) on seven towers. Legionella spp. and total bacterial count (TBC) were determined 3 days before and after each shock dose. Both strategies demonstrated that when chlorine was maintained at low levels, the Legionella count grew to levels above 10(4) CFU l(-1) while TBC still remained above 10(8 )CFU l(-1). Chlorine shock dosing was able to eliminate bacterial contamination, but only for 10-15 days. Biocide shock dosing was also insufficient to control the problem when the disinfectant concentration was administered at only one point in the plant and at the concentration of 30 ppm. On the other hand, when at a biocide concentration of 30 or 50 ppm was distributed throughout a number of points, depending on the plant hydrodynamics, Legionella counts decreased significantly and often remained below the warning limit. Moreover, the contamination of water entering the plant and the presence of sediment were also important factors for Legionella growth. For effective decontamination of outdoor industrial cooling towers, disinfectants should be distributed in a targeted way, taking into account the possible sources of contamination. The data of the research permitted to modify the procedure of disinfection for better reduce the water and aerosol contamination and consequently the exposure risk.

Storage Tank Legionella and Community

Data.gov (United States)

U.S. Environmental Protection Agency — Storage Tank Legionella and Community. This dataset is associated with the following publication: Qin, K., I. Struewing, J. Santodomingo, D. Lytle, and J. Lu....

Susceptibility of Legionella pneumophila to chlorine in tap water.

Science.gov (United States)

Kuchta, J M; States, S J; McNamara, A M; Wadowsky, R M; Yee, R B

1983-11-01

A study was conducted to compare the susceptibility of legionellae and coliforms to disinfection by chlorine. The chlorine residuals used were similar to concentrations that might be found in the distribution systems of large public potable water supplies. The effects of various chlorine concentrations, temperatures, and pH levels were considered. A number of different Legionella strains, both environmental and clinical, were tested. The results indicate that legionellae are much more resistant to chlorine than are coliform bacteria. At 21 degrees C, pH 7.6, and 0.1 mg of free chlorine residual per liter, a 99% kill of L. pneumophila was achieved within 40 min, compared with less than 1 min for Escherichia coli. The observed resistance is enhanced as conditions for disinfection become less optimal. The required contact time for the removal of L. pneumophilia was twice as long at 4 degrees C than it was at 21 degrees C. These data suggest that legionellae can survive low levels of chlorine for relatively long periods of time.

Legionella species colonization in cooling towers: risk factors and assessment of control measures.

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Mouchtouri, Varvara A; Goutziana, Georgia; Kremastinou, Jenny; Hadjichristodoulou, Christos

2010-02-01

Cooling towers can be colonized by Legionella spp, and inhalation of aerosols generated by their operation may cause Legionnaires' disease in susceptible hosts. Environmental investigations of Legionnaires' disease outbreaks linked with cooling towers have revealed poorly maintained systems, lack of control measures, and failure of system equipment. The purpose of this study was to identify Legionella-contaminated cooling towers, identify risk factors for contamination, and assess the effectiveness of control measures. A total of 96 cooling towers of public buildings were registered and inspected, and 130 samples were collected and microbiologically tested. Microbiological test results were associated with characteristics of cooling towers, water samples, inspection results, and maintenance practices. Of the total 96 cooling towers examined, 47 (48.9%) were colonized by Legionella spp, and 22 (22.9%) required remedial action. A total of 65 samples (50.0%) were positive (> or = 500 cfu L(-1)), and 30 (23%) were heavily contaminated (> or = 10(4) cfu L(-1)). Of the 69 isolates identified, 55 strains (79.7.%) were L pneumophila. Legionella colonization was positively associated with the absence of training on Legionella control (relative risk [RR] = 1.66; P = .02), absence of regular Legionella testing (RR = 2.07: P = .002), absence of sunlight protection (RR = 1.63: P = .02), with samples in which the free residual chlorine level in the water sample was cooling towers (median, 17 years; interquartile range [IQR] =5.0 to 26.0 years) compared with noncolonized cooling towers (median age, 6 years; IQR =1.0 to 13.5 years). After the 22 legionellae-positive cooling towers were disinfected with chlorine, 2 (9%) of them remained positive for Legionella spp with a concentration > or = 1000 cfu L(-1). Cooling towers can be heavily colonized by Legionella spp and thus present a potential risk for infection. This study demonstrates the importance of a risk assessment and

Screening-level assays for potentially human-infectious environmental Legionella spp.

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In spite of the fact that Legionella species can be isolated from nonclinical settings, there is no standard method to determine whether environmental legionellae may be infectious to humans. In this study, an in vivo murine model of pneumonia and three in vitro proliferation as...

A case of nosocomial Legionella pneumonia associated with a contaminated hospital cooling tower.

Science.gov (United States)

Osawa, Kayo; Shigemura, Katsumi; Abe, Yasuhisa; Jikimoto, Takumi; Yoshida, Hiroyuki; Fujisawa, Masato; Arakawa, Soichi

2014-01-01

We report the epidemiological investigation of a nosocomial pneumonia case due to Legionella pneumophila linked to a contaminated hospital cooling tower in an immune-compromised patient. A 73-year-old female patient was diagnosed with nosocomial Legionella pneumonia proven by a culture of L. pneumophila serogroup 1 from bronchoalveolar lavage fluid. Two strains isolated from the patient and two strains isolated from two cooling towers were found to be identical using repetitive-sequence-based-PCR with a 95% probability. This Legionella pneumonia case might be caused by aerosol from cooling towers on the roof of the hospital building which was contaminated by L. pneumophila. We increased up the temperature of hot water supply appropriately for prevention of Legionella breeding in an environment of patients' living. On the other hand, as the maintenance of cooling tower, we increased the frequency of Legionella culture tests from twice a year to three times a year. In addition, we introduced an automated disinfectants insertion machine and added one antiseptic reagent (BALSTER ST-40 N, Tohzai Chemical Industry Co., Ltd., Kawasaki, Japan) after this Legionella disease, and thereafter, we have no additional cases of Legionella disease or detection of Legionella spp. from the cooling tower or hot water supply. This case demonstrates the importance of detecting the infection source and carrying out environmental maintenance in cooperation with the infection control team. Copyright © 2013 Japanese Society of Chemotherapy and the Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Comparative analyses of Legionella species identifies genetic features of strains causing Legionnaires' disease.

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Gomez-Valero, Laura; Rusniok, Christophe; Rolando, Monica; Neou, Mario; Dervins-Ravault, Delphine; Demirtas, Jasmin; Rouy, Zoe; Moore, Robert J; Chen, Honglei; Petty, Nicola K; Jarraud, Sophie; Etienne, Jerome; Steinert, Michael; Heuner, Klaus; Gribaldo, Simonetta; Médigue, Claudine; Glöckner, Gernot; Hartland, Elizabeth L; Buchrieser, Carmen

2014-01-01

The genus Legionella comprises over 60 species. However, L. pneumophila and L. longbeachae alone cause over 95% of Legionnaires’ disease. To identify the genetic bases underlying the different capacities to cause disease we sequenced and compared the genomes of L. micdadei, L. hackeliae and L. fallonii (LLAP10), which are all rarely isolated from humans. We show that these Legionella species possess different virulence capacities in amoeba and macrophages, correlating with their occurrence in humans. Our comparative analysis of 11 Legionella genomes belonging to five species reveals highly heterogeneous genome content with over 60% representing species-specific genes; these comprise a complete prophage in L. micdadei, the first ever identified in a Legionella genome. Mobile elements are abundant in Legionella genomes; many encode type IV secretion systems for conjugative transfer, pointing to their importance for adaptation of the genus. The Dot/Icm secretion system is conserved, although the core set of substrates is small, as only 24 out of over 300 described Dot/Icm effector genes are present in all Legionella species. We also identified new eukaryotic motifs including thaumatin, synaptobrevin or clathrin/coatomer adaptine like domains. Legionella genomes are highly dynamic due to a large mobilome mainly comprising type IV secretion systems, while a minority of core substrates is shared among the diverse species. Eukaryotic like proteins and motifs remain a hallmark of the genus Legionella. Key factors such as proteins involved in oxygen binding, iron storage, host membrane transport and certain Dot/Icm substrates are specific features of disease-related strains.

Cloning and expression of the Legionella micdadei "common antigen" in Escherichia coli

DEFF Research Database (Denmark)

Bangsborg, Jette Marie; Collins, M T; Høiby, N

1989-01-01

To study individual Legionella antigens, a Legionella micdadei genomic library in Escherichia coli SC181 was established. Partially Sau3A digested L. micdadei DNA fragments (15-25 kilobase pairs (kb] were cloned into the tetracycline resistance gene of the cosmid vector pHC79. Four thousand...... ampicillin resistant recombinants were obtained; seven hundred were screened for expression of Legionella antigens in Western blot analysis with a polyspecific E. coli-absorbed anti-L. micdadei rabbit antibody. One of the positive clones expressed a 60 kilodalton (K) antigen, which reacted strongly...... will provide important information with respect to genetic vs. antigenic relatedness among Legionellae and other Gram-negative species, as well as to CA structure and possible function....

Legionella Persistence in Manufactured Water Systems: Pasteurization Potentially Selecting for Thermal Tolerance

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Harriet Whiley

2017-07-01

Full Text Available Legionella is an opportunistic waterborne pathogen of increasing public health significance. Pasteurization, otherwise known as super-heat and flush (increasing water temperature to above 70°C and flushing all outlets, has been identified as an important mechanism for the disinfection of Legionella in manufactured water systems. However, several studies have reported that this procedure was ineffective at remediating water distribution systems as Legionella was able to maintain long term persistent contamination. Up to 25% of L. pneumophila cells survived heat treatment of 70°C, but all of these were in a viable but non-culturable state. This demonstrates the limitations of the culture method of Legionella detection currently used to evaluate disinfection protocols. In addition, it has been demonstrated that pasteurization and nutrient starvation can select for thermal tolerant strains, where L. pneumophila was consistently identified as having greater thermal tolerance compared to other Legionella species. This review demonstrates that further research is needed to investigate the effectiveness of pasteurization as a disinfection method. In particular, it focuses on the potential for pasteurization to select for thermal tolerant L. pneumophila strains which, as the primary causative agent of Legionnaires disease, have greater public health significance compared to other Legionella species.

Genome Analysis of Legionella pneumophila Strains Using a Mixed-Genome Microarray

NARCIS (Netherlands)

Euser, S.M.; Nagelkerke, N.J.; Schuren, F.; Jansen, R.; Boer, J.W. den

2012-01-01

Background: Legionella, the causative agent for Legionnaires' disease, is ubiquitous in both natural and man-made aquatic environments. The distribution of Legionella genotypes within clinical strains is significantly different from that found in environmental strains. Developing novel genotypic

Alkaline approach to treating cooling towers for control of Legionella pneumophila

Energy Technology Data Exchange (ETDEWEB)

States, S.J.; Conley, L.F.; Towner, S.G.; Wolford, R.S.; Stephenson, T.E.; McNamara, M.; Wadowsky, R.M.; Yee, R.B.

1987-08-01

Earlier field and laboratory studies have shown that Legionella species survive and multiply in the pH range 5.5 to 9.2. Additionally, the technical feasibility of operating cooling towers at elevated alkalinities and pH has previously been documented by published guidelines. The guidelines indicate that these conditions facilitate corrosion control and favor chlorine persistence which enhances the effectiveness of continuous chlorination in biofouling control. This information suggest that control of Legionella species in cooling towers can be accomplished by operating the towers under alkaline conditions. To test this possibility, we collected water samples over a period of months from a hospital cooling tower. The samples were analyzed for a variety of chemical parameters. Subsamples were pasteurized and inoculated with non-agar-passaged Legionella pneumophila which had been maintained in tap water. Correlation of subsequent Legionella growth with corresponding pH and alkalinity values revealed statistically significant inverse associations. These data support the hypothesis that operating cooling towers outside of the optimal conditions for Legionella growth (e.g., at elevated alkalinities and a pH greater than 9) may be a useful approach to controlling growth in this habitat.

Acanthamoeba and Dictyostelium as Cellular Models for Legionella Infection

Science.gov (United States)

Swart, A. Leoni; Harrison, Christopher F.; Eichinger, Ludwig; Steinert, Michael; Hilbi, Hubert

2018-01-01

Environmental bacteria of the genus Legionella naturally parasitize free-living amoebae. Upon inhalation of bacteria-laden aerosols, the opportunistic pathogens grow intracellularly in alveolar macrophages and can cause a life-threatening pneumonia termed Legionnaires' disease. Intracellular replication in amoebae and macrophages takes place in a unique membrane-bound compartment, the Legionella-containing vacuole (LCV). LCV formation requires the bacterial Icm/Dot type IV secretion system, which translocates literally hundreds of “effector” proteins into host cells, where they modulate crucial cellular processes for the pathogen's benefit. The mechanism of LCV formation appears to be evolutionarily conserved, and therefore, amoebae are not only ecologically significant niches for Legionella spp., but also useful cellular models for eukaryotic phagocytes. In particular, Acanthamoeba castellanii and Dictyostelium discoideum emerged over the last years as versatile and powerful models. Using genetic, biochemical and cell biological approaches, molecular interactions between amoebae and Legionella pneumophila have recently been investigated in detail with a focus on the role of phosphoinositide lipids, small and large GTPases, autophagy components and the retromer complex, as well as on bacterial effectors targeting these host factors. PMID:29552544

Acanthamoeba and Dictyostelium as Cellular Models for Legionella Infection

Directory of Open Access Journals (Sweden)

A. Leoni Swart

2018-03-01

Full Text Available Environmental bacteria of the genus Legionella naturally parasitize free-living amoebae. Upon inhalation of bacteria-laden aerosols, the opportunistic pathogens grow intracellularly in alveolar macrophages and can cause a life-threatening pneumonia termed Legionnaires' disease. Intracellular replication in amoebae and macrophages takes place in a unique membrane-bound compartment, the Legionella-containing vacuole (LCV. LCV formation requires the bacterial Icm/Dot type IV secretion system, which translocates literally hundreds of “effector” proteins into host cells, where they modulate crucial cellular processes for the pathogen's benefit. The mechanism of LCV formation appears to be evolutionarily conserved, and therefore, amoebae are not only ecologically significant niches for Legionella spp., but also useful cellular models for eukaryotic phagocytes. In particular, Acanthamoeba castellanii and Dictyostelium discoideum emerged over the last years as versatile and powerful models. Using genetic, biochemical and cell biological approaches, molecular interactions between amoebae and Legionella pneumophila have recently been investigated in detail with a focus on the role of phosphoinositide lipids, small and large GTPases, autophagy components and the retromer complex, as well as on bacterial effectors targeting these host factors.

Impact of a risk management plan on Legionella contamination of dental unit water.

Science.gov (United States)

Leoni, Erica; Dallolio, Laura; Stagni, Francesca; Sanna, Tiziana; D'Alessandro, Giovanni; Piana, Gabriela

2015-02-23

The study aimed to assess the prevalence of Legionella spp. in dental unit waterlines of a dental clinic and to verify whether the microbiological parameters used as indicators of water quality were correlated with Legionella contamination. A risk management plan was subsequently implemented in the dental health care setting, in order to verify whether the adopted disinfection protocols were effective in preventing Legionella colonization. The water delivered from syringes and turbines of 63 dental units operating in a dental clinic, was monitored for counts of the heterotrophic bacteria P. aeruginosa and Legionella spp. (22 °C and 37 °C). At baseline, output water from dental units continuously treated with disinfection products was more compliant with the recommended standards than untreated and periodically treated water. However, continuous disinfection was still not able to prevent contamination by Legionella and P. aeruginosa. Legionella was isolated from 36.4%, 24.3% and 53.3% of samples from untreated, periodically and continuously treated waterlines, respectively. The standard microbiological parameters used as indicators of water quality proved to be unreliable as predictors of the presence of Legionella, whose source was identified as the tap water used to supply the dental units. The adoption of control measures, including the use of deionized water in supplying the dental unit waterlines and the application of a combined protocol of continuous and periodic disinfection, with different active products for the different devices, resulted in good control of Legionella contamination. The efficacy of the measures adopted was mainly linked to the strict adherence to the planned protocols, which placed particular stress on staff training and ongoing environmental monitoring.

Atypical presentation of Legionella pneumonia among patients with underlying cancer: A fifteen-year review.

Science.gov (United States)

del Castillo, Maria; Lucca, Anabella; Plodkowski, Andrew; Huang, Yao-Ting; Kaplan, Janice; Gilhuley, Kathleen; Babady, N Esther; Seo, Susan K; Kamboj, Mini

2016-01-01

Immunocompromised patients, especially those receiving treatment with corticosteroids and cytotoxic chemotherapy are at increased risk for developing Legionella pneumonia. The aim of this study was to determine clinical and radiographic characteristics of pulmonary infection due to Legionella in persons undergoing treatment for cancer and stem cell transplant (SCT) recipients. Retrospective review of Legionella cases at MSKCC over a fifteen-year study period from January 1999 and December 2013. Cases were identified by review of microbiology records. During the study period, 40 cases of Legionella infection were identified; nine among these were due to non-pneumophila species. Most cases occurred during the summer. The majority [8/9, (89%)] of patients with non-pneumophila infection had underlying hematologic malignancy, compared to 18/31 (58%) with Legionella pneumophila infections. Radiographic findings were varied-nodular infiltrates mimicking invasive fungal infection were seen only among patients with hematologic malignancy and hematopoietic stem cell transplant (SCT) recipients and were frequently associated with non-pneumophila infections (50% vs 16%; P = 0.0594). All cases of nodular Legionella pneumonia were found incidentally or had an indolent clinical course. Legionella should be considered in the differential diagnosis of nodular lung lesions in immunocompromised patients, especially those with hematologic malignancy and SCT recipients. Most cases of nodular disease due to Legionella are associated with non-pneumophila infections. Copyright © 2015 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Characterization of a major 31-kilodalton peptidoglycan-bound protein of Legionella pneumophila

International Nuclear Information System (INIS)

Butler, C.A.; Hoffman, P.S.

1990-01-01

A 31-kilodalton (kDa) protein was solubilized from the peptidoglycan (PG) fraction of Legionella pneumophila after treatment with either N-acetylmuramidase from the fungus Chalaropsis sp. or with mutanolysin from Streptomyces globisporus. The protein exhibited a ladderlike banding pattern by autoradiography when radiolabeled [(35S]cysteine or [35S]methionine) PG material was extensively treated with hen lysozyme. The banding patterns ranging between 31 and 45 kDa and between 55 and 60 kDa resolved as a single 31-kDa protein when the material was subsequently treated with N-acetylmuramidase. Analysis of the purified 31-kDa protein for diaminopimelic acid by gas chromatography revealed 1 mol of diaminopimelic acid per mol of protein. When outer membrane PG material containing the major outer membrane porin protein was treated with N-acetylmuramidase or mutanolysin, both the 28.5-kDa major outer membrane protein and the 31-kDa protein were solubilized from the PG material under reducing conditions. In the absence of 2-mercaptoethanol, a high-molecular-mass complex (100 kDa) was resolved. The results of this study indicate that a 31-kDa PG-bound protein is a major component of the cell wall of L. pneumophila whose function may be to anchor the major outer membrane protein to PG. Finally, a survey of other Legionella species and other serogroups of L. pneumophila suggested that PG-bound proteins may be a common feature of this genus

Frequency of legionella contamination in conditional & water distribution systems of Tehran hospitals

Directory of Open Access Journals (Sweden)

Davod Esmaieli

2008-09-01

Full Text Available Background: Legionella species are ubiquitous in natural aquatic environments, capable of existing in waters with varied temperatures, PH levels, and nutrient and oxygen contents. Of 49 known legionella species, 20 species have been linked to pneumonia in humans. Contamination by legionella has occurred in the distribution systems of many hospitals. Aerosol-generating systems such as faucets, showerheads, cooling towers, and nebulizers are responsible for their transmission from water to air. Methods: A total of 113 water samples were gathered from different wards of 32 hospitals in different geographical regions of Tehran city. These samples were concentrated by filtration, treated with the acid and temperature buffers, and isolated on a BCYE agar culture medium. Results: A total of 22 hospitals out of 33 (26.5% were contaminated by legionella species, and 30 samples (26.5% out of 113 were positive. Chlorine concentration and pH level of the water samples were 0.18-2.2 mg/l and 6.6-7.6, respectively. Conclusion: The high rate of waste water contamination in Tehran hospitals with Legionella indicates the resistance of this microorganism to chlorine and other disinfectants, or inadequate disinfection process, representing the insufficiency of the current decontamination of hospital water distribution system. Thus identifying legionella species and their controlling in water distribution system of hospitals is of great importance.

Presence and Persistence of Viable, Clinically Relevant Legionella pneumophila Bacteria in Garden Soil in the Netherlands

Science.gov (United States)

van Heijnsbergen, E.; van Deursen, A.; Bouwknegt, M.; Bruin, J. P.; Schalk, J. A. C.

2016-01-01

ABSTRACT Garden soils were investigated as reservoirs and potential sources of pathogenic Legionella bacteria. Legionella bacteria were detected in 22 of 177 garden soil samples (12%) by amoebal coculture. Of these 22 Legionella-positive soil samples, seven contained Legionella pneumophila. Several other species were found, including the pathogenic Legionella longbeachae (4 gardens) and Legionella sainthelensi (9 gardens). The L. pneumophila isolates comprised 15 different sequence types (STs), and eight of these STs were previously isolated from patients according to the European Working Group for Legionella Infections (EWGLI) database. Six gardens that were found to be positive for L. pneumophila were resampled after several months, and in three gardens, L. pneumophila was again isolated. One of these gardens was resampled four times throughout the year and was found to be positive for L. pneumophila on all occasions. IMPORTANCE Tracking the source of infection for sporadic cases of Legionnaires' disease (LD) has proven to be hard. L. pneumophila ST47, the sequence type that is most frequently isolated from LD patients in the Netherlands, is rarely found in potential environmental sources. As L. pneumophila ST47 was previously isolated from a garden soil sample during an outbreak investigation, garden soils were investigated as reservoirs and potential sources of pathogenic Legionella bacteria. The detection of viable, clinically relevant Legionella strains indicates that garden soil is a potential source of Legionella bacteria, and future research should assess the public health implication of the presence of L. pneumophila in garden soil. PMID:27316958

Presence and Persistence of Viable, Clinically Relevant Legionella pneumophila Bacteria in Garden Soil in the Netherlands.

Science.gov (United States)

van Heijnsbergen, E; van Deursen, A; Bouwknegt, M; Bruin, J P; de Roda Husman, A M; Schalk, J A C

2016-09-01

Garden soils were investigated as reservoirs and potential sources of pathogenic Legionella bacteria. Legionella bacteria were detected in 22 of 177 garden soil samples (12%) by amoebal coculture. Of these 22 Legionella-positive soil samples, seven contained Legionella pneumophila Several other species were found, including the pathogenic Legionella longbeachae (4 gardens) and Legionella sainthelensi (9 gardens). The L. pneumophila isolates comprised 15 different sequence types (STs), and eight of these STs were previously isolated from patients according to the European Working Group for Legionella Infections (EWGLI) database. Six gardens that were found to be positive for L. pneumophila were resampled after several months, and in three gardens, L. pneumophila was again isolated. One of these gardens was resampled four times throughout the year and was found to be positive for L. pneumophila on all occasions. Tracking the source of infection for sporadic cases of Legionnaires' disease (LD) has proven to be hard. L. pneumophila ST47, the sequence type that is most frequently isolated from LD patients in the Netherlands, is rarely found in potential environmental sources. As L. pneumophila ST47 was previously isolated from a garden soil sample during an outbreak investigation, garden soils were investigated as reservoirs and potential sources of pathogenic Legionella bacteria. The detection of viable, clinically relevant Legionella strains indicates that garden soil is a potential source of Legionella bacteria, and future research should assess the public health implication of the presence of L. pneumophila in garden soil. Copyright © 2016 van Heijnsbergen et al.

Multiplication of Legionella pneumophila in unsterilized tap water.

Science.gov (United States)

Yee, R B; Wadowsky, R M

1982-06-01

Naturally occurring Legionella pneumophila, an environmental isolate which had not been grown on artificial medium, was tested for the ability to multiply in tap water. A showerhead containing L. pneumophila and non-Legionellaceae bacteria was immersed in nonsterile tap water supplying this fixture. Also L. pneumophila and non-Legionellaceae bacteria were sedimented from tap water from a surgical intensive care unit. This bacterial suspension was inoculated into tap water from our laboratory. The legionellae in both suspensions multiplied in the tap water at 32, 37, and 42 degrees C. The non-Legionellaceae bacteria multiplied at 25, 32, and 37 degrees C. A water sample which was collected from the bottom of a hot water tank was found to contain L. pneumophila and non-Legionellaceae bacteria. These legionellae also multiplied when the water sample was incubated at 37 degrees C. These results indicate that L. pneumophila may multiply in warm water environments such as hot water plumbing fixtures, hot water tanks, and cooling towers.

El hospital ante un brote prolongado de legionelosis The hospital faced with a prolonged Legionella outbreak

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Juan Antonio Fernández

2004-08-01

Full Text Available Objetivo: Describir los recursos asistenciales utilizados en pacientes hospitalizados por neumonía por Legionella durante un brote ocurrido en Alcoy y compararlos con los empleados en otras neumonías. Métodos y resultados: Mediante un protocolo, se analiza y compara a 177 pacientes con neumonía por Legionella con 180 pacientes ingresados por otras neumonías, y se describe su tratamiento y los recursos empleados. La claritromicina fue el antibiótico más utilizado en ambos grupos. La estancia hospitalaria fue similar, pero los requerimientos de ventilación mecánica y cuidados intensivos fueron superiores para Legionella. La hospitalización domiciliaria se utilizó con éxito en un 15,6% de los pacientes con Legionella y en un 11,3% de los demás. El uso de oxigenoterapia domiciliaria al alta fue menor para Legionella (7,8% que para el resto de neumonías (16,7%. Conclusiones: Se destaca la mayor necesidad de ventilación mecánica en la neumonía por Legionella y los buenos resultados de la hospitalización domiciliaria dentro de los nuevos sistemas de gestión.Objective: To describe the health resources used in patients hospitalized with Legionella pneumonia during an outbreak of Legionnaire's disease in Alcoy (Spain, and to compare them with those used in other forms of pneumonia. Methods and results: Using a clinical protocol, 177 Legionella pneumonia patients were compared with 180 patients hospitalized for other types of pneumonia. Data on therapy and the resources used were collected. The most common antibiotic treatment in both groups was clarithromycin, but intensive care and mechanical ventilation requirements were greater in Legionella pneumonia. Home-based hospital care was successfully used in 15.6% of patients with Legionella pneumonia and in 11.3% of those with other types of pneumonia. Home oxygen therapy after discharge was less frequent in the Legionella pneumonia group (7.8% than in the group with non-Legionella

Conventional and Alternative Disinfection Methods of Legionella in Water Distribution Systems – Review

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Pūle Daina

2016-12-01

Full Text Available Prevalence of Legionella in drinking water distribution systems is a widespread problem. Outbreaks of Legionella caused diseases occur despite various disinfectants are used in order to control Legionella. Conventional methods like thermal disinfection, silver/copper ionization, ultraviolet irradiation or chlorine-based disinfection have not been effective in the long term for control of biofilm bacteria. Therefore, research to develop more effective disinfection methods is still necessary.

Exploring the Legionella pneumophila positivity rate in hotel water samples from Antalya, Turkey.

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Sepin Özen, Nevgün; Tuğlu Ataman, Şenay; Emek, Mestan

2017-05-01

The genus Legionella is a fastidious Gram-negative bacteria widely distributed in natural waters and man made water supply systems. Legionella pneumophila is the aetiological agent of approximately 90% of reported Legionellosis cases, and serogroup 1 is the most frequent cause of infections. Legionnaires' disease is often associated with travel and continues to be a public health concern at present. The correct water management quality practices and rapid methods for analyzing Legionella species in environmental water is a key point for the prevention of Legionnaires' disease outbreaks. This study aimed to evaluate the positivity rates and serotyping of Legionella species from water samples in the region of Antalya, Turkey, which is an important tourism center. During January-December 2010, a total of 1403 samples of water that were collected from various hotels (n = 56) located in Antalya were investigated for Legionella pneumophila. All samples were screened for L. pneumophila by culture method according to "ISO 11731-2" criteria. The culture positive Legionella strains were serologically identified by latex agglutination test. A total of 142 Legionella pneumophila isolates were recovered from 21 (37.5%) of 56 hotels. The total frequency of L. pneumophila isolation from water samples was found as 10.1%. Serological typing of 142 Legionella isolates by latex agglutination test revealed that strains belonging to L. pneumophila serogroups 2-14 predominated in the examined samples (85%), while strains of L. pneumophila serogroup 1 were less numerous (15%). According to our knowledge, our study with the greatest number of water samples from Turkey demonstrates that L. pneumophila serogroups 2-14 is the most common isolate. Rapid isolation of L. pneumophila from environmental water samples is essential for the investigation of travel related outbreaks and the possible resources. Further studies are needed to have epidemiological data and to determine the types of L

Legionella shows a diverse secondary metabolism dependent on a broad spectrum Sfp-type phosphopantetheinyl transferase

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Nicholas J. Tobias

2016-11-01

Full Text Available Several members of the genus Legionella cause Legionnaires’ disease, a potentially debilitating form of pneumonia. Studies frequently focus on the abundant number of virulence factors present in this genus. However, what is often overlooked is the role of secondary metabolites from Legionella. Following whole genome sequencing, we assembled and annotated the Legionella parisiensis DSM 19216 genome. Together with 14 other members of the Legionella, we performed comparative genomics and analysed the secondary metabolite potential of each strain. We found that Legionella contains a huge variety of biosynthetic gene clusters (BGCs that are potentially making a significant number of novel natural products with undefined function. Surprisingly, only a single Sfp-like phosphopantetheinyl transferase is found in all Legionella strains analyzed that might be responsible for the activation of all carrier proteins in primary (fatty acid biosynthesis and secondary metabolism (polyketide and non-ribosomal peptide synthesis. Using conserved active site motifs, we predict some novel compounds that are probably involved in cell-cell communication, differing to known communication systems. We identify several gene clusters, which may represent novel signaling mechanisms and demonstrate the natural product potential of Legionella.

Legionella jamestowniensis fatal pneumonia in an immunosuppressed man.

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Edelstein, Paul H

2017-01-01

A fatal case of Legionnaires' disease caused by Legionella jamestowniensis is reported in a severely immunocompromised patient with metastatic hepatocellular carcinoma, and liver and kidney transplants. L. jamestowniensis was cultured from two separate respiratory tract specimens and a PCR test for Legionella species was also positive from the same specimens. This is apparently the first reported case of human infection caused by L. jamestowniensis. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Uncovering the Legionella genus effector repertoire - strength in diversity and numbers

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Burstein, David; Amaro, Francisco; Zusman, Tal; Lifshitz, Ziv; Cohen, Ofir; Gilbert, Jack A; Pupko, Tal; Shuman, Howard A; Segal, Gil

2016-01-01

Infection by the human pathogen Legionella pneumophila relies on the translocation of ~300 virulence proteins, termed effectors, which manipulate host-cell processes. However, almost no information exists regarding effectors in other Legionella pathogens. Here we sequenced, assembled and characterized the genomes of 38 Legionella species, and predicted their effector repertoire using a previously validated machine-learning approach. This analysis revealed a treasure trove of 5,885 predicted effectors. The effector repertoire of different Legionella species was found to be largely non-overlapping, and only seven core-effectors were shared among all species studied. Species-specific effectors had atypically low GC content, suggesting exogenous acquisition, possibly from their natural protozoan hosts. Furthermore, we detected numerous novel conserved effector domains, and discovered new domain combinations, which allowed inferring yet undescribed effector functions. The effector collection and network of domain architectures described here can serve as a roadmap for future studies of effector function and evolution. PMID:26752266

Recreational Vehicle Water Tanks as a Possible Source for Legionella Infections

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Christine M. Litwin

2013-01-01

Full Text Available We investigated recreational vehicle (RV water reservoirs in response to a case of pneumonia in which Legionella pneumophila was cultured both from the patient and a RV reservoir in which he travelled. Water samples processed and cultured at the CDC according to standard protocol were positive for Legionella spp. in 4/17 (24% faucets, 1/11 (9% water tanks from 4/20 (20% RVs from three different campsites. Legionella spp. that were isolated included L. pneumophila (serogroups 1 and 6, L. anisa, L. feeleii, and L. quateriensis. Environmental controls from the potable water of the three campsites were culture-negative. A survey of maintenance practices by the RV users at the campsites revealed that chlorine disinfection of the water tanks was rarely performed. To prevent the possibility of Legionella infections, RV owners should implement regular chlorine disinfection of their water tanks and follow the recommended maintenance guidelines according to their owner's manuals.

Usefulness of real-time PCR as a complementary tool to the monitoring of Legionella spp. and Legionella pneumophila by culture in industrial cooling systems.

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Touron-Bodilis, A; Pougnard, C; Frenkiel-Lebossé, H; Hallier-Soulier, S

2011-08-01

This study was designed to evaluate the usefulness of quantification by real-time PCR as a management tool to monitor concentrations of Legionella spp. and Legionella pneumophila in industrial cooling systems and its ability to anticipate culture trends by the French standard method (AFNOR T90-431). Quantifications of Legionella bacteria were achieved by both methods on samples from nine cooling systems with different water qualities. Proportion of positive samples for L. pneumophila quantified by PCR was clearly lower in deionized or river waters submitted to a biocide treatment than in raw river waters, while positive samples for Legionella spp. were quantified for almost all the samples. For some samples containing PCR inhibitors, high quantification limits (up to 4·80 × 10(5) GU l(-1) ) did not allow us to quantify L. pneumophila, when they were quantified by culture. Finally, the monitoring of concentrations of L. pneumophila by both methods showed similar trends for 57-100% of the samples. These results suggest that, if some methodological steps designed to reduce inhibitory problems and thus decrease the quantification limits, could be developed to quantify Legionella in complex waters, the real-time PCR could be a valuable complementary tool to monitor the evolution of L. pneumophila concentrations. This study shows the possibility of using real-time PCR to monitor L. pneumophila proliferations in cooling systems and the importance to adapt nucleic acid extraction and purification protocols to raw waters. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology. No claim to French Government works.

An alkaline approach to treating cooling towers for control of Legionella pneumophila.

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States, S J; Conley, L F; Towner, S G; Wolford, R S; Stephenson, T E; McNamara, A M; Wadowsky, R M; Yee, R B

1987-08-01

Earlier field and laboratory studies have shown that Legionella species survive and multiply in the pH range 5.5 to 9.2. Additionally, the technical feasibility of operating cooling towers at elevated alkalinities and pH has previously been documented by published guidelines. The guidelines indicate that these conditions facilitate corrosion control and favor chlorine persistence which enhances the effectiveness of continuous chlorination in biofouling control. This information suggests that control of Legionella species in cooling towers can be accomplished by operating the towers under alkaline conditions. To test this possibility, we collected water samples over a period of months from a hospital cooling tower. The samples were analyzed for a variety of chemical parameters. Subsamples were pasteurized and inoculated with non-agar-passaged Legionella pneumophila which had been maintained in tap water. Correlation of subsequent Legionella growth with corresponding pH and alkalinity values revealed statistically significant inverse associations. These data support the hypothesis that operating cooling towers outside of the optimal conditions for Legionella growth (e.g., at elevated alkalinities and a pH greater than 9) may be a useful approach to controlling growth in this habitat.

Designation of the European Working Group on Legionella Infection (EWGLI) amplified fragment length polymorphism types of Legionella pneumophila serogroup 1 and results of intercentre proficiency testing Using a standard protocol

DEFF Research Database (Denmark)

Fry, N K; Bangsborg, Jette Marie; Bergmans, A

2002-01-01

The utility of amplified fragment length polymorphism (AFLP) analysis as a genotyping method for the epidemiological typing of Legionella pneumophila serogroup 1 has been previously demonstrated. This study (i). reports recommendations for the designation of the European Working Group on Legionella...... centres), and 92% (7 centres) to 100% (7 centres). The AFLP method as described is robust and rapid and allows the genotypic comparison of isolates of Legionella pneumophila between different testing centres without the need for exchange of the strains studied....

Effect of Legionella pneumophila cytotoxic protease on human neutrophil and monocyte function

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Rechnitzer, C; Kharazmi, A

1992-01-01

The extracellular metalloprotease of Legionella pneumophila, also called tissue-destructive protease or major secretory protein, has been proposed as one of the virulence factors of this organism. Considering the decisive role played by the phagocytic cells in host defense against Legionella...

High Prevalence, Genetic Diversity and Intracellular Growth Ability of Legionella in Hot Spring Environments

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Zhou, Haijian; Wang, Huanxin; Xu, Ying; Zhao, Mingqiang; Guan, Hong; Li, Machao; Shao, Zhujun

2013-01-01

Background Legionella is the causative agent of Legionnaires' disease, and hot springs are a major source of outbreaks of this disease. It is important from a public health perspective to survey hot spring environments for the presence of Legionella. Methods Prospective surveillance of the extent of Legionella pollution was conducted at three hot spring recreational areas in Beijing, China in 2011. Pulsed-field gel electrophoresis (PFGE) and sequence-based typing (SBT) were used to describe the genetic polymorphism of isolates. The intracellular growth ability of the isolates was determined by interacting with J774 cells and plating the dilutions onto BCYE agar plates. Results Overall, 51.9% of spring water samples showed Legionella-positive, and their concentrations ranged from 1 CFU/liter to 2,218 CFU/liter. The positive rates of Legionella were significantly associated with a free chlorine concentration of ≥0.2 mg/L, urea concentration of ≥0.05 mg/L, total microbial counts of ≥400 CFU/ml and total coliform of ≥3 MPN/L (pLegionella concentrations were significantly associated with sample temperature, pH, total microbial counts and total coliform (pLegionella pneumophila was the most frequently isolated species (98.9%), and the isolated serogroups included serogroups 3 (25.3%), 6 (23.4%), 5 (19.2%), 1 (18.5%), 2 (10.2%), 8 (0.4%), 10 (0.8%), 9 (1.9%) and 12 (0.4%). Two hundred and twenty-eight isolates were analyzed by PFGE and 62 different patterns were obtained. Fifty-seven L. pneumophila isolates were selected for SBT analysis and divided into 35 different sequence types with 5 main clonal groups. All the 57 isolates had high intracellular growth ability. Conclusions Our results demonstrated high prevalence and genetic polymorphism of Legionella in springs in Beijing, China, and the SBT and intracellular growth assay results suggested that the Legionella isolates of hot spring environments were pathogenic. Improved control and prevention strategies are

High prevalence, genetic diversity and intracellular growth ability of Legionella in hot spring environments.

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Tian Qin

Full Text Available BACKGROUND: Legionella is the causative agent of Legionnaires' disease, and hot springs are a major source of outbreaks of this disease. It is important from a public health perspective to survey hot spring environments for the presence of Legionella. METHODS: Prospective surveillance of the extent of Legionella pollution was conducted at three hot spring recreational areas in Beijing, China in 2011. Pulsed-field gel electrophoresis (PFGE and sequence-based typing (SBT were used to describe the genetic polymorphism of isolates. The intracellular growth ability of the isolates was determined by interacting with J774 cells and plating the dilutions onto BCYE agar plates. RESULTS: Overall, 51.9% of spring water samples showed Legionella-positive, and their concentrations ranged from 1 CFU/liter to 2,218 CFU/liter. The positive rates of Legionella were significantly associated with a free chlorine concentration of ≥0.2 mg/L, urea concentration of ≥0.05 mg/L, total microbial counts of ≥400 CFU/ml and total coliform of ≥3 MPN/L (p<0.01. The Legionella concentrations were significantly associated with sample temperature, pH, total microbial counts and total coliform (p<0.01. Legionella pneumophila was the most frequently isolated species (98.9%, and the isolated serogroups included serogroups 3 (25.3%, 6 (23.4%, 5 (19.2%, 1 (18.5%, 2 (10.2%, 8 (0.4%, 10 (0.8%, 9 (1.9% and 12 (0.4%. Two hundred and twenty-eight isolates were analyzed by PFGE and 62 different patterns were obtained. Fifty-seven L. pneumophila isolates were selected for SBT analysis and divided into 35 different sequence types with 5 main clonal groups. All the 57 isolates had high intracellular growth ability. CONCLUSIONS: Our results demonstrated high prevalence and genetic polymorphism of Legionella in springs in Beijing, China, and the SBT and intracellular growth assay results suggested that the Legionella isolates of hot spring environments were pathogenic. Improved control

Evaluation of Legionella Air Contamination in Healthcare Facilities by Different Sampling Methods: An Italian Multicenter Study.

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Montagna, Maria Teresa; De Giglio, Osvalda; Cristina, Maria Luisa; Napoli, Christian; Pacifico, Claudia; Agodi, Antonella; Baldovin, Tatjana; Casini, Beatrice; Coniglio, Maria Anna; D'Errico, Marcello Mario; Delia, Santi Antonino; Deriu, Maria Grazia; Guida, Marco; Laganà, Pasqualina; Liguori, Giorgio; Moro, Matteo; Mura, Ida; Pennino, Francesca; Privitera, Gaetano; Romano Spica, Vincenzo; Sembeni, Silvia; Spagnolo, Anna Maria; Tardivo, Stefano; Torre, Ida; Valeriani, Federica; Albertini, Roberto; Pasquarella, Cesira

2017-06-22

Healthcare facilities (HF) represent an at-risk environment for legionellosis transmission occurring after inhalation of contaminated aerosols. In general, the control of water is preferred to that of air because, to date, there are no standardized sampling protocols. Legionella air contamination was investigated in the bathrooms of 11 HF by active sampling (Surface Air System and Coriolis ® μ) and passive sampling using settling plates. During the 8-hour sampling, hot tap water was sampled three times. All air samples were evaluated using culture-based methods, whereas liquid samples collected using the Coriolis ® μ were also analyzed by real-time PCR. Legionella presence in the air and water was then compared by sequence-based typing (SBT) methods. Air contamination was found in four HF (36.4%) by at least one of the culturable methods. The culturable investigation by Coriolis ® μ did not yield Legionella in any enrolled HF. However, molecular investigation using Coriolis ® μ resulted in eight HF testing positive for Legionella in the air. Comparison of Legionella air and water contamination indicated that Legionella water concentration could be predictive of its presence in the air. Furthermore, a molecular study of 12 L. pneumophila strains confirmed a match between the Legionella strains from air and water samples by SBT for three out of four HF that tested positive for Legionella by at least one of the culturable methods. Overall, our study shows that Legionella air detection cannot replace water sampling because the absence of microorganisms from the air does not necessarily represent their absence from water; nevertheless, air sampling may provide useful information for risk assessment. The liquid impingement technique appears to have the greatest capacity for collecting airborne Legionella if combined with molecular investigations.

Evaluation of Legionella Air Contamination in Healthcare Facilities by Different Sampling Methods: An Italian Multicenter Study

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Montagna, Maria Teresa; De Giglio, Osvalda; Cristina, Maria Luisa; Napoli, Christian; Pacifico, Claudia; Agodi, Antonella; Baldovin, Tatjana; Casini, Beatrice; Coniglio, Maria Anna; D’Errico, Marcello Mario; Delia, Santi Antonino; Deriu, Maria Grazia; Guida, Marco; Laganà, Pasqualina; Liguori, Giorgio; Moro, Matteo; Mura, Ida; Pennino, Francesca; Privitera, Gaetano; Romano Spica, Vincenzo; Sembeni, Silvia; Spagnolo, Anna Maria; Tardivo, Stefano; Torre, Ida; Valeriani, Federica; Albertini, Roberto; Pasquarella, Cesira

2017-01-01

Healthcare facilities (HF) represent an at-risk environment for legionellosis transmission occurring after inhalation of contaminated aerosols. In general, the control of water is preferred to that of air because, to date, there are no standardized sampling protocols. Legionella air contamination was investigated in the bathrooms of 11 HF by active sampling (Surface Air System and Coriolis®μ) and passive sampling using settling plates. During the 8-hour sampling, hot tap water was sampled three times. All air samples were evaluated using culture-based methods, whereas liquid samples collected using the Coriolis®μ were also analyzed by real-time PCR. Legionella presence in the air and water was then compared by sequence-based typing (SBT) methods. Air contamination was found in four HF (36.4%) by at least one of the culturable methods. The culturable investigation by Coriolis®μ did not yield Legionella in any enrolled HF. However, molecular investigation using Coriolis®μ resulted in eight HF testing positive for Legionella in the air. Comparison of Legionella air and water contamination indicated that Legionella water concentration could be predictive of its presence in the air. Furthermore, a molecular study of 12 L. pneumophila strains confirmed a match between the Legionella strains from air and water samples by SBT for three out of four HF that tested positive for Legionella by at least one of the culturable methods. Overall, our study shows that Legionella air detection cannot replace water sampling because the absence of microorganisms from the air does not necessarily represent their absence from water; nevertheless, air sampling may provide useful information for risk assessment. The liquid impingement technique appears to have the greatest capacity for collecting airborne Legionella if combined with molecular investigations. PMID:28640202

Effects of culture conditions and biofilm formation on the iodine susceptibility of Legionella pneumophila

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Cargill, K. L.; Pyle, B. H.; Sauer, R. L.; McFeters, G. A.

1992-01-01

The susceptibility of Legionella pneumophila to iodination was studied with cultures grown in well water, on rich agar media, and attached to stainless-steel surfaces. Legionella pneumophila grown in water cultures in association with other microorganisms were less sensitive to disinfection by chlorine and iodine than were agar-passaged cultures. Differences in sensitivity to disinfection between water-cultured and agar-grown legionellae were determined by comparing C x T values (concentration in milligrams per litre multiplied by time in minutes to achieve 99% decrease in viability) and CM x T values (concentration in molarity). Iodine (1500x) gave a greater difference in CM x T values than did chlorine (68x). Iodine was 50 times more effective than chlorine when used with agar-grown cultures but was only twice as effective when tested against water-grown Legionella cultures. C x T x S values (C x T multiplied by percent survivors), which take into consideration the percent surviving bacteria, were used to compare sensitivities in very resistant populations, such as those in biofilms. Water cultures of legionellae associated with stainless-steel surfaces were 135 times more resistant to iodination than were unattached legionellae, and they were 210,000 times more resistant than were agar-grown cultures. These results indicate that the conditions under which legionellae are grown can dramatically affect their susceptibility to some disinfectants and must be considered when evaluating the efficacy of a disinfecting agent.

Diverse protist grazers select for virulence-related traits in Legionella

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Amaro, Francisco; Wang, Wen; Gilbert, Jack A; Roger Anderson, O; Shuman, Howard A

2015-01-01

It is generally accepted that selection for resistance to grazing by protists has contributed to the evolution of Legionella pneumophila as a pathogen. Grazing resistance is becoming more generally recognized as having an important role in the ecology and evolution of bacterial pathogenesis. However, selection for grazing resistance presupposes the existence of protist grazers that provide the selective pressure. To determine whether there are protists that graze on pathogenic Legionella species, we investigated the existence of such organisms in a variety of environmental samples. We isolated and characterized diverse protists that graze on L. pneumophila and determined the effects of adding L. pneumophila on the protist community structures in microcosms made from these environmental samples. Several unrelated organisms were able to graze efficiently on L. pneumophila. The community structures of all samples were markedly altered by the addition of L. pneumophila. Surprisingly, some of the Legionella grazers were closely related to species that are known hosts for L. pneumophila, indicating the presence of unknown specificity determinants for this interaction. These results provide the first direct support for the hypothesis that protist grazers exert selective pressure on Legionella to acquire and retain adaptations that contribute to survival, and that these properties are relevant to the ability of the bacteria to cause disease in people. We also report a novel mechanism of killing of amoebae by one Legionella species that requires an intact Type IV secretion system but does not involve intracellular replication. We refer to this phenomenon as ‘food poisoning'. PMID:25575308

Application of ozonation process for the removal of Legionella pneumophila from water

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Mohammad Safaee

2015-09-01

Full Text Available Background: Legionella pneumophila mortality and morbidity is a health concern worldwide. Due to the role of water in transmission of Legionenlla, several techniques have been used for water disinfection. This research was aimed to analyze the efficacy of ozonation process and the effects of bacterial density, contact time and pH on the removal of Legionella pneumophila from water. Methods: Legionella pneumophila was isolated from hospital water line and spiked into sterile drinking water with 300, 700 and 1000 CFU/ml densities. Ozonation was conducted within 1 L batch glass reactor with injection of 5 mg/h and contact time of 5 to 30 minutes at pH = 5, 7 and 9. Legionella culture was performed in supplemented BCYE containing GVPC and thermal treatment. After ozonation, the developed colonies were identified via biochemical and morphological tests. Results: In pH =5, the contact time 25 min and pH= 7 as well as the contact time 30 min, increase of legionella density from 300 to 1000 CFU/ml led to the reduction of removal efficiency from 100 to 87% and 100 to 82%, respectively. In pH=9 and contact time 20 min with the same bacterial density, 300 to 1000 CFU/ml, the disinfection efficacy was decreased from 100 to 91.5 %. Conclusion: Ozonation is an appropriate technique for elimination of legionella from water. The increased bacterial density led to the reduction of removal efficiency. The lowest and highest performance rates were obtained in pH=7 and 9, respectively.

Comparing methods of determining Legionella spp. in complex water matrices.

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Díaz-Flores, Álvaro; Montero, Juan Carlos; Castro, Francisco Javier; Alejandres, Eva María; Bayón, Carmen; Solís, Inmaculada; Fernández-Lafuente, Roberto; Rodríguez, Guillermo

2015-04-29

Legionella testing conducted at environmental laboratories plays an essential role in assessing the risk of disease transmission associated with water systems. However, drawbacks of culture-based methodology used for Legionella enumeration can have great impact on the results and interpretation which together can lead to underestimation of the actual risk. Up to 20% of the samples analysed by these laboratories produced inconclusive results, making effective risk management impossible. Overgrowth of competing microbiota was reported as an important factor for culture failure. For quantitative polymerase chain reaction (qPCR), the interpretation of the results from the environmental samples still remains a challenge. Inhibitors may cause up to 10% of inconclusive results. This study compared a quantitative method based on immunomagnetic separation (IMS method) with culture and qPCR, as a new approach to routine monitoring of Legionella. First, pilot studies evaluated the recovery and detectability of Legionella spp using an IMS method, in the presence of microbiota and biocides. The IMS method results were not affected by microbiota while culture counts were significantly reduced (1.4 log) or negative in the same samples. Damage by biocides of viable Legionella was detected by the IMS method. Secondly, a total of 65 water samples were assayed by all three techniques (culture, qPCR and the IMS method). Of these, 27 (41.5%) were recorded as positive by at least one test. Legionella spp was detected by culture in 7 (25.9%) of the 27 samples. Eighteen (66.7%) of the 27 samples were positive by the IMS method, thirteen of them reporting counts below 10(3) colony forming units per liter (CFU l(-1)), six presented interfering microbiota and three presented PCR inhibition. Of the 65 water samples, 24 presented interfering microbiota by culture and 8 presented partial or complete inhibition of the PCR reaction. So the rate of inconclusive results of culture and PCR was 36

Improving the Diagnosis of Legionella Pneumonia within a Healthcare System through a Systematic Consultation and Testing Program.

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Decker, Brooke K; Harris, Patricia L; Muder, Robert R; Hong, Jae H; Singh, Nina; Sonel, Ali F; Clancy, Cornelius J

2016-08-01

Legionella testing is not recommended for all patients with pneumonia, but rather for particular patient subgroups. As a result, the overall incidence of Legionella pneumonia may be underestimated. To determine the incidence of Legionella pneumonia in a veteran population in an endemic area after introduction of a systematic infectious diseases consultation and testing program. In response to a 2011-2012 outbreak, the VA Pittsburgh Healthcare System mandated infectious diseases consultations and testing for Legionella by urine antigen and sputum culture in all patients with pneumonia. Between January 2013 and December 2015, 1,579 cases of pneumonia were identified. The incidence of pneumonia was 788/100,000 veterans per year, including 352/100,000 veterans per year and 436/100,000 veterans per year with community-associated pneumonia (CAP) and health care-associated pneumonia, respectively. Ninety-eight percent of patients with suspected pneumonia were tested for Legionella by at least one method. Legionella accounted for 1% of pneumonia cases (n = 16), including 1.7% (12/706) and 0.6% (4/873) of CAP and health care-associated pneumonia, respectively. The yearly incidences of Legionella pneumonia and Legionella CAP were 7.99 and 5.99/100,000 veterans, respectively. The sensitivities of urine antigen and sputum culture were 81% and 60%, respectively; the specificity of urine antigen was >99.97%. Urine antigen testing and Legionella cultures increased by 65% and 330%, respectively, after introduction of our program. Systematic testing of veterans in an endemic area revealed a higher incidence of Legionella pneumonia and CAP than previously reported. Widespread urine antigen testing was not limited by false positivity.

Legionella feeleii: an unusual organism associated with cutaneous infection in an immunocompromised patient.

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Verykiou, S; Goodhead, C; Parry, G; Meggitt, S

2018-04-01

We report a 23-year-old immunocompromised woman who, following cardiac transplantation, presented with an unusual cutaneous eruption. She developed a widespread pustular rash, systemic symptoms and a high temperature with raised inflammatory markers. The diagnosis was reached when a skin biopsy was cultured onto Legionella agar (buffered charcoal yeast extract) and Legionella feeleii was isolated. The patient was treated with 6 weeks of moxifloxacin and her cutaneous lesions gradually resolved. Cutaneous Legionella infections are uncommon and usually affect immunocompromised patients. © 2017 British Association of Dermatologists.

Ciliate Paramecium is a natural reservoir of Legionella pneumophila

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Watanabe, Kenta; Nakao, Ryo; Fujishima, Masahiro; Tachibana, Masato; Shimizu, Takashi; Watarai, Masahisa

2016-04-01

Legionella pneumophila, the causative agent of Legionnaires’ disease, replicates within alveolar macrophages and free-living amoebae. However, the lifestyle of L. pneumophila in the environment remains largely unknown. Here we established a novel natural host model of L. pneumophila endosymbiosis using the ciliate Paramecium caudatum. We also identified Legionella endosymbiosis-modulating factor A (LefA), which contributes to the change in life stage from endosymbiosis to host lysis, enabling escape to the environment. We isolated L. pneumophila strains from the environment, and they exhibited cytotoxicity toward P. caudatum and induced host lysis. Acidification of the Legionella-containing vacuole (LCV) was inhibited, and enlarged LCVs including numerous bacteria were observed in P. caudatum infected with L. pneumophila. An isogenic L. pneumophila lefA mutant exhibited decreased cytotoxicity toward P. caudatum and impaired the modification of LCVs, resulting in the establishment of endosymbiosis between them. Our results suggest that L. pneumophila may have a mechanism to switch their endosymbiosis in protistan hosts in the environment.

Fast label-free detection of Legionella spp. in biofilms by applying immunomagnetic beads and Raman spectroscopy.

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Kusić, Dragana; Rösch, Petra; Popp, Jürgen

2016-03-01

Legionellae colonize biofilms, can form a biofilm by itself and multiply intracellularly within the protozoa commonly found in water distribution systems. Approximately half of the known species are pathogenic and have been connected to severe multisystem Legionnaires' disease. The detection methods for Legionella spp. in water samples are still based on cultivation, which is time consuming due to the slow growth of this bacterium. Here, we developed a cultivation-independent, label-free and fast detection method for legionellae in a biofilm matrix based on the Raman spectroscopic analysis of isolated single cells via immunomagnetic separation (IMS). A database comprising the Raman spectra of single bacterial cells captured and separated from the biofilms formed by each species was used to build the identification method based on a support vector machine (SVM) discriminative classifier. The complete method allows the detection of Legionella spp. in 100 min. Cross-reactivity of Legionella spp. specific immunomagnetic beads to the other studied genera was tested, where only small cell amounts of Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli compared to the initial number of cells were isolated by the immunobeads. Nevertheless, the Raman spectra collected from isolated non-targeted bacteria were well-discriminated from the Raman spectra collected from isolated Legionella cells, whereby the Raman spectra of the independent dataset of Legionella strains were assigned with an accuracy of 98.6%. In addition, Raman spectroscopy was also used to differentiate between isolated Legionella species. Copyright © 2016 Elsevier GmbH. All rights reserved.

A new oligonucleotide microarray for detection of pathogenic and non-pathogenic Legionella spp.

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Boyang Cao

Full Text Available Legionella pneumophila has been recognized as the major cause of legionellosis since the discovery of the deadly disease. Legionella spp. other than L. pneumophila were later found to be responsible to many non-pneumophila infections. The non-L. pneumophila infections are likely under-detected because of a lack of effective diagnosis. In this report, we have sequenced the 16S-23S rRNA gene internal transcribed spacer (ITS of 10 Legionella species and subspecies, including L. anisa, L. bozemanii, L. dumoffii, L. fairfieldensis, L. gormanii, L. jordanis, L. maceachernii, L. micdadei, L. pneumophila subspp. fraseri and L. pneumophila subspp. pasculleii, and developed a rapid oligonucleotide microarray detection technique accordingly to identify 12 most common Legionella spp., which consist of 11 pathogenic species of L. anisa, L. bozemanii, L. dumoffii, L. gormanii, L. jordanis, L. longbeachae, L. maceachernii, L. micdadei, and L. pneumophila (including subspp. pneumophila, subspp. fraseri, and subspp. pasculleii and one non-pathogenic species, L. fairfieldensis. Twenty-nine probes that reproducibly detected multiple Legionella species with high specificity were included in the array. A total of 52 strains, including 30 target pathogens and 22 non-target bacteria, were used to verify the oligonucleotide microarray assay. The sensitivity of the detection was at 1.0 ng with genomic DNA or 13 CFU/100 mL with Legionella cultures. The microarray detected seven samples of air conditioner-condensed water with 100% accuracy, validating the technique as a promising method for applications in basic microbiology, clinical diagnosis, food safety, and epidemiological surveillance. The phylogenetic study based on the ITS has also revealed that the non-pathogenic L. fairfieldensis is the closest to L. pneumophila than the nine other pathogenic Legionella spp.

A New Oligonucleotide Microarray for Detection of Pathogenic and Non-Pathogenic Legionella spp.

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Cao, Boyang; Liu, Xiangqian; Yu, Xiang; Chen, Min; Feng, Lu; Wang, Lei

2014-01-01

Legionella pneumophila has been recognized as the major cause of legionellosis since the discovery of the deadly disease. Legionella spp. other than L. pneumophila were later found to be responsible to many non-pneumophila infections. The non-L. pneumophila infections are likely under-detected because of a lack of effective diagnosis. In this report, we have sequenced the 16S-23S rRNA gene internal transcribed spacer (ITS) of 10 Legionella species and subspecies, including L. anisa, L. bozemanii, L. dumoffii, L. fairfieldensis, L. gormanii, L. jordanis, L. maceachernii, L. micdadei, L. pneumophila subspp. fraseri and L. pneumophila subspp. pasculleii, and developed a rapid oligonucleotide microarray detection technique accordingly to identify 12 most common Legionella spp., which consist of 11 pathogenic species of L. anisa, L. bozemanii, L. dumoffii, L. gormanii, L. jordanis, L. longbeachae, L. maceachernii, L. micdadei, and L. pneumophila (including subspp. pneumophila, subspp. fraseri, and subspp. pasculleii) and one non-pathogenic species, L. fairfieldensis. Twenty-nine probes that reproducibly detected multiple Legionella species with high specificity were included in the array. A total of 52 strains, including 30 target pathogens and 22 non-target bacteria, were used to verify the oligonucleotide microarray assay. The sensitivity of the detection was at 1.0 ng with genomic DNA or 13 CFU/100 mL with Legionella cultures. The microarray detected seven samples of air conditioner-condensed water with 100% accuracy, validating the technique as a promising method for applications in basic microbiology, clinical diagnosis, food safety, and epidemiological surveillance. The phylogenetic study based on the ITS has also revealed that the non-pathogenic L. fairfieldensis is the closest to L. pneumophila than the nine other pathogenic Legionella spp. PMID:25469776

Prevalence of Legionella strains in cooling towers and legionellosis cases in New Zealand.

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Lau, Robert; Maqsood, Saadia; Harte, David; Caughley, Brian; Deacon, Rob

2013-01-01

Over 3,900 water samples from 688 cooling towers were tested for Legionella in 2008 in New Zealand. Of 80 (2.05% isolation rate) Legionella isolates, 10 (12.5%) were L. pneumophila serogroup 1; 10 (12.5%) were L. anisa; nine (11.2%) were L. pneumophila serogroup 8; and one (1.2%) was L. longbeachae serogroup 2. Forty-one (51.2%) Legionella isolates were L. pneumophila serogroups. Over 3,990 water samples from 606 cooling towers were tested for Legionella in 2009 in New Zealand. Of 51 (1.28% isolation rate) Legionella isolates, 18 (35.3%) were L. pneumophila serogroup 1, and 39 (76.4%) were other L. pneumophila serogroups. L. pneumophila serogroups were significantly associated with legionellosis cases in 2008 and 2009. L. longbeachae serogroups were equally significantly associated with legionellosis cases. This significant association of L. longbeachae with legionellosis particularly of L. longbeachae serogroup 1 is unique in that part of the world. The authors' study also showed that the aqueous environment of the cooling tower is not a natural habitat for pathogenic L. longbeachae. Regular monitoring and maintenance of cooling towers have prevented outbreaks of legionellosis.

Humidifier prevents corrosion and legionella and saves water and energy; Bevochtigingssysteem voorkomt corrosie en legionella en bespaart water en energie

Energy Technology Data Exchange (ETDEWEB)

Huizinga, H.T. [Heat Transfer Holland, Zuidwolde (Netherlands)

2009-04-15

The renewal of the central water humidifier in the laboratory of DSM-Resins (chemical industry) in Zwolle, Netherlands, leads to a better air conditioning system and prevents corrosion and legionella. At the same time, water and energy consumption are substantially reduced. This renewal fits perfectly within DSM's company policy to decrease the annual energy consumption by 2 %. [Dutch] Het vernieuwen van het centrale waterbevochtigingssysteem in het laboratorium van DSM-Resins te Zwolle verbetert het luchtbehandelingssysteem en voorkomt corrosie en legionella. Tevens vindt er een besparing plaats in water en energiegebruik. Deze vernieuwing past in de beleidsdoelstelling van DSM om iedere jaar 2% minder energie te gebruiken.

Satellite growth of Legionella pneumophila with an environmental isolate of Flavobacterium breve.

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Wadowsky, R M; Yee, R B

1983-12-01

Legionella pneumophila serogroup 1 was observed to satellite around colonies of Flavobacterium breve on an L-cysteine-deficient medium which did not support growth of legionellae. Both isolates were recovered from the hot water tanks of hospitals. Ferric PPi stimulated satellite growth between 0.01 and 0.1%.

Satellite growth of Legionella pneumophila with an environmental isolate of Flavobacterium breve.

OpenAIRE

Wadowsky, R M; Yee, R B

1983-01-01

Legionella pneumophila serogroup 1 was observed to satellite around colonies of Flavobacterium breve on an L-cysteine-deficient medium which did not support growth of legionellae. Both isolates were recovered from the hot water tanks of hospitals. Ferric PPi stimulated satellite growth between 0.01 and 0.1%.

[Presence of Legionella spp. in household drinking water reservoirs in Resistencia, Chaco, Argentina. Preliminary report].

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Lösch, Liliana S; Merino, Luis A

Legionella spp. is an environmental bacterium that can survive in a wide range of physicochemical conditions and may colonize distribution systems of drinking water and storage tanks. Legionella pneumophila is the major waterborne pathogen that can cause 90% of Legionnaires' disease cases. The aim of this study was to detect the presence of Legionella spp. in household drinking water tanks in the city of Resistencia, Chaco. The detection of Legionella in water samples was performed by culture methods as set out in ISO 11731:1998. Thirty two water samples were analyzed and Legionella spp. was recovered in 12 (37.5%) of them. The monitoring of this microorganism in drinking water is the first step towards addressing the control of its spread to susceptible hosts. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Legionella species diversity and dynamics from surface reservoir to tap water: from cold adaptation to thermophily.

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Lesnik, René; Brettar, Ingrid; Höfle, Manfred G

2016-05-01

Water samples of the Drinking Water Supply System (DWSS) of the city of Braunschweig were analysed for its Legionella species composition using genus-specific PCR amplicons and single-strand conformation polymorphism (SSCP) fingerprint analyses based on 16S rRNA genes. These analyses comprised the whole supply chain including raw water, treatment process and large-scale storage, and a seasonal study of finished drinking water sampled monthly from cold and hot tap water. Treatment of raw water had a major impact on Legionella species by reducing their diversity and abundances. The Legionella species composition of the tap water was highly distinct from that of both source waters. In cold water, 8-14 different phylotypes of Legionella (PTLs) were observed per sample with relative abundances ranging from >1% to 53%. In hot water, L. pneumophila was present during all seasons at high relative abundances (8-40%) accompanied by 5-14 other PTLs of which 6 PTLs were in common with cold water. This thermophilic Legionella community, including L. pneumophila, was able to grow in the hot water above 50 °C. Such thermophilic Legionella populations are of general relevance for drinking water management and public health, but also for the ecology and evolution of the genus Legionella.

Legionellosis and Lung Abscesses: Contribution of Legionella Quantitative Real-Time PCR to an Adapted Followup

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G. Descours

2013-01-01

Full Text Available We report a case of severe Legionnaires' disease (LD complicated by a lung abscess in an immunocompetent patient who required ECMO therapy and thoracic surgery. The results of repeated Legionella quantitative real-time PCR performed on both sera and respiratory samples correlated with the LD severity and the poor clinical outcome. Moreover, the PCR allowed for the detection of Legionella DNA in the lung abscess specimen, which was negative when cultured for Legionella. This case report provides a logical basis for further investigations to examine whether the Legionella quantitative PCR could improve the assessment of LD severity and constitute a prognostic marker.

The role of biofilms and protozoa in Legionella pathogenesis: implications for drinking water

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Current models to study Legionella pathogenesis include the use of primary macrophages and monocyte cell lines, various free-living protozoan species and murine models of pneumonia. However, there are very few studies of Legionella spp. pathogenesis aimed at associating the role ...

Legionella Risk Management and Control in Potable Water Systems: Argument for the Abolishment of Routine Testing.

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Whiley, Harriet

2016-12-24

Legionella is an opportunistic pathogen of public health significance. One of the main sources of Legionella is potable water systems. As a consequence of aging populations there is an increasing demographic considered at high risk for Legionellosis and, as such, a review of the guidelines is required. Worldwide, Legionella has been detected from many potable water sources, suggesting it is ubiquitous in this environment. Previous studies have identified the limitations of the current standard method for Legionella detection and the high possibility of it returning both false negative and false positive results. There is also huge variability in Legionella test results for the same water sample when conducted at different laboratories. However, many guidelines still recommend the testing of water systems. This commentary argues for the removal of routine Legionella monitoring from all water distribution guidelines. This procedure is financially consuming and false negatives may result in managers being over-confident with a system or a control mechanism. Instead, the presence of the pathogen should be assumed and focus spent on managing appropriate control measures and protecting high-risk population groups.

Influence of climate and geography on the occurrence of Legionella and amoebae in composting facilities.

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Conza, Lisa; Casati Pagani, Simona; Gaia, Valeria

2014-11-24

The incidence of Legionnaires' disease (LD) in southern Switzerland is three times higher than in northern Switzerland. Climatic and geographic factors may be potential causes for this difference.We studied the prevalence of Legionella and free-living amoebae (FLA) in compost and bioaerosol in two Swiss regions to understand the role of climate and geography in the transmission of LD. We also tried to investigate whether or not compost storage duration would influence the composition of Legionella and FLA communities. A larger proportion of compost heaps in facilities from southern Switzerland harbor more diverse Legionella compared to the north (P=0.0146). FLA were isolated from composts in northern facilities at slightly higher rates (88.2% vs. 69.2%) and at lower rates from bioaerosols (6.3% vs. 13%) than in southern Switzerland. The diversity of FLA was higher in northern than in southern Switzerland (80% vs. 65%). A general decrease in the presence and variety of species was observed with decreasing compost storage time length. A discriminant model showed that values of vapour pressure, relative humidity and temperature distinguish the two regions, which were also characterised by different contamination rates by FLA and Legionella. The duration of outdoor storage may favour contamination of the compost by Legionella, and may increase the number and isolation of Legionella naturally occurring in compost. The climate in the south seems to favour higher Legionella contamination of compost heaps: this could explain the higher incidence of LD in southern Switzerland.

Industrial Cooling Tower Disinfection Treatment to Prevent Legionella spp.

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Matteo Iervolino

2017-09-01

Full Text Available The contamination of industrial cooling towers has been identified as one cause of legionellosis, but the real risk has been underestimated. Two different disinfection treatments were tested on Legionella colonization in an industrial Cooling Tower System (CTS. Environmental monitoring of Legionella, P. aeruginosa, and a heterotrophic plate count (HPC at 36 °C was performed from June to October 2016. The disinfection procedures adopted were based on hydrogen peroxide (H2O2 and silver salts (Ag+, in addition to an anti-algal treatment, then using hyperclorination as a shock, and then continuous treatment by sodium hypochlorite (NaClO. L. pneumophila serogroup 8 was found at a concentration of 5.06 Log cfu/L after the CTS filling; a shock treatment performed by H2O2/Ag+ produced a rapid increase in contamination up to 6.14 Log cfu/L. The CTS activity was stopped and two subsequent shock treatments were performed using NaClO, followed by continuous hyperclorination. These procedures showed a significant decrease (p < 0.05 in Legionella concentration (1.77 Log cfu/L. The same trend was observed for P. aeruginosa (0.55 Log cfu/100 mL and HPC (1.95 Log cfu/mL at 36 °C. Environmental monitoring and the adoption of maintenance procedures, including anti-scale treatment, and physical, chemical, and microbiological control, ensure the good performance of a CTS, reducing the Legionella risk for public health.

Industrial Cooling Tower Disinfection Treatment to Prevent Legionella spp.

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Iervolino, Matteo; Mancini, Benedetta; Cristino, Sandra

2017-09-26

The contamination of industrial cooling towers has been identified as one cause of legionellosis, but the real risk has been underestimated. Two different disinfection treatments were tested on Legionella colonization in an industrial Cooling Tower System (CTS). Environmental monitoring of Legionella , P. aeruginosa , and a heterotrophic plate count (HPC) at 36 °C was performed from June to October 2016. The disinfection procedures adopted were based on hydrogen peroxide (H₂O₂) and silver salts (Ag⁺), in addition to an anti-algal treatment, then using hyperclorination as a shock, and then continuous treatment by sodium hypochlorite (NaClO). L . pneumophila serogroup 8 was found at a concentration of 5.06 Log cfu/L after the CTS filling; a shock treatment performed by H₂O₂/Ag⁺ produced a rapid increase in contamination up to 6.14 Log cfu/L. The CTS activity was stopped and two subsequent shock treatments were performed using NaClO, followed by continuous hyperclorination. These procedures showed a significant decrease ( p Legionella concentration (1.77 Log cfu/L). The same trend was observed for P . aeruginosa (0.55 Log cfu/100 mL) and HPC (1.95 Log cfu/mL) at 36 °C. Environmental monitoring and the adoption of maintenance procedures, including anti-scale treatment, and physical, chemical, and microbiological control, ensure the good performance of a CTS, reducing the Legionella risk for public health.

Two nursing home outbreaks of respiratory infection with Legionella sainthelensi.

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Loeb, M; Simor, A E; Mandell, L; Krueger, P; McArthur, M; James, M; Walter, S; Richardson, E; Lingley, M; Stout, J; Stronach, D; McGeer, A

1999-05-01

To describe outbreaks of infection caused by Legionella sainthelensi occurring in older residents of two nursing homes and to determine risk factors for the development of infection. Descriptive epidemiology and a case-control study. Two nursing homes (140 beds and 254 beds in nursing homes A and B, respectively) located in southern Ontario, Canada, experiencing outbreaks of respiratory tract infection in July and August 1994. Case-residents of the two nursing homes who met clinical and laboratory criteria for Legionella infection. Control-residents were defined as those who were in the homes during the outbreaks and were asymptomatic. Active surveillance was conducted in both nursing homes to identify symptomatic residents. Residents with fever or respiratory tract symptoms had nasopharyngeal swabs taken for viral antigen detection and culture, urine for Legionella antigen detection, and acute and convalescent serology for viruses, Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella. Chest X-rays were performed, and an attempt was made to obtain blood and sputum cultures. Water samples from shower heads, faucets, and air conditioning units were collected for Legionella culture and polymerase chain reaction (PCR) assay. A case-control study was done to assess possible risk factors for legionellosis. Twenty-nine cases -- 17 in nursing home A; 12 in nursing home B - were identified. Four (14%) case-residents had documented pneumonia and four case-residents died. Univariate analysis revealed that a history of stroke (odds ratio (OR) 2.3 (95% CI, 1.0-5.3)), eating pureed food (OR 4.6 (95% CI, 1.6-12.7)), and having fluids administered with medication (OR 2.5 (95% CI, 1.0-5.9)) were significant risk factors. Cases were less likely to wear dentures (OR .4 (95% CI, .2-.9)) or to eat solid food (OR .3, (95% CI, .1-.6)). Only eating pureed food remained significant in a multivariable analysis (OR 4.6 (95% CI, 1.6-13.0, P = .01)). This report describes outbreaks of

Environmental Legionella spp. collected in urban test sites of South East Queensland, Australia, are virulent to human macrophages in vitro.

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Lawrence, Amba; Eglezos, Sofroni; Huston, Wilhelmina

2016-01-01

Legionellae are frequent contaminants of potable water supplies, resulting in sporadic infections and occasional outbreaks. Isolates of Legionella were collected from urban test sites within South East Queensland and evaluated for their virulence potential in vitro. Two strains (from the species Legionella londiniensis and Legionella quinlivanii) were demonstrated to have the ability to infect human macrophages, while a strain from the species Legionella anisa did not maintain an infection over the same time course. This suggests that the spectrum of urban environmentally associated Legionella with potential to cause human disease might be greater than currently considered. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

MTOR-Driven Metabolic Reprogramming Regulates Legionella pneumophila Intracellular Niche Homeostasis

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Abshire, Camille F.; Roy, Craig R.

2016-01-01

Vacuolar bacterial pathogens are sheltered within unique membrane-bound organelles that expand over time to support bacterial replication. These compartments sequester bacterial molecules away from host cytosolic immunosurveillance pathways that induce antimicrobial responses. The mechanisms by which the human pulmonary pathogen Legionella pneumophila maintains niche homeostasis are poorly understood. We uncovered that the Legionella-containing vacuole (LCV) required a sustained supply of host lipids during expansion. Lipids shortage resulted in LCV rupture and initiation of a host cell death response, whereas excess of host lipids increased LCVs size and housing capacity. We found that lipids uptake from serum and de novo lipogenesis are distinct redundant supply mechanisms for membrane biogenesis in Legionella-infected macrophages. During infection, the metabolic checkpoint kinase Mechanistic Target of Rapamycin (MTOR) controlled lipogenesis through the Serum Response Element Binding Protein 1 and 2 (SREBP1/2) transcription factors. In Legionella-infected macrophages a host-driven response that required the Toll-like receptors (TLRs) adaptor protein Myeloid differentiation primary response gene 88 (Myd88) dampened MTOR signaling which in turn destabilized LCVs under serum starvation. Inactivation of the host MTOR-suppression pathway revealed that L. pneumophila sustained MTOR signaling throughout its intracellular infection cycle by a process that required the upstream regulator Phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) and one or more Dot/Icm effector proteins. Legionella-sustained MTOR signaling facilitated LCV expansion and inhibition of the PI3K-MTOR-SREPB1/2 axis through pharmacological or genetic interference or by activation of the host MTOR-suppression response destabilized expanding LCVs, which in turn triggered cell death of infected macrophages. Our work identified a host metabolic requirement for LCV homeostasis and demonstrated that L

Prevention of legionella in dwellings and buildings; Legionellapreventie in woningen en gebouwen

Energy Technology Data Exchange (ETDEWEB)

Van Mil, R.; Van der Kooij, D.; Kolner, W.P.P.; Wessels, R.; Offinga, M.; Scheffer, W.; Van Wolferen, H.; Doldersum, R.; Van der Lugt, W.; Bertrand, F.; Nijlant, E.

2011-04-15

In 10 articles and 1 interview attention is paid to several aspects of Legionella in water heaters, mains, and sanitary installations in dwellings and other buildings. [Dutch] In 10 artikelen en 1 interview wordt aandacht besteed aan verschillende aspecten met betrekking tot legionella in sanitaire installaties, waterverwarmingsinstallaties, en waterleidingen in woningen en andere gebouwen.

[Legionella spp. contamination in indoor air: preliminary results of an Italian multicenter study].

Science.gov (United States)

Montagna, Maria Teresa; De Giglio, Osvalda; Napoli, Christian; Cannova, Lucia; Cristina, Maria Luisa; Deriu, Maria Grazia; Delia, Santi Antonino; Giuliano, Ada; Guida, Marco; Laganà, Pasqualina; Liguori, Giorgio; Mura, Ida; Pennino, Francesca; Rossini, Angelo; Tardivo, Stefano; Torre, Ida; Torregrossa, Maria Valeria; Villafrate, Maria Rosaria; Albertini, Roberto; Pasquarella, Cesira

2014-01-01

To propose a standardized protocol for the evaluation of Legionella contamination in air. A bathroom having a Legionella contamination in water >1,000 cfu/l was selected in 10 different healthcare facilities. Air contamination was assessed by active (Surface Air System, SAS) and passive (Index of Microbial Air, IMA) sampling for 8 hours, about 1 m away from the floor and 50 cm from the tap water. Two hundred liters of air were sampled by SAS every 12 min, after flushing water for 2 min. The IMA value was calculated as the mean value of colony forming units/16 plates exposed during sampling (2 plates/hour). Water contamination was evaluated at T0, after 4 and 8 hours, according to the standard methods. Air contamination by Legionella was found in three healthcare facilities (one with active and two with passive sampling), showing a concomitant tap water contamination (median=40,000; range 1,100-43,000 cfu/l). The remaining seven hospitals isolated Legionella spp. exclusively from water samples (median=8,000; range 1,200-70,000 cfu/l). Our data suggest that environmental Legionella contamination cannot be assessed only through the air sampling, even in the presence of an important water contamination.

Colonization of Legionella species in Turkish baths in hotels in Alanya, Turkey.

Science.gov (United States)

Erdogan, Haluk; Arslan, Hande

2015-05-01

This study evaluated the prevalence of Legionella species in water samples collected from Turkish baths in hotels in Alanya, Turkey, from August 2003 to September 2013. Water samples were collected in 100-mL sterile containers and then concentrated by filtration. Heat treatment was used to eliminate other microorganisms from the samples, which were then spread on Legionella-selective-buffered charcoal yeast extract alpha (BCYE-α) agar and on BCYE-α agar supplemented with glycine, vancomycin, polymyxin, and cycloheximide. Cysteine-dependent colonies were identified by latex agglutination. In total, 135 samples from 52 hotels with Turkish baths were evaluated. Legionella species were identified in 11/52 (21.2%) hotels and 18/135 (13.3%) samples. The most frequently isolated species was Legionella pneumophila, with most isolates belonging to serogroups 6 (55.6%) and 1 (22.2%). The colony count was 1000 CFU mL(-1) in three samples. These findings suggest that the hot water systems of Turkish baths in hotels must be viewed as a possible source of travel-associated Legionnaires' disease, and preventative measures should be put in place.

Real-time PCR to supplement gold-standard culture-based detection of Legionella in environmental samples.

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Collins, S; Jorgensen, F; Willis, C; Walker, J

2015-10-01

Culture remains the gold-standard for the enumeration of environmental Legionella. However, it has several drawbacks including long incubation and poor sensitivity, causing delays in response times to outbreaks of Legionnaires' disease. This study aimed to validate real-time PCR assays to quantify Legionella species (ssrA gene), Legionella pneumophila (mip gene) and Leg. pneumophila serogroup-1 (wzm gene) to support culture-based detection in a frontline public health laboratory. Each qPCR assay had 100% specificity, excellent sensitivity (5 GU/reaction) and reproducibility. Comparison of the assays to culture-based enumeration of Legionella from 200 environmental samples showed that they had a negative predictive value of 100%. Thirty eight samples were positive for Legionella species by culture and qPCR. One hundred samples were negative by both methods, whereas 62 samples were negative by culture but positive by qPCR. The average log10 increase between culture and qPCR for Legionella spp. and Leg. pneumophila was 0·72 (P = 0·0002) and 0·51 (P = 0·006), respectively. The qPCR assays can be conducted on the same 1 l water sample as culture thus can be used as a supplementary technique to screen out negative samples and allow more rapid indication of positive samples. The assay could prove informative in public health investigations to identify or rule out sources of Legionella as well as to specifically identify Leg. pneumophila serogroup 1 in a timely manner not possible with culture. © 2015 The Society for Applied Microbiology.

A rapid detection method using flow cytometry to monitor the risk of Legionella in bath water.

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Taguri, Toshitsugu; Oda, Yasunori; Sugiyama, Kanji; Nishikawa, Toru; Endo, Takuro; Izumiyama, Shinji; Yamazaki, Masayuki; Kura, Fumiaki

2011-07-01

Legionella species are the causative agents of human legionellosis, and bathing facilities have been identified as the sources of infection in several outbreaks in Japan. Researchers in Japan have recently reported evidence of significant associations between bacterial counts and the occurrence of Legionella in bathing facilities and in a hot tub model. A convenient and quantitative bacterial enumeration method is therefore required as an indicator of Legionella contamination or disinfection to replace existing methods such as time-consuming Legionella culture and expensive Legionella-DNA amplification. In this study, we developed a rapid detection method (RDM) to monitor the risk of Legionella using an automated microbial analyzing device based on flow cytometry techniques to measure the total number of bacteria in water samples within two minutes, by detecting typical patterns of scattered light and fluorescence. We first compared the results of our RDM with plate counting results for five filtered hot spring water samples spiked with three species of bacteria, including Legionella. Inactivation of these samples by chlorine was also assessed by the RDM, a live/dead bacterial fluorescence assay and plate counting. Using the RDM, the lower limit of quantitative bacterial counts in the spiked samples was determined as 3.0×10(3)(3.48log)counts mL(-1). We then used a laboratory model of a hot tub and found that the RDM could monitor the growth curve of naturally occurring heterotrophic bacteria with 1 and 2 days' delayed growth of amoeba and Legionella, respectively, and could also determine the killing curve of these bacteria by chlorination. Finally, samples with ≥3.48 or bacterial counts mL(-1) were tested using the RDM from 149 different hot tubs, and were found to be significantly associated with the positive or negative detection of Legionella with 95% sensitivity and 84% specificity. These findings indicated that the RDM can be used for Legionella control at

Genome Dynamics in Legionella: The Basis of Versatility and Adaptation to Intracellular Replication

Science.gov (United States)

Gomez-Valero, Laura; Buchrieser, Carmen

2013-01-01

Legionella pneumophila is a bacterial pathogen present in aquatic environments that can cause a severe pneumonia called Legionnaires’ disease. Soon after its recognition, it was shown that Legionella replicates inside amoeba, suggesting that bacteria replicating in environmental protozoa are able to exploit conserved signaling pathways in human phagocytic cells. Comparative, evolutionary, and functional genomics suggests that the Legionella–amoeba interaction has shaped this pathogen more than previously thought. A complex evolutionary scenario involving mobile genetic elements, type IV secretion systems, and horizontal gene transfer among Legionella, amoeba, and other organisms seems to take place. This long-lasting coevolution led to the development of very sophisticated virulence strategies and a high level of temporal and spatial fine-tuning of bacteria host–cell interactions. We will discuss current knowledge of the evolution of virulence of Legionella from a genomics perspective and propose our vision of the emergence of this human pathogen from the environment. PMID:23732852

Occurrence and parameters of frequency of Legionella in warm water systems of hospitals and hotels in Lower Saxony.

Science.gov (United States)

Habicht, W; Müller, H E

1988-03-01

A total of 1241 water samples was investigated from 103 hospitals and 62 hotels in Lower Saxony 1985-87. 331 of 949 samples from hospitals and 26 of 292 samples from hotels were Legionella positive. All together 70% of the hospitals and 18% of the hotels investigated were Legionella positive, and 836 strains of Legionella were isolated (Table 1). As they could be diagnosed they belong to L. pneumophila SG1 306 strains, SG2 36 strains, SG3 127 strains, SG4 45 strain, SG5 29 strain, SG6 106 strains, SG9 13 strains and SG10 13 strains. Further 134 strains belonging to L. pneumophila but not to SG1-SG12 show cross reactions with serogroups 5, 8, and 10. Finally, 16 strains belong to L. dumoffii and 1 strain to L. anisa (Table 2). The following parameters of water samples were studied, too: temperature, pH value, conductivity, concentration of iron, of organic matter, of other bacteria, occurrence of amoebas, and the materials of water plumbing systems. Most samples contained concentrations of Legionella in the range of 10(1)-10(3) CFU/ml, highest concentrations were 10(5) CFU/ml (Fig. 1). Most frequently, Legionella were isolated within the range of temperature of 35-45 degrees C. However, a few of the water samples were positive for Legionella even up to 66 degrees C (Fig. 3). The conductivity has no and the pH value (Fig. 2) has only little influence on the occurrence of Legionella. There is a positive correlation between concentration of iron and frequency of Legionella (Fig. 4). Also organic matter (Fig. 6) and amoebas (Table 3) seem to enhance the occurrence of Legionella. Plumbing systems consisting of copper showed an inhibitory effect on Legionella during the first five years, whereas no effect could be detected in older systems (Fig. 5).

Severe Pneumonia Caused by Legionella pneumophila: Differential Diagnosis and Therapeutic Considerations.

Science.gov (United States)

Chahin, Abdullah; Opal, Steven M

2017-03-01

Severe legionella pneumonia poses a diagnostic challenge and requires early intervention. Legionnaire's disease can have several presenting signs, symptoms, and laboratory abnormalities that suggest that Legionella pneumophila is the pathogen, but none of these are sufficient to distinguish L pneumophila pneumonia from other respiratory pathogens. L pneumophila is primarily an intracellular pathogen and needs treatment with antibiotics that efficiently enter the intracellular space. Copyright © 2016 Elsevier Inc. All rights reserved.

[Pulmonary Legionella infection with CNS manifestations].

Science.gov (United States)

Pedersen, S W; Kollerup, I

1998-01-12

A 39 year-old woman with Legionella pneumonia and severe neurological signs is presented. The patient displayed severe gait disturbance, ataxia and anartria. No substantial remission in symptoms was found at a six month follow up. The case and the relevant literature are reviewed.

Molecular diagnosis of Legionella infections--Clinical utility of front-line screening as part of a pneumonia diagnostic algorithm.

Science.gov (United States)

Gadsby, Naomi J; Helgason, Kristjan O; Dickson, Elizabeth M; Mills, Jonathan M; Lindsay, Diane S J; Edwards, Giles F; Hanson, Mary F; Templeton, Kate E

2016-02-01

Urinary antigen testing for Legionella pneumophila serogroup 1 is the leading rapid diagnostic test for Legionnaires' Disease (LD); however other Legionella species and serogroups can also cause LD. The aim was to determine the utility of front-line L. pneumophila and Legionella species PCR in a severe respiratory infection algorithm. L. pneumophila and Legionella species duplex real-time PCR was carried out on 1944 specimens from hospitalised patients over a 4 year period in Edinburgh, UK. L. pneumophila was detected by PCR in 49 (2.7%) specimens from 36 patients. During a LD outbreak, combined L. pneumophila respiratory PCR and urinary antigen testing had optimal sensitivity and specificity (92.6% and 98.3% respectively) for the detection of confirmed cases. Legionella species was detected by PCR in 16 (0.9%) specimens from 10 patients. The 5 confirmed and 1 probable cases of Legionella longbeachae LD were both PCR and antibody positive. Front-line L. pneumophila and Legionella species PCR is a valuable addition to urinary antigen testing as part of a well-defined algorithm. Cases of LD due to L. longbeachae might be considered laboratory-confirmed when there is a positive Legionella species PCR result and detection of L. longbeachae specific antibody response. Copyright © 2015 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Rate of Legionella pneumophila colonization in hospital hot water network after time flow taps installation.

Science.gov (United States)

Totaro, M; Valentini, P; Costa, A L; Giorgi, S; Casini, B; Baggiani, A

2018-01-01

In hospital water systems legionellae may be resistant to disinfectants in pipework, which is a problem particularly in areas where there is low flow or stagnation of water. We evaluated legionella colonization of a water network of an Italian hospital after time flow taps (TFTs) installation in proximity to dead legs. The water volume flushed was 64 L/day from May 2016, and 192 L/day from December 2016. Before TFTs installation, Legionella pneumophila sg2-14 was detected in all points (4 × 10 4  ± 3.1 × 10 4  cfu/L). All sites remained positive (2.9 × 10 4  ± 1.9 × 10 4  cfu/L) through November 2016. From December 2016 legionella persisted in one point only (2 × 10 2 to 6.8 × 10 3  cfu/L). TFTs with chemical disinfection may reduce legionella colonization associated with dead legs. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Tunge- og stemmebåndsparese efter endotrakeal intubation for Legionella-pneumoni

DEFF Research Database (Denmark)

Sønnichsen, Rikke; Lauritsen, Anne Oberg

2013-01-01

Extracranial involvement of the hypoglossal nerve and recurrent laryngeal branch of the vagal nerve can be a complication of anaesthetic airway management (Tapia's syndrome) or focal involvement due to Legionella infection. We present a patient with bilateral hypoglossal and unilateral recurrent...... laryngeal nerves palsy after a complicated intubation and a Legionella infection. Clarithromycin therapy was started. Within months, tongue mobility and swallowing gradually improved. Two months after discharge persisting unilateral recurrent nerve palsy was observed....

Legionella confirmation in cooling tower water. Comparison of culture, real-time PCR and next generation sequencing.

Science.gov (United States)

Farhat, Maha; Shaheed, Raja A; Al-Ali, Haider H; Al-Ghamdi, Abdullah S; Al-Hamaqi, Ghadeer M; Maan, Hawraa S; Al-Mahfoodh, Zainab A; Al-Seba, Hussain Z

2018-02-01

To investigate the presence of Legionella spp in cooling tower water. Legionella proliferation in cooling tower water has serious public health implications as it can be transmitted to humans via aerosols and cause Legionnaires' disease. Samples of cooling tower water were collected from King Fahd Hospital of the University (KFHU) (Imam Abdulrahman Bin Faisal University, 2015/2016). The water samples were analyzed by a standard Legionella culture method, real-time polymerase chain reaction (RT-PCR), and 16S rRNA next-generation sequencing. In addition, the bacterial community composition was evaluated. All samples were negative by conventional Legionella culture. In contrast, all water samples yielded positive results by real-time PCR (105 to 106 GU/L). The results of 16S rRNA next generation sequencing showed high similarity and reproducibility among the water samples. The majority of sequences were Alpha-, Beta-, and Gamma-proteobacteria, and Legionella was the predominant genus. The hydrogen-oxidizing gram-negative bacterium Hydrogenophaga was present at high abundance, indicating high metabolic activity. Sphingopyxis, which is known for its resistance to antimicrobials and as a pioneer in biofilm formation, was also detected. Our findings indicate that monitoring of Legionella in cooling tower water would be enhanced by use of both conventional culturing and molecular methods.

Ecology of Legionella within water cooling circuits of nuclear power plants along the French Loire River

International Nuclear Information System (INIS)

Jakubek, Delphine

2012-01-01

The cooling circuits of nuclear power plants, by their mode of operating, can select thermophilic microorganisms including the pathogenic organism Legionella pneumophila. To control the development of this genus, a disinfection treatment of water cooling systems with monochloramine can be used. To participate in the management of health and environmental risks associated with the physico-chemical and microbiological modification of water collected from the river, EDF is committed to a process of increasing knowledge about the ecology of Legionella in cooling circuits and its links with its environment (physical, chemical and microbiological) supporting or not their proliferation. Thus, diversity and dynamics of culturable Legionella pneumophila were determined in the four nuclear power plants along the Loire for a year and their links with physico-chemical and microbiological parameters were studied. This study revealed a high diversity of Legionella pneumophila subpopulations and their dynamic seems to be related to the evolution of a small number of subpopulations. Legionella subpopulations seem to maintain strain-specific relationships with biotic parameters and present different sensitivities to physico-chemical variations. The design of cooling circuits could impact the Legionella community. The use of monochloramine severely disrupts the ecosystem but does not select biocide tolerant subpopulations. (author)

Hot water systems as sources of Legionella pneumophila in hospital and nonhospital plumbing fixtures.

Science.gov (United States)

Wadowsky, R M; Yee, R B; Mezmar, L; Wing, E J; Dowling, J N

1982-05-01

Samples obtained from plumbing systems of hospitals, nonhospital institutions and homes were cultured for Legionella spp. by plating the samples directly on a selective medium. Swab samples were taken from the inner surfaces of faucet assemblies (aerators, spouts, and valve seats), showerheads, and shower pipes. Water and sediment were collected from the bottom of hot-water tanks. Legionella pneumophila serogroups 1, 5, and 6 were recovered from plumbing fixtures of the hospitals and nonhospital institutions and one of five homes. The legionellae (7 to 13,850 colony-forming units per ml) were also present in water and sediment from hot-water tanks maintained at 30 to 54 degrees C, but not in those maintained at 71 and 77 degrees C. Legionella micdadei was isolated from one tank. Thus legionellae are present in hot-water tanks which are maintained at warm temperatures or whose design results in warm temperatures at the bottom of the tanks. We hypothesize that hot-water tanks are a breeding site and a major source of L. pneumophila for the contamination of plumbing systems. The existence of these bacteria in the plumbing systems and tanks was not necessarily associated with disease. The extent of the hazard of this contamination needs to be delineated.

Hot water systems as sources of Legionella pneumophila in hospital and nonhospital plumbing fixtures

Energy Technology Data Exchange (ETDEWEB)

Wadowsky, R.M.; Yee, R.B.; Mezmar, L.; Wing, E.J.; Dowling, J.N.

1982-05-01

Samples obtained from plumbing systems of hospitals, nonhospital institutions, and homes were cultured for Legionella spp. by plating the samples directly on a selective medium. Swab samples were taken from the inner surfaces of faucet assemblies (aerators, spouts, and valve seats), showerheads, and shower pipes. Water and sediment were collected from the bottom of hot-water tanks. Legionella pnenumophila serogroups 1.5, and 6 were recovered from plubming fixtures of the hospitals and nonhospital institutions and one of five homes. The legionellae (7 to 13,850 colony-forming units per ml) were also present in water and sediment from hot-water tanks maintained at 30 to 54/sup 0/C, but not in those maintained at 71 and 77/sup 0/C. Legionella micdadei was isolated from one tank. Thus legionellae are present in hot-water tanks which are maintained at warm temperatures or whose design results in warm temperatures at the bottom of the tanks. We hypothesize that hot-water tanks are a breeding site and a major source of L. pneumophila for the contamination of plumbing systems. The existence of these bacteria in the plumbing systems and tanks was not necessarily associated with disease. The extent of the hazard of this contamination needs to be delineated.

Molecular characterization of Legionella pneumophila-induced interleukin-8 expression in T cells

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Mukaida Naofumi

2010-01-01

Full Text Available Abstract Background Legionella pneumophila is the causative agent of human Legionnaire's disease. During infection, the bacterium invades macrophages and lung epithelial cells, and replicates intracellularly. However, little is known about its interaction with T cells. We investigated the ability of L. pneumophila to infect and stimulate the production of interleukin-8 (IL-8 in T cells. The objective of this study was to assess whether L. pneumophila interferes with the immune system by interacting and infecting T cells. Results Wild-type L. pneumophila and flagellin-deficient Legionella, but not L. pneumophila lacking a functional type IV secretion system Dot/Icm, replicated in T cells. On the other hand, wild-type L. pneumophila and Dot/Icm-deficient Legionella, but not flagellin-deficient Legionella or heat-killed Legionella induced IL-8 expression. L. pneumophila activated an IL-8 promoter through the NF-κB and AP-1 binding regions. Wild-type L. pneumophila but not flagellin-deficient Legionella activated NF-κB, p38 mitogen-activated protein kinase (MAPK, Jun N-terminal kinase (JNK, and transforming growth factor β-associated kinase 1 (TAK1. Transfection of dominant negative mutants of IκBα, IκB kinase, NF-κB-inducing kinase, TAK1, MyD88, and p38 MAPK inhibited L. pneumophila-induced IL-8 activation. Inhibitors of NF-κB, p38 MAPK, and JNK blocked L. pneumophila-induced IL-8 expression. In addition, c-Jun, JunD, cyclic AMP response element binding protein, and activating transcription factor 1, which are substrates of p38 MAPK and JNK, bound to the AP-1 site of the IL-8 promoter. Conclusions Taken together, L. pneumophila induced a flagellin-dependent activation of TAK1, p38 MAPK, and JNK, as well as NF-κB and AP-1, which resulted in IL-8 production in human T cells, presumably contributing to the immune response in Legionnaire's disease.

Multiple regression as a preventive tool for determining the risk of Legionella spp.

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Enrique Gea-Izquierdo

2012-04-01

Full Text Available To determine the interrelationship between health & hygiene conditions for prevention of legionellosis, the compositionof materials used in water distribution systems, the water origin and Legionella pneumophila risk. Material and methods. Include adescriptive study and multiple regression analysis on a sample of golf course sprinkler irrigation systems (n=31 pertaining to hotelslocated on the Costa del Sol (Malaga, Spain. The study was carried out in 2009. Results. Presented a significant lineal relation, withall the independent variables contributing significantly (p<0.05 to the model’s fit. The relationship between water type and the risk ofLegionella, as well as the material composition and the latter, is lineal and positive. In contrast, the relationship between health-hygieneconditions and Legionella risk is lineal and negative. Conclusion. The characterization of Legionella pneumophila concentration, asdefined by the risk in water and through use of the predictive method, can contribute to the consideration of new influence variables inthe development of the agent, resulting in improved control and prevention of the disease.

α-Hydroxyketone Synthesis and Sensing by Legionella and Vibrio

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Hubert Hilbi

2012-03-01

Full Text Available Bacteria synthesize and sense low molecular weight signaling molecules, termed autoinducers, to measure their population density and community complexity. One class of autoinducers, the α-hydroxyketones (AHKs, is produced and detected by the water-borne opportunistic pathogens Legionella pneumophila and Vibrio cholerae, which cause Legionnaires’ disease and cholera, respectively. The “Legionella quorum sensing” (lqs or “cholera quorum sensing” (cqs genes encode enzymes that produce and sense the AHK molecules “Legionella autoinducer-1” (LAI-1; 3-hydroxypentadecane-4-one or cholera autoinducer-1 (CAI-1; 3-hydroxytridecane-4-one. AHK signaling regulates the virulence of L. pneumophila and V. cholerae, pathogen-host cell interactions, formation of biofilms or extracellular filaments, expression of a genomic “fitness island” and competence. Here, we outline the processes, wherein AHK signaling plays a role, and review recent insights into the function of proteins encoded by the lqs and cqs gene clusters. To this end, we will focus on the autoinducer synthases catalysing the biosynthesis of AHKs, on the cognate trans-membrane sensor kinases detecting the signals, and on components of the down-stream phosphorelay cascade that promote the transmission and integration of signaling events regulating gene expression.

Hartmannella vermiformis inhibition of Legionella pneumophila cultivability

Science.gov (United States)

Hartmannella vermiformis is frequently isolated from drinking water (DW) and is permissive to Legionella pneumophila intracellular replication. Thus, H. vermiformis may play an important role in the growth and survival potential of such environmental pathogens. In this study, Pag...

Legionella oakridgensis: laboratory diagnosis of a human infection.

OpenAIRE

Tang, P W; Toma, S; MacMillan, L G

1985-01-01

We report the laboratory diagnosis of a case of pneumonia caused by Legionella oakridgensis. L. oakridgensis, originally isolated from industrial cooling towers, has not previously been associated with human disease.

AUTOMATED DEAD-END ULTRAFILTRATION FOR ENHANCED SURVEILLANCE OF LEGIONELLA 2 PNEUMOPHILA AND LEGIONELLA SPP. IN COOLING TOWER WATERS

Energy Technology Data Exchange (ETDEWEB)

Brigmon, R.; Leskinen, S.; Kearns, E.; Jones, W.; Miller, R.; Betivas, C.; Kingsley, M.; Lim, D.

2011-10-10

Detection of Legionella pneumophila in cooling towers and domestic hot water systems involves concentration by centrifugation or membrane filtration prior to inoculation onto growth media or analysis using techniques such as PCR or immunoassays. The Portable Multi-use Automated Concentration System (PMACS) was designed for concentrating microorganisms from large volumes of water in the field and was assessed for enhancing surveillance of L. pneumophila at the Savannah River Site, SC. PMACS samples (100 L; n = 28) were collected from six towers between August 2010 and April 2011 with grab samples (500 ml; n = 56) being collected before and after each PMACS sample. All samples were analyzed for the presence of L. pneumophila by direct fluorescence immunoassay (DFA) using FITC-labeled monoclonal antibodies targeting serogroups 1, 2, 4 and 6. QPCR was utilized for detection of Legionella spp. in the same samples. Counts of L. pneumophila from DFA and of Legionella spp. from qPCR were normalized to cells/L tower water. Concentrations were similar between grab and PMACS samples collected throughout the study by DFA analysis (P = 0.4461; repeated measures ANOVA). The same trend was observed with qPCR. However, PMACS concentration proved advantageous over membrane filtration by providing larger volume, more representative samples of the cooling tower environment, which led to reduced variability among sampling events and increasing the probability of detection of low level targets. These data highlight the utility of the PMACS for enhanced surveillance of L. pneumophila by providing improved sampling of the cooling tower environment.

Virulence properties of the Legionella pneumophila cell envelope

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Olga eShevchuk

2011-04-01

Full Text Available The bacterial envelope plays a crucial role in the pathogenesis of infectious diseases. In this review, we summarize the current knowledge of the structure and molecular composition of the Legionella pneumophila cell envelope. We describe LPS biosynthesis and the biological activities of membrane and periplasmic proteins and discuss their decisive functions during the pathogen-host interaction. In addition to adherence, invasion and intracellular survival of L. pneumophila, special emphasis is laid on iron acquisition, detoxification, key elicitors of the immune response and the diverse functions of outer membrane vesicles. The critical analysis of the literature reveals that the dynamics and phenotypic plasticity of the Legionella cell surface during the different metabolic stages requires more attention in the future.

Legionellae in water heating systems. Legionellen in Warmwasserbereitungsanlagen

Energy Technology Data Exchange (ETDEWEB)

1991-10-01

A Public Health Office inquiry submitted to the Building Surveyor's Office about prophylactic measures taken to protect the health of bathers at the Vonderort saltwater pools was followed by a detailed inquiry among AMEV members. It was found that most of the persons interviewed did not have sufficient experience in using water heating methods which completely ban legionellae. However, several administrative authorities considered a 60deg C thermal tap water disinfection a necessary protective measure. A circular regulation was subsequently issued by the Northrhine-Westphalian Ministry for Building Construction and Housing to improve legionella protection. Details are also given about the protective measures and maintenance schemes issued by the Public Health Office for drinking water and space HVAC systems. (BWI).

Legionella pneumonia associated with severe acute respiratory distress syndrome and diffuse alveolar hemorrhage - A rare association

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Muhammad Kashif

2017-01-01

Full Text Available Legionella pneumophila is a common, usually underreported and undiagnosed cause of community acquired pneumonia which can lead to significant morbidity and mortality. Diffuse alveolar hemorrhage rarely have been associated with legionella infection. We present a 61-year-old man with hypertension, diabetes mellitus and obesity admitted with severe acute respiratory distress syndrome. He was found to have Legionella pneumonia with associated diffuse alveolar hemorrhage diagnosed with bronchoscopic sequential bronchoalveolar lavage. He was successfully managed with antibiotics, lung protective strategies and intravenous pulse dose steroids. This patient highlights the unusual association of Legionella infection and diffuse alveolar hemorrhage. Additionally, the case re-enforces the need for early and aggressive evaluation and management of patients presenting with pneumonia and progressive hypoxia despite adequate treatment.

Thermal disinfection of hotels, hospitals, and athletic venues hot water distribution systems contaminated by Legionella species.

Science.gov (United States)

Mouchtouri, Varvara; Velonakis, Emmanuel; Hadjichristodoulou, Christos

2007-11-01

Legionella spp. (> or = 500 cfu liter(-1)) were detected in 92 of 497 water distribution systems (WDS) examined. Thermal disinfection was applied at 33 WDS. After the first and second application of the disinfection procedure, 15 (45.4%) and 3 (9%) positive for remedial actions WDS were found, respectively. Legionella pneumophila was more resistant to thermal disinfection than Legionella non-pneumophila spp. (relative risk [RR]=5.4, 95% confidence intervals [CI]=1-35). WDS of hotels with oil heater were more easily disinfected than those with electrical or solar heater (RR=0.4 95% CI=0.2-0.8). Thermal disinfection seems not to be efficient enough to eliminate legionellae, unless repeatedly applied and in combination with extended heat flushing, and faucets chlorine disinfection.

A multicenter evaluation of genotypic methods for the epidemiologic typing of Legionella pneumophila serogroup 1

DEFF Research Database (Denmark)

Fry, Norman K.; Alexiou-Daniel, Stella; Bangsborg, Jette Marie

1999-01-01

OBJECTIVES: To compare genotypic methods for epidemiologic typing of Legionella pneumophila serogroup (sg) 1, in order to determine the best available method within Europe for implementation and standardization by members of the European Working Group on Legionella Infections. METHODS: Coded...

The E. coli immunosorbent as used in serodiagnosis of Legionella infections studied by crossed immunoelectrophoresis

DEFF Research Database (Denmark)

Bangsborg, Jette Marie; Friis-Møller, A; Rechnitzer, C

1988-01-01

In this study we investigated an immunosorbent, E. coli blocking fluid (BF), proposed for use in the Legionella Indirect Fluorescent Antibody Test (IFA). With crossed immunoelectrophoresis (CIE) of clinically relevant Legionella species, only one heat-stable antigen (no. 1) cross...

Survival of Legionella in earthquake-induced soil disturbance (liquefaction) in residential areas, Christchurch, New Zealand: implications for disease.

Science.gov (United States)

Graham, Frances F; Harte, David Jg

2017-05-12

To investigate a possible link between liquefaction dust exposure and the noticeable increase in legionellosis cases in response to major earthquakes in 2010 and 2011 that resulted in widespread soil disturbance (liquefaction) in parts of Christchurch, New Zealand. We culture tested liquefaction-affected soil for Legionella spp. in the six months following the first earthquake in 2010. Thirty silt samples were collected randomly from locations within Christchurch's metropolitan area that were affected by liquefaction. The samples were tested to determine the presence of Legionella using qualitative and quantitative methods. Liquefaction-affected soil samples from three sites were further subjected to particle size distribution analysis and determination of major oxides. A controlled field study was established using six silt samples and one control (commercial compost), seeded with a wild-type strain of Legionella bozemanae serogroup (sg) 1 and persistence monitored over a 60-day period by culturing for the presence of Legionella. Dry matter determinations were undertaken so that total Legionella could be calculated on a dry weight basis. Legionella bacteria were undetectable after day one in the silt samples. However, L. bozemanae sg1 was detected in the control sample for the entire study period. This study showed that the liquefaction-affected soil could not contribute directly to the observed increase in legionellosis cases after the earthquakes due to its inability to support growth and survival of the Legionella bacteria.

Neumonía por Legionella pneumophila: Experiencia en un Hospital Universitario de Buenos Aires Neumonia due to Legionella pneumophila. Experience gathered in a University Hospital in Buenos Aires

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Carlos M. Luna

2004-04-01

Full Text Available La enfermedad de los legionarios es una causa de neumonía adquirida en la comunidad (NAC reconocida en todo el mundo. En Latinoamérica su incidencia es desconocida. En este estudio se analizó a 9 pacientes con NAC por Legionella pneumophila atendidos entre 1997 y 2001 en el Hospital de Clínicas José de San Martín de la Universidad de Buenos Aires. Se registraron datos de antecedentes, enfermedad actual, contactos, exposición laboral, examen físico, pruebas de laboratorio y uso previo de antibióticos, y se tomó en cuenta la presencia de criterios de gravedad. Nueve pacientes presentaron diagnóstico de NAC por Legionella, ninguno refirió antecedentes de viajes recientes; cuatro de ellos debieron ser internados en unidades de cuidado intensivo. Siete pacientes tenían antecedentes de tabaquismo, 4 tenían EPOC y un paciente linfoma no-Hodgkin. Nuestra casuística corrobora la baja especificidad de la clínica y estudios complementarios para predecir esta etiología. El aislamiento de Legionella es dificultoso, la seroconversión permite el diagnóstico retrospectivo y requiere plazos prolongados y el antígeno urinario aporta un diagnóstico inmediato. Cuando la legionelosis aparece en casos aislados, como ocurriría en Argentina, si no se piensa en esta etiología no se llegará al diagnóstico. Legionella pneumophila es un patógeno de NAC en nuestro medio, debe buscarse mejor, particularmente en pacientes graves, inmunodeprimidos y en fumadores con enfermedad pulmonar obstructiva crónica (EPOC.Legionnaires’ disease is a well recognized cause of community acquired pneumonia (CAP all around the world. In Latin America its incidence remains unknown. This study analyzed a cohort of 9 patients with CAP due to Legionella pneumophila observed from 1997 to 2001, in the Hospital de Clínicas José de San Martín, University of Buenos Aires. Clinical history included recent illnesses, work exposure, physical exam, prior antibiotic use and

Hyperoxia accelerates Fas-mediated signaling and apoptosis in the lungs of Legionella pneumophila pneumonia

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Tanabe Yoshinari

2011-04-01

Full Text Available Abstract Background Oxygen supplementation is commonly given to the patients with severe pneumonia including Legionella disease. Recent data suggested that apoptosis may play an important role, not only in the pathogenesis of Legionella pneumonia, but also in oxygen-induced tissue damage. In the present study, the lethal sensitivity to Legionella pneumonia were compared in the setting of hyperoxia between wild-type and Fas-deficient mice. Findings C57BL/6 mice and B6.MRL-Faslpr mice characterized with Fas-deficiency were used in this study. After intratracheal administration of L. pneumophila, mice were kept in hyperoxic conditions (85-90% O2 conc. in an airtight chamber for 3 days. Bone-marrow derived macrophages infected with L. pneumophila were also kept in hyperoxic conditions. Caspase activity and cytokine production were determined by using commercially available kits. Smaller increases of several apoptosis markers, such as caspase-3 and -8, were demonstrated in Fas-deficient mice, even though the bacterial burdens in Fas-deficient and wild type mice were similar. Bone-marrow derived macrophages from Fas-deficient mice were shown to be more resistant to Legionella-induced cytotoxicity than those from wild-type mice under hyperoxia. Conclusions These results demonstrated that Fas-mediated signaling and apoptosis may be a crucial factor in the pathogenesis of Legionella pneumonia in the setting of hyperoxia.

Prevalence of Legionella spp. in water systems of hospitals and hotels in South Western Greece.

Science.gov (United States)

Fragou, K; Kokkinos, P; Gogos, C; Alamanos, Y; Vantarakis, A

2012-01-01

The aim of the present study was to determine the prevalence of Legionella spp. in water systems of hospitals and hotels located in South Western Greece, to study the molecular epidemiology of the isolated strains and their possible association with bacterial contamination (total count and Pseudomonas aeruginosa), the water pH, and temperature. A prevalence survey for Legionella spp. by culturing techniques in water distribution systems of eight hospitals and nine hotels occurred in South Western Greece. Water sampling and microbiological analysis were carried out following the ISO methods. Legionella pneumophila was detected in 33% and 36% of the distribution systems of hospitals and hotels, respectively. Our survey results suggest a frequent prevalence of elevated concentrations of Legionella spp. in water systems of hospitals and hotels. Our investigation has confirmed the need to regularly monitor the microbiological condition of water systems in hospitals and hotels.

Detection of airborne Legionella while showering using liquid impingement and fluorescent in situ hybridization (FISH).

Science.gov (United States)

Deloge-Abarkan, Magali; Ha, Thi-Lan; Robine, Enric; Zmirou-Navier, Denis; Mathieu, Laurence

2007-01-01

Aerosols of water contaminated with Legionella bacteria constitute the only mode of exposure for humans. However, the prevention strategy against this pathogenic bacteria risk is managed through the survey of water contamination. No relationship linked the Legionella bacteria water concentration and their airborne abundance. Therefore, new approaches in the field of the metrological aspects of Legionella bioaerosols are required. This study was aimed at testing the main principles for bioaerosol collection (solid impaction, liquid impingement and filtration) and the in situ hybridization (FISH) method, both in laboratory and field assays, with the intention of applying such methodologies for airborne Legionella bacteria detection while showering. An aerosolization chamber was developed to generate controlled and reproducible L. pneumophila aerosols. This tool allowed the identification of the liquid impingement method as the most appropriate one for collecting airborne Legionella bacteria. The culturable fraction of airborne L. pneumophila recovered with the liquid impingement principle was 4 and 700 times higher compared to the impaction and filtration techniques, respectively. Moreover, the concentrations of airborne L. pneumophila in the impinger fluid were on average 7.0 x 10(5) FISH-cells m(-3) air with the fluorescent in situ hybridization (FISH) method versus 9.0 x 10(4) CFU m(-3) air with the culture method. These results, recorded under well-controlled conditions, were confirmed during the field experiments performed on aerosols generated by hot water showers in health institutions. This new approach may provide a more accurate characterization of aerobiocontamination by Legionella bacteria.

Interactive Effects of Corrosion, Copper, and Chloramines on Legionella and Mycobacteria in Hot Water Plumbing.

Science.gov (United States)

Rhoads, William J; Pruden, Amy; Edwards, Marc A

2017-06-20

Complexities associated with drinking water plumbing systems can result in undesirable interactions among plumbing components that undermine engineering controls for opportunistic pathogens (OPs). In this study, we examine the effects of plumbing system materials and two commonly applied disinfectants, copper and chloramines, on water chemistry and the growth of Legionella and mycobacteria across a transect of bench- and pilot-scale hot water experiments carried out with the same municipal water supply. We discovered that copper released from corrosion of plumbing materials can initiate evolution of >1100 times more hydrogen (H 2 ) from water heater sacrificial anode rods than does presence of copper dosed as soluble cupric ions. H 2 is a favorable electron donor for autotrophs and causes fixation of organic carbon that could serve as a nutrient for OPs. Dosed cupric ions acted as a disinfectant in stratified stagnant pipes, inhibiting culturable Legionella and biofilm formation, but promoted Legionella growth in pipes subject to convective mixing. This difference was presumably due to continuous delivery of nutrients to biofilm on the pipes under convective mixing conditions. Chloramines eliminated culturable Legionella and prevented L. pneumophila from recolonizing biofilms, but M. avium gene numbers increased by 0.14-0.76 logs in the bulk water and were unaffected in the biofilm. This study provides practical confirmation of past discrepancies in the literature regarding the variable effects of copper on Legionella growth, and confirms prior reports of trade-offs between Legionella and mycobacteria if chloramines are applied as secondary disinfectant residual.

Legionella pneumonia presenting with bilateral flank pain, hyponatraemia and acute renal failure

OpenAIRE

Birkin, Celia; Biyani, Chandra Shekhar; Browning, Anthony J.

2011-01-01

Legionnaires’ disease (LD) is an often overlooked but a possible cause of sporadic community acquired pneumonia. High fever, cough and gastrointestinal symptoms are non-specific symptoms. Hyponatremia is more common in LD than pneumonia linked with other causes. A definitive diagnosis is usually confirmed by culture, urinary antigen testing for Legionella species. Macolide or quinolone antibiotic is the treatment of choice. We describe a case of Legionella pneumonia presenting with high fever...

Detection of Legionella species in environmental water by the quantitative PCR method in combination with ethidium monoazide treatment.

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Inoue, Hiroaki; Takama, Tomoko; Yoshizaki, Miwa; Agata, Kunio

2015-01-01

We detected Legionella species in 111 bath water samples and 95 cooling tower water samples by using a combination of conventional plate culture, quantitative polymerase chain reaction (qPCR) and qPCR combined with ethidium monoazide treatment (EMA-qPCR) methods. In the case of bath water samples, Legionella spp. were detected in 30 samples by plate culture, in 85 samples by qPCR, and in 49 samples by EMA-qPCR. Of 81 samples determined to be Legionella-negative by plate culture, 56 and 23 samples were positive by qPCR and EMA-qPCR, respectively. Therefore, EMA treatment decreased the number of Legionella-positive bath water samples detected by qPCR. In contrast, EMA treatment had no effect on cooling tower water samples. We therefore expect that EMA-qPCR is a useful method for the rapid detection of viable Legionella spp. from bath water samples.

Recirculation, stagnation and ventilation: The 2014 legionella episode

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Russo, Ana; Soares, Pedro M. M.; Gouveia, Célia M.; Cardoso, Rita M.; Trigo, Ricardo M.

2017-04-01

Legionella transmission through the atmosphere is unusual, but not unprecedented. A scientific paper published in 2006 reports a surge in Pas-de-Calais, France, in which 86 people have been infected by bacteria released by a cooling tower more than 6 km away [3]. Similarly, in Norway, in 2005, there was another case where contamination spread beyond 10 km, although more concentrated within a radius of 1 km from an industrial unit [2]. An unprecedented large Legionella outbreak occurred in November 2014 nearby Lisbon, Portugal. As of 7 November 2014, 375 individuals become hill and 12 died infected by the Legionella pneumophila bacteria, contracted by inhalation of steam droplets of contaminated water (aerosols). These droplets are so small that can carry the bacteria directly to the lungs, depositing it in the alveoli. One way of studying the propagation of legionella episodes is through the use of aerosol dispersion models. However, such approaches often require detailed 3D high resolution wind data over the region, which isn't often available for long periods. The likely impact of wind on legionella transmission can also be understood based on the analysis of special types of flow conditions such as stagnation, recirculation and ventilation [1, 4]. The Allwine and Whiteman (AW) approach constitutes a straightforward method to assess the assimilative and dispersal capacities of different airsheds [1,4], as it only requires hourly wind components. Thus, it has the advantage of not needing surface and upper air meteorological observations and a previous knowledge of the atmospheric transport and dispersion conditions. The objective of this study is to analyze if the legionella outbreak event which took place in November 2014 had extreme potential recirculation and/or stagnation characteristics. In order to accomplish the proposed objective, the AW approach was applied for a hindcast time-series covering the affected area (1989-2007) and then for an independent

[Evaluation of a Legionella outbreak emerged in a recently opening hotel].

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Erdoğan, Haluk; Arslan, Hande

2013-04-01

Legionnaires' disease (LD) is a systemic infection caused by Legionella species especially colonized in the water systems. Hotels are common locations in which waterwork-associated sporadic or epidemic legionellosis can be detected. The aim of this study was to evaluate a small Legionella outbreak emerged in a recently opened 600-bed hotel in Alanya, a touristic county in Mediterranean part of Turkey. A 66 years old male patient who stayed in this hotel opened on May 15th, 2009, was admitted to our hospital on May 21st, 2009 with the complaints of high fever, headache and diarrhea lasting for three days. Since chest X-ray revealed non-homogenous density increase in left middle and inferior zone, the patient was diagnosed as atypical pneumoniae and LD was confirmed by positive urinary Legionella antigen test (Card test, BinaxNOW®Legionella Urinary Antigen Test; Alere Co, USA) result. Following the identification of the index case, the records of our hospital were reviewed and revealed another case being treated with the diagnosis of community acquired pneumonia who was also the guest of the same hotel. This patient was then diagnosed as LD by positive urinary antigen test. Since new cases were identified during the following days (May 22, 25 and 26) the Antalya County Health Department and hotel management were informed about a cluster of LD. In addition subsequent investigation for environmental surveillance and water sampling were conducted. The LD diagnosis and environmental inspections were performed according to the procedure described in the guideline from "Turkish Ministry of Health Travel-Associated Legionnaires' Disease Control Programme". Five definitive cases and one presumptive case of LD were identified during the outbreak period (May 20-26, 2009). All of the cases were successfully treated (intravenous ciprofloxacin or levofloxacin or clarithromycin), however one patient died due to sudden death during sleep after being discharged. Since sputum

Molecular characterization of viable Legionella spp. in cooling tower water samples by combined use of ethidium monoazide and PCR.

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Inoue, Hiroaki; Fujimura, Reiko; Agata, Kunio; Ohta, Hiroyuki

2015-01-01

Viable Legionella spp. in environmental water samples were characterized phylogenetically by a clone library analysis combining the use of ethidium monoazide and quantitative PCR. To examine the diversity of Legionella spp., six cooling tower water samples and three bath water samples were collected and analyzed. A total of 617 clones were analyzed for their 16S rRNA gene sequences and classified into 99 operational taxonomic units (OTUs). The majority of OTUs were not clustered with currently described Legionella spp., suggesting the wide diversity of not-yet-cultured Legionella groups harbored in cooling tower water environments.

Influenceof antimicrobial therapy on the sensitivity of legionella PCR - three case report

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Renato Eržen

2007-02-01

Full Text Available Background: L. pneumophila is a possible causative agent of severe community and hospital acquired pneumonia. Available diagnostic tests have a lot of shortcomings. Detection of Legionella DNA with the PCR technique is a promissing new method allowing diagnosis within clinically useful time.Methods: Three cases of severe Legionella pneumonia were followed with the PCR technique, urinary antigen and serologic methods.Results: Diagnostic tests have different sensitivity and specificity and also different shortcomings. Serologic tests are unable to provide diagnosis within clinically useful time. Urinary antigen is specific just for L. pneumophila serotype 1. Antimicrobial treatment has impact on the sensitivity of Legionella PCR.Conclusions: Detection of L. pneumophila infection with the PCR technique in addition to urinary antigen testing is likely to be the best diagnostic tool for the detection of all species within a time frame that will affect clinical management.

Evaluation of Legionella real-time PCR against traditional culture for routine and public health testing of water samples.

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Collins, S; Stevenson, D; Walker, J; Bennett, A

2017-06-01

To evaluate the usefulness of Legionella qPCR alongside traditional culture for enumeration of Legionella from water samples as part of both routine and public health investigation testing. Routine water samples (n = 2002) and samples from public health investigations (n = 215) were analysed by culture and qPCR for Legionella spp., Legionella pneumophila and L. pneumophila sg-1. A negative qPCR result was highly predictive of a negative culture result for all water systems (negative predictive values, NPV from 97·4 to 100%). Positive predictive values (PPV) were lower (0-50%). Results for qPCR were generally larger than culture with average log 10 differences of 1·1 for Legionella spp. and 1·2 for L. pneumophila. Alert and action levels of 1000 and 10 000 GU per litre, respectively, are proposed for Legionella qPCR for hot and cold water systems (HCWS). The use of qPCR significantly reduced the time to results for public health investigations by rapidly identifying potential sources and ruling out others, thus enabling a more rapid and efficient response. The high NPV of qPCR supports its use to rapidly screen out negative samples without culture. Alert and action levels for Legionella qPCR for HCWS are proposed. Quantitative PCR will be a valuable tool for both routine and public health testing. This study generated comparative data of >2000 water samples by qPCR and culture. Action and alert levels have been recommended that could enable duty holders to interpret qPCR results to facilitate timely Legionella control and public health protection. © 2017 Crown copyright. Journal of Applied Microbiology © 2017 The Society for Applied Microbiology.

Presence of Legionella spp. in Hot Water Networks of Different Italian Residential Buildings: A Three-Year Survey.

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Totaro, Michele; Valentini, Paola; Costa, Anna Laura; Frendo, Lorenzo; Cappello, Alessia; Casini, Beatrice; Miccoli, Mario; Privitera, Gaetano; Baggiani, Angelo

2017-10-26

Although the European reports highlight an increase in community-acquired Legionnaires' disease cases, the risk of Legionella spp. in private houses is underestimated. In Pisa (Italy) we performed a three-year survey on Legionella presence in 121 buildings with an independent hot water production (IB); 64 buildings with a central hot water production (CB); and 35 buildings with a solar thermal system for hot water production (TB). From all the 220 buildings Legionella spp. was researched in two hot water samples collected either at the recirculation point or on the first floor and on the last floor, while the potable water quality was analysed in three cold water samples collected at the inlet from the aqueduct network, at the exit from the autoclave, and at the most remote tap. Legionella pneumophila sg1, Legionella pneumophila sg2-16, and non- pneumophila Legionella species were detected in 26% of the hot water networks, mostly in CB and TB. In these buildings we detected correlations between the presence of Legionella and the total chlorine concentration decrease and/or the increase of the temperature. Cold water resulted free from microbiological hazards, with the exception of Serratia liquefaciens and Enterobacter cloacae isolated at the exit from two different autoclaves. We observed an increase in total microbial counts at 22 °C and 37 °C between the samples collected at the most remote taps compared to the ones collected at the inlet from the aqueduct. The study highlights a condition of potential risk for susceptible categories of population and supports the need for measures of risk assessment and control.

Post-translational modifications are key players of the Legionella pneumophila infection strategy

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Michard, Céline; Doublet, Patricia

2015-01-01

Post-translational modifications (PTMs) are widely used by eukaryotes to control the enzymatic activity, localization or stability of their proteins. Traditionally, it was believed that the broad biochemical diversity of the PTMs is restricted to eukaryotic cells, which exploit it in extensive networks to fine-tune various and complex cellular functions. During the last decade, the advanced detection methods of PTMs and functional studies of the host–pathogen relationships highlight that bacteria have also developed a large arsenal of PTMs, particularly to subvert host cell pathways to their benefit. Legionella pneumophila, the etiological agent of the severe pneumonia legionellosis, is the paradigm of highly adapted intravacuolar pathogens that have set up sophisticated biochemical strategies. Among them, L. pneumophila has evolved eukaryotic-like and rare/novel PTMs to hijack host cell processes. Here, we review recent progress about the diversity of PTMs catalyzed by Legionella: ubiquitination, prenylation, phosphorylation, glycosylation, methylation, AMPylation, and de-AMPylation, phosphocholination, and de-phosphocholination. We focus on the host cell pathways targeted by the bacteria catalyzed PTMs and we stress the importance of the PTMs in the Legionella infection strategy. Finally, we highlight that the discovery of these PTMs undoubtedly made significant breakthroughs on the molecular basis of Legionella pathogenesis but also lead the way in improving our knowledge of the eukaryotic PTMs and complex cellular processes that are associated to. PMID:25713573

The presence and growth of Legionella species in thermostatic shower mixer taps: an exploratory field study

NARCIS (Netherlands)

Joost van Hoof; P.W.J.J. van der Wielen; E. van der Blom; O.W.W. Nuijten; L. Hornstra

2014-01-01

Legislation in the Netherlands requires routine analysis of drinking water samples for cultivable Legionella species from high-priority installations. A field study was conducted to investigate the presence of Legionella species in thermostatic shower mixer taps. Water samples and the interior of

Legionella pneumophila control in practice. Legionellenbekaempfung in der Praxis

Energy Technology Data Exchange (ETDEWEB)

Scharff, K

1989-01-01

Legionella pneumophila are wide-spread, rod-shaped bacilli (24 species with 40 serogroups are known to date) which preferably occur in water (lower growth limit is at 20deg C). Details are given on recommendations issued by the Federal Public Health Office. Thermal disinfection should be preferred to a chemical disinfection of drinking water. Recommendations such as water heating to 60deg C, regular cleaning of central clear-water reservoirs, self-draining shower hoses and shower heads, shut-off of unused pipe sections and connecting pipes should be put into practice applying easy-to-handle 60deg C tap water heating systems, circulating pipes, heated inlet pipes, decentralized flow heaters, storage system cleaning and pipe shut-off measures. Legionella research needs to be continued. (HWJ).

Genetic relatedness of Legionella longbeachae isolates from human and environmental sources in Australia

International Nuclear Information System (INIS)

Lanser, J.A.; Doyle, R.; Sangster, N.; Steele, T.W.; Adams, M.

1990-01-01

The genetic relatedness of Legionella longbeachae isolated in Australia since 1987 was investigated by restriction fragment length polymorphism (RFLP) analysis and allozyme electrophoresis. Three radiolabeled probes were used in Southern hybridizations for the RFLP studies. They were Escherichia coli 16S and 23S rRNA and cloned fragments of L. longbeachae selected empirically from genomal banks in lambda and a cosmid. The legionellae included in the study comprised 11 Legionella longbeachae serogroup 1 organisms isolated form humans, 28 L. longbeachae serogroup 1 isolates from environmental sources, 3 L. longbeachae serogroup 2 environmental isolates. These were compared with the American Type Culture Collection reference strains of both serogroups and some other related Legionella species. Results of allozyme and RFLP analysis showed that all the isolates from humans and all but three of the environmental L. longbeachae serogroup 1 isolates were closely related. They were also closely related to L. longbeachae serogroup 1 ATCC 33462. There was wider variation among the three L. longbeachae serogroup 2 environmental isolates. One of these was closely related to L. longbeachae serogroup 2 ATCC 33484. RFLP studies with the rRNA probe provided the most discrimination among isolates but did not distinguish between the two serogroups

Hospital-acquired Legionella infections: an update on the procedures for controlling environmental contamination.

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Borella, P; Bargellini, A; Marchegiano, P; Vecchi, E; Marchesi, I

2016-01-01

The waterborne healthcare-associated infections are mainly sustained by Legionella and Pseudomonas spp. Various water factors and plumbing characteristics, and the interaction with other water microorganisms are considered to be predictive of Legionella contamination. It is therefore mandatory to organize plans of surveillance, prevention and control in order to avoid disease appearance in immunosuppressed patients, with higher risk of death. Guidelines for the prevention of Legionnaires' disease have been published, benefiting those who face this problem, but definitive standardized solutions do not exist yet. Here we describe fifteen years of activity, during which our study group gathered interesting data on the control of Legionella contamination. Water disinfection is not generally sufficient to control the risk of infection, but a complex water safety plan should be developed, including system maintenance, training of staff and implementation of a clinical surveillance system aimed at early detection of cases. Concerning the control measures, we evaluated the effectiveness of different treatments suggested to reduce Legionella spp contamination, comparing our results with the current literature data. The performance ranking was highest for the filter, followed by boilers at high temperature, monochloramine and, at a lower level, chlorine dioxide; the effectiveness of hyperchlorination was limited, and thermal shock was even more ineffective.

Viability-qPCR for detecting Legionella: Comparison of two assays based on different amplicon lengths.

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Ditommaso, Savina; Giacomuzzi, Monica; Ricciardi, Elisa; Zotti, Carla M

2015-08-01

Two different real-time quantitative PCR (PMA-qPCR) assays were applied for quantification of Legionella spp. by targeting a long amplicon (approx 400 bp) of 16S rRNA gene and a short amplicon (approx. 100 bp) of 5S rRNA gene. Purified DNA extracts from pure cultures of Legionella spp. and from environmental water samples were quantified. Application of the two assays to quantify Legionella in artificially contaminated water achieved that both assays were able to detect Legionella over a linear range of 10 to 10(5) cells ml(-1). A statistical analysis of the standard curves showed that both assays were linear with a good correlation coefficient (R(2) = 0.99) between the Ct and the copy number. Amplification with the reference assay was the most effective for detecting low copy numbers (1 bacterium per PCR mixture). Using selective quantification of viable Legionella by the PMA-qPCR method we obtained a greater inhibition of the amplification of the 400-bp 16S gene fragment (Δlog(10) = 3.74 ± 0.39 log(10) GU ml(-1)). A complete inhibition of the PCR signal was obtained when heat-killed cells in a concentration below 1 × 10(5) cells ml(-1) were pretreated with PMA. Analysing short amplicon sizes led to only 2.08 log reductions in the Legionella dead-cell signal. When we tested environmental water samples, the two qPCR assays were in good agreement according to the kappa index (0.741). Applying qPCR combined with PMA treatment, we also obtained a good agreement (kappa index 0.615). The comparison of quantitative results shows that both assays yielded the same quantification sensitivity (mean log = 4.59 vs mean log = 4.31). Copyright © 2015 Elsevier Ltd. All rights reserved.

Widespread molecular detection of Legionella pneumophila Serogroup 1 in cold water taps across the United States

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In the United States 3,522 cases of legionellosis were reported to the Center for Disease Control and Prevention in 2009. Of these reports, it is estimated that 84% are caused by the microorganism Legionella pneumophila Serogroup (Sg) 1. Legionella spp. have been isolated and r...

Effects of holding time and measurement error on culturing Legionella in environmental water samples.

Science.gov (United States)

Flanders, W Dana; Kirkland, Kimberly H; Shelton, Brian G

2014-10-01

Outbreaks of Legionnaires' disease require environmental testing of water samples from potentially implicated building water systems to identify the source of exposure. A previous study reports a large impact on Legionella sample results due to shipping and delays in sample processing. Specifically, this same study, without accounting for measurement error, reports more than half of shipped samples tested had Legionella levels that arbitrarily changed up or down by one or more logs, and the authors attribute this result to shipping time. Accordingly, we conducted a study to determine the effects of sample holding/shipping time on Legionella sample results while taking into account measurement error, which has previously not been addressed. We analyzed 159 samples, each split into 16 aliquots, of which one-half (8) were processed promptly after collection. The remaining half (8) were processed the following day to assess impact of holding/shipping time. A total of 2544 samples were analyzed including replicates. After accounting for inherent measurement error, we found that the effect of holding time on observed Legionella counts was small and should have no practical impact on interpretation of results. Holding samples increased the root mean squared error by only about 3-8%. Notably, for only one of 159 samples, did the average of the 8 replicate counts change by 1 log. Thus, our findings do not support the hypothesis of frequent, significant (≥= 1 log10 unit) Legionella colony count changes due to holding. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

A comparison of assays measuring the viability of Legionella pneumophila after treatment with copper and silver ions

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Background: The relatively high prevalence of Legionella pneumophila in premise plumbing systems has been widely reported. Published reports indicate Legionella has a comparatively high resistance to chlorine and moreover has the ability to grow in phagocytic amoeba which could p...

Impact of drinking water conditions and copper materials on downstream biofilm microbial communities and legionella pneumophila colonization

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Legionella pneumophila, the medically important species within the genus Legionella, is a concern in engineered water systems. Its ability to amplify within free-living amoebae is well documented, but its interactions/ecology within the microbial community of drinking water biofi...

Legionella detection and subgrouping in water air-conditioning cooling tower systems in Kuwait.

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Al-Matawah, Qadreyah; Al-Zenki, Sameer; Al-Azmi, Ahmad; Al-Waalan, Tahani; Al-Salameen, Fadila; Hejji, Ahmad Ben

2015-07-01

The main aim of the study was to test for the presence of Legionnaires' disease-causing microorganisms in air-conditioned buildings in Kuwait using molecular technologies. For this purpose, 547 samples were collected from 38 cooling towers for the analysis of Legionella pneumophila. These samples included those from water (n = 178), air (n = 231), and swabs (n = 138). Out of the 547 samples, 226 (41%) samples were presumptive positive for L. pneumophila, with L. pneumophila viable counts in the positive water samples ranging from 1 to 88 CFU/ml. Of the Legionella culture-positive samples, 204 isolates were examined by latex agglutination. These isolates were predominately identified as L. pneumophila serogroup (sg) 2-14. Using the Dresden panel of monoclonal antibodies, 74 representatives isolates were further serogrouped. Results showed that 51% of the isolates belonged to serogroup 7 followed by 1 (18%) and 3 (18%). Serogroups 4 (4%) and 10 (7%) were isolated at a lower frequency, and two isolates could not be assigned to a serogroup. These results indicate the wide prevalence of L. pneumophila serogroup 7 as the predominant serogroup at the selected sampling sites. Furthermore, the 74 L. pneumophila (sg1 = 13; sg3 = 13; sg4 = 3; sg7 = 38; sg10 = 5; sgX = 2) isolates were genotyped using the seven gene protocol sequence-based typing (SBT) scheme developed by the European Working Group for Legionella Infections (EWGLI). The results show that Legionella isolates were discriminated into nine distinct sequence typing (ST) profiles, five of which were new to the SBT database of EWGLI. Additionally, all of the ST1 serogroup 1 isolates were of the OLDA/Oxford subgroup. These baseline data will form the basis for the development of a Legionella environmental surveillance program and used for future epidemiological investigations.

Dendrimers and polyamino-phenolic ligands: activity of new molecules against Legionella pneumophila biofilms.

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Elisa eAndreozzi

2016-03-01

Full Text Available Legionnaires’ disease is a potentially fatal pneumonia caused by Legionella pneumophila, an aquatic bacterium often found within the biofilm niche. In man-made water systems microbial biofilms increase the resistance of legionella to disinfection, posing a significant threat to public health. Disinfection methods currently used in water systems have been shown to be ineffective against legionella over the long-term, allowing recolonization by the biofilm-protected microorganisms. In this study, the anti-biofilm activity of previously fabricated polyamino-phenolic ligands and polyamidoamine dendrimers was investigated against legionella mono-species and multi-species biofilms formed by L. pneumophila in association with other bacteria that can be found in tap water (Aeromonas hydrophila, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae. Bacterial ability to form biofilms was verified using a crystal violet colorimetric assay and testing cell viability by real-time quantitative PCR and Plate Count assay. The concentration of the chemicals tested as anti-biofilm agents was chosen based on cytotoxicity assays: the highest non-cytotoxic chemical concentration was used for biofilm inhibition assays, with dendrimer concentration ten-fold higher than polyamino-phenolic ligands. While Macrophen and Double Macrophen were the most active substances among polyamino-phenolic ligands, dendrimers were overall two-fold more effective than all other compounds with a reduction up to 85% and 73% of legionella and multi-species biofilms, respectively. Chemical interaction with matrix molecules is hypothesized, based on SEM images and considering the low or absent anti-microbial activity on planktonic bacteria showed by flow cytometry. These data suggest that the studied compounds, especially dendrimers, could be considered as novel molecules in the design of research projects aimed at the development of efficacious anti-biofilm disinfection

[Disinfectants and main sanitary and preventive measures for protection of ventilation and air-conditioning systems from Legionella contamination].

Science.gov (United States)

Gerasimov, V N; Golov, E A; Khramov, M V; Diatlov, I A

2008-01-01

The study was devoted to selection and assessment of disinfecting preparations for prevention of contamination by Legionella. Using system of criteria for quality assessment of disinfectants, seven newdomestic ones belonging to quaternary ammonium compounds class or to oxygen-containing preparations and designed for disinfecting of air-conditioning and ventilation systems were selected. Antibacterial and disinfecting activities of working solutions of disinfectants were tested in laboratory on the test-surfaces and test-objects of premises' air-conditioning and ventilation systems contaminated with Legionella. High antimicrobial and disinfecting activity of new preparations "Dezactiv-M", "ExtraDez", "Emital-Garant", "Aquasept Plus", "Samarovka", "Freesept", and "Ecobreeze Oxy" during their exposure on objects and materials contaminated with Legionella was shown. Main sanitary and preventive measures for defending of air-conditioning and ventilation systems from contamination by Legionella species were presented.

Isolation, identification, characterization and antibiotic sensitivity profile of pathogenic Legionella pneumophila isolates from different water sources

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Kannan Subbaram

2017-05-01

Conclusions: Serious and fatal L. pneumophila infections may be transmitted through water. Legionella can survive under various conditions in various water sources. L. pneumophila is the important pathogen causing human disease. Great challenge prevails to health care professionals because these Legionellae acquired antibiotic resistance to many routinely prescribed antibiotics.

[The hazards of hospitals and selected public buildings of Legionella pneumophila].

Science.gov (United States)

Sikora, Agnieszka; Kozioł-Montewka, Maria; Wójtowicz-Bobin, Małgorzata; Gładysz, Iwona; Dobosz, Paulina

2013-11-01

The registered infection and outbreaks of epidemic tend to monitor potential reservoirs of Legionella infection. According to the Act of 29 March 2007 on the requirements for the quality of water intended for human consumption are required to test for the presence and number of Legionella in the water system of hospitals. In case of detection of L. pneumophila serogroup 1 (SG 1) or increased above normal number other serogroups of bacteria it is necessary to eradicate these bacteria from the water system. The aim of this study was to assess the degree of contamination of the water supply system of selected public buildings and analyze the effectiveness of disinfection methods for the elimination of L. pneumophila in hot water systems. The materials for this study were hot and cold water samples which were collected from the water supply system of 23 different objects. Enumeration of Legionella bacteria in water samples was determined by membrane filtration (FM) and/or by surface inoculation methods according to the standards: PN-ISO 11731: 2002: "The quality of the water. Detection and enumeration of Legionella" and PN-EN ISO 11731-2: 2008: "Water quality--Detection and enumeration of Legionella--Part 2: Methodology of membrane filtration for water with a small number of bacteria". L. pneumophila was present in 164 samples of hot water, which accounted for 76.99%. In all tested water samples L. pneumophila SG 2-14 strains were detected. The most virulent strain--L. pneumophila SG 1 was not detected. In examined 23 objects in 12 of L. pneumophila exceed acceptable levels > 100 CFU/100 ml. The presence of L. pneumophila SG 2-14 demonstrated in all examined objects, indicating the risk of infection, and the need for permanent monitoring of the water system supply. The thermal disinfection is the most common, inexpensive, and effective method of control of L. pneumophila used in examined objects, but does not eliminate bacterial biofilm. Disinfection using the filters

Legionella pneumophila-Derived Outer Membrane Vesicles Promote Bacterial Replication in Macrophages.

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Anna Lena Jung

2016-04-01

Full Text Available The formation and release of outer membrane vesicles (OMVs is a phenomenon of Gram-negative bacteria. This includes Legionella pneumophila (L. pneumophila, a causative agent of severe pneumonia. Upon its transmission into the lung, L. pneumophila primarily infects and replicates within macrophages. Here, we analyzed the influence of L. pneumophila OMVs on macrophages. To this end, differentiated THP-1 cells were incubated with increasing doses of Legionella OMVs, leading to a TLR2-dependent classical activation of macrophages with the release of pro-inflammatory cytokines. Inhibition of TLR2 and NF-κB signaling reduced the induction of pro-inflammatory cytokines. Furthermore, treatment of THP-1 cells with OMVs prior to infection reduced replication of L. pneumophila in THP-1 cells. Blocking of TLR2 activation or heat denaturation of OMVs restored bacterial replication in the first 24 h of infection. With prolonged infection-time, OMV pre-treated macrophages became more permissive for bacterial replication than untreated cells and showed increased numbers of Legionella-containing vacuoles and reduced pro-inflammatory cytokine induction. Additionally, miRNA-146a was found to be transcriptionally induced by OMVs and to facilitate bacterial replication. Accordingly, IRAK-1, one of miRNA-146a's targets, showed prolonged activation-dependent degradation, which rendered THP-1 cells more permissive for Legionella replication. In conclusion, L. pneumophila OMVs are initially potent pro-inflammatory stimulators of macrophages, acting via TLR2, IRAK-1, and NF-κB, while at later time points, OMVs facilitate L. pneumophila replication by miR-146a-dependent IRAK-1 suppression. OMVs might thereby promote spreading of L. pneumophila in the host.

Anti-Legionella dumoffii Activity of Galleria mellonella Defensin and Apolipophorin III

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Małgorzata Cytryńska

2012-12-01

Full Text Available The gram-negative bacterium Legionella dumoffii is, beside Legionella pneumophila, an etiological agent of Legionnaires’ disease, an atypical form of pneumonia. The aim of this study was to determine the antimicrobial activity of Galleria mellonella defense polypeptides against L. dumoffii. The extract of immune hemolymph, containing a mixture of defense peptides and proteins, exhibited a dose-dependent bactericidal effect on L. dumoffii. The bacterium appeared sensitive to a main component of the hemolymph extract, apolipophorin III, as well as to a defense peptide, Galleria defensin, used at the concentrations 0.4 mg/mL and 40 μg/mL, respectively. L. dumoffii cells cultured in the presence of choline were more susceptible to both defense factors analyzed. A transmission electron microscopy study of bacterial cells demonstrated that Galleria defensin and apolipophorin III induced irreversible cell wall damage and strong intracellular alterations, i.e., increased vacuolization, cytoplasm condensation and the appearance of electron-white spaces in electron micrographs. Our findings suggest that insects, such as G. mellonella, with their great diversity of antimicrobial factors, can serve as a rich source of compounds for the testing of Legionella susceptibility to defense-related peptides and proteins.

Cultural and Molecular Evidence of Legionella spp. Colonization in Dental Unit Waterlines: Which Is the Best Method for Risk Assessment?

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Ditommaso, Savina; Giacomuzzi, Monica; Ricciardi, Elisa; Zotti, Carla M

2016-02-06

Legionella spp. are ubiquitous in aquatic habitats and water distribution systems, including dental unit waterlines (DUWLs). The aim of the present study was to determine the prevalence of Legionella in DUWLs and tap water samples using PMA-qPCR and standard culture methods. The total viable counts (TVCs) of aerobic heterotrophic bacteria in the samples were also determined. Legionella spp. were detected and quantified using the modified ISO 11731 culture method. Extracted genomic DNA was analysed using the iQ-Check Quanti Legionella spp. kit, and the TVCs were determined according to the ISO protocol 6222. Legionella spp. were detected in 100% of the samples using the PMA-qPCR method, whereas these bacteria were detected in only 7% of the samples using the culture method. The number of colony forming units (CFUs) of the TVCs in the DUWL and tap water samples differed, with the bacterial load being significantly lower in the tap water samples (p-value = 0). The counts obtained were within the Italian standard range established for potable water in only 5% of the DUWL water samples and in 77% of the tap water samples. Our results show that the level of Legionella spp. contamination determined using the culture method does not reflect the true scale of the problem, and consequently we recommend testing for the presence of aerobic heterotrophic bacteria based on the assumption that Legionella spp. are components of biofilms.

Mistaken identity: Legionella micdadei appearing as acid-fast bacilli on lung biopsy of a hematopoietic stem cell transplant patient.

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Waldron, P R; Martin, B A; Ho, D Y

2015-02-01

Legionella micdadei is a potential cause of invasive lung infections in immunocompromised hosts. On biopsy specimens, it can appear as an acid-fast bacillus (AFB) and can be mistaken for a member of genus Mycobacterium. As Legionella requires selective media to grow in culture, and the commonly used, commercially available urine antigen test for Legionella only detects Legionella pneumophila serogroup-1, but not L. micdadei, it is important to consider this organism in the differential diagnosis for AFB in immunocompromised hosts. We report a case of L. micdadei infection, which was initially treated empirically for non-tuberculous mycobacteria based on AFB staining of biopsy tissue before the final diagnosis was made. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Antibiotic susceptibility of Legionella strains isolated from public water sources in Macau and Guangzhou.

Science.gov (United States)

Xiong, Lina; Yan, He; Shi, Lei; Mo, Ziyao

2016-12-01

The purpose of this study was to investigate the susceptibility of waterborne strains of Legionella to eight antimicrobials commonly used in legionellosis therapy. The minimum inhibitory concentrations (MICs) of 66 environmental Legionella strains, isolated from fountains and cooling towers of public facilities (hotels, schools, and shopping malls) in Macau and Guangzhou, were tested using the microdilution method in buffered yeast extract broth. The MIC 50 /MIC 90 values for erythromycin, cefotaxime (CTX), doxycycline (DOC), minocycline (MIN), azithromycin, ciprofloxacin, levofloxacin (LEV), and moxifloxacin were 0.125/0.5 mg/L, 4/8 mg/L, 8/16 mg/L, 4/8 mg/L, 0.125/0.5 mg/L, 0.031/0.031 mg/L, 0.031/0.031 mg/L, and 0.031/0.062 mg/L, respectively. Legionella isolates were inhibited by either low concentrations of macrolides and fluoroquinolones, or high concentrations of CTX and tetracycline drugs. LEV was the most effective drug against different Legionella species and serogroups of L. pneumophila isolates. The latter were inhibited in decreasing order by MIN > CTX >DOC, while non-L. pneumophila isolates were inhibited by CTX> MIN >DOC. In this study, we evaluated drug resistance of pathogenic bacteria from the environment. This may help predict the emergence of drug resistance, improve patient outcomes, and reduce hospitalization costs.

Relapse of Legionella longbeachae infection in an immunocompromised patient

NARCIS (Netherlands)

van't Hullenaar, N. G.; van Ketel, R. J.; Kuijper, E. J.; Bakker, P. J.; Dankert, J.

1996-01-01

We describe the first known case of Legionella longbeachae infection in the Netherlands in a patient with myasthenia gravis. Infection with L. longbeachae relapsed after prolonged therapy with erythromycin. No environmental source of L. longbeachae could be traced

Legionella pneumophila: the paradox of a highly sensitive opportunistic waterborne pathogen able to persist in the environment

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Jean-Marc eBerjeaud

2016-04-01

Full Text Available Legionella pneumophila, the major causative agent of Legionnaires’ disease, is found in freshwater environments in close association with free-living amoebae and multispecies biofilms, leading to persistence, spread, biocide resistance, and elevated virulence of the bacterium. Indeed, legionellosis outbreaks are mainly due to the ability of this bacterium to colonize and persist in water facilities, despite harsh physical and chemical treatments. However, these treatments are not totally efficient and, after a lag period, L. pneumophila may be able to quickly re-colonize these systems. Several natural compounds (biosurfactants, antimicrobial peptides… with anti-Legionella properties have recently been described in the literature, highlighting their specific activities against this pathogen. In this review, we first consider this hallmark of Legionella to resist killing, in regard to its biofilm or host-associated life style. Then, we focus more accurately on natural anti-Legionella molecules described so far, which could provide new eco-friendly and alternative ways to struggle against this important pathogen in plumbing.

Activity of Six Essential Oils Extracted from Tunisian Plants against Legionella pneumophila.

Science.gov (United States)

Chaftar, Naouel; Girardot, Marion; Quellard, Nathalie; Labanowski, Jérôme; Ghrairi, Tawfik; Hani, Khaled; Frère, Jacques; Imbert, Christine

2015-10-01

The aim of this study was to investigate the composition of six essential oils extracted from Tunisian plants, i.e., Artemisia herba-alba Asso, Citrus sinensis (L.) Osbeck, Juniperus phoenicea L., Rosmarinus officinalis L., Ruta graveolens L., and Thymus vulgaris L., and to evaluate their activity against Legionella pneumophila (microdilution assays). Eight Legionella pneumophila strains were studied, including the two well-known serogroup 1 Lens and Paris strains as controls and six environmental strains isolated from Tunisian spas belonging to serogroups 1, 4, 5, 6, and 8. The essential oils were generally active against L. pneumophila. The activities of the A. herba-alba, C. sinensis, and R. officinalis essential oils were strain-dependent, whereas those of the J. phoenicea and T. vulgaris oils, showing the highest anti-Legionella activities, with minimum inhibitory concentrations (MICs) lower than 0.03 and lower than or equal to 0.07 mg/ml, respectively, were independent of the strains' serogroup. Moreover, the microorganisms treated with T. vulgaris essential oil were shorter, swollen, and less electron-dense compared to the untreated controls. Isoborneol (20.91%), (1S)-α-pinene (18.30%) β-phellandrene (8.08%), α-campholenal (7.91%), and α-phellandrene (7.58%) were the major components isolated from the J. phoenicea oil, while carvacrol (88.50%) was the main compound of the T. vulgaris oil, followed by p-cymene (7.86%). This study highlighted the potential interest of some essential oils extracted from Tunisian plants as biocides to prevent the Legionella risk. Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.

Investigation of Legionella Contamination in Bath Water Samples by Culture, Amoebic Co-Culture, and Real-Time Quantitative PCR Methods.

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Edagawa, Akiko; Kimura, Akio; Kawabuchi-Kurata, Takako; Adachi, Shinichi; Furuhata, Katsunori; Miyamoto, Hiroshi

2015-10-19

We investigated Legionella contamination in bath water samples, collected from 68 bathing facilities in Japan, by culture, culture with amoebic co-culture, real-time quantitative PCR (qPCR), and real-time qPCR with amoebic co-culture. Using the conventional culture method, Legionella pneumophila was detected in 11 samples (11/68, 16.2%). Contrary to our expectation, the culture method with the amoebic co-culture technique did not increase the detection rate of Legionella (4/68, 5.9%). In contrast, a combination of the amoebic co-culture technique followed by qPCR successfully increased the detection rate (57/68, 83.8%) compared with real-time qPCR alone (46/68, 67.6%). Using real-time qPCR after culture with amoebic co-culture, more than 10-fold higher bacterial numbers were observed in 30 samples (30/68, 44.1%) compared with the same samples without co-culture. On the other hand, higher bacterial numbers were not observed after propagation by amoebae in 32 samples (32/68, 47.1%). Legionella was not detected in the remaining six samples (6/68, 8.8%), irrespective of the method. These results suggest that application of the amoebic co-culture technique prior to real-time qPCR may be useful for the sensitive detection of Legionella from bath water samples. Furthermore, a combination of amoebic co-culture and real-time qPCR might be useful to detect viable and virulent Legionella because their ability to invade and multiply within free-living amoebae is considered to correlate with their pathogenicity for humans. This is the first report evaluating the efficacy of the amoebic co-culture technique for detecting Legionella in bath water samples.

[Genomic DNA fingerprints of Legionella pneumophila serogroup 2 strains as an epidemiologic marker].

Science.gov (United States)

Bender-Beck, L; Mühlenberg, W; Lück, P C; Ott, M; Horbach, I; Fehrenbach, F J; Wewalka, G; Hacker, J

1995-08-01

Using pulsed-field gel electrophoresis, DNA fingerprints of eleven Legionella pneumophila isolates of serogroup 2 were generated. It was shown that two strains from a patient suffering from pneumonia as well as three environmental strains isolated from the shower in the hotel where the patient stayed 5 days before his illness were identical. Six strains of the same serogroup isolated from other sources were clearly separated. Thus, DNA fingerprints by pulsed-field gel electrophoresis are excellent epidemiological markers for the rarely occurring serogroup 2 of Legionella pneumophila.

Evaluation and comparison of multiple test methods, including real-time PCR, for Legionella detection in clinical specimens.

Directory of Open Access Journals (Sweden)

Adriana Peci

2016-08-01

Full Text Available Legionella is a gram-negative bacterium that can cause Pontiac fever, a mild upper respiratory infection and Legionnaire’s disease, a more severe illness. We aimed to compare the performance of urine antigen, culture and PCR test methods and to determine if sputum is an alternative to the use of more invasive bronchoalveolar lavage (BAL. Data for this study included specimens tested for Legionella at PHOL from January 1, 2010 to April 30, 2014, as part of routine clinical testing. We found sensitivity of UAT compared to culture to be 87%, specificity 94.7%, positive predictive value (PPV 63.8% and negative predictive value (NPV 98.5%. Sensitivity of UAT compared to PCR was 74.7%, specificity 98.3%, PPV 77.7% and NPV 98.1%. Of 146 patients who had a Legionella positive result by PCR, only 66(45.2% also had a positive result by culture. Sensitivity for culture was the same using either sputum or BAL (13.6%; sensitivity for PCR was 10.3% for sputum and 12.8% for BAL. Both sputum and BAL yield similar results despite testing methods (Fisher Exact p-values=1.0, for each test. In summary, all test methods have inherent weaknesses in identifying Legionella; thereforemore than one testing method should be used. Obtaining a single specimen type from patients with pneumonia limits the ability to diagnose Legionella, particularly when urine is the specimen type submitted. Given ease of collection, and similar sensitivity to BAL, clinicians are encouraged to submit sputum in addition to urine when BAL submission is not practical, from patients being tested for Legionella.

Modelling characteristics to predict Legionella contamination risk - Surveillance of drinking water plumbing systems and identification of risk areas.

Science.gov (United States)

Völker, Sebastian; Schreiber, Christiane; Kistemann, Thomas

2016-01-01

For the surveillance of drinking water plumbing systems (DWPS) and the identification of risk factors, there is a need for an early estimation of the risk of Legionella contamination within a building, using efficient and assessable parameters to estimate hazards and to prioritize risks. The precision, accuracy and effectiveness of ways of estimating the risk of higher Legionella numbers (temperature, stagnation, pipe materials, etc.) have only rarely been empirically assessed in practice, although there is a broad consensus about the impact of these risk factors. We collected n = 807 drinking water samples from 9 buildings which had had Legionella spp. occurrences of >100 CFU/100mL within the last 12 months, and tested for Legionella spp., L. pneumophila, HPC 20°C and 36°C (culture-based). Each building was sampled for 6 months under standard operating conditions in the DWPS. We discovered high variability (up to 4 log(10) steps) in the presence of Legionella spp. (CFU/100 mL) within all buildings over a half year period as well as over the course of a day. Occurrences were significantly correlated with temperature, pipe length measures, and stagnation. Logistic regression modelling revealed three parameters (temperature after flushing until no significant changes in temperatures can be obtained, stagnation (low withdrawal, qualitatively assessed), pipe length proportion) to be the best predictors of Legionella contamination (>100 CFU/100 mL) at single outlets (precision = 66.7%; accuracy = 72.1%; F(0.5) score = 0.59). Copyright © 2015 Elsevier GmbH. All rights reserved.

Experimental human-like model to assess the part of viable Legionella reaching the thoracic region after nebulization.

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Jérémie Pourchez

Full Text Available The incidence of Legionnaires' disease (LD in European countries and the USA has been constantly increasing since 1998. Infection of humans occurs through aerosol inhalation. To bridge the existing gap between the concentration of Legionella in a water network and the deposition of bacteria within the thoracic region (assessment of the number of viable Legionella, we validated a model mimicking realistic exposure through the use of (i recent technology for aerosol generation and (ii a 3D replicate of the human upper respiratory tract. The model's sensitivity was determined by monitoring the deposition of (i aerosolized water and Tc99m radio-aerosol as controls, and (ii bioaerosols generated from both Escherichia coli and Legionella pneumophila sg 1 suspensions. The numbers of viable Legionella prior to and after nebulization were provided by culture, flow cytometry and qPCR. This study was designed to obtain more realistic data on aerosol inhalation (vs. animal experimentation and deposition at the thoracic region in the context of LD. Upon nebulization, 40% and 48% of the initial Legionella inoculum was made of cultivable and non-cultivable cells, respectively; 0.7% of both populations reached the filter holder mimicking the thoracic region in this setup. These results are in agreement with experimental data based on quantitative microbial risk assessment methods and bring new methods that may be useful for preventing LD.

[Identification of Systemic Contaminations with Legionella Spec. in Drinking Water Plumbing Systems: Sampling Strategies and Corresponding Parameters].

Science.gov (United States)

Völker, S; Schreiber, C; Müller, H; Zacharias, N; Kistemann, T

2017-05-01

After the amendment of the Drinking Water Ordinance in 2011, the requirements for the hygienic-microbiological monitoring of drinking water installations have increased significantly. In the BMBF-funded project "Biofilm Management" (2010-2014), we examined the extent to which established sampling strategies in practice can uncover drinking water plumbing systems systemically colonized with Legionella. Moreover, we investigated additional parameters that might be suitable for detecting systemic contaminations. We subjected the drinking water plumbing systems of 8 buildings with known microbial contamination (Legionella) to an intensive hygienic-microbiological sampling with high spatial and temporal resolution. A total of 626 drinking hot water samples were analyzed with classical culture-based methods. In addition, comprehensive hygienic observations were conducted in each building and qualitative interviews with operators and users were applied. Collected tap-specific parameters were quantitatively analyzed by means of sensitivity and accuracy calculations. The systemic presence of Legionella in drinking water plumbing systems has a high spatial and temporal variability. Established sampling strategies were only partially suitable to detect long-term Legionella contaminations in practice. In particular, the sampling of hot water at the calorifier and circulation re-entrance showed little significance in terms of contamination events. To detect the systemic presence of Legionella,the parameters stagnation (qualitatively assessed) and temperature (compliance with the 5K-rule) showed better results. © Georg Thieme Verlag KG Stuttgart · New York.

Preferential colonization and release of Legionella pneumophila from mature drinking water biofilms grown on copper versus unplasticized polyvinylchloride coupons

Science.gov (United States)

Legionella persistence and amplification in premise drinking water systems is a known contributor to legionellosis outbreaks, especially in the presence of suitable eukaryotic hosts. Here we examined Legionella pneumophila behavior within drinking water biofilms grown on copper ...

Genetic typing in a cluster of Legionella pneumophila infections

NARCIS (Netherlands)

van Ketel, R. J.; de Wever, B.

1989-01-01

Legionella pneumophila strains isolated from six patients, three air-conditioning- and cooling tower-derived strains, and three hot water supply-derived strains were analyzed by three genetic typing methods. The results of the whole-cell DNA restriction endonuclease analysis and the restriction

Investigation of Legionella Contamination in Bath Water Samples by Culture, Amoebic Co-Culture, and Real-Time Quantitative PCR Methods

Directory of Open Access Journals (Sweden)

Akiko Edagawa

2015-10-01

Full Text Available We investigated Legionella contamination in bath water samples, collected from 68 bathing facilities in Japan, by culture, culture with amoebic co-culture, real-time quantitative PCR (qPCR, and real-time qPCR with amoebic co-culture. Using the conventional culture method, Legionella pneumophila was detected in 11 samples (11/68, 16.2%. Contrary to our expectation, the culture method with the amoebic co-culture technique did not increase the detection rate of Legionella (4/68, 5.9%. In contrast, a combination of the amoebic co-culture technique followed by qPCR successfully increased the detection rate (57/68, 83.8% compared with real-time qPCR alone (46/68, 67.6%. Using real-time qPCR after culture with amoebic co-culture, more than 10-fold higher bacterial numbers were observed in 30 samples (30/68, 44.1% compared with the same samples without co-culture. On the other hand, higher bacterial numbers were not observed after propagation by amoebae in 32 samples (32/68, 47.1%. Legionella was not detected in the remaining six samples (6/68, 8.8%, irrespective of the method. These results suggest that application of the amoebic co-culture technique prior to real-time qPCR may be useful for the sensitive detection of Legionella from bath water samples. Furthermore, a combination of amoebic co-culture and real-time qPCR might be useful to detect viable and virulent Legionella because their ability to invade and multiply within free-living amoebae is considered to correlate with their pathogenicity for humans. This is the first report evaluating the efficacy of the amoebic co-culture technique for detecting Legionella in bath water samples.

A STUDY ON LEGIONELLA PNEUMOPHILA, WATER CHEMISTRY, AND ATMOSPHERIC CONDITIONS IN COOLING TOWERS AT THE SAVANNAH RIVER SITE

Energy Technology Data Exchange (ETDEWEB)

Smith, C.; Brigmon, R.

2009-10-20

Legionnaires disease is a pneumonia caused by the inhalation of the bacterium Legionella pneumophila. The majority of illnesses have been associated with cooling towers since these devices can harbor and disseminate the bacterium in the aerosolized mist generated by these systems. Historically, Savannah River Site (SRS) cooling towers have had occurrences of elevated levels of Legionella in all seasons of the year and in patterns that are difficult to predict. Since elevated Legionella in cooling tower water are a potential health concern a question has been raised as to the best control methodology. In this work we analyze available chemical, biological, and atmospheric data to determine the best method or key parameter for control. The SRS 4Q Industrial Hygiene Manual, 4Q-1203, 1 - G Cooling Tower Operation and the SRNL Legionella Sampling Program, states that 'Participation in the SRNL Legionella Sampling Program is MANDATORY for all operating cooling towers'. The resulting reports include L. pneumophila concentration information in cells/L. L. pneumophila concentrations >10{sup 7} cells/L are considered elevated and unsafe so action must be taken to reduce these densities. These remedial actions typically include increase biocide addition or 'shocking'. Sometimes additional actions are required if the problem persists including increase tower maintenance (e.g. cleaning). Evaluation of 14 SRS cooling towers, seven water quality parameters, and five Legionella serogroups over a three-plus year time frame demonstrated that cooling tower water Legionella densities varied widely though out this time period. In fact there was no one common consistent significant variable across all towers. The significant factors that did show up most frequently were related to suspended particulates, conductivity, pH, and dissolved oxygen, not chlorine or bromine as might be expected. Analyses of atmospheric data showed that there were more frequent significant

Effect of Legionella pneumophila sonicate on killing of Listeria monocytogenes by human polymorphonuclear neutrophils and monocytes

DEFF Research Database (Denmark)

Rechnitzer, C; Bangsborg, Jette Marie; Shand, G H

1993-01-01

Legionella pneumophila shares with other intracellular pathogens the ability to resist intracellular killing within phagocytes. An increasing number of cellular components of L. pneumophila are proposed as pathogenic factors of the organism. At the site of infection, the phagocytic cells will be ......Legionella pneumophila shares with other intracellular pathogens the ability to resist intracellular killing within phagocytes. An increasing number of cellular components of L. pneumophila are proposed as pathogenic factors of the organism. At the site of infection, the phagocytic cells...... are most likely to represent the inhibitory factors. The inhibitory activity of L. pneumophila sonic extract appears to be related to inhibition of killing mechanisms since uptake of Listeria was not affected by the sonicate. Our observations indicate that as Legionella infection progresses, bacterial...

Seasonal distribution of Legionella spp. and L. pneumophila in a river in Taiwan evaluated with culture-confirmed and direct DNA extraction methods

Science.gov (United States)

Tung, Min-Che; Chang, Tien-Yu; Hsu, Bing-Mu; Shen, Shu-Min; Huang, Jen-Te; Kao, Po-Min; Chiu, Yi-Chou; Fan, Cheng-Wei; Huang, Yu-Li

2013-07-01

In this study, we evaluated the presence and amount of Legionella in along a river in Taiwan, and the relations between seasonal distribution of Legionella spp. and geographic characteristics in the watershed were also evaluated. Water samples were pre-treated and analyzed with culture-confirmed and direct DNA extraction methods. For culture-confirmed method, water samples were cultivated through a series of selective media, and candidate colonies were confirmed by PCR. For direct DNA extraction method, direct DNA extraction was performed from pre-treated water samples. The DNA extracts were analyzed with PCR and DNA sequence analysis for species determination, quantitative PCR (qPCR) was performed to quantify Legionella concentration in the water sample. In all, 150 water samples were included in this study, with 73 (48.6%) water samples detected with Legionella spp., and 17 with L. pneumophila. Over 80% Legionella spp. detections were through direct DNA extraction method, but more than 80% L. pneumophila detections were through culture-confirmed method. While detection of Legionella spp. was done with two methods, positive results were found through only one method. Legionella spp. was detected in all seasons with detection rate ranging between 34.3-58.8% and seasonal average concentration from 1.9 × 102 to 7.1 × 103 CFU/L. Most of the L. pneumophila detections were from samples collected in fall (38.2%) and summer (6.0%), which also coincided with increased cases of Legionellosis reported through Center of Disease Control in Taiwan. The high prevalence and concentration of Legionella spp. and L. pneumophila in the surface waters should be further evaluated for potential health risks.

A single Legionella pneumophila genotype in the freshwater system in a ship experiencing three separate outbreaks of legionellosis in 6 years

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Catrine Ahlen

2016-08-01

Full Text Available Background: Recurrent legionella outbreaks at one and the same location are common. We have identified a single Legionella pneumophila genotype associated with recurrent Legionella outbreaks over 6 years. Methods: Field emergency surveys following Legionella outbreaks were performed on a vessel in 2008, 2009 and 2013. Water samples from both the distribution and technical parts of the potable water system were analyzed with respect to L. pneumophila [Real-Time PCR, cultivation, serotyping and genotyping (PFGE] and free-living amoebae, (FLA. Results: Legionella pneumophila serogroup 1 was present in the ship's potable water system during every outbreak. Genotyping of the 2008 survey material showed two separate PFGE genotypes while those in 2009 and 2013 demonstrated the presence of only one of the two genotypes. FLA with intracellular L. pneumophila of the same genotype were also detected. Analyses of the freshwater system on a ship following three separate Legionella outbreaks, for L. pneumophila and FLAs, revealed a single L. pneumophila genotype and FLA (Hartmanella. Conclusions: It is reasonable to assume that the L. pneumophila genotype detected in the freshwater system was the causal agent in the outbreaks onboard. Persistence of an apparently low-pathogenic L. pneumophila genotype and FLA in a potable water system represent a potential risk for recurrent outbreaks.

Rapid quantification of viable Legionella in nuclear cooling tower waters using filter cultivation, fluorescent in situ hybridization and solid-phase cytometry.

Science.gov (United States)

Baudart, J; Guillaume, C; Mercier, A; Lebaron, P; Binet, M

2015-05-01

To develop a rapid and sensitive method to quantify viable Legionella spp. in cooling tower water samples. A rapid, culture-based method capable of quantifying as few as 600 Legionella microcolonies per litre within 2 days in industrial waters was developed. The method combines a short cultivation step of microcolonies on GVPC agar plate, specific detection of Legionella cells by a fluorescent in situ hybridization (FISH) approach, and a sensitive enumeration using a solid-phase cytometer. Following optimization of the cultivation conditions, the qualitative and quantitative performance of the method was assessed and the method was applied to 262 nuclear power plant cooling water samples. The performance of this method was in accordance with the culture method (NF-T 90-431) for Legionella enumeration. The rapid detection of viable Legionella in water is a major concern to the effective monitoring of this pathogenic bacterium in the main water sources involved in the transmission of legionellosis infection (Legionnaires' disease). The new method proposed here appears to be a robust, efficient and innovative means for rapidly quantifying cultivable Legionella in cooling tower water samples within 48 h. © 2015 The Society for Applied Microbiology.

Health risks from exposure to Legionella in reclaimed water aerosols: Toilet flushing, spray irrigation, and cooling towers.

Science.gov (United States)

Hamilton, Kerry A; Hamilton, Mark T; Johnson, William; Jjemba, Patrick; Bukhari, Zia; LeChevallier, Mark; Haas, Charles N

2018-05-01

The use of reclaimed water brings new challenges for the water industry in terms of maintaining water quality while increasing sustainability. Increased attention has been devoted to opportunistic pathogens, especially Legionella pneumophila, due to its growing importance as a portion of the waterborne disease burden in the United States. Infection occurs when a person inhales a mist containing Legionella bacteria. The top three uses for reclaimed water (cooling towers, spray irrigation, and toilet flushing) that generate aerosols were evaluated for Legionella health risks in reclaimed water using quantitative microbial risk assessment (QMRA). Risks are compared using data from nineteen United States reclaimed water utilities measured with culture-based methods, quantitative PCR (qPCR), and ethidium-monoazide-qPCR. Median toilet flushing annual infection risks exceeded 10 -4 considering multiple toilet types, while median clinical severity infection risks did not exceed this value. Sprinkler and cooling tower risks varied depending on meteorological conditions and operational characteristics such as drift eliminator performance. However, the greatest differences between risk scenarios were due to 1) the dose response model used (infection or clinical severity infection) 2) population at risk considered (residential or occupational) and 3) differences in laboratory analytical method. Theoretical setback distances necessary to achieve a median annual infection risk level of 10 -4 are proposed for spray irrigation and cooling towers. In both cooling tower and sprinkler cases, Legionella infection risks were non-trivial at potentially large setback distances, and indicate other simultaneous management practices could be needed to manage risks. The sensitivity analysis indicated that the most influential factors for variability in risks were the concentration of Legionella and aerosol partitioning and/or efficiency across all models, highlighting the importance of

Evaluation and Comparison of Multiple Test Methods, Including Real-time PCR, for Legionella Detection in Clinical Specimens

Science.gov (United States)

Peci, Adriana; Winter, Anne-Luise; Gubbay, Jonathan B.

2016-01-01

Legionella is a Gram-negative bacterium that can cause Pontiac fever, a mild upper respiratory infection and Legionnaire’s disease, a more severe illness. We aimed to compare the performance of urine antigen, culture, and polymerase chain reaction (PCR) test methods and to determine if sputum is an acceptable alternative to the use of more invasive bronchoalveolar lavage (BAL). Data for this study included specimens tested for Legionella at Public Health Ontario Laboratories from 1st January, 2010 to 30th April, 2014, as part of routine clinical testing. We found sensitivity of urinary antigen test (UAT) compared to culture to be 87%, specificity 94.7%, positive predictive value (PPV) 63.8%, and negative predictive value (NPV) 98.5%. Sensitivity of UAT compared to PCR was 74.7%, specificity 98.3%, PPV 77.7%, and NPV 98.1%. Out of 146 patients who had a Legionella-positive result by PCR, only 66 (45.2%) also had a positive result by culture. Sensitivity for culture was the same using either sputum or BAL (13.6%); sensitivity for PCR was 10.3% for sputum and 12.8% for BAL. Both sputum and BAL yield similar results regardless testing methods (Fisher Exact p-values = 1.0, for each test). In summary, all test methods have inherent weaknesses in identifying Legionella; therefore, more than one testing method should be used. Obtaining a single specimen type from patients with pneumonia limits the ability to diagnose Legionella, particularly when urine is the specimen type submitted. Given ease of collection and similar sensitivity to BAL, clinicians are encouraged to submit sputum in addition to urine when BAL submission is not practical from patients being tested for Legionella. PMID:27630979

[Community-acquired pneumonia due to Legionella pneumophila serogroup 1. Study of 97 cases].

Science.gov (United States)

Benito, José Ramón; Montejo, José Miguel; Cancelo, Laura; Zalacaín, Rafael; López, Leyre; Fernández Gil de Pareja, Joaquín; Alonso, Eva; Oñate, Javier

2003-10-01

Legionella pneumophila is the causal agent of 5% to 12% of sporadic community-acquired pneumonia cases, though rates are changing with the use of new diagnostic methods. This is a retrospective study of all patients admitted to our hospital with community-acquired pneumonia due to Legionella pneumophila between 1997 and 2001. Diagnostic criteria included either a positive Legionella serogroup 1 urinary antigen test or seroconversion and a chest radiograph consistent with pneumonia. A total of 97 patients were studied. Ninety cases (92.8%) were community-acquired and 7 (7.2%) were associated with travelling. In 82 cases (84.5%) the presentation was sporadic. Seventy-five patients were smokers (77.3%). The most common symptoms were fever in 91 patients (93.8%) and cough in 67 (68.1%). In five patients (5.2%) creatine phosphokinase concentrations were over 5 times their baseline values (in two over 100 times); four of these patients presented acute renal failure. Seroconversion was observed in 23/42 patients (54.8%). There were no statistically significant differences between the administration of erythromycin or clarithromycin in monotherapy, or in combination with rifampin. Nineteen patients (19.6%) presented acute renal failure and mechanical ventilation was necessary in 22 (22.7%). Twelve patients died (12.5%). Independent prognostic factors associated with death included respiratory rate > 30 breaths/min, urea > 60 mg/dL and PaO2 scale scores and the presence of complications or mortality. The Legionella urinary antigen test permits early diagnosis and treatment of this disease. The severity scale is an indicator of complications or death.

Applicability assessment of ceramic microbeads coated with hydroxyapatite-binding silver/titanium dioxide ceramic composite earthplus™ to the eradication of Legionella in rainwater storage tanks for household use.

Science.gov (United States)

Oana, Kozue; Kobayashi, Michiko; Yamaki, Dai; Sakurada, Tsukasa; Nagano, Noriyuki; Kawakami, Yoshiyuki

2015-01-01

Water environments appear to be the habitats of Legionella species. Legionellosis is considered as a preventable illness because bacterial reservoirs can be controlled and removed. Roof-harvested rainwater has attracted significant attention not only as a groundwater recharge but also as a potential alternative source of nonpotable water. We successfully developed ceramic microbeads coated with hydroxyapatite-binding silver/titanium dioxide ceramic composite earthplus™ using the thermal spraying method. The ceramic microbeads were demonstrated to have bactericidal activities against not only Legionella but also coliform and heterotrophic bacteria. Immersing the ceramic microbeads in household rainwater storage tanks was demonstrated to yield the favorable eradication of Legionella organisms. Not only rapid-acting but also long-lasting bactericidal activities of the ceramic microbead were exhibited against Legionella pneumophila. However, time-dependent attenuation of the bactericidal activities against Legionella were also noted in the sustainability appraisal experiment. Therefore, the problems to be overcome surely remain in constantly managing the Legionella-pollution by means of immersing the ceramic microbeads. The results of our investigation apparently indicate that the earthplus™-coated ceramic microbeads would become the favorable tool for Legionella measures in household rainwater storage tanks, which may become the natural reservoir for Legionella species. Our investigation would justify further research and data collection to obtain more reliable procedures to microbiologically regulate the Legionella in rainwater storage tanks.

Applicability assessment of ceramic microbeads coated with hydroxyapatite-binding silver/titanium dioxide ceramic composite earthplus™ to the eradication of Legionella in rainwater storage tanks for household use

Science.gov (United States)

Oana, Kozue; Kobayashi, Michiko; Yamaki, Dai; Sakurada, Tsukasa; Nagano, Noriyuki; Kawakami, Yoshiyuki

2015-01-01

Water environments appear to be the habitats of Legionella species. Legionellosis is considered as a preventable illness because bacterial reservoirs can be controlled and removed. Roof-harvested rainwater has attracted significant attention not only as a groundwater recharge but also as a potential alternative source of nonpotable water. We successfully developed ceramic microbeads coated with hydroxyapatite-binding silver/titanium dioxide ceramic composite earthplus™ using the thermal spraying method. The ceramic microbeads were demonstrated to have bactericidal activities against not only Legionella but also coliform and heterotrophic bacteria. Immersing the ceramic microbeads in household rainwater storage tanks was demonstrated to yield the favorable eradication of Legionella organisms. Not only rapid-acting but also long-lasting bactericidal activities of the ceramic microbead were exhibited against Legionella pneumophila. However, time-dependent attenuation of the bactericidal activities against Legionella were also noted in the sustainability appraisal experiment. Therefore, the problems to be overcome surely remain in constantly managing the Legionella-pollution by means of immersing the ceramic microbeads. The results of our investigation apparently indicate that the earthplus™-coated ceramic microbeads would become the favorable tool for Legionella measures in household rainwater storage tanks, which may become the natural reservoir for Legionella species. Our investigation would justify further research and data collection to obtain more reliable procedures to microbiologically regulate the Legionella in rainwater storage tanks. PMID:26346201

Identification of mip-like genes in the genus Legionella

DEFF Research Database (Denmark)

Cianciotto, N P; Bangsborg, Jette Marie; Eisenstein, B I

1990-01-01

The mip gene of Legionella pneumophila serogroup 1 strain AA100 encodes a 24-kilodalton surface protein (Mip) and enhances the abilities of L. pneumophila to parasitize human macrophages and to cause pneumonia in experimental animals. To determine whether this virulence factor is conserved in the...

Molecular Detection of Legionella spp. and their associations with Mycobacterium spp., Pseudomonas aeruginosa and amoeba hosts in a drinking water distribution system.

Science.gov (United States)

Lu, J; Struewing, I; Vereen, E; Kirby, A E; Levy, K; Moe, C; Ashbolt, N

2016-02-01

This study investigated waterborne opportunistic pathogens (OPs) including potential hosts, and evaluated the use of Legionella spp. for indicating microbial water quality for OPs within a full-scale operating drinking water distribution system (DWDS). To investigate the occurrence of specific microbial pathogens within a major city DWDS we examined large volume (90 l drinking water) ultrafiltration (UF) concentrates collected from six sites between February, 2012 and June, 2013. The detection frequency and concentration estimates by qPCR were: Legionella spp. (57%/85 cell equivalent, CE l(-1) ), Mycobacterium spp. (88%/324 CE l(-1) ), Pseudomonas aeruginosa (24%/2 CE l(-1) ), Vermamoeba vermiformis (24%/2 CE l(-1) ) and Acanthamoeba spp. (42%/5 cyst equivalent, CE l(-1) ). There was no detection of the following microorganisms: human faecal indicator Bacteroides (HF183), Salmonella enterica, Campylobacter spp., Escherichia coli O157:H7, Giardia intestinalis, Cryptosporidium spp. or Naegleria fowleri. There were significant correlations between the qPCR signals of Legionella spp. and Mycobacterium spp., and their potential hosts V. vermiformis and Acanthamoeba spp. Sequencing of Legionella spp. demonstrated limited diversity, with most sequences coming from two dominant groups, of which the larger dominant group was an unidentified species. Other known species including Legionella pneumophila were detected, but at low frequency. The densities of Legionella spp. and Mycobacterium spp. were generally higher (17 and 324 folds, respectively) for distal sites relative to the entry point to the DWDS. Legionella spp. occurred, had significant growth and were strongly associated with free-living amoebae (FLA) and Mycobacterium spp., suggesting that Legionella spp. could provide a useful DWDS monitoring role to indicate potential conditions for non-faecal OPs. The results provide insight into microbial pathogen detection that may aid in the monitoring of microbial water

Bacterial community dynamics in a cooling tower with emphasis on pathogenic bacteria and Legionella species using universal and genus-specific deep sequencing.

Science.gov (United States)

Pereira, Rui P A; Peplies, Jörg; Höfle, Manfred G; Brettar, Ingrid

2017-10-01

Cooling towers are the major source of outbreaks of legionellosis in Europe and worldwide. These outbreaks are mostly associated with Legionella species, primarily L. pneumophila, and its surveillance in cooling tower environments is of high relevance to public health. In this study, a combined NGS-based approach was used to study the whole bacterial community, specific waterborne and water-based bacterial pathogens, especially Legionella species, targeting the 16S rRNA gene. This approach was applied to water from a cooling tower obtained by monthly sampling during two years. The studied cooling tower was an open circuit cooling tower with lamellar cooling situated in Braunschweig, Germany. A highly diverse bacterial community was observed with 808 genera including 25 potentially pathogenic taxa using universal 16S rRNA primers. Sphingomonas and Legionella were the most abundant pathogenic genera. By applying genus-specific primers for Legionella, a diverse community with 85 phylotypes, and a representative core community with substantial temporal heterogeneity was observed. A high percentage of sequences (65%) could not be affiliated to an acknowledged species. L. pneumophila was part of the core community and the most abundant Legionella species reinforcing the importance of cooling towers as its environmental reservoir. Major temperature shifts (>10 °C) were the key environmental factor triggering the reduction or dominance of the Legionella species in the Legionella community dynamics. In addition, interventions by chlorine dioxide had a strong impact on the Legionella community composition but not on the whole bacterial community. Overall, the presented results demonstrated the value of a combined NGS approach for the molecular monitoring and surveillance of health related pathogens in man-made freshwater systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Genotypic variability and persistence of Legionella pulsed-field gel electrophoresis patterns in 16 cooling towers in Shanghai, China].

Science.gov (United States)

Chen, Ming-liang; Wang, Gang-yi; Chen, Min; Zhou, Hai-jian; Shao, Zhu-jun; Zhang, Xi; Wu, Fan

2010-07-01

To investigate the genotypic characteristics and persistence of Legionella pulsed-field gel electrophoresis (PFGE) patterns in 16 air-conditioner cooling towers in six different public sites of Shanghai. From May to October, continuous sampling was operated once per month in 2007. Legionella strains isolated from the 16 cooling towers were confirmed by serological and latex agglutination. PFGE was applied for the fingerprinting of the isolates, while the cluster results of PFGE were analyzed by BioNumerics software. 131 strains of Legionella were isolated, including L. pneumophila, L. bozemanae, L. micdadei and L. anisa. 52 distinguishable PFGE patterns were differentiated among the 16 cooling towers, with 37 patterns were owned by just one cooling tower, which was not shared with other cooling towers, while 15 patterns were shared by more than 2 cooling towers. All the cooling towers had ≥ 2 PFGE patterns, while in 13 cooling towers the same PFGE patterns were recovered during the six months. From June to October of 2007, 18 strains of Legionella belonging to the PFGE pattern of LPAs.SH0078 were isolated continuously from 6 cooling towers. This study demonstrated great genotypic diversity and complexity of Legionella in cooling towers. Persistence of the PFGE patterns was observed in 81.25% of the cooling towers. The PFGE pattern of LPAs. SH0078 was distributed widely, suggesting it might be the dominate strain in Shanghai.

Origin and prevention of infection with Legionella pneumophila through cooling towers and evaporative cooling towers

International Nuclear Information System (INIS)

Schulze-Roebbecke, R.

1994-01-01

Evaporative cooling towers and industrial ventilator cooling towers have repeatedly been described as the origin of Legionnaires' disease. This article describes the design and function of cooling towers and evaporative cooling towers, sums up knowledge on the colonization of such systems with Legionella pneumophila, and describes conditions permitting the transmission of Legionella. Furthermore, design, maintenance, cleaning and disinfection measures are indicated which are believed to reduce the risk of infection through industrial and evaporative cooling towers. (orig.) [de

Master manipulators: an update on Legionella pneumophila Icm/Dot translocated substrates and their host targets

Science.gov (United States)

Isaac, Dervla T; Isberg, Ralph

2014-01-01

Macrophages are the front line of immune defense against invading microbes. Microbes, however, have evolved numerous and diverse mechanisms to thwart these host immune defenses and thrive intracellularly. Legionella pneumophila, a Gram-negative pathogen of amoebal and mammalian phagocytes, is one such microbe. In humans, it causes a potentially fatal pneumonia referred to as Legionnaires' disease. Armed with the Icm/Dot type IV secretion system, which is required for virulence, and approximately 300 translocated proteins, Legionella is able to enter host cells, direct the biogenesis of its own vacuolar compartment, and establish a replicative niche, where it grows to high levels before lysing the host cell. Efforts to understand the pathogenesis of this bacterium have focused on characterizing the molecular activities of its many effectors. In this article, we highlight recent strides that have been made in understanding how Legionella effectors mediate host-pathogen interactions. PMID:24762308

Interaction of legionella pneumophila and helicobacter pylori with bacterial species isolated from drinking water biofilms

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Azevedo Nuno F

2011-03-01

Full Text Available Abstract Background It is well established that Legionella pneumophila is a waterborne pathogen; by contrast, the mode of Helicobacter pylori transmission remains unknown but water seems to play an important role. This work aims to study the influence of five microorganisms isolated from drinking water biofilms on the survival and integration of both of these pathogens into biofilms. Results Firstly, both pathogens were studied for auto- and co-aggregation with the species isolated from drinking water; subsequently the formation of mono and dual-species biofilms by L. pneumophila or H. pylori with the same microorganisms was investigated. Neither auto- nor co-aggregation was observed between the microorganisms tested. For biofilm studies, sessile cells were quantified in terms of total cells by SYTO 9 staining, viable L. pneumophila or H. pylori cells were quantified using 16 S rRNA-specific peptide nucleic acid (PNA probes and cultivable cells by standard culture techniques. Acidovorax sp. and Sphingomonas sp. appeared to have an antagonistic effect on L. pneumophila cultivability but not on the viability (as assessed by rRNA content using the PNA probe, possibly leading to the formation of viable but noncultivable (VBNC cells, whereas Mycobacterium chelonae increased the cultivability of this pathogen. The results obtained for H. pylori showed that M. chelonae and Sphingomonas sp. help this pathogen to maintain cultivability for at least 24 hours. Conclusions It appears that M. chelonae may have an important role in the survival of both pathogens in drinking water. This work also suggests that the presence of some microorganisms can decrease the cultivability of L. pneumophila but not the viability which indicates that the presence of autochthonous microorganisms can lead to misleading results when the safety of water is assessed by cultivable methods alone.

Free-living protozoa in drinking water supplies: community composition and role as hosts for Legionella pneumophila

OpenAIRE

Valster, R.M.

2011-01-01

Free-living protozoa in drinking water supplies: community composition and role as hosts for Legionella pneumophila Free-living protozoa, which feed on bacteria, play an important role in the communities of microorganisms and invertebrates in drinking water supplies and in (warm) tap water installations. Several bacteria, including opportunistic human pathogens such as Legionella pneumophila, are able to survive and replicate within protozoan hosts, and certain free-living protozoa are opp...

Chest X-ray in Legionella pneumonia (Legionnaires' disease)

Energy Technology Data Exchange (ETDEWEB)

Meenhorst, P.L.; Mulder, J.D.

1983-08-01

The authors compared the radiological evolution and patterns of Legionella pneumophila pneumonia in 13 immunocompromised and 13 non-immunocompromised patients. Apart from the occurrence of cavitation and the longer time it took before consolidations cleared in immunocompromised patients no differences were found between the two groups of patients.

The chest X-ray in Legionella pneumonia (Legionnaires' disease)

International Nuclear Information System (INIS)

Meenhorst, P.L.; Mulder, J.D.

1983-01-01

The authors compared the radiological evolution and patterns of Legionella pneumophila pneumonia in 13 immunocompromised and 13 non-immunocompromised patients. Apart from the occurrence of cavitation and the longer time it took before consolidations cleared in immunocompromised patients no differences were found between the two groups of patients. (orig.)

SULFAMETHOXAZOLE-TRIMETHOPRIM TREATMENT OF GUINEA PIGS INFECTED WITH 'LEGIONELLA PNEUMPOPHILA'

Science.gov (United States)

Legionnaires' disease is a bacterial pneumonia caused by Legionella pneumophila. Many antibiotics inhibit the growth of L. pneumophila in vitro, but only erythromycin and rifampin have been clinically effective. Parallel results have been observed in guinea pigs infected ip with ...

Legionella pneumophila transcriptome during intracellular multiplication in human macrophages

Directory of Open Access Journals (Sweden)

Sebastien P Faucher

2011-04-01

Full Text Available Legionella pneumophila is the causative agent of Legionnaires’ disease, an acute pulmonary infection. L. pneumophila is able to infect and multiply in both phagocytic protozoa, such as Acanthamoeba castellanii, and mammalian professional phagocytes. The best-known L. pneumophila virulence determinant is the Icm/Dot Type IVB secretion system (TFBSS, which is used to translocate more than 150 effector proteins to host cells. While the transcriptional response of Legionella to the intracellular environment of A. castellanii has been investigated, much less is known about the Legionella transcriptional response inside human macrophages. In this study, the transcriptome of L. pneumophila was monitored during exponential and post-exponential phase in rich AYE broth as well as during infection of human cultured macrophages. This was accomplished with microarrays and an RNA amplification procedure called SCOTS to detect small amounts of mRNA from low numbers of intracellular bacteria. Among the genes induced intracellularly are those involved in amino acid biosynthetic pathways leading to L-arginine, L-histidine and L-proline as well as many transport systems involved in amino acid and iron uptake. Gene involved in catabolism of glycerol is also induced during intracellular growth and could be used as a carbon source. The genes encoding the Icm/Dot system are not differentially expressed inside cells compared to control bacteria grown in rich broth, but the genes encoding several translocated effectors are strongly induced. Moreover, we used the transcriptome data to predict previously unrecognized Icm/Dot effector genes based on their expression pattern and confirmed translocation for three candidates. This study provides a comprehensive view of how L. pneumophila responds to the human macrophage intracellular environment.

Growth of Legionella anisa in a model drinking water system to evaluate different shower outlets and the impact of cast iron rust.

Science.gov (United States)

van der Lugt, Wilco; Euser, Sjoerd M; Bruin, Jacob P; Den Boer, Jeroen W; Walker, Jimmy T; Crespi, Sebastian

2017-11-01

Legionella continues to be a problem in water systems. This study investigated the influence of different shower mixer faucets, and the influence of the presence of cast iron rust from a drinking water system on the growth of Legionella. The research is conducted using a model of a household containing four drinking water systems. All four systems, which contained standard plumbing components including copper pipes and a water heater, were filled with unchlorinated drinking water. Furthermore, all systems had three different shower faucets: (A) a stainless-steel faucet, (B) a brass-ceramic faucet, and (C) a brass thermostatic faucet. System 1 was solely filled with drinking water. System 2 was filled with drinking water, and cast iron rust. System 3 was contaminated with Legionella, and system 4 was contaminated with a Legionella, and cast iron rust. During a period of 34 months, 450 cold water samples were taken from 15 sample points of the four drinking water systems, and tested for Legionella according to the Dutch Standard (NEN 6265). In system 4, with added cast iron rust, the stainless-steel mixer faucet (A) had the highest concentration of Legionella at >4.3log10CFU/l (>20,000CFU/l) and was positive in 46.4% of samples. In contrast, the stainless-steel mixer faucet (A) of system 3 without cast iron rust showed 14.3% positive samples with a maximum concentration of 3.9log10CFU/l (7600CFU/l) Legionella. Additionally, both contaminated systems (3 and 4), with the brass thermostatic faucet (C), tested positive for Legionella. System 3 in 85.7% of the samples, with a maximum concentration of 4.38log10CFU/l (24,200CFU/l), and system 4 in 64.3% of the samples with a maximum concentration of 4.13log10CFU/l (13.400CFU/l). These results suggest that both the type of faucet used in a drinking water system and the presence or absence of cast iron rust influence the growth of Legionella. Copyright © 2017 Elsevier GmbH. All rights reserved.

An ELISA test for the detection of antibodies to Legionella pneumophila.

OpenAIRE

Wreghitt, T G; Nagington, J; Gray, J

1982-01-01

An enzyme-linked immunosorbent assay (ELISA) test has been developed to detect antibodies to Legionella pneumophila serogroup 1. There is good correlation between indirect fluorescent antibody (IFA) and ELISA titres but ELISA is more sensitive.

INVESTIGATION OF LEGIONELLA SPECIES IN TEHRAN’S HOSPITAL WATER SUPPLIES

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MOHAMMAD RAFIEE

2015-03-01

Full Text Available The present work was performed to investigate the presence of Legionella spp. and its common species in hospital water supplies. Considering the drawback of culture method, polymerase chain reaction (PCR assays were developed to detect the gene 16S rRNA regardless of the bacterial serotype. Four well-established DNA extraction protocols (freeze & thaw and phenol-chloroform as two manual protocols and two commercial kits were examined and critiqued to release DNA from bacterial cells. A total of 45 samples were collected from seven distinct hospitals’ sites during a period of 10 months. The PCR assay was exploited to amplify a 654-bp fragment of the 16S rRNA gene. Legionella were detected in 13 samples (28.9% by all of the methods applied for DNA extraction. Considerable differences were noted in the yield of extracted nucleic acids. Legionella were not detected in any of the samples when DNA extraction by freeze & thaw was used. Omitting this method and comparing manual protocol with commercial kits, Kappa coefficient was calculated as 0.619 with p < 0.05. Although no meaningful differences were found between the kits, DNA extraction with Bioneer kit displayed a higher sensitivity than classical Qiagen. Showerheads and cold-water taps were the most and least contaminated sources with 55.5 and 9 percent positive samples, respectively. Moreover two positive samples were identified for species by DNA sequencing and submitted to the Gene Bank database with accession Nos. FJ480932 and FJ480933.

Metabolism of the vacuolar pathogen Legionella and implications for virulence.

Science.gov (United States)

Manske, Christian; Hilbi, Hubert

2014-01-01

Legionella pneumophila is a ubiquitous environmental bacterium that thrives in fresh water habitats, either as planktonic form or as part of biofilms. The bacteria also grow intracellularly in free-living protozoa as well as in mammalian alveolar macrophages, thus triggering a potentially fatal pneumonia called "Legionnaires' disease." To establish its intracellular niche termed the "Legionella-containing vacuole" (LCV), L. pneumophila employs a type IV secretion system and translocates ~300 different "effector" proteins into host cells. The pathogen switches between two distinct forms to grow in its extra- or intracellular niches: transmissive bacteria are virulent for phagocytes, and replicative bacteria multiply within their hosts. The switch between these forms is regulated by different metabolic cues that signal conditions favorable for replication or transmission, respectively, causing a tight link between metabolism and virulence of the bacteria. Amino acids represent the prime carbon and energy source of extra- or intracellularly growing L. pneumophila. Yet, the genome sequences of several Legionella spp. as well as transcriptome and proteome data and metabolism studies indicate that the bacteria possess broad catabolic capacities and also utilize carbohydrates such as glucose. Accordingly, L. pneumophila mutant strains lacking catabolic genes show intracellular growth defects, and thus, intracellular metabolism and virulence of the pathogen are intimately connected. In this review we will summarize recent findings on the extra- and intracellular metabolism of L. pneumophila using genetic, biochemical and cellular microbial approaches. Recent progress in this field sheds light on the complex interplay between metabolism, differentiation and virulence of the pathogen.

Prevalence and distribution of Legionella spp in potable water systems in Germany, risk factors associated with contamination, and effectiveness of thermal disinfection.

Science.gov (United States)

Kruse, Eva-Brigitta; Wehner, Arno; Wisplinghoff, Hilmar

2016-04-01

Worldwide, Legionella spp are a common cause of community-acquired pneumonia. Potable water systems are a main reservoir; however, exposure in the community is unknown. Water samples from 718 buildings in Germany were collected. Possible risk factors were prospectively recorded. All samples were tested for Legionella spp using cultural microbiologic methods. Samples were assigned to 1 of 5 levels of contamination. Statistical analysis was performed to determine the influence of risk factors for contamination and, in a subgroup of buildings, for unsuccessful thermal disinfection. In total, 4,482 water samples from 718 different water supply systems were analyzed. In 233 buildings (32.7%), Legionella spp were identified, 148 (63.5%) of which had a medium or higher level of contamination. The most common species was Legionella pneumophila (94%). Contamination was strongly associated with temperature in the circulation, but not with the size of the building, time of the year, or transport time to the laboratory. Thermal disinfection was successful in fewer than half of the buildings. There is relevant exposure to Legionella spp in the community. Water systems are not always up to current technical standards. Although microbiological risk assessment remains a challenge, there is a case for monitoring for Legionella spp outside of hospitals. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Legionella and Mycobacterium Occurrence/Persistence in Homes and Office Buildings

Science.gov (United States)

Legionella and non-tuberculous Mycobacterium species are two of the more important environmental pathogens that cause human health effects. They contribute to the highest economic burden and one of the heaviest disease burdens of all of the waterborne pathogens that pose a risk t...

Physical and chemical parameter correlations with technical and technological characteristics of heating systems and the presence of Legionella spp. in the hot water supply.

Science.gov (United States)

Rakić, Anita; Štambuk-Giljanović, Nives

2016-02-01

The purpose of this study was to evaluate the prevalence of Legionella spp. and compare the quality of hot water between four facilities for accommodation located in Southern Croatia (the Split-Dalmatian County). The research included data collection on the technical and technological characteristics in the period from 2009 to 2012. The survey included a type of construction material for the distribution and internal networks, heating system water heater type, and water consumption. Changes in water quality were monitored by determination of the physical and chemical parameters (temperature, pH, free chlorine residual concentrations, iron, zinc, copper and manganese) in the samples, as well as the presence and concentration of bacteria Legionella spp. The temperature is an important factor for the development of biofilms, and it is in negative correlation with the appearance of Legionella spp. Positive correlations between the Fe and Zn concentrations and Legionella spp. were established, while the inhibitory effect of a higher Cu concentration on the Legionella spp. concentration was proven. Legionella spp. were identified in 38/126 (30.2%) of the water samples from the heating system with zinc-coated pipes, as well as in 78/299 (26.1%) of the samples from systems with plastic pipes. A similar number of Legionella spp. positive samples were established regardless of the type of the water heating system (central or independent). The study confirms the necessity of regular microbial contamination monitoring of the drinking water distribution systems (DWDSs).

Comparison of five methods for extraction of Legionella pneumophila from respiratory specimens.

Science.gov (United States)

Wilson, Deborah; Yen-Lieberman, Belinda; Reischl, Udo; Warshawsky, Ilka; Procop, Gary W

2004-12-01

The efficiencies of five commercially available nucleic acid extraction methods were evaluated for the recovery of a standardized inoculum of Legionella pneumophila in respiratory specimens (sputum and bronchoalveolar lavage [BAL] specimens). The concentrations of Legionella DNA recovered from sputa with the automated MagNA Pure (526,200 CFU/ml) and NucliSens (171,800 CFU/ml) extractors were greater than those recovered with the manual methods (i.e., Roche High Pure kit [133,900 CFU/ml], QIAamp DNA Mini kit [46,380 CFU/ml], and ViralXpress kit [13,635 CFU/ml]). The rank order was the same for extracts from BAL specimens, except that for this specimen type the QIAamp DNA Mini kit recovered more than the Roche High Pure kit.

Riesgos por Legionella, Prevención y Control

OpenAIRE

Martín Romero, Magdalena

2014-01-01

Para un buen control de riesgos por Legionella pneumophila, es importante conocer con detalle esta bacteria, los efectos que causa en el hombre, las principales fuentes de contagio y los medios para evitarlo. Este es el objetivo del presente trabajo. La legionelosis a pesar de ser percibida como una enfermedad infecciosa potencialmente erradicable, se puede controlar con medidas higiénico- sanitarias en las instalaciones implicadas.

Legionella pneumophila secretes a mitochondrial carrier protein during infection.

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Pavel Dolezal

2012-01-01

Full Text Available The Mitochondrial Carrier Family (MCF is a signature group of integral membrane proteins that transport metabolites across the mitochondrial inner membrane in eukaryotes. MCF proteins are characterized by six transmembrane segments that assemble to form a highly-selective channel for metabolite transport. We discovered a novel MCF member, termed Legionellanucleotide carrier Protein (LncP, encoded in the genome of Legionella pneumophila, the causative agent of Legionnaire's disease. LncP was secreted via the bacterial Dot/Icm type IV secretion system into macrophages and assembled in the mitochondrial inner membrane. In a yeast cellular system, LncP induced a dominant-negative phenotype that was rescued by deleting an endogenous ATP carrier. Substrate transport studies on purified LncP reconstituted in liposomes revealed that it catalyzes unidirectional transport and exchange of ATP transport across membranes, thereby supporting a role for LncP as an ATP transporter. A hidden Markov model revealed further MCF proteins in the intracellular pathogens, Legionella longbeachae and Neorickettsia sennetsu, thereby challenging the notion that MCF proteins exist exclusively in eukaryotic organisms.

Legionella contamination in hot water systems of hospitals, nursing homes, hotels, factories and spas in Tuscany-Italy

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Antonella Lo Nostro

2011-03-01

Full Text Available

Abstract Following the report of many cases of Legionnaires’ disease associated with accommodation facilities such as hotels, spas, workplaces, hospitals and nursing homes, we verified if Legionella pneumophila and Legionella spp. were present in some of those structures in Tuscany, in order to estimate the species and serogroups in circulation. Legionella pneumophila serogroup 1 (30.9% was the most frequently isolated species along with serogroups 3 (16.1% and 6 (13.3%; these three serogroups are identified, in literature, as those most responsible for Legionnaires’ disease (LD. Studying all analyzed structures, we found some parts of the water system where Legionella concentration was higher than 103CFU/L, indicated, in Italy, as the maximum admitted concentration value above which a decontamination treatment is necessary when one or more cases of healthcare-acquired Legionnaires’ disease are observed. Moreover disinfection is recommended in any case when counts exceed 104CFU/L.
Consequently, in order to prevent cases of Legionnaires’ disease, a continuous surveillance of the water
systems of all accommodation facilities is necessary, with particular attention to hospitals and nursing
homes where immunocompromised patients lodge, so as to promptly estimate the presence of the pathogen and consequently plan the most suitable intervention activities. We concluded that, in any structure, a continuous surveillance and disinfecting treatment of water systems is necessary. Moreover, after any disinfection treatment the temperature of the hot water flowing in the system must be necessarily maintained near 51°C in order to minimize the probability of recontamination from Legionella and limit the
risk of LD in consumers.

A hospital outbreak of Legionella from a contaminated water supply.

Science.gov (United States)

Tercelj-Zorman, Marjeta; Seljak, Marija; Stare, Janez; Mencinger, Joze; Rakovec, Joze; Rylander, Ragnar; Strle, Franc

2004-03-01

The authors performed a cross-sectional epidemiological survey to investigate the source of a hospital Legionella outbreak originating in contaminated water. Water temperature and air humidity were measured around possible contamination sources. A dead-end pipe was found to contain Legionella pneumophila serogroup 1. All individuals who acquired legionellosis had spent at least 30 min within 2 m of the contamination source. Among staff, 41 of 71 were exposed, and 31 of these fell ill. All 7 patients exposed to the contaminated water acquired legionellosis. None of the 94 bed-ridden patients from the same units developed the disease. An aerosol with 60% relative air humidity was formed near the suspect water faucets, but the humidity fell rapidly farther from the water source, suggesting that desiccation decreased the risk of infection. The healthy personnel and patients closest to the source acquired legionellosis, suggesting that risk was related less to compromised patients than to exposure.

[Sequence-based typing of enviromental Legionella pneumophila isolates in Guangzhou].

Science.gov (United States)

Zhang, Ying; Qu, Pinghua; Zhang, Jian; Chen, Shouyi

2011-03-01

To characterize the genes of Legionella pneumophila isolated from different water source in Guangzhou from 2006 to 2009. To genotype the strains by using sequence-based typing (SBT) scheme. In total 44 L. pneumophila strains were identified by SBT with 7 diversifying genes of flaA, asd, mip, pilE, mompS, proA and neuA. Analysis of the amplicons sequence was taken in the European Working Group for Legionella Infections (EWGLI) international SBT database to obtain the allelic profiles and sequence types (STs). Serogroups were typed by latex agglutination test. Data from SBT revealed a high diversity among the strains and ST01 accounts for 30% (13/ 44). Fifteen new STs were discovered from 20 STs and 2 of them were newly assigned (ST887 and ST888) by EWGLI. SBT Phylogenetic tree was generated by SplitsTree and BURST programs. High diversity and specificity were observed of the L. pneumophila strains in Guangzhou. SBT is useful for L. pneumophila genomic study and epidemiological surveillance.

Comparative and functional genomics of Legionella identified eukaryotic like proteins as key players in host-pathogen interactions

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Laura eGomez-Valero

2011-10-01

Full Text Available Although best known for its ability to cause severe pneumonia in people whose immune defenses are weakened, Legionella pneumophila and Legionella longbeachae are two species of a large genus of bacteria that are ubiquitous in nature, where they parasitize protozoa. Adaptation to the host environment and exploitation of host cell functions are critical for the success of these intracellular pathogens. The establishment and publication of the complete genome sequences of L. pneumophila and L. longbeachae isolates paved the way for major breakthroughs in understanding the biology of these organisms. In this review we present the knowledge gained from the analyses and comparison of the complete genome sequences of different L. pneumophila and L. longbeachae strains. Emphasis is given on putative virulence and Legionella life cycle related functions, such as the identification of an extended array of eukaryotic-like proteins, many of which have been shown to modulate host cell functions to the pathogen's advantage. Surprisingly, many of the eukaryotic domain proteins identified in L. pneumophila as well as many substrates of the Dot/Icm type IV secretion system essential for intracellular replication are different between these two species, although they cause the same disease. Finally, evolutionary aspects regarding the eukaryotic like proteins in Legionella are discussed.

Longitudinale studie naar de aanwezigheid van legionella en amoeben in drinkwaterinstallaties

NARCIS (Netherlands)

Schalk JAC; Redeker S; Docters van Leeuwen AE; Lodder WJ; de Roda Husman AM; LZO; cib

2012-01-01

In Nederland wordt bij prioritaire instellingen met collectieve leidingwaterinstallaties, zoals ziekenhuizen en verzorgingstehuizen, twee keer per jaar gecontroleerd of legionella in de waterleidingen aanwezig is. De concentratie legionellabacteriën in het water moet wettelijk lager zijn dan 100

Sequence analysis of the Legionella micdadei groELS operon

DEFF Research Database (Denmark)

Hindersson, P; Høiby, N; Bangsborg, Jette Marie

1991-01-01

A 2.7 kb DNA fragment encoding the 60 kDa common antigen (CA) and a 13 kDa protein of Legionella micdadei was sequenced. Two open reading frames of 57,677 and 10,456 Da were identified, corresponding to the heat shock proteins GroEL and GroES, respectively. Typical -35, -10, and Shine-Dalgarno heat...

Onderzoek naar aanwezigheid van legionella in biologische luchtwassers bij stallen

NARCIS (Netherlands)

Melse, R.W.; Schalk, J.A.C.; Bartels, A.A.

2015-01-01

In an earlier study it was concluded, based on literature and interviews, that biotrickling filters might be responsible for airborne transmission of Legionella bacteria. Risk factors in this type of systems are recirculating of trickling water with a pH close to neutral and the use of spray nozzles

The Legionella pneumophila Collagen-Like Protein Mediates Sedimentation, Autoaggregation, and Pathogen-Phagocyte Interactions

Science.gov (United States)

Abdel-Nour, Mena; Duncan, Carla; Prashar, Akriti; Rao, Chitong; Ginevra, Christophe; Jarraud, Sophie; Low, Donald E.; Ensminger, Alexander W.; Terebiznik, Mauricio R.

2014-01-01

Although only partially understood, multicellular behavior is relatively common in bacterial pathogens. Bacterial aggregates can resist various host defenses and colonize their environment more efficiently than planktonic cells. For the waterborne pathogen Legionella pneumophila, little is known about the roles of autoaggregation or the parameters which allow cell-cell interactions to occur. Here, we determined the endogenous and exogenous factors sufficient to allow autoaggregation to take place in L. pneumophila. We show that isolates from Legionella species which do not produce the Legionella collagen-like protein (Lcl) are deficient in autoaggregation. Targeted deletion of the Lcl-encoding gene (lpg2644) and the addition of Lcl ligands impair the autoaggregation of L. pneumophila. In addition, Lcl-induced autoaggregation requires divalent cations. Escherichia coli producing surface-exposed Lcl is able to autoaggregate and shows increased biofilm production. We also demonstrate that L. pneumophila infection of Acanthamoeba castellanii and Hartmanella vermiformis is potentiated under conditions which promote Lcl dependent autoaggregation. Overall, this study shows that L. pneumophila is capable of autoaggregating in a process that is mediated by Lcl in a divalent-cation-dependent manner. It also reveals that Lcl potentiates the ability of L. pneumophila to come in contact, attach, and infect amoebae. PMID:24334670

A Preliminary study on the prevalence of Legionella pneumophila infection in Lebanon

International Nuclear Information System (INIS)

Hamze, M.; Mallat, H.; Mokhbat, J.

2009-01-01

After the first outbreak of Legionnaire disease was described for the first time in1976, legionellosis has been increasingly recognized in association with many outbreaks, both community and hospital acquired. This disease remains a model of water borne transmission. In Lebanon, no report has yet been published on the prevalence of Legionella pneumophila infections. This study aims to evaluate the prevalence of legionellosis in hospitalized patients with community acquired pneumonia (CAP) and in patients with nosocomial pneumonia (HAP). The study was conducted between April 2004 and August 2007. Eleven community hospitals participated to this endeavour. Laboratory evaluation was conducted in two centers (Middle East Health Institute, Bsalim, Lebanon and Nini Hospital, Tripoli, Lebanon). Two hundred and forty two urinary samples and ninety one pulmonary samples from 242 patients were analyzed. The age range was 16 to 71 years. Two hundred and fifteen were from community acquired pneumonias and twenty seven were nosocomially acquired in intensive care units. The urinary antigen was investigated in 242 patients; the Binax kit ® was used in this research. In lung secretions of 91 patients, the presence of Legionella pneumophila was searched for using direct immunofluorescence method and culture. Among the 215 urinary samples from patients with CAP, three were positive for Legionella antigen with a prevalence of 1.4 %. Among the 27 patients with HAP, one was positive for Legionella antigen with a prevalence of 3.7%. This preliminary study reveals the fact that legionellosis is indeed present in Lebanon, hence the importance of considering it in the work-up and the management of patients with pneumonia. Hospital laboratories should therefore routin ely search for this pathogen through at least urinary antigen detection. Health authorities should also enforce microbiological regulations concerning water sanitation in hospitals and in the community to prevent the

Detection limits of Legionella pneumophila in environmental samples after co-culture with Acanthamoeba polyphaga

Science.gov (United States)

2013-01-01

Background The efficiency of recovery and the detection limit of Legionella after co-culture with Acanthamoeba polyphaga are not known and so far no investigations have been carried out to determine the efficiency of the recovery of Legionella spp. by co-culture and compare it with that of conventional culturing methods. This study aimed to assess the detection limits of co-culture compared to culture for Legionella pneumophila in compost and air samples. Compost and air samples were spiked with known concentrations of L. pneumophila. Direct culturing and co-culture with amoebae were used in parallel to isolate L. pneumophila and recovery standard curves for both methods were produced for each sample. Results The co-culture proved to be more sensitive than the reference method, detecting 102-103 L. pneumophila cells in 1 g of spiked compost or 1 m3 of spiked air, as compared to 105-106 cells in 1 g of spiked compost and 1 m3 of spiked air. Conclusions Co-culture with amoebae is a useful, sensitive and reliable technique to enrich L. pneumophila in environmental samples that contain only low amounts of bacterial cells. PMID:23442526

Rash, disseminated intravascular coagulation and legionella: Episode 10 and a rewind into the past

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Prashanth M. Thalanayar

2015-01-01

Full Text Available Legionella pneumophila is the most common cause of legionellosis and is one of the organisms causing atypical pneumonia. We report the presentation of disseminated intravascular coagulation (DIC and skin rash in a single case of severe Legionella pneumonia. The unique clinical presentation of a diffuse rash diagnosed as purpura fulminans and the unpredictable variations encountered during the diagnostic work-up of the case make this write-up crucial. This article synthesizes all reported cases of L. pneumonia associated with cutaneous manifestations as well as cases presenting with DIC. Furthermore, this manuscript illustrates the correlation between cutaneous and coagulopathic manifestations, and morbidity and mortality from L. pneumonia.

Occurrence of Legionella in hot water systems of single-family residences in suburbs of two German cities with special reference to solar and district heating.

Science.gov (United States)

Mathys, Werner; Stanke, Juliane; Harmuth, Margarita; Junge-Mathys, Elisabeth

2008-03-01

A total of 452 samples from hot water systems of randomly selected single family residences in the suburbs of two German cities were analysed for the occurrence of Legionella. Technical data were documented using a standardized questionnaire to evaluate possible factors promoting the growth of the bacterium in these small plumbing systems. All houses were supplied with treated groundwater from public water works. Drinking water quality was within the limits specified in the German regulations for drinking water and the water was not chlorinated. The results showed that plumbing systems in private houses that provided hot water from instantaneous water heaters were free of Legionella compared with a prevalence of 12% in houses with storage tanks and recirculating hot water where maximum counts of Legionella reached 100,000 CFU/100ml. The presence of L. pneumophila accounted for 93.9% of all Legionella positive specimens of which 71.8% belonged to serogroup 1. The volume of the storage tank, interrupting circulation for several hours daily and intermittently raising hot water temperatures to >60 degrees C had no influence on Legionella counts. Plumbing systems with copper pipes were more frequently contaminated than those made of synthetic materials or galvanized steel. An inhibitory effect due to copper was not present. Newly constructed systems (water preparation had a marked influence. More than 50% of all houses using district heating systems were colonized by Legionella. Their significantly lower hot water temperature is thought to be the key factor leading to intensified growth of Legionella. Although hot water systems using solar energy to supplement conventional hot water supplies operate at temperatures 3 degrees C lower than conventional systems, this technique does not seem to promote proliferation of the bacterium. Our data show convincingly that the temperature of the hot water is probably the most important or perhaps the only determinant factor for

Brote epidémico de neumonías por Legionella pneumophila en niños cubanos

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Roberto Razón Behar

2002-09-01

Full Text Available La Legionella pneumophila es uno de los patógenos responsable de neumonías atípicas, a través de la inhalación de aerosoles o aspiración de líquidos infectados. Se detectó un brote epidémico de neumonías por Legionella, originado por la aspiración de agua contaminada de una piscina en un grupo de niños cubanos. El agente causal se identificó en 5 de 9 pacientes, por la técnica de inmunofluorescencia indirecta en muestras de sueros pareados. Los síntomas y signos más frecuentes fueron malestar general, anorexia, astenia, fiebre persistente de 39 °C a 40 °C (103 °F a 105 °F, mialgias, cefaleas, náuseas, vómitos, dolor abdominal, diarreas, tos húmeda, dolor torácico y polipnea. Durante el desarrollo de la enfermedad, el tratamiento antibiótico fue empírico (incluyendo los macrólidos, por no tener confirmado el diagnóstico. Todos los pacientes evolucionaron satisfactoriamente. Se reportó un brote epidémico de neumonías por Legionella en niños por primera vez en Cuba, lo cual tiene importancia clínica y epidemiológica.The legionella pneumophila is one of the pathogens responsible for atypic pneumonias by the inhalation of aerosols or aspiration of infected liquids. An epidemic outbreak of pneumonias caused by Legionella was detected among a group of Cuban children. It was originated by the aspiration of contaminated water in a swimming pool. The causal agent was identified in 5 of 9 patients by using the indirect immunofluorescence technique in samples of matched sera. The most frequent symptoms and signs were malaise, anorexia, asthenia, persistent fever from 39°C to 40°C (103° F to 105° F, myalgias, headache, nauseas, vomits, abdominal pain, diarrheas, moist cough, thoracic pain and polypnoea. The antibiotic treatment was empiric (including the macrolides during the development of the disease, since the diagnosis was not confirmed. The patients’ evolution was satisfactory. An epidemic outbreak of pneumonias

Discovery of Ubiquitin Deamidases in the Pathogenic Arsenal of Legionella pneumophila

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Dylan Valleau

2018-04-01

Full Text Available Summary: Legionella pneumophila translocates the largest known arsenal of over 330 pathogenic factors, called “effectors,” into host cells during infection, enabling L. pneumophila to establish a replicative niche inside diverse amebas and human macrophages. Here, we reveal that the L. pneumophila effectors MavC (Lpg2147 and MvcA (Lpg2148 are structural homologs of cycle inhibiting factor (Cif effectors and that the adjacent gene, lpg2149, produces a protein that directly inhibits their activity. In contrast to canonical Cifs, both MavC and MvcA contain an insertion domain and deamidate the residue Gln40 of ubiquitin but not Gln40 of NEDD8. MavC and MvcA are functionally diverse, with only MavC interacting with the human E2-conjugating enzyme UBE2N (Ubc13. MavC deamidates the UBE2N∼Ub conjugate, disrupting Lys63 ubiquitination and dampening NF-κB signaling. Combined, our data reveal a molecular mechanism of host manipulation by pathogenic bacteria and highlight the complex regulatory mechanisms integral to L. pneumophila’s pathogenic strategy. : Legionella pneumophila, possessing the largest known arsenal of effectors, continues to reveal unique approaches to host cell control. Valleau et al. decrypt the functions of a trio of effectors, discovering a pair of ubiquitin-specific deamidases, their regulation by a neighboring dual-specificity protein inhibitor, and a mechanism of NF-κB suppression. Keywords: pathogen-host interaction, ubiquitination, Legionella, UBE2N/Ubc13, NF-κB signaling, Type IV secretion system, effectors, metaeffector, cycle inhibiting factor

Necessity and effect of combating Legionella pneumophila in municipal shower systems.

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Ragnhild Wiik

Full Text Available The objective was to obtain research-based, holistic knowledge about necessity and effect of practiced measures against L. pneumophila in municipal shower systems in Stavanger, Norway. The effects of hot water treatment and membrane-filtering were investigated and compared to no intervention at all. The studies were done under real-world conditions. Additionally, a surveillance pilot study of municipal showers in Stavanger was performed. The validity of high total plate count (TPC as an indication of L. pneumophila was evaluated. A simplified method, named "dripping method", for detection and quantification of L. pneumophila was developed. The sensitivity of the dripping method is 5 colony-forming units of L. pneumophila/ml. The transference of L. pneumophila from shower water to aerosols was studied. Interviews and observational studies among the stakeholders were done in order to identify patterns of communication and behavior in a Legionella risk perspective. No substantial effects of the measures against L. pneumophila were demonstrated, except for a distally placed membrane filter. No significant positive correlation between TPC and L. pneumophila concentrations were found. L. pneumophila serogroup 2-14 was demonstrated in 21% of the 29 buildings tested in the surveillance pilot. Relatively few cells of L. pneumophila were transferred from shower water to aerosols. Anxiety appeared as the major driving force in the risk governance of Legionella. In conclusion, the risk of acquiring Legionnaires' disease from municipal shower systems is evaluated as low and uncertain. By eliminating ineffective approaches, targeted Legionella risk governance can be practiced. Risk management by surveillance is evaluated as appropriate.

Detection of Legionella by quantitative-polymerase chain reaction (qPCR) for monitoring and risk assessment

DEFF Research Database (Denmark)

Krøjgaard, Louise H.; Krogfelt, Karen A.; Albrechtsen, Hans-Jorgen

2011-01-01

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...

Legionella species and serogroups in Malaysian water cooling towers: identification by latex agglutination and PCR-DNA sequencing of isolates.

Science.gov (United States)

Yong, Stacey Foong Yee; Goh, Fen-Ning; Ngeow, Yun Fong

2010-03-01

In this study, we investigated the distribution of Legionella species in water cooling towers located in different parts of Malaysia to obtain information that may inform public health policies for the prevention of legionellosis. A total of 20 water samples were collected from 11 cooling towers located in three different states in east, west and south Malaysia. The samples were concentrated by filtration and treated with an acid buffer before plating on to BCYE agar. Legionella viable counts in these samples ranged from 100 to 2,000 CFU ml(-1); 28 isolates from the 24 samples were examined by latex agglutination as well as 16S rRNA and rpoB PCR-DNA sequencing. These isolates were identified as Legionella pneumophila serogroup 1 (35.7%), L. pneumophila serogroup 2-14 (39%), L. pneumophila non-groupable (10.7%), L. busanensis, L. gormanii, L. anisa and L. gresilensis. L. pneumophila was clearly the predominant species at all sampling sites. Repeat sampling from the same cooling tower and testing different colonies from the same water sample showed concurrent colonization by different serogroups and different species of Legionella in some of the cooling towers.

Two Related Occupational Cases of Legionella longbeachae Infection, Quebec, Canada

Science.gov (United States)

Lajoie, Élisabeth; Lord, Judith; Lalancette, Cindy; Marchand, Geneviève; Levac, Éric; Lemieux, Marc-André; Hudson, Patricia; Lajoie, Louise

2016-01-01

Two patients with no exposure to gardening compost had related Legionella longbeachae infections in Quebec, Canada. Epidemiologic investigation and laboratory results from patient and soil samples identified the patients’ workplace, a metal recycling plant, as the likely source of infection, indicating a need to suspect occupational exposure for L. longbeachae infections. PMID:27314946

Isolation of Legionella pneumophila from hospital cooling towers in Johor, Malaysia.

Science.gov (United States)

Abdul Samad, B H; Suhaili, M R; Baba, N; Rajasekaran, G

2004-08-01

Water-based cooling towers and their water supply at two hospitals in Johor were surveyed for the presence Legionella pneumophila. L. pneumophila were grown from 19 (76%) out of 25 collected water samples. One hospital cooling tower was contaminated with L. pneumophila serogroup 1.

Multiplication of Legionella pneumophila in unsterilized tap water.

OpenAIRE

Yee, R B; Wadowsky, R M

1982-01-01

Naturally occurring Legionella pneumophila, an environmental isolate which had not been grown on artificial medium, was tested for the ability to multiply in tap water. A showerhead containing L. pneumophila and non-Legionellaceae bacteria was immersed in nonsterile tap water supplying this fixture. Also L. pneumophila and non-Legionellaceae bacteria were sedimented from tap water from a surgical intensive care unit. This bacterial suspension was inoculated into tap water from our laboratory....

Detection of Legionella bozemanae, a New Cause of Septic Arthritis, by PCR Followed by Specific Culture

DEFF Research Database (Denmark)

Just, Søren Andreas; Knudsen, John Bonde; Uldum, Søren Anker

2012-01-01

Legionella bozemanae is a rare isolate in clinical specimens. We describe a case of joint infection due to L. bozemanae in an immunocompromised patient with dermatomyositis. Without the use of PCR screening or culture on specialized medium, the organism would not have been detected.......Legionella bozemanae is a rare isolate in clinical specimens. We describe a case of joint infection due to L. bozemanae in an immunocompromised patient with dermatomyositis. Without the use of PCR screening or culture on specialized medium, the organism would not have been detected....

Legionella pneumophila: risk assessment and strategy for the prevention and control of nosocomial infections

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Salvo Torrisi

2012-06-01

Full Text Available The term “Legionellosis” includes all forms of disease caused by microorganisms of the genus Legionella; it may manifest as a flu-like shape (Pontiac fever, or with severe pneumonia with high mortality (Legionnaires Disease. The causative agent was Legionella pneumophila in the literature although other strains of the genus Legionella are classified as pathogens, mode of transmission is through inhalation of aerosol particles produced by hot water or air conditioning systems: for this reason in community settings and nosocomial L. pneumophila represents a serious public health problem. In the light of epidemiological data since the year 2000 the Italian State has issued a series of provisions laws concerning the prevention and control of nosocomial Legionellosis environment and community.The present work aims to evaluate the presence of Legionella species and L. pneumophila comparing the different approaches proposed by the Guidelines of the regions of Lombardy and Piedmont in terms of assessment and prevention of risk “Legionellosis” in the field of nosocomial infection. The analytical methods used are those provided by the Regional Guidelines: the official method in the second CSR April 4 Method 2000 and UNI EN ISO 11731-1: 2008. Checks have been performed on equipment for the comparison of cold water, hot water and air conditioning in nursing homes, retirement homes and hospitals.The results obtained show that the method CSR April 4, 2000 restricts the search to L. pneumophila permitting, than the method EN ISO 11731-1: 2008, to carry out a risk assessment well targeted to the actual pathogen.The culture method for the detection of L. pneumophila allows you to not only prevention, but also to implement a series of targeted interventions following the directions of the legislation.

Characterization of an acetyltransferase that detoxifies aromatic chemicals in Legionella pneumophila

DEFF Research Database (Denmark)

Kubiak, Xavier Jean Philippe; Dervins-Ravault, Delphine; Pluvinage, Benjamin

2012-01-01

Legionella pneumophila is an opportunistic pathogen and the causative agent of Legionnaires' disease. Despite being exposed to many chemical compounds in its natural and man-made habitats (natural aquatic biotopes and man-made water systems), L. pneumophila is able to adapt and survive in these e...

Exploring Anti-Bacterial Compounds against Intracellular Legionella

Science.gov (United States)

Harrison, Christopher F.; Kicka, Sébastien; Trofimov, Valentin; Berschl, Kathrin; Ouertatani-Sakouhi, Hajer; Ackermann, Nikolaus; Hedberg, Christian; Cosson, Pierre; Soldati, Thierry; Hilbi, Hubert

2013-01-01

Legionella pneumophila is a ubiquitous fresh-water bacterium which reproduces within its erstwhile predators, environmental amoeba, by subverting the normal pathway of phagocytosis and degradation. The molecular mechanisms which confer resistance to amoeba are apparently conserved and also allow replication within macrophages. Thus, L. pneumophila can act as an ‘accidental’ human pathogen and cause a severe pneumonia known as Legionnaires’ disease. The intracellular localisation of L. pneumophila protects it from some antibiotics, and this fact must be taken into account to develop new anti-bacterial compounds. In addition, the intracellular lifestyle of L. pneumophila may render the bacteria susceptible to compounds diminishing bacterial virulence and decreasing intracellular survival and replication of this pathogen. The development of a single infection cycle intracellular replication assay using GFP-producing L. pneumophila and Acanthamoeba castellanii amoeba is reported here. This fluorescence-based assay allows for continuous monitoring of intracellular replication rates, revealing the effect of bacterial gene deletions or drug treatment. To examine how perturbations of the host cell affect L. pneumophila replication, several known host-targeting compounds were tested, including modulators of cytoskeletal dynamics, vesicle scission and Ras GTPase localisation. Our results reveal a hitherto unrealized potential antibiotic property of the β-lactone-based Ras depalmitoylation inhibitor palmostatin M, but not the closely related inhibitor palmostatin B. Further characterisation indicated that this compound caused specific growth inhibition of Legionella and Mycobacterium species, suggesting that it may act on a common bacterial target. PMID:24058631

Exploring anti-bacterial compounds against intracellular Legionella.

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Christopher F Harrison

Full Text Available Legionella pneumophila is a ubiquitous fresh-water bacterium which reproduces within its erstwhile predators, environmental amoeba, by subverting the normal pathway of phagocytosis and degradation. The molecular mechanisms which confer resistance to amoeba are apparently conserved and also allow replication within macrophages. Thus, L. pneumophila can act as an 'accidental' human pathogen and cause a severe pneumonia known as Legionnaires' disease. The intracellular localisation of L. pneumophila protects it from some antibiotics, and this fact must be taken into account to develop new anti-bacterial compounds. In addition, the intracellular lifestyle of L. pneumophila may render the bacteria susceptible to compounds diminishing bacterial virulence and decreasing intracellular survival and replication of this pathogen. The development of a single infection cycle intracellular replication assay using GFP-producing L. pneumophila and Acanthamoebacastellanii amoeba is reported here. This fluorescence-based assay allows for continuous monitoring of intracellular replication rates, revealing the effect of bacterial gene deletions or drug treatment. To examine how perturbations of the host cell affect L. pneumophila replication, several known host-targeting compounds were tested, including modulators of cytoskeletal dynamics, vesicle scission and Ras GTPase localisation. Our results reveal a hitherto unrealized potential antibiotic property of the β-lactone-based Ras depalmitoylation inhibitor palmostatin M, but not the closely related inhibitor palmostatin B. Further characterisation indicated that this compound caused specific growth inhibition of Legionella and Mycobacterium species, suggesting that it may act on a common bacterial target.

Accuracy and precision of Legionella isolation by US laboratories in the ELITE program pilot study.

Science.gov (United States)

Lucas, Claressa E; Taylor, Thomas H; Fields, Barry S

2011-10-01

A pilot study for the Environmental Legionella Isolation Techniques Evaluation (ELITE) Program, a proficiency testing scheme for US laboratories that culture Legionella from environmental samples, was conducted September 1, 2008 through March 31, 2009. Participants (n=20) processed panels consisting of six sample types: pure and mixed positive, pure and mixed negative, pure and mixed variable. The majority (93%) of all samples (n=286) were correctly characterized, with 88.5% of samples positive for Legionella and 100% of negative samples identified correctly. Variable samples were incorrectly identified as negative in 36.9% of reports. For all samples reported positive (n=128), participants underestimated the cfu/ml by a mean of 1.25 logs with standard deviation of 0.78 logs, standard error of 0.07 logs, and a range of 3.57 logs compared to the CDC re-test value. Centering results around the interlaboratory mean yielded a standard deviation of 0.65 logs, standard error of 0.06 logs, and a range of 3.22 logs. Sampling protocol, treatment regimen, culture procedure, and laboratory experience did not significantly affect the accuracy or precision of reported concentrations. Qualitative and quantitative results from the ELITE pilot study were similar to reports from a corresponding proficiency testing scheme available in the European Union, indicating these results are probably valid for most environmental laboratories worldwide. The large enumeration error observed suggests that the need for remediation of a water system should not be determined solely by the concentration of Legionella observed in a sample since that value is likely to underestimate the true level of contamination. Published by Elsevier Ltd.

Structural and functional studies of a Cu+-ATPase from Legionella pneumophila

DEFF Research Database (Denmark)

Mattle, Daniel

During his studies, Daniel Mattle explored the copper(I) export mechanism of a P-type Cu+ ATPase from Legionella pneumophila – a homologue to the human Cu+ ATPases. Cu+ ATPases are responsible for the homeostatic control of the physiological relevant – but toxic – copper(I) cations. To assess...

The Sensitization of Legionella pneumophila to Some Antibiotics by Reserpine and Anti-Legionella Effects of Different Benzofuranone Derivatives

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Mohsen Khaleghi

2015-10-01

Full Text Available Background: Legionella pneumophila is  a  dangerous pathogenic bacterium can cause serious infectious diseases especially in hospitalized immuno-compromised patients. This bacterium is shown to be resistant against different antibiotics. Resistance against a wide range of antibiotics is usually mediated by efflux pump in bacteria. Efflux pumps are proteinaceous transporters localized in the cytoplasmic membrane of all kinds of cells which excreted antibiotics outside the cells. However, synthesis of new anti-Legionella compounds or selection of resistant modulating agents are useful strategy to combat with L. pneumophilain the future.Methods: In this study the antibacterial activity of some benzofuranone derivatives have been investigated by disk diffusion method against L. pneumophila. Also the sensitivity of this test strain was evaluated against 19 antibiotics and the combination effect of reserpine at a sub-inhibitory concentration was further studied with these antibiotics using disk diffusion method with some modifications.Conclusion: Among the different synthetic compounds which were tested against L. pneumophila, the most antibacterial activity was observed for compounds 1j and 1m which contain hydroxyl and methoxy groups on the C-6 and C-7 positionsagainst L. pneumophila. To evaluate whether efflux pumps are active in L. pneumophila or not an efflux inhibitor (reserpine was tested in combination of different antibiotics against this test strain. Reserpine significantly enhanced the antibacterial activities of kanamycin, nitrofurantoin, co-trimoxazole, erythromycin, ofloxacillin, gentamycin, rifampin, ciprofloxacin, nalidixic acid, minocycline, tobramycin, and amikacin against L. pneumophila which shows the resistances to these antibiotics are mediated by efflux system in this bacterium.

Tracking Legionella in air generated from a biological treatment plant: a case study of the outbreak of legionellosis in Norway

Science.gov (United States)

Blatny, Janet M.; Olsen, Jaran S.; Andreassen, Øyvind; Waagen, Viggo; Reif, Bjørn Anders P.

2011-05-01

Two outbreaks of legionellosis occurred in the Sarpsborg/Fredrikstad region southeast of Norway in 2005 and 2008 where more than 60 exposed individuals were infected and 10 case patients died. The air scrubber at Borregaard, a wood-based chemical factory, was identified as the outbreak source. High concentration levels of Legionella species, including the etiological agent L. pneumophila SG1 was found in the aeration ponds, which belongs to Borregaard's biological treatment plant. Results showed that these ponds were able to generate Legionella-containing aerosols that were transported by the wind as such aerosols were measured up to 200 meters downwind of the pond. Our studies did not detect L. pneumophila SG1 isolates, only L. pneumophila SG4 during the air sampling measurement campaign. Furthermore, the operational conditions of the air scrubber proved to be harsh for Legionella growth as the outbreak L. pneumophila strains were not able to grow at 45ºC and pH8 (conditions during the outbreaks). These results, together, lead us to suggest that the aeration pond should be regarded as the primary amplifier and disseminator of Legionella and L. pneumophila and thereby most likely being the outbreak source.

Legionella longbeachae detected in an industrial cooling tower linked to a legionellosis outbreak, New Zealand, 2015; possible waterborne transmission?

Science.gov (United States)

Thornley, C N; Harte, D J; Weir, R P; Allen, L J; Knightbridge, K J; Wood, P R T

2017-08-01

A legionellosis outbreak at an industrial site was investigated to identify and control the source. Cases were identified from disease notifications, workplace illness records, and from clinicians. Cases were interviewed for symptoms and risk factors and tested for legionellosis. Implicated environmental sources were sampled and tested for legionella. We identified six cases with Legionnaires' disease and seven with Pontiac fever; all had been exposed to aerosols from the cooling towers on the site. Nine cases had evidence of infection with either Legionella pneumophila serogroup (sg) 1 or Legionella longbeachae sg1; these organisms were also isolated from the cooling towers. There was 100% DNA sequence homology between cooling tower and clinical isolates of L. pneumophila sg1 using sequence-based typing analysis; no clinical L. longbeachae isolates were available to compare with environmental isolates. Routine monitoring of the towers prior to the outbreak failed to detect any legionella. Data from this outbreak indicate that L. pneumophila sg1 transmission occurred from the cooling towers; in addition, L. longbeachae transmission was suggested but remains unproven. L. longbeachae detection in cooling towers has not been previously reported in association with legionellosis outbreaks. Waterborne transmission should not be discounted in investigations for the source of L. longbeachae infection.

Assessment of intercentre reproducibility and epidemiological concordance of Legionella pneumophila serogroup 1 genotyping by amplified fragment length polymorphism analysis

DEFF Research Database (Denmark)

Fry, N K; Bangsborg, Jette Marie; Bernander, S

2000-01-01

The aims of this work were to assess (i) the intercentre reproducibility and epidemiological concordance of amplified fragment length polymorphism analysis for epidemiological typing of Legionella pneumophila serogroup 1, and (ii) the suitability of the method for standardisation and implementation...... by members of the European Working Group on Legionella Infections. Fifty coded isolates comprising two panels of well-characterised strains, a "reproducibility" panel (n=20) and an "epidemiologically related" panel (n=30), were sent to 13 centres in 12 European countries. Analysis was undertaken in each...... using gel analysis software yielded R=1.00 and E=1.00, with 12, 13 or 14 types. This method can be used as a simple, rapid screening tool for epidemiological typing of isolates of Legionella pneumophila serogroup 1. Results demonstrate that the method can be highly reproducible (R=1...

Atypical Pneumonia: Updates on Legionella, Chlamydophila, and Mycoplasma Pneumonia.

Science.gov (United States)

Sharma, Lokesh; Losier, Ashley; Tolbert, Thomas; Dela Cruz, Charles S; Marion, Chad R

2017-03-01

Community-acquired pneumonia (CAP) has multiple causes and is associated with illness that requires admission to the hospital and mortality. The causes of atypical CAP include Legionella species, Chlamydophila, and Mycoplasma. Atypical CAP remains a diagnostic challenge and, therefore, likely is undertreated. This article reviews the advancements in the evaluation and treatment of patients and discusses current conflicts and controversies of atypical CAP. Copyright © 2016 Elsevier Inc. All rights reserved.

Legionella detection in oropharyngeal aspirates of transplant patients prior to surgery

Czech Academy of Sciences Publication Activity Database

Jarešová, M.; Hložánek, I.; Stříž, I.; Petříčková, Kateřina; Kocmoud, Z.

2006-01-01

Roč. 25, - (2006), s. 63-64 ISSN 0934-9723 R&D Projects: GA ČR GA310/01/0095; GA MŠk LN00B030 Institutional research plan: CEZ:AV0Z50200510 Keywords : legionella * organ transplantation * pcr Subject RIV: EE - Microbiology, Virology Impact factor: 2.330, year: 2006

Fatal coinfection with Legionella pneumophila serogroup 8 and Aspergillus fumigatus.

Science.gov (United States)

Guillouzouic, Aurélie; Bemer, Pascale; Gay-Andrieu, Françoise; Bretonnière, Cédric; Lepelletier, Didier; Mahé, Pierre-Joachim; Villers, Daniel; Jarraud, Sophie; Reynaud, Alain; Corvec, Stéphane

2008-02-01

Legionella pneumophila is an important cause of community-acquired and nosocomial pneumonia. We report on a patient who simultaneously developed L. pneumophila serogroup 8 pneumonia and Aspergillus fumigatus lung abscesses. Despite appropriate treatments, Aspergillus disease progressed with metastasis. Coinfections caused by L. pneumophila and A. fumigatus remain exceptional. In apparently immunocompetent patients, corticosteroid therapy is a key risk factor for aspergillosis.

Legionella pneumophila infection of Drosophila S2 cells induces only minor changes in mitochondrial dynamics.

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Elizabeth Wen Sun

Full Text Available During infection of cells by Legionella pneumophila, the bacterium secretes a large number of effector proteins into the host cell cytoplasm, allowing it to alter many cellular processes and make the vacuole and the host cell into more hospitable environments for bacterial replication. One major change induced by infection is the recruitment of ER-derived vesicles to the surface of the vacuole, where they fuse with the vacuole membrane and prevent it from becoming an acidified, degradative compartment. However, the recruitment of mitochondria to the region of the vacuole has also been suggested by ultrastructural studies. In order to test this idea in a controlled and quantitative experimental system, and to lay the groundwork for a genome-wide screen for factors involved in mitochondrial recruitment, we examined the behavior of mitochondria during the early stages of Legionella pneumophila infection of Drosophila S2 cells. We found that the density of mitochondria near vacuoles formed by infection with wild type Legionella was not different from that found in dotA(- mutant-infected cells during the first 4 hours after infection. We then examined 4 parameters of mitochondrial motility in infected cells: velocity of movement, duty cycle of movement, directional persistence and net direction. In the 4 hours following infection, most of these measures were indistinguishable between wild type and dotA(-.infection. However, wild type Legionella did induce a modest shift in the velocity distribution toward faster movement compared dotA(- infection, and a small downward shift in the duty cycle distribution. In addition, wild type infection produced mitochondrial movement that was biased in the direction of the bacterial vacuole relative to dotA-, although not enough to cause a significant accumulation within 10 um of the vacuole. We conclude that in this host cell, mitochondria are not strongly recruited to the vacuole, nor is their motility

Hijacking of the Host Ubiquitin Network by Legionella pneumophila

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Jiazhang Qiu

2017-12-01

Full Text Available Protein ubiquitination is critical for regulation of numerous eukaryotic cellular processes such as protein homeostasis, cell cycle progression, immune response, DNA repair, and vesicular trafficking. Ubiquitination often leads to the alteration of protein stability, subcellular localization, or interaction with other proteins. Given the importance of ubiquitination in the regulation of host immunity, it is not surprising that many infectious agents have evolved strategies to interfere with the ubiquitination network with sophisticated mechanisms such as functional mimicry. The facultative intracellular pathogen Legionella pneumophila is the causative agent of Legionnaires' disease. L. pneumophila is phagocytosed by macrophages and is able to replicate within a niche called Legionella-containing vacuole (LCV. The biogenesis of LCV is dependent upon the Dot/Icm type IV secretion system which delivers more than 330 effector proteins into host cytosol. The optimal intracellular replication of L. pneumophila requires the host ubiquitin-proteasome system. Furthermore, membranes of the bacterial phagosome are enriched with ubiquitinated proteins in a way that requires its Dot/Icm type IV secretion system, suggesting the involvement of effectors in the manipulation of the host ubiquitination machinery. Here we summarize recent advances in our understanding of mechanisms exploited by L. pneumophila effector proteins to hijack the host ubiquitination pathway.

DIAGNOSTICO SEROLÓGICO DE NEUMONIA POR LEGIONELLA. INCIDENCIA EN UN PERIODO DE TRES AÑOS EN EL AREA SANITARIA OESTE DE VALLADOLID

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M.A. Mazón

2005-12-01

Full Text Available ABSTRACT:Introduction: Legionella species are Gram-negative bacilli. There are described for the first time in 70's associated to the Legionnarie's disease. Presently, more than 34 species of Legionella have been identified, 20 of which have been found pathogenic for the man. The clinical manifestations of Legionella infections are primarily respiratory. The most common presentation is acute pneumonia, which varies in severity from mild illness that does not require hospitalization to fatal pneumonia.Material and Methods: The results corresponding to the determination of antibodies to L. pneumophila (Gull Laboratories by indirect inmunofluorescence (IFI have been analysed and reviewed. This conventional inmunofluorescent test measures antibodies versus a pool of 1, 2, 3, 4, 5, 6, 7 and 8 serogroups. During the 3 years of surveillance period 1249 determinations by IFI were performed in our Hospital. The determination of urinary antigen of Legionella for the qualitative detection of the antigen to L. pneumophila serogroup 1 was made in almost all studied samples by using a fast inmunochromatographical technique (Binax NOW.Results and Discussion: Of the 1249 cases of nosocomial pneumonia (diagnosed by a positive result of IFI Legionella test recorded during the period, 12 cases met the criteria for infection with L. pneumophila serogroup 1. Later, clinical histories were reviewed and it was observed that the ages of the confirmed cases oscillated between the 40 and 87 years, with an average of age of 40, of which 8 were men and 4 women. From the point of view of factors of risk, 6 patients were smokers. Clinically, the displayed symptoms were general malaise, fever high and pattern of pulmonary infiltration in all the cases, migraine in 3 cases, diarrhoea in 5 cases and arthralgias and muscle aches in 3 cases. The analytical parameters in common were high VSG and leukocytosis. Hyponatremia 1/1024, what it demonstrates a clear seroconversion. In

Growth of legionella and other heterotrophic bacteria in a circulating cooling water system exposed to ultraviolet irradiation

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Kusnetsov, J.M.; Miettinen, I.T.; Martikainen, P.J.; Keskitalo, P.J.; Ahonen, H.E.; Tulkki, A.I.

1994-01-01

The effect of ultraviolet irradiation on the growth and occurrence of legionella and other heterotrophic bacteria in a circulating cooling water system was studied. Water of the reservoir was circulated once in 28 h through a side-stream open channel u.v. radiator consisting of two lamps. Viable counts of legionellas and heterotrophic bacteria in water immediately after the u.v. treatment were 0-12 and 0.7-1.2% of those in the reservoir, respectively. U.v. irradiation increased the concentration of easily assimilable organic carbon. In the u.v. irradiated water samples incubated in the laboratory the viable counts of heterotropic bacteria reached the counts in reservoir water within 5 d. The increase in viable counts was mainly due to reactivation of bacterial cells damaged by u.v. light, not because of bacterial multiplication. Despite u.v. irradiation the bacterial numbers in the reservoir water, including legionellas, did not decrease during the experimental period of 33 d. The main growth of bacteria in the reservoir occurred in biofilm and sediment, which were never exposed to u.v. irradiation. (Author)

Field evaluation of a new point-of-use faucet filter for preventing exposure to Legionella and other waterborne pathogens in health care facilities.

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Baron, Julianne L; Peters, Tammy; Shafer, Raymond; MacMurray, Brian; Stout, Janet E

2014-11-01

Opportunistic waterborne pathogens (eg, Legionella, Pseudomonas) may persist in water distribution systems despite municipal chlorination and secondary disinfection and can cause health care-acquired infections. Point-of-use (POU) filtration can limit exposure to pathogens; however, their short maximum lifetime and membrane clogging have limited their use. A new faucet filter rated at 62 days was evaluated at a cancer center in Northwestern Pennsylvania. Five sinks were equipped with filters, and 5 sinks served as controls. Hot water was collected weekly for 17 weeks and cultured for Legionella, Pseudomonas, and total bacteria. Legionella was removed from all filtered samples for 12 weeks. One colony was recovered from 1 site at 13 weeks; however, subsequent tests were negative through 17 weeks of testing. Total bacteria were excluded for the first 2 weeks, followed by an average of 1.86 log reduction in total bacteria compared with controls. No Pseudomonas was recovered from filtered or control faucets. This next generation faucet filter eliminated Legionella beyond the 62 day manufacturers' recommended maximum duration of use. These new POU filters will require fewer change-outs than standard filters and could be a cost-effective method for preventing exposure to Legionella and other opportunistic waterborne pathogens in hospitals with high-risk patients. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Detection of Legionella, L. pneumophila and Mycobacterium avium complex (MAC) along potable water distribution pipelines.

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Whiley, Harriet; Keegan, Alexandra; Fallowfield, Howard; Bentham, Richard

2014-07-18

Inhalation of potable water presents a potential route of exposure to opportunistic pathogens and hence warrants significant public health concern. This study used qPCR to detect opportunistic pathogens Legionella spp., L. pneumophila and MAC at multiple points along two potable water distribution pipelines. One used chlorine disinfection and the other chloramine disinfection. Samples were collected four times over the year to provide seasonal variation and the chlorine or chloramine residual was measured during collection. Legionella spp., L. pneumophila and MAC were detected in both distribution systems throughout the year and were all detected at a maximum concentration of 103 copies/mL in the chlorine disinfected system and 106, 103 and 104 copies/mL respectively in the chloramine disinfected system. The concentrations of these opportunistic pathogens were primarily controlled throughout the distribution network through the maintenance of disinfection residuals. At a dead-end and when the disinfection residual was not maintained significant (p pipeline and sampling period. Total coliforms were not present in any water sample collected. This study demonstrates the ability of Legionella spp., L. pneumophila and MAC to survive the potable water disinfection process and highlights the need for greater measures to control these organisms along the distribution pipeline and at point of use.

Radiographic analysis of the course of Legionella pneumonia

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Lo, C.D.; MacKeen, A.D.; Campbell, D.R.; Fraser, D.B.; Marrie, T.J. (Dalhousie Univ., Halifax, Nova Scotia (Canada))

1983-06-01

The radiographic findings in the acute phase of Legionella pneumonia are generally non-specific and have been previously documented. A retrospective assessment of 12 patients with this bacterial pneumonia revealed that resolution of the radiographic findings was prolonged in five. The predominant feature in such patients is the transient finding of interstitial consolidation following the air-space consolidation, not unlike that of Mycoplasma or viral pneumonia. Eventual return to normal was evident in three patients and residual parenchymal fibrosis was noted in two patients.

Radiographic analysis of the course of Legionella pneumonia

International Nuclear Information System (INIS)

Lo, C.D.; MacKeen, A.D.; Campbell, D.R.; Fraser, D.B.; Marrie, T.J.

1983-01-01

The radiographic findings in the acute phase of Legionella pneumonia are generally non-specific and have been previously documented. A retrospective assessment of 12 patients with this bacterial pneumonia revealed that resolution of the radiographic findings was prolonged in five. The predominant feature in such patients is the transient finding of interstitial consolidation following the air-space consolidation, not unlike that of Mycoplasma or viral pneumonia. Eventual return to normal was evident in three patients and residual parenchymal fibrosis was noted in two patients

Different distribution patterns of ten virulence genes in Legionella reference strains and strains isolated from environmental water and patients.

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Zhan, Xiao-Yong; Hu, Chao-Hui; Zhu, Qing-Yi

2016-04-01

Virulence genes are distinct regions of DNA which are present in the genome of pathogenic bacteria and absent in nonpathogenic strains of the same or related species. Virulence genes are frequently associated with bacterial pathogenicity in genus Legionella. In the present study, an assay was performed to detect ten virulence genes, including iraA, iraB, lvrA, lvrB, lvhD, cpxR, cpxA, dotA, icmC and icmD in different pathogenicity islands of 47 Legionella reference strains, 235 environmental strains isolated from water, and 4 clinical strains isolated from the lung tissue of pneumonia patients. The distribution frequencies of these genes in reference or/and environmental L. pneumophila strains were much higher than those in reference non-L. pneumophila or/and environmental non-L. pneumophila strains, respectively. L. pneumophila clinical strains also maintained higher frequencies of these genes compared to four other types of Legionella strains. Distribution frequencies of these genes in reference L. pneumophila strains were similar to those in environmental L. pneumophila strains. In contrast, environmental non-L. pneumophila maintained higher frequencies of these genes compared to those found in reference non-L. pneumophila strains. This study illustrates the association of virulence genes with Legionella pathogenicity and reveals the possible virulence evolution of non-L. pneumophia strains isolated from environmental water.

Travel-associated infections caused by unusual serogroups of Legionella pneumophila identified using Legionella BIOCHIP slides in Turkey and Iraq.

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Kocazeybek, Bekir S; Yuksel, Pelin; Keskin, Dilek; Sheikh, Suhail; Habip, Zafer; Yavuzer, Serap Sahin; Caliskan, Reyhan; Altun, Yagız Meric; Kuskucu, Mert; Cengiz, Mahir; Dinc, Harika Oyku; Karakullukcu, Asiye; Ergin, Sevgi; Saribas, Suat; Yilmaz, Nail; Tokman, Hrisi Bahar

2016-01-01

Although Legionella pneumophila serogroup 1 is the common disease causing serogroup, rare serogroups can also may cause legionellosis. A 54-year-old male patient (index case) reported that he had been on a religious trip (for visiting, tomb of Ali, which is important for Shias) to Iraq with a large group (50 shia pilgrims from Kars city of Turkey) two weeks prior to admission. Due to civil war, the hotel where the patient stayed in Iraq lacked proper hygiene. A large number of people in the travel group were experiencing the same symptoms. Other five cases were 2 males (ages; 50, 45) and 3 females including the wife of the index case (ages; 50, 28, 27). The detection of L. pneumophila IgG and IgM was performed by anti-L. pneumophila Indirect Immunofluorescent IgM, IgG kit. Legionella 1 biochip/verification BIOCHIP slides were used for serogrouping in Euroimmun AG, Leubeck, Germany. In index case, L. pneumophila IgM was positive with a titer of 1/32 titer. IgG was negative with a 1/100 titer. Another case (28 year old female), had clinical symptoms identical to the index case. L. pneumophila IgM and IgG were positive with titers of 1/64 and 1/100, respectively. These two cases were diagnosed with Legionnaires' disease caused by L. pneumophila serogroup 12 (index case) and female (28-year-old) by serogroup 11. The other 4 cases were diagnosed with possible Pontiac fever caused by L. pneumophila serogroups 14 (wife of the index case), 4, and 6 whereas the serogroup of L. pneumophila detected in 27 years old female case could not be identified. A major limitation of this work is the absence of genotyping and the serogroup difference between index case and his wife who shared the same hotel. We suggest that this serogroup difference may be caused by (for men and women) sitting separately in Islamic rules. On the other hand, the movement of people in the context of mutual visits between countries or neighboring countries for tourism-related (i.e., for religious events

Discriminatory usefulness of pulsed-field gel electrophoresis and sequence-based typing in Legionella outbreaks.

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Quero, Sara; García-Núñez, Marian; Párraga-Niño, Noemí; Barrabeig, Irene; Pedro-Botet, Maria L; de Simon, Mercè; Sopena, Nieves; Sabrià, Miquel

2016-06-01

To compare the discriminatory power of pulsed-field gel electrophoresis (PFGE) and sequence-based typing (SBT) in Legionella outbreaks for determining the infection source. Twenty-five investigations of Legionnaires' disease were analyzed by PFGE, SBT and Dresden monoclonal antibody. The results suggested that monoclonal antibody could reduce the number of Legionella isolates to be characterized by molecular methods. The epidemiological concordance PFGE-SBT was 100%, while the molecular concordance was 64%. Adjusted Wallace index (AW) showed that PFGE has better discriminatory power than SBT (AWSBT→PFGE = 0.767; AWPFGE→SBT = 1). The discrepancies appeared mostly in sequence type (ST) 1, a worldwide distributed ST for which PFGE discriminated different profiles. SBT discriminatory power was not sufficient verifying the infection source, especially in worldwide distributed STs, which were classified into different PFGE patterns.

Occurrence of Opportunistic Pathogens Legionella pneumophila and non-tuberculous mycobacteria in hospital plumbing systems

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Occurrence of Opportunistic Pathogens Legionella pneumophila and non-tuberculous mycobacteria in hospital plumbing systems Jill Hoelle, Michael Coughlin, Elizabeth Sotkiewicz, Jingrang Lu, Stacy Pfaller, Mark Rodgers, and Hodon Ryu U.S. Environmental Protection Agency, Cincinnati...

[i]Legionella spp[/i]., amoebae and not-fermenting Gram negative bacteria in an Italian university hospital water system

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Pasqualina Laganà

2014-09-01

Full Text Available [b]Introduction. [/b]In hospital and other health care facilities, contamination of water systems by potentially infectious microorganisms, such as bacteria, viruses and protozoa, is a source of nosocomial infections, which may originate fromcolonization of water pipes, cooling towers, spa pools, taps, showers and water supplies. [b]Objective. [/b]The study focuses on the occurrence of [i]Legionella spp.[/i], free-living amoebae and non-fermenting Gram-negative microorganisms in a University hospital water system located in the town of Messina (Sicily, Italy, which had never been examined previously. Materials and Methods. From January 2008 – March 2009, hot tap water samples were collected from 10 wards.[i] Legionella spp[/i]. recovered on selective culture medium were identified by microagglutination latex test; free-living amoebae were cultured using [i]Escherichia coli [/i]as a food source. Non-fermenting Gram negative microorganisms were identified by API 20 NE strips. [b]Results.[/b] [i]Legionella spp.[/i] were found in 33.33% of the samples. [i]L. pneumophila[/i] serogroup 1 was recovered from the Laboratory Diagnostic and Anaesthesia-Neurology Wards, with a peak of 3.5 × 10[sup]4[/sup] cfu/L in May 2008. [i]L. pneumophila[/i] serogroups 2–14 were found in the Othorhinolaryngology, Pathologic Anatomy, Paediatrics and Surgery Wards, and peaked (4 × 10[sup]4[/sup] cfu/L in April 2008. Pseudomonadaceae and Hyphomycetes were also detected. Legionella spp. were recovered from samples positive for non-pathogenic amoebae [i]Hartmannella spp[/i]. [b]Conclusion.[/b] This first study of a Messina hospital water system suggested potential health risks related to the detection of [i]Hartmannella spp[/i]., as reservoirs for[i] Legionella spp.[/i], and Pseudomonas aeruginosa, a Gram negative non-fermenting bacterium frequently causing nosocomial pneumonia. The urgent need for monitoring programmes and prevention measures to ensure hospital water

The Role of Biofilms in Drinking Water Exposure to Potentially Pathogenic Legionella spp.

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Legionellosis is a bacterial infection caused by species of the genera Legionella and is the most common waterborne disease reported in the United States. This type of infection has two clinically distinct forms: Legionnaire's disease, a severe type of infection, which include...

Molecular Survey of the Occurrence of Legionella spp., Mycobacterium spp., Pseudomonas aeruginosa, and Amoeba Hosts in Two Chloraminated Drinking Water Distribution Systems

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Wang, Hong; Edwards, Marc; Falkinham, Joseph O.

2012-01-01

The spread of opportunistic pathogens via public water systems is of growing concern. The purpose of this study was to identify patterns of occurrence among three opportunistic pathogens (Legionella pneumophila, Mycobacterium avium, and Pseudomonas aeruginosa) relative to biotic and abiotic factors in two representative chloraminated drinking water distribution systems using culture-independent methods. Generally, a high occurrence of Legionella (≥69.0%) and mycobacteria (100%), lower occurrence of L. pneumophila (≤20%) and M. avium (≤33.3%), and rare detection of Pseudomonas aeruginosa (≤13.3%) were observed in both systems according to quantitative PCR. Also, Hartmanella vermiformis was more prevalent than Acanthamoeba, both of which are known hosts for opportunistic pathogen amplification, the latter itself containing pathogenic members. Three-minute flushing served to distinguish distribution system water from plumbing in buildings (i.e., premise plumbing water) and resulted in reduced numbers of copies of Legionella, mycobacteria, H. vermiformis, and 16S rRNA genes (P Legionella and H. vermiformis, were noted, emphasizing potential microbial ecological relationships. Overall, the results provide insight into factors that may aid in controlling opportunistic pathogen proliferation in real-world water systems. PMID:22752174

Geostatistics – a tool applied to the distribution of Legionella pneumophila in a hospital water system

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Pasqualina Laganà

2015-12-01

Full Text Available [b]Introduction.[/b] Legionnaires’ disease is normally acquired by inhalation of legionellae from a contaminated environmental source. Water systems of large buildings, such as hospitals, are often contaminated with legionellae and therefore represent a potential risk for the hospital population. The aim of this study was to evaluate the potential contamination of [i]Legionella pneumophila[/i] (LP in a large hospital in Italy through georeferential statistical analysis to assess the possible sources of dispersion and, consequently, the risk of exposure for both health care staff and patients. [b]Materials and Method. [/b]LP serogroups 1 and 2–14 distribution was considered in the wards housed on two consecutive floors of the hospital building. On the basis of information provided by 53 bacteriological analysis, a ‘random’ grid of points was chosen and spatial geostatistics or [i]FAIk Kriging[/i] was applied and compared with the results of classical statistical analysis. [b]Results[/b]. Over 50% of the examined samples were positive for [i]Legionella pneumophila[/i]. LP 1 was isolated in 69% of samples from the ground floor and in 60% of sample from the first floor; LP 2–14 in 36% of sample from the ground floor and 24% from the first. The iso-estimation maps show clearly the most contaminated pipe and the difference in the diffusion of the different [i]L. pneumophila[/i] serogroups. [b]Conclusion.[/b] Experimental work has demonstrated that geostatistical methods applied to the microbiological analysis of water matrices allows a better modeling of the phenomenon under study, a greater potential for risk management and a greater choice of methods of prevention and environmental recovery to be put in place with respect to the classical statistical analysis.

Prevalence and Molecular Characteristics of Waterborne Pathogen Legionella in Industrial Cooling Tower Environments.

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Li, Lijie; Qin, Tian; Li, Yun; Zhou, Haijian; Song, Hongmei; Ren, Hongyu; Li, Liping; Li, Yongguang; Zhao, Dong

2015-10-12

Cooling towers are a source of Legionnaires' disease. It is important from a public health perspective to survey industrial cooling towers for the presence of Legionella. Prospective surveillance of the extent of Legionella pollution was conducted at factories in Shijiazhuang, China between March 2011 and September 2012. Overall, 35.7% of 255 industrial cooling tower water samples showed Legionella-positive, and their concentrations ranged from 100 Colony-Forming Units (CFU)/liter to 88,000 CFU/liter, with an average concentration of 9100 CFU/liter. A total of 121 isolates were obtained. All isolates were L. pneumophila, and the isolated serogroups included serogroups 1 (68 isolates, 56.2%), 6 (25, 20.7%), 5 (12, 9.9%), 8 (8, 6.6%), 3 (6, 5.0%) and 9 (2, 1.6%). All 121 isolates were analyzed by pulsed-field gel electrophoresis (PFGE) and 64 different patterns were obtained. All 121 isolates were analyzed sequence-based typing (SBT), a full 7-allele profile was obtained from 117 isolates. One hundred and seventeen isolates were divided into 49 sequence types. Two virulence genes, lvh and rtxA, are analyzed by polymerase chain reaction (PCR). 92.6% (112/121) and 98.3% (119/121) isolates carried lvh and rtxA respectively and 90.9% (110/121) of tested isolates carried both genes. Our results demonstrated high prevalence and genetic polymorphism of L. pneumophila in industrial cooling tower environments in Shijiazhang, China, and the SBT and virulence gene PCR results suggested that the isolates were pathogenic. Improved control and prevention strategies are urgently needed.

Prevalence and Molecular Characteristics of Waterborne Pathogen Legionella in Industrial Cooling Tower Environments

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Lijie Li

2015-10-01

Full Text Available Cooling towers are a source of Legionnaires’ disease. It is important from a public health perspective to survey industrial cooling towers for the presence of Legionella. Prospective surveillance of the extent of Legionella pollution was conducted at factories in Shijiazhuang, China between March 2011 and September 2012. Overall, 35.7% of 255 industrial cooling tower water samples showed Legionella-positive, and their concentrations ranged from 100 Colony-Forming Units (CFU/liter to 88,000 CFU/liter, with an average concentration of 9100 CFU/liter. A total of 121 isolates were obtained. All isolates were L. pneumophila, and the isolated serogroups included serogroups 1 (68 isolates, 56.2%, 6 (25, 20.7%, 5 (12, 9.9%, 8 (8, 6.6%, 3 (6, 5.0% and 9 (2, 1.6%. All 121 isolates were analyzed by pulsed-field gel electrophoresis (PFGE and 64 different patterns were obtained. All 121 isolates were analyzed sequence-based typing (SBT, a full 7-allele profile was obtained from 117 isolates. One hundred and seventeen isolates were divided into 49 sequence types. Two virulence genes, lvh and rtxA, are analyzed by polymerase chain reaction (PCR. 92.6% (112/121 and 98.3% (119/121 isolates carried lvh and rtxA respectively and 90.9% (110/121 of tested isolates carried both genes. Our results demonstrated high prevalence and genetic polymorphism of L. pneumophila in industrial cooling tower environments in Shijiazhang, China, and the SBT and virulence gene PCR results suggested that the isolates were pathogenic. Improved control and prevention strategies are urgently needed.

The membrane protein LasM Promotes the Culturability of Legionella pneumophila in Water

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Laam Li

2016-09-01

Full Text Available The water-borne pathogen Legionella pneumophila (Lp strongly expresses the lpg1659 gene in water. This gene encodes a hypothetical protein predicted to be a membrane protein using in silico analysis. While no conserved domains were identified in Lpg1659, similar proteins are found in many Legionella species and other aquatic bacteria. RT-qPCR showed that lpg1659 is positively regulated by the alternative sigma factor RpoS, which is essential for Lp to survive in water. These observations suggest an important role of this novel protein in the survival of Lp in water. Deletion of lpg1659 did not affect cell morphology, membrane integrity or tolerance to high temperature. Moreover, lpg1659 was dispensable for growth of Lp in rich medium, and during infection of the amoeba Acanthamoeba castellanii and of THP-1 human macrophages. However, deletion of lpg1659 resulted in an early loss of culturability in water, while over-expression of this gene promoted the culturability of Lp. Therefore, these results suggest that lpg1659 is required for Lp to maintain culturability, and possibly long-term survival, in water. Since the loss of culturability observed in the absence of Lpg1659 was complemented by the addition of trace metals into water, this membrane protein is likely a transporter for acquiring essential trace metal for maintaining culturability in water and potentially in other metal-deprived conditions. Given its role in the survival of Lp in water, Lpg1659 was named LasM for Legionella aquatic survival membrane protein.

Legionella control in power station cooling towers using oxidising biocides

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Sailer, Christian; Rawlinson, Julia; Killeen, Paul [Ecolab PTY LTD, Ascot, WA (Australia)

2009-02-15

Power stations have used oxidising biocides such as chlorine or bromine for many years to control microbial growth in their cooling towers. In this paper Ecolab trademark looks at the direct effect halogen concentration has on Legionella populations in order to determine the most effective halogenation rate required to ensure that the site key performance indicator (KPI) of < 100 colony-forming units (cfu) per mL can be maintained. (orig.)

Caspase-1 but Not Caspase-11 Is Required for NLRC4-Mediated Pyroptosis and Restriction of Infection by Flagellated Legionella Species in Mouse Macrophages and In Vivo.

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Cerqueira, Daiane M; Pereira, Marcelo S F; Silva, Alexandre L N; Cunha, Larissa D; Zamboni, Dario S

2015-09-01

Gram-negative bacteria from the Legionella genus are intracellular pathogens that cause a severe form of pneumonia called Legionnaires' disease. The bacteria replicate intracellularly in macrophages, and the restriction of bacterial replication by these cells is critical for host resistance. The activation of the NAIP5/NLRC4 inflammasome, which is readily triggered in response to bacterial flagellin, is essential for the restriction of bacterial replication in murine macrophages. Once activated, this inflammasome induces pore formation and pyroptosis and facilitates the restriction of bacterial replication in macrophages. Because investigations related to the NLRC4-mediated restriction of Legionella replication were performed using mice double deficient for caspase-1 and caspase-11, we assessed the participation of caspase-1 and caspase-11 in the functions of the NLRC4 inflammasome and the restriction of Legionella replication in macrophages and in vivo. By using several species of Legionella and mice singly deficient for caspase-1 or caspase-11, we demonstrated that caspase-1 but not caspase-11 was required for pore formation, pyroptosis, and restriction of Legionella replication in macrophages and in vivo. By generating F1 mice in a mixed 129 × C57BL/6 background deficient (129 × Casp-11(-/-) ) or sufficient (129 × C57BL/6) for caspase-11 expression, we found that caspase-11 was dispensable for the restriction of Legionella pneumophila replication in macrophages and in vivo. Thus, although caspase-11 participates in flagellin-independent noncanonical activation of the NLRP3 inflammasome, it is dispensable for the activities of the NLRC4 inflammasome. In contrast, functional caspase-1 is necessary and sufficient to trigger flagellin/NLRC4-mediated restriction of Legionella spp. infection in macrophages and in vivo. Copyright © 2015 by The American Association of Immunologists, Inc.

Combined use of real-time PCR and nested sequence-based typing in survey of human Legionella infection.

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Qin, T; Zhou, H; Ren, H; Shi, W; Jin, H; Jiang, X; Xu, Y; Zhou, M; Li, J; Wang, J; Shao, Z; Xu, X

2016-07-01

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.

Detection of Legionella, L. pneumophila and Mycobacterium Avium Complex (MAC) along Potable Water Distribution Pipelines

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Whiley, Harriet; Keegan, Alexandra; Fallowfield, Howard; Bentham, Richard

2014-01-01

Inhalation of potable water presents a potential route of exposure to opportunistic pathogens and hence warrants significant public health concern. This study used qPCR to detect opportunistic pathogens Legionella spp., L. pneumophila and MAC at multiple points along two potable water distribution pipelines. One used chlorine disinfection and the other chloramine disinfection. Samples were collected four times over the year to provide seasonal variation and the chlorine or chloramine residual was measured during collection. Legionella spp., L. pneumophila and MAC were detected in both distribution systems throughout the year and were all detected at a maximum concentration of 103 copies/mL in the chlorine disinfected system and 106, 103 and 104 copies/mL respectively in the chloramine disinfected system. The concentrations of these opportunistic pathogens were primarily controlled throughout the distribution network through the maintenance of disinfection residuals. At a dead-end and when the disinfection residual was not maintained significant (p < 0.05) increases in concentration were observed when compared to the concentration measured closest to the processing plant in the same pipeline and sampling period. Total coliforms were not present in any water sample collected. This study demonstrates the ability of Legionella spp., L. pneumophila and MAC to survive the potable water disinfection process and highlights the need for greater measures to control these organisms along the distribution pipeline and at point of use. PMID:25046636

Current and Emerging Legionella Diagnostics for Laboratory and Outbreak Investigations

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Mercante, Jeffrey W.

2015-01-01

SUMMARY 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. PMID:25567224

The Toolbox for Uncovering the Functions of Legionella Dot/Icm Type IVb Secretion System Effectors: Current State and Future Directions

Directory of Open Access Journals (Sweden)

Gunnar N. Schroeder

2018-01-01

Full Text Available The defective in organelle trafficking/intracellular multiplication (Dot/Icm Type IVb secretion system (T4SS is the essential virulence factor for the intracellular life style and pathogenicity of Legionella species. Screens demonstrated that an individual L. pneumophila strain can use the Dot/Icm T4SS to translocate an unprecedented number of more than 300 proteins into host cells, where these, so called Icm/Dot-translocated substrates (IDTS or effectors, manipulate host cell functions to the benefit of the bacteria. Bioinformatic analysis of the pan-genus genome predicts at least 608 orthologous groups of putative effectors. Deciphering the function of these effectors is key to understanding Legionella pathogenesis; however, the analysis is challenging. Substantial functional redundancy renders classical, phenotypic screening of single gene deletion mutants mostly ineffective. Here, I review experimental approaches that were successfully used to identify, validate and functionally characterize T4SS effectors and highlight new methods, which promise to facilitate unlocking the secrets of Legionella's extraordinary weapons arsenal.

Legionella pneumoni hos patienter, der er i behandling med infliximab

DEFF Research Database (Denmark)

Vinter, Hanne; Nielsen, Henrik Ib

2009-01-01

Therapy with tumour necrosis factor-alfa inhibitors is widely used in various inflammatory disorders, but adverse events from severe infections with intracellular pathogens may occur. We describe two cases of severe pulmonary legionellosis in patients treated with infliximab for Crohn's disease a...... and psoriasis, respectively. We conclude that legionella infections are probably more frequent in patients receiving immunosuppressive therapy with tumour necrosis factor-alfa inhibitors than in the background population. Udgivelsesdato: 2009-Jan-19...

Relationships between Free-Living Protozoa, Cultivable Legionella spp., and Water Quality Characteristics in Three Drinking Water Supplies in the Caribbean▿†

OpenAIRE

Valster, Rinske M.; Wullings, Bart A.; van den Berg, Riemsdijk; van der Kooij, Dick

2011-01-01

The study whose results are presented here aimed at identifying free-living protozoa (FLP) and conditions favoring the growth of these organisms and cultivable Legionella spp. in drinking water supplies in a tropical region. Treated and distributed water (±30°C) of the water supplies of three Caribbean islands were sampled and investigated with molecular techniques, based on the 18S rRNA gene. The protozoan host Hartmannella vermiformis and cultivable Legionella pneumophila were observed in a...

Epidemiology and Ecology of Opportunistic Premise Plumbing Pathogens: Legionella pneumophila, Mycobacterium avium, and Pseudomonas aeruginosa

Science.gov (United States)

BACKGROUND: Legionella pneumophila, Mycobacterium avium, and Pseudomonas aeruginosa are opportunistic premise plumbing pathogens (OPPPs) that persist and grow in household plumbing, habitats they share with humans. Infections caused by these OPPPs involve individuals with preexis...

Occupational risk for Legionella infection among dental healthcare workers: meta-analysis in occupational epidemiology.

Science.gov (United States)

Petti, Stefano; Vitali, Matteo

2017-07-13

The occupational risk for Legionella infection among dental healthcare workers (DHCWs) is conjectured because of the risk of routine inhalation of potentially contaminated aerosols produced by the dental instruments. Nevertheless, occupational epidemiology studies are contrasting. This meta-analysis assessed the level of scientific evidence regarding the relative occupational risk for Legionella infection among DHCWs. Literature search was performed without time and language restrictions, using broad data banks (PubMed, Scopus, Web of Science, GOOGLE Scholar) and generic keywords ('legionella' AND 'dent*'). Analytical cross-sectional studies comparing prevalence of high serum Legionella antibody levels in DHCWs and occupationally unexposed individuals were considered. The relative occupational risk was assessed through prevalence ratio (PR) with 95% CI. Between-study heterogeneity was assessed (Cochran's Q test) and was used to choose the meta-analytic method. Study quality (modified Newcastle-Ottawa Scale) and publication bias (Begg and Mazumdar's test, Egger and colleagues' test, trim and fill R 0 method) were assessed formally and considered for the sensitivity analysis. Sensitivity analysis to study inclusion, subgroup analyses (dental staff categories; publication year, before vs after 1998, ie, 5 years after the release by the Centers for Disease Control and Prevention of the infection control guidelines in dental healthcare setting) were performed. Seven studies were included (2232 DHCWs, 1172 occupationally unexposed individuals). No evidence of publication bias was detected. The pooled PR estimate was statistically non-significant at 95% level (1.7; 95% CI 0.8 to 3.2), study-quality adjustment did not change the PR considerably (PR, 1.5; 95% CI 0.5 to 4.1). PR was statistically significant before 1998 and no longer significant after 1998. Subgroup analysis according to DHCW categories was inconclusive. There is no scientific evidence that DHCWs are

Legionnaires' Disease Outbreak Caused by Endemic Strain of Legionella pneumophila, New York, New York, USA, 2015.

Science.gov (United States)

Lapierre, Pascal; Nazarian, Elizabeth; Zhu, Yan; Wroblewski, Danielle; Saylors, Amy; Passaretti, Teresa; Hughes, Scott; Tran, Anthony; Lin, Ying; Kornblum, John; Morrison, Shatavia S; Mercante, Jeffrey W; Fitzhenry, Robert; Weiss, Don; Raphael, Brian H; Varma, Jay K; Zucker, Howard A; Rakeman, Jennifer L; Musser, Kimberlee A

2017-11-01

During the summer of 2015, New York, New York, USA, had one of the largest and deadliest outbreaks of Legionnaires' disease in the history of the United States. A total of 138 cases and 16 deaths were linked to a single cooling tower in the South Bronx. Analysis of environmental samples and clinical isolates showed that sporadic cases of legionellosis before, during, and after the outbreak could be traced to a slowly evolving, single-ancestor strain. Detection of an ostensibly virulent Legionella strain endemic to the Bronx community suggests potential risk for future cases of legionellosis in the area. The genetic homogeneity of the Legionella population in this area might complicate investigations and interpretations of future outbreaks of Legionnaires' disease.

Legionella pneumophila infection presenting as headache, confusion and dysarthria in a human immunodeficiency virus-1 (HIV-1 positive patient: case report

Directory of Open Access Journals (Sweden)

Robbins Nathaniel M

2012-09-01

Full Text Available Abstract Background Legionella pneumophila is a common cause of community-acquired pneumonia. Central nervous system dysfunction is common, and diagnosis in the absence of pulmonary symptoms can be challenging. Here we describe an atypical clinical presentation of Legionella infection in a patient with HIV who was found to have an unusual neuroradiologic lesion that further served to obscure the diagnosis. This is the first such description in a patient with Legionellosis and HIV coinfection. Case presentation A 43 year-old HIV positive man presented to our hospital with dysarthria, fevers, headache, and altered mental status. Initial work-up revealed pneumonia and a lesion of the splenium of the corpus callosum on magnetic resonance imaging. He was subsequently diagnosed with Legionella pneumonia and treated with complete symptom resolution. Conclusions Neurologic abnormalities are frequent in Legionellosis, but the diagnosis may be difficult in the absence of overt respiratory symptoms and in the presence of HIV coinfection. A high index of suspicion and early initiation of empiric antibiotics is imperative since early treatment may help prevent long-term sequelae. Neuroimaging abnormalities, though rare, can help the physician narrow down the diagnosis and avoid unnecessary invasive testing. Future studies should aim to elucidate the as yet unknown role of neuroimaging in the diagnoses and prognostication of Legionellosis, as well as the interaction between Legionella infection and HIV.

Effect of temperature and colonization of Legionella pneumophila and Vermamoeba vermiformis on bacterial community composition of copper drinking water biofilms.

Science.gov (United States)

Buse, Helen Y; Ji, Pan; Gomez-Alvarez, Vicente; Pruden, Amy; Edwards, Marc A; Ashbolt, Nicholas J

2017-07-01

It is unclear how the water-based pathogen, Legionella pneumophila (Lp), and associated free-living amoeba (FLA) hosts change or are changed by the microbial composition of drinking water (DW) biofilm communities. Thus, this study characterized the bacterial community structure over a 7-month period within mature (> 600-day-old) copper DW biofilms in reactors simulating premise plumbing and assessed the impact of temperature and introduction of Lp and its FLA host, Vermamoeba vermiformis (Vv), co-cultures (LpVv). Sequence and quantitative PCR (qPCR) analyses indicated a correlation between LpVv introduction and increases in Legionella spp. levels at room temperature (RT), while at 37°C, Lp became the dominant Legionella spp. qPCR analysis suggested Vv presence may not be directly associated with Lp biofilm growth at RT and 37°C, but may contribute to or be associated with non-Lp legionellae persistence at RT. Two-way PERMANOVA and PCoA revealed that temperature was a major driver of microbiome diversity. Biofilm community composition also changed over the seven-month period and could be associated with significant shifts in dissolved oxygen, alkalinity and various metals in the influent DW. Hence, temperature, biofilm age, DW quality and transient intrusions/amplification of pathogens and FLA hosts may significantly impact biofilm microbiomes and modulate pathogen levels over extended periods. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Rapid detection and typing of pathogenic nonpneumophila Legionella spp. isolates using a multiplex real-time PCR assay.

Science.gov (United States)

Benitez, Alvaro J; Winchell, Jonas M

2016-04-01

We developed a single tube multiplex real-time PCR assay that allows for the rapid detection and typing of 9 nonpneumophila Legionella spp. isolates that are clinically relevant. The multiplex assay is capable of simultaneously detecting and discriminating L. micdadei, L. bozemanii, L. dumoffii, L. longbeachae, L. feeleii, L. anisa, L. parisiensis, L. tucsonensis serogroup (sg) 1 and 3, and L. sainthelensis sg 1 and 2 isolates. Evaluation of the assay with nucleic acid from each of these species derived from both clinical and environmental isolates and typing strains demonstrated 100% sensitivity and 100% specificity when tested against 43 other Legionella spp. Typing of L. anisa, L. parisiensis, and L. tucsonensis sg 1 and 3 isolates was accomplished by developing a real-time PCR assay followed by high-resolution melt (HRM) analysis targeting the ssrA gene. Further typing of L. bozemanii, L. longbeachae, and L. feeleii isolates to the serogroup level was accomplished by developing a real-time PCR assay followed by HRM analysis targeting the mip gene. When used in conjunction with other currently available diagnostic tests, these assays may aid in rapidly identifying specific etiologies associated with Legionella outbreaks, clusters, sporadic cases, and potential environmental sources. Published by Elsevier Inc.

Rapid on-site monitoring of Legionella pneumophila in cooling tower water using a portable microfluidic system.

Science.gov (United States)

Yamaguchi, Nobuyasu; Tokunaga, Yusuke; Goto, Satoko; Fujii, Yudai; Banno, Fumiya; Edagawa, Akiko

2017-06-08

Legionnaires' disease, predominantly caused by the bacterium Legionella pneumophila, has increased in prevalence worldwide. The most common mode of transmission of Legionella is inhalation of contaminated aerosols, such as those generated by cooling towers. Simple, rapid and accurate methods to enumerate L. pneumophila are required to prevent the spread of this organism. Here, we applied a microfluidic device for on-chip fluorescent staining and semi-automated counting of L. pneumophila in cooling tower water. We also constructed a portable system for rapid on-site monitoring and used it to enumerate target bacterial cells rapidly flowing in the microchannel. A fluorescently-labelled polyclonal antibody was used for the selective detection of L. pneumophila serogroup 1 in the samples. The counts of L. pneumophila in cooling tower water obtained using the system and fluorescence microscopy were similar. The detection limit of the system was 10 4  cells/ml, but lower numbers of L. pneumophila cells (10 1 to 10 3  cells/ml) could be detected following concentration of 0.5-3 L of the water sample by filtration. Our technique is rapid to perform (1.5 h), semi-automated (on-chip staining and counting), and portable for on-site measurement, and it may therefore be effective in the initial screening of Legionella contamination in freshwater.

Pneumonia a Legionella – A propósito de um caso clínico

Directory of Open Access Journals (Sweden)

A.S. Marques

2005-03-01

Full Text Available Resumo: A Legionella como agente etiológico de pneumonia adquirida na comunidade (PAC é provavelmente subvalorizada, não só porque exige a utilização de métodos diagnósticos específicos como existem várias espécies e serogrupos que não são facilmente identificados pelos testes laboratoriais disponíveis. Em estudos europeus e norte-americanos, este agente é responsável por 2 a 15% de todos os casos de pneumonias adquiridas na comunidade que requerem hospitalização, figurando entre as quatro primeiras causas quando se utilizam métodos de cultura, sendo a segunda causa das que exigem tratamento em unidades de cuidados intensivos.Apresenta-se o caso clínico de um homem de 43 anos, fumador e sob corticoterapia por patologia ocular, que surge com uma pneumonia grave complicada de síndroma de dificuldade respiratória do adulto (ARDS. Necessitou de tratamento em unidade de cuidados intensivos, nomeadamente ventilação mecânica.A investigação etiológica permitiu identificar o agente responsável, a Legionella pneumophila tipo 1.Os autores fazem uma revisão desta patologia, discutindo a epidemiologia, o quadro clínico e as particularidades de diagnóstico e terapêutica.Rev Port Pneumol 2005; XI (2: 165-173 Abstract: Legionella, as a cause of community-acquired pneumonia, is probably under-recognized because the diagnosis relies on the use of specific tests as well the existence of an in-numerous species and serogroups not easily identify by the tests available.In studies from Europe and North America, it ranged from 2 to 15 percent of all community-acquired pneumonias that required hospitalisation, in the first four causes when culture methods were done and the second cause of those admitted in the intensive care units.We do a case report of 43 year-old man with history of cigarette smoking and corticosteroid therapy for a ocular disease, that presents with a

Simultaneous detection of Legionella species and L. anisa, L. bozemanii, L. longbeachae and L. micdadei using conserved primers and multiple probes in a multiplex real-time PCR assay.

Science.gov (United States)

Cross, Kristen E; Mercante, Jeffrey W; Benitez, Alvaro J; Brown, Ellen W; Diaz, Maureen H; Winchell, Jonas M

2016-07-01

Legionnaires' disease is a severe respiratory disease that is estimated to cause between 8,000 and 18,000 hospitalizations each year, though the exact burden is unknown due to under-utilization of diagnostic testing. Although Legionella pneumophila is the most common species detected in clinical cases (80-90%), other species have also been reported to cause disease. However, little is known about Legionnaires' disease caused by these non-pneumophila species. We designed a multiplex real-time PCR assay for detection of all Legionella spp. and simultaneous specific identification of four clinically-relevant Legionella species, L. anisa, L. bozemanii, L. longbeachae, and L. micdadei, using 5'-hydrolysis probe real-time PCR. The analytical sensitivity for detection of nucleic acid from each target species was ≤50fg per reaction. We demonstrated the utility of this assay in spiked human sputum specimens. This assay could serve as a tool for understanding the scope and impact of non-pneumophila Legionella species in human disease. Published by Elsevier Inc.

[Outbreak of hospital acquired Legionnaires' disease in patients of ophthalmic ward. Nosocomial Legionella infections for the first time observed in Poland].

Science.gov (United States)

Stypułkowska-Misiurewicz, Hanna; Pancer, Katarzyna; Krogulska, Bozena; Matuszewska, Renata

2007-01-01

The aim of the paper is to describe the criteria used for identification of first and so far the only one outbreak of hospital bacterial infections due to L. pneumophila. The infected persons were patients hospitalized at ophthalmic ward for more than 10 days. Four patients were found ill among 27 hospitalized (15%) at ophthalmic ward and 3 of them died (75%) in spite treatment in intensive care unit. The source of infection was found in the hospital hot water system. It was shown that L. pneumophila sg 1 and sg 2-14 were settled in the tanks and pipelines of hot water installations. The high number of L. pneumophila sg I and sg 2-14 colony forming units (> 10 000 cfu /100 ml) were found in the water specimens taken from the hospital water system, showing the high risk of Legionella infection for patients. Cleaning and disinfection of hot water system was repeated three times using composition every time modified as stronger mechanical, thermal and chemical methods. Complete elimination of Legionella from hot water system was achieved after cutting off deadlegs of water and replacement of both old hot water reservoirs with new ones. Collected experience served for preparation of guidelines for control and prevention of Legionella infections in hospital buildings, published on National Institute of Hygiene web site A month later Polish Ministry of Health published the Directives concerning the quality of drinking water to which the control of Legionella infection has been included.

Alternatives for thermal legionella control; Alternatieven thermische legionellabestrijding

Energy Technology Data Exchange (ETDEWEB)

Van Lieshout, M.

2008-03-15

One supplier considers his system a breakthrough in legionella control. Another claims decisively that his system provides the only affordable and effective solution. It is clear that manufacturers have their own way of finding alternatives in those cases where thermal control for complex existing installations prove not to be effective. (mk) [Dutch] De ene leverancier noemt zijn systeem een doorbraak in de legionellabestrijding. Een ander beweert met grote stelligheid dat zijn systeem de enige betaalbare en effectieve oplossing is. Duidelijk is dat fabrikanten op hun eigen manier een oplossing zoeken naar alternatieven, daar waar het thermisch beheer voor complexe bestaande installaties niet effectief blijk te zijn.

A Multiplex PCR for Detection of Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophila, and Bordetella pertussis in Clinical Specimens

National Research Council Canada - National Science Library

McDonough, E. A; Barrozo, C. P; Russell, K. L; Metzgar, D

2005-01-01

A multiplex PCR was developed that is capable of detecting four of the most important bacterial agents of atypical pneumophia, Mycaplasma pneumoniae, Chlamydophia pneumoniae, Legionella pneumophila...

PCR method for the rapid detection and discrimination of Legionella spp. based on the amplification of pcs, pmtA, and 16S rRNA genes.

Science.gov (United States)

Janczarek, Monika; Palusińska-Szysz, Marta

2016-05-01

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.

A multicenter study of viable PCR using propidium monoazide to detect Legionella in water samples.

Science.gov (United States)

Scaturro, Maria; Fontana, Stefano; Dell'eva, Italo; Helfer, Fabrizia; Marchio, Michele; Stefanetti, Maria Vittoria; Cavallaro, Mario; Miglietta, Marilena; Montagna, Maria Teresa; De Giglio, Osvalda; Cuna, Teresa; Chetti, Leonarda; Sabattini, Maria Antonietta Bucci; Carlotti, Michela; Viggiani, Mariagabriella; Stenico, Alberta; Romanin, Elisa; Bonanni, Emma; Ottaviano, Claudio; Franzin, Laura; Avanzini, Claudio; Demarie, Valerio; Corbella, Marta; Cambieri, Patrizia; Marone, Piero; Rota, Maria Cristina; Bella, Antonino; Ricci, Maria Luisa

2016-07-01

Legionella quantification in environmental samples is overestimated by qPCR. Combination with a viable dye, such as Propidium monoazide (PMA), could make qPCR (named then vPCR) very reliable. In this multicentre study 717 artificial water samples, spiked with fixed concentrations of Legionella and interfering bacterial flora, were analysed by qPCR, vPCR and culture and data were compared by statistical analysis. A heat-treatment at 55 °C for 10 minutes was also performed to obtain viable and not-viable bacteria. When data of vPCR were compared with those of culture and qPCR, statistical analysis showed significant differences (P 0.05). Overall this study provided a good experimental reproducibility of vPCR but also highlighted limits of PMA in the discriminating capability of dead and live bacteria, making vPCR not completely reliable. Copyright © 2016 Elsevier Inc. All rights reserved.

Detection methods for legionellae. Possibilities and limitations of detection methods; Niet alle detectiemethoden geschikt voor legionellagroei. Mogelijkheden en beperkingen detectiemethoden

Energy Technology Data Exchange (ETDEWEB)

Scheffer, W.

2011-06-15

This article provides an overview of existing and new methods for detecting legionella in water. It offers insight in the characteristics and applications of existing and new detection methods. However, it is impossible to assess the value of alternative methods at the moment. That will require additional research. [Dutch] Een overzicht is gemaakt van bestaande en nieuwe methoden om legionella in water aan te tonen. Daarmee wordt inzicht verkregen in de kenmerken en toepassingsmogelijkheden van bestaande en nieuwe detectiemethoden. De waarde van alternatieve methoden in een installatie kan echter nog niet worden beoordeeld. Daarvoor is nader onderzoek nodig.

Chlamydia trachomatis contains a protein similar to the Legionella pneumophila mip gene product

DEFF Research Database (Denmark)

Lundemose, AG; Birkelund, Svend; Fey, SJ

1991-01-01

A 27kDa Chlamydia trachomatis L2 protein was characterized by the use of monoclonal antibodies and by two-dimensional gel electrophoresis. The protein was shown to be located in the membrane of reticulate bodies as well as elementary bodies. Its synthesis could be detected from 10 hours post-infe...... potentiator (mip) gene of Legionella pneumophila....

Measurements of water temperature in fountains as an indicator of potential secondary water pollution caused by Legionella bacteria

Directory of Open Access Journals (Sweden)

Bąk Joanna

2018-01-01

Full Text Available At high air temperatures persisting for a long time, water temperature in the fountains may also increase significantly. This can cause a sudden and significant increase in Legionella bacteria, which results in secondary water contamination. This phenomenon with water – air aerosol generated by fountains can be very dangerous for people. During the test, water temperature measurements in fountains in Poland were made. These research tests was conducted in the spring and summer. The research was conducted in order to determine whether there is a possibility of growth of Legionella bacteria. One of the aims of the study was to determine what temperature range occurs in the fountains and how the temperature changes in the basin of the fountain and when the highest temperature occurs. Single temperature measurements were made and also the temperature distribution was measured during daylight hours. The water temperature in most cases was greater than 20°C, but in no case exceed 26°C. The paper presents also the review about the effect of water temperature on the presence and bacterial growth. The study confirmed the existence of the risk of increasing the number of bacteria of the genus Legionella in the water in the fountains.

Measurements of water temperature in fountains as an indicator of potential secondary water pollution caused by Legionella bacteria

Science.gov (United States)

Bąk, Joanna

2018-02-01

At high air temperatures persisting for a long time, water temperature in the fountains may also increase significantly. This can cause a sudden and significant increase in Legionella bacteria, which results in secondary water contamination. This phenomenon with water - air aerosol generated by fountains can be very dangerous for people. During the test, water temperature measurements in fountains in Poland were made. These research tests was conducted in the spring and summer. The research was conducted in order to determine whether there is a possibility of growth of Legionella bacteria. One of the aims of the study was to determine what temperature range occurs in the fountains and how the temperature changes in the basin of the fountain and when the highest temperature occurs. Single temperature measurements were made and also the temperature distribution was measured during daylight hours. The water temperature in most cases was greater than 20°C, but in no case exceed 26°C. The paper presents also the review about the effect of water temperature on the presence and bacterial growth. The study confirmed the existence of the risk of increasing the number of bacteria of the genus Legionella in the water in the fountains.

Genome Sequence of Legionella massiliensis, Isolated from a Cooling Tower Water Sample.

Science.gov (United States)

Pagnier, Isabelle; Croce, Olivier; Robert, Catherine; Raoult, Didier; La Scola, Bernard

2014-10-16

We present the draft genome sequence of Legionella massiliensis strain LegA(T), recovered from a cooling tower water sample, using an amoebal coculture procedure. The strain described here is composed of 4,387,007 bp, with a G+C content of 41.19%, and its genome has 3,767 protein-coding genes and 60 predicted RNA genes. Copyright © 2014 Pagnier et al.

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.

Science.gov (United States)

Ditommaso, Savina; Ricciardi, Elisa; Giacomuzzi, Monica; Arauco Rivera, Susan R; Ceccarelli, Adriano; Zotti, Carla M

2014-12-01

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). Copyright © 2014 Elsevier Inc. All rights reserved.

Molecular typing of Legionella pneumophila from air-conditioning cooling waters using mip gene, SBT, and FAFLP methods.

Science.gov (United States)

Gong, Xiangli; Li, Juntao; Zhang, Ying; Hou, Shuiping; Qu, Pinghua; Yang, Zhicong; Chen, Shouyi

2017-08-01

Legionella spp. are important waterborne pathogens. Molecular typing has become an important method for outbreaks investigations and source tracking of Legionnaires. In a survey program conducted by the Guangzhou Center for Disease Control and Prevention, multiple serotypes Legionella pneumophila (L. pneumophila) were isolated from waters in air-conditioning cooling towers in urban Guangzhou region, China between 2008 and 2011. Three genotyping methods, mip (macrophage infectivity potentiator) genotyping, SBT (sequence-based typing), and FAFLP (fluorescent amplified fragment length polymorphism analysis) were used to type these waterborne L. pneumophila isolates. The three methods were capable of typing all the 134 isolates and a reference strain of L. pneumophila (ATCC33153), with discriminatory indices of 0.7034, 0.9218, and 0.9376, for the mip, SBT, and FAFLP methods respectively. Among the 9 serotypes of the 134 isolates, 10, 50, and 34 molecular types were detected by the mip, SBT, and FAFLP methods respectively. The mip genotyping and SBT typing are more feasible for inter-laboratory results sharing and comparison of different types of L. pneumophila. The SBT and FAFLP typing methods were rapid with higher discriminatory abilities. Combinations of two or more of the typing methods enables more accurate typing of Legionella isolates for outbreak investigations and source tracking of Legionnaires. Copyright © 2017 Elsevier B.V. All rights reserved.

Impact of Chlorine and Heat on the Survival of Hartmannella vermiformis and Subsequent Growth of Legionella pneumophila.

Science.gov (United States)

Kuchta, J M; Navratil, J S; Shepherd, M E; Wadowsky, R M; Dowling, J N; States, S J; Yee, R B

1993-12-01

Hartmannella vermiformis, a common amoebal inhabitant of potable-water systems, supports intracellular multiplication of Legionella pneumophila and is probably important in the transportation and amplification of legionellae within these systems. To provide a practical guide for decontamination of potable-water systems, we assessed the chlorine and heat resistance of H. vermiformis. H. vermiformis cysts and trophozoites were treated independently with chlorine at concentrations of 2.0 to 10.0 ppm for 30 min and then cocultured with L. pneumophila. Both cysts and trophozoites were sensitive to concentrations between 2.0 and 4.0 ppm and above (trophozoites somewhat more so than cysts), and 10.0 ppm was lethal to both forms. Hartmannellae treated with chlorine up to a concentration of 4.0 ppm supported the growth of legionellae. To determine whether heat would be an effective addendum to chlorine treatment of amoebae, hartmannellae were subjected to temperatures of 55 and 60 degrees C for 30 min and alternatively to 50 degrees C followed by treatment with chlorine at a concentration of 2 ppm. Fewer than 0.05% of the amoebae survived treatment at 55 degrees C, and there were no survivors at 60 degrees C. Pretreatment at 50 degrees C appeared to make hartmannella cysts more susceptible to chlorine but did not further reduce the concentration of trophozoites.

Your Garden Hose: A potential health risk due to Legionella spp. growth facilitated by free-living amoebae

Science.gov (United States)

Common garden hoses may generate aerosols of inhalable size (Legionella bacteria, Legionnaires' disease or Pontiac fever may result. Noting clinical cases have been linked to garden hose use. The hose environment is ideal ...

Draft genome sequences of six neonatal meningitis-causing escherichia coli isolates (SP-4, SP-5, SP-13, SP-16, SP-46, and SP-65)

Science.gov (United States)

Neonatal meningitis Escherichia coli isolates (SP-4, SP-5, SP-13, SP-16, SP-46, and SP-65) were recovered from infants in the Netherlands from 1989 to 1997. Here, we report the draft genome sequences for these six E. coli isolates, which are currently being used to validate food safety processing te...

Zakażenia pałeczkami Legionella pneumophila – opis przypadku

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Bolesław Kalicki

2011-12-01

Full Text Available Legionella pneumophila jest wewnątrzkomórkowym patogenem zasiedlającym środowiska wodne. Do zakażenia dochodzi drogą inhalacji zakażonego aerozolu, rzadziej poprzez aspirację. Rozprzestrzenianie się zachodzi drogą krwionośną, limfatyczną i przez ciągłość. Choroba rozwija się w postaci dwóch klinicznie odrębnych zespołów: choroby legionistów i gorączki Pontiac. Pozapłucne postaci legionelozy spotyka się niezmiernie rzadko. Powikłania mogą występować w postaci niedodmy, wysięku, zrostów, ropni płuc, ropniaków opłucnej, przetok oskrzelowo-opłucnowych, a w konsekwencji mogą prowadzić do niewydolności wielonarządowej. W diagnostyce zakażenia Legionella pneumophila stosuje się izolację i hodowlę bakterii uzyskanych z tkanek chorego na specjalnych podłożach, metody genetyczne bądź też testy serologiczne. W leczeniu skuteczne są antybiotyki z grupy makrolidów, a w ciężkiej postaci choroby także fluorochinolony. Leczeniem alternatywnym jest kombinacja trimetoprym + sulfametoksazol. W artykule przedstawiono opis przypadku 14-letniego chłopca, który został przyjęty do Kliniki z powodu gorączki, osłabienia, wymiotów, bólów brzucha i głowy. U dziecka wykonano serię badań wyjaśniających przyczynę dolegliwości. Stwierdzono podwyższone wykładniki stanu zapalnego z towarzyszącą leukopenią i trombocytopenią. W przebiegu choroby pojawiły się kaszel i wysypka. W badaniach dodatkowych wysunięto podejrzenie zajęcia układu sercowo-naczyniowego. Podejrzewając zakażenie atypowe, do leczenia dołączono makrolid, po którym uzyskano poprawę stanu klinicznego i ustąpienie objawów. Otrzymany później wynik badania w kierunku Legionella pneumophila wskazywał na możliwość zakażenia o tej etiologii.

In Vitro Response of Guinea Pig Peritoneal Macrophages to Legionella pneumophila

Science.gov (United States)

1981-03-01

In Vitro Responlse of Guinea Pig Peritoneal Macrophages to Legionella pneumophila It. A. KISIIIMi~O~’ .1. Ii.,W11ITE, F. G. SIREY, V. (U.1 Mc(GANN, R...Tlhe inter- act ion between L. lincumnophila andl( peritoneal macrophages front normial guinea pigs or front animials that had survived infection was...roagglujtiniat titer) guinea pig serum to The purp~ose of this study "as to investigate contain approximately 108 organisms per ml. the phagocytic and

Field testing hot water temperature reduction as an energy-saving measure--does the Legionella presence change in a clinic's plumbing system?

Science.gov (United States)

Völker, Sebastian; Kistemann, Thomas

2015-01-01

Legionella spp. represent a significant health risk for humans. To ensure hygienically safe drinking water, technical guidelines recommend a central potable water hot (PWH) supply temperature of at least 60°C at the calorifier. In a clinic building we monitored whether slightly lowered temperatures in the PWH system led to a systemic change in the growth of these pathogens. In four separate phases we tested different scenarios concerning PWH supply temperatures and disinfection with chlorine dioxide (ClO2). In each phase, we took 5 sets of samples at 17 representative sampling points in the building's drinking water plumbing system. In total we collected 476 samples from the PWH system. All samples were tested (culture-based) for Legionella spp. and serogroups. Additionally, quantitative parameters at each sampling point were collected, which could possibly be associated with the presence of Legionella spp. (Pseudomonas aeruginsoa, heterotrophic plate count at 20°C and 36°C, temperatures, time until constant temperatures were reached, and chlorine dioxide concentration). The presence of Legionella spp. showed no significant reactions after reducing the PWH supply temperature from 63°C to 60°C and 57°C, as long as disinfection with ClO2 was maintained. After omitting the disinfectant, the PWH system showed statistically significant growth rates at 57°C. PWH temperatures which are permanently lowered to less than recommended values should be carefully accompanied by frequent testing, a thorough evaluation of the building's drinking water plumbing system, and hygiene expertise.

Protein expression, crystallization and preliminary X-ray crystallographic studies of LidA from Legionella pneumophila

International Nuclear Information System (INIS)

Zhu, Wenzhuang; Meng, Geng; Liu, Yong; Zhang, Feiyun; Zheng, Xiaofeng

2011-01-01

The crystallization of recombinant lidA, a translocated substrate of the Legionella pneumophila Dot/Icm type IV secretion system, is reported. Crystals were obtained and diffracted to 2.75 Å in space group P2 1 2 1 2 1 . LidA, a translocated substrate of the Legionella pneumophila Dot/Icm type IV secretion system, is associated with maintenance of bacterial integrity and interferes with the early secretory pathway. However, the precise mechanism of LidA in these processes remains elusive. To further investigate the structure and function of LidA, the full-length protein was successfully expressed in Escherichia coli and purified. LidA was crystallized using sitting-drop vapour diffusion and diffracted to a resolution of 2.75 Å. The crystal belonged to space group P2 1 2 1 2 1 , with unit-cell parameters a = 57.5, b = 64.5, c = 167.3 Å, α = β = γ = 90°. There is one molecule per asymmetric unit

Functional Analysis of the Alternative Sigma-28 Factor FliA and Its Anti-Sigma Factor FlgM of the Nonflagellated Legionella Species L. oakridgensis.

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Tlapák, Hana; Rydzewski, Kerstin; Schulz, Tino; Weschka, Dennis; Schunder, Eva; Heuner, Klaus

2017-06-01

Legionella oakridgensis causes Legionnaires' disease but is known to be less virulent than Legionella pneumophila L. oakridgensis is one of the Legionella species that is nonflagellated. The genes of the flagellar regulon are absent, except those encoding the alternative sigma-28 factor (FliA) and its anti-sigma-28 factor (FlgM). Similar to L. oakridgensis , Legionella adelaidensis and Legionella londiniensis , located in the same phylogenetic clade, have no flagellar regulon, although both are positive for fliA and flgM Here, we investigated the role and function of both genes to better understand the role of FliA, the positive regulator of flagellin expression, in nonflagellated strains. We demonstrated that the FliA gene of L. oakridgensis encodes a functional sigma-28 factor that enables the transcription start from the sigma-28-dependent promoter site. The investigations have shown that FliA is necessary for full fitness of L. oakridgensis Interestingly, expression of FliA-dependent genes depends on the growth phase and temperature, as already shown for L. pneumophila strains that are flagellated. In addition, we demonstrated that FlgM is a negative regulator of FliA-dependent gene expression. FlgM seems to be degraded in a growth-phase- and temperature-dependent manner, instead of being exported into the medium as reported for most bacteria. The degradation of FlgM leads to an increase of FliA activity. IMPORTANCE A less virulent Legionella species, L. oakridgensis , causes Legionnaires' disease and is known to not have flagella, even though L. oakridgensis has the regulator of flagellin expression (FliA). This protein has been shown to be involved in the expression of virulence factors. Thus, the strain was chosen for use in this investigation to search for FliA target genes and to identify putative virulence factors of L. oakridgensis One of the five major target genes of FliA identified here encodes the anti-FliA sigma factor FlgM. Interestingly, in

Phylogenetic Analysis and Antimicrobial Profiles of Cultured Emerging Opportunistic Pathogens (Phyla Actinobacteria and Proteobacteria) Identified in Hot Springs.

Science.gov (United States)

Jardine, Jocelyn Leonie; Abia, Akebe Luther King; Mavumengwana, Vuyo; Ubomba-Jaswa, Eunice

2017-09-15

Hot spring water may harbour emerging waterborne opportunistic pathogens that can cause infections in humans. We have investigated the diversity and antimicrobial resistance of culturable emerging and opportunistic bacterial pathogens, in water and sediment of hot springs located in Limpopo, South Africa. Aerobic bacteria were cultured and identified using 16S ribosomal DNA (rDNA) gene sequencing. The presence of Legionella spp. was investigated using real-time polymerase chain reaction. Isolates were tested for resistance to ten antibiotics representing six different classes: β-lactam (carbenicillin), aminoglycosides (gentamycin, kanamycin, streptomycin), tetracycline, amphenicols (chloramphenicol, ceftriaxone), sulphonamides (co-trimoxazole) and quinolones (nalidixic acid, norfloxacin). Gram-positive Kocuria sp. and Arthrobacter sp. and gram-negative Cupriavidus sp., Ralstonia sp., Cronobacter sp., Tepidimonas sp., Hafnia sp. and Sphingomonas sp. were isolated, all recognised as emerging food-borne pathogens. Legionella spp. was not detected throughout the study. Isolates of Kocuria , Arthrobacter and Hafnia and an unknown species of the class Gammaproteobacteria were resistant to two antibiotics in different combinations of carbenicillin, ceftriaxone, nalidixic acid and chloramphenicol. Cronobacter sp. was sensitive to all ten antibiotics. This study suggests that hot springs are potential reservoirs for emerging opportunistic pathogens, including multiple antibiotic resistant strains, and highlights the presence of unknown populations of emerging and potential waterborne opportunistic pathogens in the environment.

Legionella Effector AnkX Disrupts Host Cell Endocytic Recycling in a Phosphocholination-Dependent Manner

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Samual C. Allgood

2017-09-01

Full Text Available The facultative intracellular bacterium Legionella pneumophila proliferates within amoebae and human alveolar macrophages, and it is the causative agent of Legionnaires' disease, a life-threatening pneumonia. Within host cells, L. pneumophila establishes a replicative haven by delivering numerous effector proteins into the host cytosol, many of which target membrane trafficking by manipulating the function of Rab GTPases. The Legionella effector AnkX is a phosphocholine transferase that covalently modifies host Rab1 and Rab35. However, a detailed understanding of the biological consequence of Rab GTPase phosphocholination remains elusive. Here, we broaden the understanding of AnkX function by presenting three lines of evidence that it interferes with host endocytic recycling. First, using immunogold transmission electron microscopy, we determined that GFP-tagged AnkX ectopically produced in mammalian cells localizes at the plasma membrane and tubular membrane compartments, sites consistent with targeting the endocytic recycling pathway. Furthermore, the C-terminal region of AnkX was responsible for association with the plasma membrane, and we determined that this region was also able to bind the phosphoinositide lipids PI(3P and PI(4P in vitro. Second, we observed that mCherry-AnkX co-localized with Rab35, a regulator of recycling endocytosis and with major histocompatibility class I protein (MHC-I, a key immunoregulatory protein whose recycling from and back to the plasma membrane is Rab35-dependent. Third, we report that during infection of macrophages, AnkX is responsible for the disruption of endocytic recycling of transferrin, and AnkX's phosphocholination activity is critical for this function. These results support the hypothesis that AnkX targets endocytic recycling during host cell infection. Finally, we have demonstrated that the phosphocholination activity of AnkX is also critical for inhibiting fusion of the Legionella

Legionella spp. Risk Assessment in Recreational and Garden Areas of Hotels

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Antonios Papadakis

2018-03-01

Full Text Available Several Travel-associated Legionnaires’ disease (TALD cases occur annually in Europe. Except from the most obvious sites (cooling towers and hot water systems, infections can also be associated with recreational, water feature, and garden areas of hotels. This argument is of great interest to better comprehend the colonization and to calculate the risk to human health of these sites. From July 2000–November 2017, the public health authorities of the Island of Crete (Greece inspected 119 hotels associated with TALD, as reported through the European Legionnaires’ Disease Surveillance Network. Five hundred and eighteen samples were collected from decorative fountain ponds, showers near pools and spas, swimming pools, spa pools, garden sprinklers, drip irrigation systems (reclaimed water and soil. Of those, 67 (12.93%, originating from 43 (35.83% hotels, tested positive for Legionella (Legionella pneumophila serogroups 1, 2, 3, 6, 7, 8, 13, 14, 15 and non-pneumophila species (L. anisa, L. erythra, L. taurinensis, L. birminghamensis, L. rubrilucens. A Relative Risk (R.R. > 1 (p < 0.0001 was calculated for chlorine concentrations of less than 0.2 mg/L (R.R.: 54.78, star classification (<4 (R.R.: 4.75 and absence of Water Safety Plan implementation (R.R.: 3.96. High risk (≥104 CFU/L was estimated for pool showers (16.42%, garden sprinklers (7.46% and pool water (5.97%.

Legionella spp. Risk Assessment in Recreational and Garden Areas of Hotels.

Science.gov (United States)

Papadakis, Antonios; Chochlakis, Dimosthenis; Sandalakis, Vassilios; Keramarou, Maria; Tselentis, Yannis; Psaroulaki, Anna

2018-03-26

Several Travel-associated Legionnaires' disease (TALD) cases occur annually in Europe. Except from the most obvious sites (cooling towers and hot water systems), infections can also be associated with recreational, water feature, and garden areas of hotels. This argument is of great interest to better comprehend the colonization and to calculate the risk to human health of these sites. From July 2000-November 2017, the public health authorities of the Island of Crete (Greece) inspected 119 hotels associated with TALD, as reported through the European Legionnaires' Disease Surveillance Network. Five hundred and eighteen samples were collected from decorative fountain ponds, showers near pools and spas, swimming pools, spa pools, garden sprinklers, drip irrigation systems (reclaimed water) and soil. Of those, 67 (12.93%), originating from 43 (35.83%) hotels, tested positive for Legionella ( Legionella pneumophila serogroups 1, 2, 3, 6, 7, 8, 13, 14, 15 and non-pneumophila species ( L. anisa , L. erythra , L. taurinensis , L. birminghamensis , L. rubrilucens ). A Relative Risk (R.R.) > 1 ( p < 0.0001) was calculated for chlorine concentrations of less than 0.2 mg/L (R.R.: 54.78), star classification (<4) (R.R.: 4.75) and absence of Water Safety Plan implementation (R.R.: 3.96). High risk (≥10⁴ CFU/L) was estimated for pool showers (16.42%), garden sprinklers (7.46%) and pool water (5.97%).

How to prevent legionella infestation. Pt. 1. Central freshwater heating systems; Wie man Legionellen vermeiden. T. 1. Zentrale Trinkwassererwaermungsanlagen

Energy Technology Data Exchange (ETDEWEB)

Kremer, Robert [DVGW-Fachausschuss Trinkwasserhygiene in Gebaeuden, Leverkusen (Germany)

2009-01-15

The contribution focuses on hygienically safe freshwater heating. Legionella prophylaxis is discussed, as are new findings concerning practical implementation of new requirements on modern freshwater supply systems. (orig.)

Genomic characterization of a large outbreak of Legionella pneumophila serogroup 1 strains in Quebec City, 2012.

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Simon Lévesque

Full Text Available During the summer of 2012, a major Legionella pneumophila serogroup 1 outbreak occurred in Quebec City, Canada, which caused 182 declared cases of Legionnaire's disease and included 13 fatalities. Legionella pneumophila serogroup 1 isolates from 23 patients as well as from 32 cooling towers located in the vicinity of the outbreak were recovered for analysis. In addition, 6 isolates from the 1996 Quebec City outbreak and 4 isolates from patients unrelated to both outbreaks were added to allow comparison. We characterized the isolates using pulsed-field gel electrophoresis, sequence-based typing, and whole genome sequencing. The comparison of patients-isolated strains to cooling tower isolates allowed the identification of the tower that was the source of the outbreak. Legionella pneumophila strain Quebec 2012 was identified as a ST-62 by sequence-based typing methodology. Two new Legionellaceae plasmids were found only in the epidemic strain. The LVH type IV secretion system was found in the 2012 outbreak isolates but not in the ones from the 1996 outbreak and only in half of the contemporary human isolates. The epidemic strains replicated more efficiently and were more cytotoxic to human macrophages than the environmental strains tested. At least four Icm/Dot effectors in the epidemic strains were absent in the environmental strains suggesting that some effectors could impact the intracellular replication in human macrophages. Sequence-based typing and pulsed-field gel electrophoresis combined with whole genome sequencing allowed the identification and the analysis of the causative strain including its likely environmental source.

Identification of vacuoles containing extraintestinal differentiated forms of Legionella pneumophila in colonized Caenorhabditis elegans soil nematodes.

Science.gov (United States)

Hellinga, Jacqueline R; Garduño, Rafael A; Kormish, Jay D; Tanner, Jennifer R; Khan, Deirdre; Buchko, Kristyn; Jimenez, Celine; Pinette, Mathieu M; Brassinga, Ann Karen C

2015-08-01

Legionella pneumophila, a causative agent of Legionnaires' disease, is a facultative intracellular parasite of freshwater protozoa. Legionella pneumophila features a unique developmental network that involves several developmental forms including the infectious cyst forms. Reservoirs of L. pneumophila include natural and man-made freshwater systems; however, recent studies have shown that isolates of L. pneumophila can also be obtained directly from garden potting soil suggesting the presence of an additional reservoir. A previous study employing the metazoan Caenorhabditis elegans, a member of the Rhabditidae family of free-living soil nematodes, demonstrated that the intestinal lumen can be colonized with L. pneumophila. While both replicative forms and differentiated forms were observed in C. elegans, these morphologically distinct forms were initially observed to be restricted to the intestinal lumen. Using live DIC imaging coupled with focused transmission electron microscopy analyses, we report here that L. pneumophila is able to invade and establish Legionella-containing vacuoles (LCVs) in the intestinal cells. In addition, LCVs containing replicative and differentiated cyst forms were observed in the pseudocoelomic cavity and gonadal tissue of nematodes colonized with L. pneumophila. Furthermore, establishment of LCVs in the gonadal tissue was Dot/Icm dependent and required the presence of the endocytic factor RME-1 to gain access to maturing oocytes. Our findings are novel as this is the first report, to our knowledge, of extraintestinal LCVs containing L. pneumophila cyst forms in C. elegans tissues, highlighting the potential of soil-dwelling nematodes as an alternate environmental reservoir for L. pneumophila. © 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

[Investigation of Legionella pneumophila seropositivity in the professional long distance drivers as a risky occupation].

Science.gov (United States)

Polat, Yusuf; Ergin, Cağri; Kaleli, Ilknur; Pinar, Ahmet

2007-04-01

Contaminated water sources, reservoirs and systems such as evaporative condensers of air-conditioners are known to be the main transmission routes of Legionella spp. which are ubiquitous aquatic bacteria. By virtue of this point the aim of this study was to investigate the rate of Legionella pneumophila seropositivity in a profession considered as risky due to the direct and prolonged exposure to air-conditioning and air-circulating systems. For this purpose, in the period of February-August 2004 a total of 79 male subjects (63 were bus drivers and 16 were driver assistants) who were continously travelling to two different route (South part as hot climate and Middle/North parts as cold climate of Turkey) from Denizli province coach station (a province located in internal Aegian where accepted as crossroads), were included to the study. The mean age and mean working duration of bus drivers were 43.0 +/- 1.1 years and 20.0 +/- 1.1 years, respectively, while these values were 22.5 +/- 0.9 years and 4.0 +/- 0.6 years, respectively, for the drivers' assistants. The serum samples collected from the subjects were screened by a commercial indirect immunofluorescence method (Euroimmun, Germany) using L. pneumophila serogrup 1-14 antigens for the presence of specific antibodies. Additionally, air-conditioners' moisture exhaust samples of the busses in which seropositive subjects travelling with have been examined by culture and 5S rRNA gene targeted polymerase chain reaction (PCR) methods, for the presence of Legionella spp. The overall L. pneumophila seropositivity rate was detected as 15.2% (12/79). This rate was 19% (12/63) for bus drivers while all of the drivers' assistants were found seronegative. The seropositivity rate was found statistically higher in the personnel who were travelling to the hot climates (10/36, 27.8%) than those who travel to cold climates (2/43, 4.6%), (p travel. Our data indicated that long distance bus drivers were chronically exposed to this

Free-living protozoa in drinking water supplies: community composition and role as hosts for Legionella pneumophila

NARCIS (Netherlands)

Valster, R.M.

2011-01-01

Free-living protozoa in drinking water supplies: community composition and role as hosts for Legionella pneumophila

Free-living protozoa, which feed on bacteria, play an important role in the communities of microorganisms and invertebrates in drinking water supplies and in (warm)

Occurrence of Legionella pneumophila and Hartmannella vermiformis in fresh water environments and their interactions in biofilms

NARCIS (Netherlands)

Kuiper, M.W.

2006-01-01

Legionella pneumophila, the causative agent of Legionnaires’ disease, is widespread in natural fresh water environments and is also frequently found in man-made water systems. Microbial biofilms and protozoa are known to play a major role in the proliferation of L. pneumophila. Biofilms provide

Field inversion gel electrophoretic analysis of Legionella pneumophila strains associated with nosocomial legionellosis in children.

Science.gov (United States)

Green, M; Wald, E R; Dashefsky, B; Barbadora, K; Wadowsky, R M

1996-01-01

Two nosocomial cases of Legionnaires' disease occurred in children. Legionella pneumophila serogroup 1 was isolated from both patients and 30 of 39 plumbing system sites in the hospital. The patient and hospital environmental isolates yielded identical field inversion gel electrophoretic patterns which differed from patterns observed with epidemiologically unrelated strains.

Identification and DNA fingerprinting of Legionella strains by randomly amplified polymorphic DNA analysis.

OpenAIRE

Bansal, N S; McDonell, F

1997-01-01

The randomly amplified polymorphic DNA (RAPD) technique was used in the development of a fingerprinting (typing) and identification protocol for Legionella strains. Twenty decamer random oligonucleotide primers were screened for their discriminatory abilities. Two candidate primers were selected. By using a combination of these primers, RAPD analysis allowed for the differentiation between all different species, between the serogroups, and further differentiation between subtypes of the same ...

Legionella risk assessment in water installations Algoritmo de evaluación del riesgo de transmisión de 'Legionella' en instalaciones de transporte y tratamiento de masa de agua

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Paulino Pastor Pérez

2005-12-01

Full Text Available Legionelose is an illness produced as a consequence of the inhalation of bacteria of the specie Legionella, which occasionally may colonize some of the water installations of the buildings.This article describes a Legionella risk assessment algorithm particularized for every type of installation covering all the specific characteristics of every piece of equipment, but keeping a common similar structure that allows easiness of use and homogeneous results. This algorithm has been developed by the Experts Commission of the Ministry of Health.The main use of these kind of tools is to minimize as much as possible the subjectivity of the inspectors in the identification and assessment of risks associated to the installations. These types of algorithms are applicable in risks depending on a relative low number of parameters that are somehow easy to control, as it happens in the water installations in the buildings.It has been chosen to develop a global index rated from 0 to 100 (meaning 0 minimum risk and 100 maximum risk distributed in term in three sub indexes, which define the main risk aspects to be taken into account.Structural Index: design.Maintenance Index: maintenance quality.Operational Index: performance of the equipment.Covering all the different aspects of the life of the installations.La legionelosis es una enfermedad producida por la inhalación de bacterias de la especie Legionella, que ocasionalmente pueden colonizar algunas instalaciones de la edificación que utilizan agua para su funcionamiento.El presente articulo describe un algoritmo de evaluación del riesgo de transmisión de legionelosis particularizado para cada tipo de instalación de riesgo a fin de cubrir las características especificas de cada equipo, pero con una estructura común similar, para asegurar la sencillez de uso y la homogeneidad de resultados. Este algoritmo ha sido desarrollado en el seno de la Comisión de Expertos de Legionella del Ministerio de Sanidad

High Prevalence and Genetic Polymorphisms of Legionella in Natural and Man-Made Aquatic Environments in Wenzhou, China

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Leyi Zhang

2017-02-01

Full Text Available 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

The Amoebal MAP Kinase Response to Legionella pneumophila Is Regulated by DupA

OpenAIRE

Li, Zhiru; Dugan, Aisling S.; Bloomfield, Gareth; Skelton, Jason; Ivens, Alasdair; Losick, Vicki; Isberg, Ralph R.

2009-01-01

The amoeba Dictyostelium discoideum can support replication of Legionella pneumophila. Here we identify the dupA gene, encoding a putative tyrosine kinase/dual-specificity phosphatase, in a screen for D. discoideum mutants altered in allowing L. pneumophila intracellular replication. Inactivation of dupA resulted in depressed L. pneumophila growth and sustained hyperphosphorylation of the amoebal MAP kinase ERK1, consistent with loss of a phosphatase activity. Bacterial challenge of wild-type...

Control of Branchionus sp. and Amoeba sp. in cultures of Arthrospira sp. Control de Branchionus sp. y Amoeba sp. en cultivos de Arthrospira sp.

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Carlos Méndez

2012-09-01

Full Text Available Cultivation of cyanobacterium Arthrospira sp. has been developed in many countries for the production of proteins, pigments and other compounds. Outdoor mass cultures are often affected by biological contamination, drastically reducing productivity as far as bringing death. This study evaluates the control of Branchionus sp. and Amoeba sp. with two chemical compounds: urea (U and ammonium bicarbonate (AB, in laboratory conditions and outdoor mass culture of Arthrospira sp. The lethal concentration 100 (LC100 at 24 h for Branchionus sp. and Amoeba sp. determined was of 60-80 mg L-1 (U and 100-150 mg L-1 (AB. The average effective inhibition concentration for 50% of the population (IC50 in Arthrospira sp., after 72 h, was 80 mg L-1 (U and 150 mg L-1 (AB. The application of doses of 60 mg L-1 (U or 100 mg L-1 (AB in the outdoor mass culture of this contaminated microalga, completely inhibited grazing and did not affect the growth of Arthrospira sp. but rather promoted rapid recovery of algal density at levels prior to infestation. These compounds provided an economical and effective control of predators in cultures of Arthrospira sp.El cultivo de la cianobacteria Arthrospira sp. ha sido desarrollado en muchos países para la obtención de proteínas, pigmentos y otros compuestos. Cultivo que a nivel industrial se ve afectado frecuentemente por contaminación biológica, reduciendo drásticamente la productividad hasta causar la muerte. Este estudio evalúa el control de Branchionus sp. y de Amoeba sp. con dos compuestos químicos, la urea (U y bicarbonato de amonio (AB en cultivos de Arthrospira sp. La concentración letal 100 (LC100 determinada a las 24 h para Branchionus sp. y Amoeba sp. fue de 60-80 mg L-1 (U y 100-150 mg L-1 (AB. La concentración media de inhibición efectiva, después de 72 h, para el 50% de la población (IC50 en Arthrospira fue de 80 mg L-1 (U y 150 mg L-1 (AB. La aplicación de dosis de 60 mg L-1 (U ó 100 mg L-1 (AB en

Detection of protozoan hosts for Legionella pneumophila in engineered water systems by using a biofilm batch test

NARCIS (Netherlands)

Valster, R.M.; Wullings, B.A.; Kooij, van der D.

2010-01-01

Legionella pneumophila proliferates in aquatic habitats within free-living protozoa, 17 species of which have been identified as hosts by using in vitro experiments. The present study aimed at identifying protozoan hosts for L. pneumophila by using a biofilm batch test (BBT). Samples (600 ml)

Septic arthritis due to Legionella cincinnatiensis: case report and review of the literature.

Science.gov (United States)

Banderet, Florian; Blaich, Annette; Soleman, Evelin; Gaia, Valeria; Osthoff, Michael

2017-08-01

Legionella spp. are an important cause of pulmonary and rarely extrapulmonary infections. L. cincinnatiensis has only been implicated in five cases to date. We herein report the first case of L. cincinnatiensis septic arthritis in a 90-year old lady with a past medical history of chronic kidney disease. She developed septic arthritis of her left wrist after having received intraarticular corticosteroid injections and oral corticosteroids administered for presumed chondrocalcinosis. Appropriate antimicrobial treatment of L. cincinnatiensis septic arthritis was delayed until identification of this organism in joint biopsies by broad-range bacterial PCR targeting the 16S rRNA gene with subsequent rDNA sequence analysis and by culture on special media. Reviewing all reported cases of septic arthritis caused by Legionella spp. other than L. cincinnatiensis it is notable that diagnosis was established by PCR in the majority of cases and only subsequently confirmed by special culture. Although most patients were immunosuppressed, outcome was favourable. Treatment consisted of a fluoroquinolone alone or in combination with rifampicin or a macrolide. Our case highlights the need for a high index of suspicion for infections with unusual/fastidious organisms when symptoms are suggestive of septic arthritis but conventional methods fail to identify a causative organism.

Legionella phosphatase hydrolyzes phosphatidylinositol 4,5-bisphosphate and inosital triphosphate in human neutrophils

International Nuclear Information System (INIS)

Dowling, J.N.; Saha, A.K.; Glew, R.H.

1987-01-01

Legionella are facultative intracellular bacterial pathogens which multiply in host phagocytes. L. micdadei cells contain an acid phosphatase (ACP) that blocks superoxide anion production by human neutrophils stimulated with the formylated peptide, fMLP. The possibility that ACP acts by interefering with polyphosphoinositide metabolism and the production of the intracellular second messenger, inositol triphosphate (IP 3 ) was explored. When neutrophil phosphoinositides were labeled with 32 P, incubation of the cells with ACP caused an 85% loss of the labeled phosphatidylinositol-4,5-bisphosphate (PIP 2 ) over 2 h. Treatment of [ 3 H]inositol-labeled neutrophils with ACP for 30 min resulted in a 20% decrease of labeled PIP 2 . Following fMLP stimulation, the fractional reduction in PIP 2 and the fractional increase in IP 3 was the same in ACP-treated and untreated neutrophils, but the total quantity of IP 3 was reduced by ACP pre-treatment. The reduction in IP 3 generated following fMLP stimulation seems to be due primarily to the decreased amount of PIP 2 available for hydrolysis. However, some loss of IP 3 due to direct hydrolysis by ACP cannot be ruled out. The Legionella phosphatase may compromise neutrophil response to the bacteria by hydrolyzing PIP 2 , the prognitor of IP 3 , and by hydrolyzing IP 3 itself

Perfil clínico, epidemiológico e etiológico de pacientes com pneumonia adquirida na comunidade internados em um hospital geral da microrregião de Sumaré, SP Clinical, epidemiological, and etiological profile of inpatients with community-acquired pneumonia at a general hospital in the Sumaré microregion of Brazil

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Maria Rita Donalisio

2011-04-01

Full Text Available OBJETIVO: Analisar aspectos clínicos, etiológicos e epidemiológicos das pneumonias adquiridas na comunidade (PAC em indivíduos internados. MÉTODOS: Foram estudados prospectivamente 66 pacientes com PAC maiores de 14 anos no Hospital Estadual Sumaré, localizado na cidade de Sumaré (SP, entre outubro de 2005 e setembro de 2007. Coletamos dados sobre história clínica, exame clínico, escore pneumonia severity index (PSI e exames laboratoriais (hemocultura, bacterioscopia/cultura de escarro, sorologias para Chlamydophila pneumoniae, Mycoplasma pneumoniae e Legionella pneumophila, além de antígenos urinários de Legionella sp. e Streptococcus pneumoniae. RESULTADOS: A idade média dos pacientes foi de 53 anos, a maioria tinha baixa escolaridade, e 55,7% apresentavam pelo menos uma comorbidade no momento da internação. O percentual de idosos vacinados contra influenza entre os internados foi significativamente menor que os da comunidade dos municípios da microrregião de Sumaré (52,6% vs. > 70%. A febre foi menos frequente entre os idosos (p OBJECTIVE: To analyze the clinical, etiological, and epidemiological aspects of community-acquired pneumonia (CAP in hospitalized individuals. METHODS: We prospectively studied 66 patients (> 14 years of age with CAP admitted to the Hospital Estadual Sumaré, located in the Sumaré microregion of Brazil, between October of 2005 and September of 2007. We collected data related to clinical history, physical examination, pneumonia severity index (PSI scores, and laboratory tests (blood culture; sputum smear microscopy and culture; serology for Chlamydophila pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila; and detection of Legionella sp. and Streptococcus pneumoniae antigens in urine. RESULTS: The mean age of patients was 53 years. Most had a low level of education, and 55.7% presented with at least one comorbidity at the time of hospitalization. The proportion of elderly people vaccinated

Legionella Bozemanae, a New Cause of Septic Arthritis diagnosed by 16S PCR followed by specific culture

DEFF Research Database (Denmark)

Just, Søren Andreas; Bonde Knudsen, John; Skov, Marianne Nielsine

This is the first report ever to demonstrate that L. Bozemanae can colonize synovial joints leading to infectious arthritis. L. Bozemanae is a rare Legionella species, earlier described as a cause of cavitating lung infections with up to 40% mortality (2). L. Bozemanae is missed by standard...

Supply of domestic hot Water at comfortable temperatures by low-temperature district heating without risk of Legionella

DEFF Research Database (Denmark)

Yang, Xiaochen

disinfection efficacy for Legionella if supplied by LTDH, and inject no additives into the water. Thus, they can be considered as feasible sterilization solutions. In terms of the DHW system design methods, in addition to ensure the safe and hygiene DHW supply, the potential DHW systems should also...... temperature for space heating but lower than LTDH. Therefore, to meet the comfort and hygiene requirements for DHW supply, supplementary heating methods should be combined. However, one obstacle to realize the LTDH/ULTDH is the concern of the violation of the comfort and hygiene requirements of DHW supply....... According to the Danish standard, the supply for DHW should be able to reach 45 °C for the kitchen use and 40 °C for other uses for comfort. Regarding to the hygiene requirements, large DHW system with DHW storage tank and circulation has to use high temperature regime to get rid of Legionella. The storage...

Legionella spp. and legionellosis in southeastern Italy: disease epidemiology and environmental surveillance in community and health care facilities

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Barbuti Giovanna

2010-11-01

Full Text Available Abstract Background Following the publication of the Italian Guidelines for the control and prevention of legionellosis an environmental and clinical surveillance has been carried out in Southeastern Italy. The aim of the study is to identify the risk factors for the disease, so allowing better programming of the necessary prevention measures. Methods During the period January 2000 - December 2009 the environmental surveillance was carried out by water sampling of 129 health care facilities (73 public and 56 private hospitals and 533 buildings within the community (63 private apartments, 305 hotels, 19 offices, 4 churches, 116 gyms, 3 swimming pools and 23 schools. Water sampling and microbiological analysis were carried out following the Italian Guidelines. From January 2005, all facilities were subject to risk analysis through the use of a standardized report; the results were classified as good (G, medium (M and bad (B. As well, all the clinical surveillance forms for legionellosis, which must be compiled by physicians and sent to the Regional Centre for Epidemiology (OER, were analyzed. Results Legionella spp. was found in 102 (79.1% health care facilities and in 238 (44.7% community buildings. The percentages for the contamination levels 10,000 cfu/L were respectively 33.1%, 53.4% and 13.5% for samples from health care facilities and 33.5%, 43.3% and 23.2% for samples from the community. Both in hospital and community environments, Legionella pneumophila serogroup (L. pn sg 2-14 was the most frequently isolate (respectively 54.8% and 40.8% of positive samples, followed by L. pn sg 1 (respectively 31.3% and 33%. The study showed a significant association between M or B score at the risk analysis and Legionella spp. positive microbiological test results (p Conclusions Our experience suggests that risk analysis and environmental microbiological surveillance should be carried out more frequently to control the environmental spread of Legionella

Seroprevalencia de Leptospira sp., Rickettsia sp. Ehrlichia sp. en trabajadores rurales del departamento de Sucre, Colombia Seroprevalence of Leptospira sp., Rickettsia sp. and Ehrlichia sp. in rural workers of Sucre, Colombia

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Rodrigo Ríos

2008-06-01

Full Text Available Objective. Determinar la seroprevalencia de Leptospira sp., Rickettsia sp. y Ehrlichia sp. en trabajadores de áreas rurales del departamento de Sucre. Material y métodos. Se realizó un estudio escriptivo, prospectivo, de corte transversal, que pretendió determinar la seroprevalencia e Leptospira sp., Rickettsia sp. y Ehrlichia sp. en 90 trabajadores de áreas rurales del departamento de Sucre. Se estableció la presencia de anticuerpos séricos anti-IgM específicos anti-Leptospira por la técnica de ELISA indirecta. Para la determinación de Rickettsia sp. y Ehrlichia sp. se uso la técnica de inmunofluorescencia indirecta. Resultados. La población evaluada estaba compuesta por 27 (30% ordeñadores, 21 (23% jornaleros, 18 (20% profesionales del campo y 24 (27% que realizaban otras actividades. Ventidós (24% muestras resultaron positivas en alguna de las pruebas. De éstas, 12 (13,3% fueron positivas para Leptospira sp., 7 (7,8% para Rickettsia sp. y 3 (3,3% ara Ehrlichia sp. Conclusión. Este fue el primer estudio que se llevó a cabo en el departamento de Sucre y permitió demostrar que existe una prevalencia importante de Leptospira p.,Rickettsia sp. y Ehrlichia sp.. Los factores de riesgo ocupacional fueron factores determinantes en la seropositividad.Objective. To determine the seroprevalence of Leptospira sp., Rickettsia sp. and Ehrlichia sp. in agricultural workers of Sucre. Methods. A descriptive prospective cross-sectional study was conducted in ninety rural workers of Sucre. Presence of serum antibodies anti-IgM specific anti-Leptospira by indirect ELISA was established. For the determination of Rickettsia and Ehrlichia indirect inmunoflorescence was used. Results.The population was composed by 27 (30% milkers, 21 (23% day workers, 18 farm professionals (20% and 24 (26% workers in others activities. A total of 22 (24% samples were positive to some test. Twelve (13.3% were positive to Leptospira sp., seven (7.8% to Rickettsia sp

Molecular Detection of Legionella spp. and their associations with Mycobacterium spp., Pseudomonas aeruginosa and amoeba hosts in a drinking water distribution system

Data.gov (United States)

U.S. Environmental Protection Agency — Quantity of Legionella spp., Mycobacterium spp., Acanthamoeba,Vermamoeba vermiformis and Pseudomonas aeruginosa were estimated using qPCR methods. This dataset is...

Surface display of a massively variable lipoprotein by a Legionella diversity-generating retroelement.

Science.gov (United States)

Arambula, Diego; Wong, Wenge; Medhekar, Bob A; Guo, Huatao; Gingery, Mari; Czornyj, Elizabeth; Liu, Minghsun; Dey, Sanghamitra; Ghosh, Partho; Miller, Jeff F

2013-05-14

Diversity-generating retroelements (DGRs) are a unique family of retroelements that confer selective advantages to their hosts by facilitating localized DNA sequence evolution through a specialized error-prone reverse transcription process. We characterized a DGR in Legionella pneumophila, an opportunistic human pathogen that causes Legionnaires disease. The L. pneumophila DGR is found within a horizontally acquired genomic island, and it can theoretically generate 10(26) unique nucleotide sequences in its target gene, legionella determinent target A (ldtA), creating a repertoire of 10(19) distinct proteins. Expression of the L. pneumophila DGR resulted in transfer of DNA sequence information from a template repeat to a variable repeat (VR) accompanied by adenine-specific mutagenesis of progeny VRs at the 3'end of ldtA. ldtA encodes a twin-arginine translocated lipoprotein that is anchored in the outer leaflet of the outer membrane, with its C-terminal variable region surface exposed. Related DGRs were identified in L. pneumophila clinical isolates that encode unique target proteins with homologous VRs, demonstrating the adaptability of DGR components. This work characterizes a DGR that diversifies a bacterial protein and confirms the hypothesis that DGR-mediated mutagenic homing occurs through a conserved mechanism. Comparative bioinformatics predicts that surface display of massively variable proteins is a defining feature of a subset of bacterial DGRs.

Acanthamoeba polyphaga resuscitates viable non-culturable Legionella pneumophila after disinfection.

Science.gov (United States)

García, María Teresa; Jones, Snake; Pelaz, Carmen; Millar, Richard D; Abu Kwaik, Yousef

2007-05-01

Amoebae are the natural hosts for Legionella pneumophila and play essential roles in bacterial ecology and infectivity to humans. When L. pneumophila colonizes an aquatic installation, it can persist for years despite repeated treatments with disinfectants. We hypothesized that freshwater amoebae play an important role in bacterial resistance to disinfectants, and in subsequent resuscitation of viable non-culturable (VNC) L. pneumophila that results in re-emergence of the disease-causing strain in the disinfected water source. Our work showed that in the absence of Acanthamoeba polyphaga, seven L. pneumophila strains became non-culturable after treatment by 256 p.p.m. of sodium hypochlorite (NaOCl). In contrast, intracellular L. pneumophila within A. polyphaga was resistant to 1024 p.p.m. of NaOCl. In addition, L. pneumophila-infected A. polyphaga exhibited increased resistance to NaOCl. When chlorine-sterilized water samples were co-cultured with A. polyphaga, the non-culturable L. pneumophila were resuscitated and proliferated robustly within A. polyphaga. Upon treatment by NaOCl, uninfected amoebae differentiated into cysts within 48 h. In contrast, L. pneumophila-infected A. polyphaga failed to differentiate into cysts, and L. pneumophila was never detected in cysts of A. polyphaga. We conclude that amoebic trophozoites protect intracellular L. pneumophila from eradication by NaOCl, and play an essential role in resuscitation of VNC L. pneumophila in NaOCl-disinfected water sources. Intracellular L. pneumophila within trophozoites of A. polyphaga block encystation of the amoebae, and the resistance of both organisms to NaOCl is enhanced. To ensure long-term eradication and complete loss of the VNC state of L. pneumophila, we recommend that Legionella-protozoa co-culture should be an important tool to ensure complete loss of the VNC state of L. pneumophila.

Effect of non-Legionellaceae bacteria on the multiplication of Legionella pneumophila in potable water.

OpenAIRE

Wadowsky, R M; Yee, R B

1985-01-01

A naturally occurring suspension of Legionella pneumophila and associated microbiota contained three unidentified non-Legionellaceae bacteria which supported satellite growth of a subculture of L. pneumophila on an L-cysteine-deficient medium and another bacterium which did not support growth of the subculture. Washed suspensions containing 10(3), 10(5), 10(7), or 10(8) CFU of a mixture of isolates of these non-Legionellaceae bacteria failed to support the multiplication of an isolate of agar...

Invasion of Eukaryotic Cells by Legionella Pneumophila: A Common Strategy for all Hosts?

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Paul S Hoffman

1997-01-01

Full Text Available Legionella pneumophila is an environmental micro-organism capable of producing an acute lobar pneumonia, commonly referred to as Legionnaires’ disease, in susceptible humans. Legionellae are ubiquitous in aquatic environments, where they survive in biofilms or intracellularly in various protozoans. Susceptible humans become infected by breathing aerosols laden with the bacteria. The target cell for human infection is the alveolar macrophage, in which the bacteria abrogate phagolysosomal fusion. The remarkable ability of L pneumophila to infect a wide range of eukaryotic cells suggests a common strategy that exploits very fundamental cellular processes. The bacteria enter host cells via coiling phagocytosis and quickly subvert organelle trafficking events, leading to formation of a replicative phagosome in which the bacteria multiply. Vegetative growth continues for 8 to 10 h, after which the bacteria develop into a short, highly motile form called the ‘mature form’. The mature form exhibits a thickening of the cell wall, stains red with the Gimenez stain, and is between 10 and 100 times more infectious than agar-grown bacteria. Following host cell lysis, the released bacteria infect other host cells, in which the mature form differentiates into a Gimenez-negative vegetative form, and the cycle begins anew. Virulence of L pneumophila is considered to be multifactorial, and there is growing evidence for both stage specific and sequential gene expression. Thus, L pneumophila may be a good model system for dissecting events associated with the host-parasite interactions.

Planktonic replication is essential for biofilm formation by Legionella pneumophila in a complex medium under static and dynamic flow conditions

DEFF Research Database (Denmark)

Mampel, J.; Spirig, T.; Weber, S.S.

2006-01-01

Legionella pneumophila persists for a long time in aquatic habitats, where the bacteria associate with biofilms and replicate within protozoan predators. While L. pneumophila serves as a paradigm for intracellular growth within protozoa, it is less clear whether the bacteria form or replicate...

Insufficient knowledge on legionella control; Kennis legionellabeheersing ontbreekt nogal eens

Energy Technology Data Exchange (ETDEWEB)

Kordes, B. [Kordes Advies, Wijhe (Netherlands); Nuijten, O. [Isso, Rotterdam (Netherlands)

2011-05-15

After the lethal incident in the cooling tower of Amsterdam in 2006, legislation has been adapted. Parties that operate a wet cooling tower need to take precautions to prevent risks for the surroundings and to prevent unusual events or limit these to the best possible extent. Moreover, compliance with the Activities Decree (article 3.16a on legionella prevention in the Environmental legislation) is required. [Dutch] Na het incident met dodelijke afloop in de koeltoren in Amsterdam in 2006 is de wetgeving aangepast. Degene die een natte koeltoren beheert moet risico's voor de omgeving en ongewone voorvallen voorkomen of deze zoveel mogelijk beperken. Ook moet ten minste aan Activiteitenbesluit (artikel 3.16a over legionellapreventie in de Milieuwetgeving) worden voldaan.

Effect of Various Water Chemistry Factors on Legionella Proliferation and the Premise Plumbing Microbiome Composition

OpenAIRE

Proctor, Caitlin Rose

2014-01-01

Premise plumbing, the pipes and fixtures at the building level, present a unique challenge for maintaining drinking water quality. Of particular concern are opportunistic pathogens, including Legionella pneumophila which can regrow in premise plumbing and cause disease in immunocompromised populations. The goal of this work was to explore engineering methods for control of L. pneumophila and total regrowth. The first line of study involved a series of experiments with simulated glass water he...

Studio del comportamento di Acanthamoeba. polyphaga in presenza di Legionella pneumophila e di altri batteri ad habitat acquatico

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M. Bondi

2003-05-01

Full Text Available Le amebe a vita libera sono state oggetto di diversi studi negli ultimi anni, non solo per le loro potenzialità patogene nei confronti dell’uomo, ma anche per l’importante ruolo che svolgono in natura, dove agiscono come predatori in grado di controllare le popolazioni batteriche. Alcuni degli organismi fagocitati però possono evitare la lisi fagosomiale e mantenere la loro condizione vitale a livello intracellulare, divenendo endosimbionti. Le amebe fungono così da riserva per questi batteri, proteggendoli da difficili condizioni extracellulari e provvedendo ad un ambiente consono alla loro replicazione. Tale tipo di interazione è particolarmente studiata in Legionella pneumophila, dal momento che l’ampia diffusione di questo germe, nonché la sua virulenza, pare siano fortemente influenzate dalla capacità di parassitare protozoi appartenenti ai generi Acanthamoeba, Naegleria e Balamuthia. Al fine di ottenere maggiori informazioni sui fattori favorenti o inibenti lo sviluppo di questi protozoi, è stato studiato il comportamento di un ceppo di Acanthamoeba polyphaga coltivato, in solido e in liquido, in associazione con L. pneumophila ed altri batteri ad habitat acquatico (Pseudomonas, Aeromonas, Achromobacter, Burkholderia. Su tappeti di cellule batteriche allestiti in Non Nutrient Agar (NNA, A.polyphaga si è mostrata in grado di moltiplicarsi utilizzando come nutrimento tutti i ceppi testati, nonostante alcuni, come Burkholderia cepacia SSV6 e Achromobacter xylox SS28, risultino più idonei al suo sviluppo. In piastre a pozzetti addizionate di acqua condottata autoclavata, il protozoo ha mostrato una buona capacità di sopravvivenza, non risultando inoltre influenzato dalla presenza di legionella o dei batteri acquatici testati. Dal momento che, fra i batteri descritti come capaci di vita intra-amebica, sono inclusi patogeni quali Chlamydia, Legionella, Listeria e Rickettsiae, risulta necessario riconsiderare la rilevanza clinica

Influence of Sampling Season and Sampling Protocol on Detection of Legionella Pneumophila Contamination in Hot Water / Paraugu Ņemšanas Sezonalitātes Un Paraugu Ņemšanas Metodes Ietekme Uz Legionella Pneumophila Kontaminācijas Noteikšanu Karstajš Ūdenī

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Pūle Daina

2016-08-01

Full Text Available Legionella pneumophila is an environmental pathogen of engineered water systems that can cause different forms of legionellosis - from mild fever to potentially lethal pneumonia. Low concentrations of legionellae in natural habitats can increase markedly in engineered hot water systems where water temperatures are below 55 °C. In the current study, we aimed to investigate the influence of sampling season, hot water temperature and sampling protocol on occurrence of L. pneumophila. A total of 120 hot water samples from 20 apartment buildings were collected in two sampling periods - winter 2014 (n = 60 and summer 2015 (n = 60. Significantly higher occurrence of L. pneumophila was observed in summer 2015. Significant differences in temperature for negative and positive samples were not observed, which can be explained by low water temperatures at the point of water consumption. Temperature above 55 °C was observed only once, for all other sampling events it ranged from 14 °C to 53 °C.

Métodos analíticos para el estudio de Legionella

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Carmen Pelaz Antolín

2006-12-01

Full Text Available Los ensayos para la determinación de Legionella en muestras de agua son uno de los aspectos contemplados en la legislación española sobre prevención de legionelosis. La periodicidad de estos ensayos en función del tipo de instalación, los laboratorios que los realizan, y las acciones correctoras que derivan de ellos en función de los recuentos bacterianos son acciones incluidas en los planes de mantenimiento preventivo de las instalaciones consideradas de riesgo (Real Decreto 865/2003. La comparación de nuestra legislación con otras legislaciones o recomendaciones adoptadas en otros paises (Reino Unido, Francia, Australia, América permite conocer nuestro grado de exigencia en relación a algunos de los parámetros contemplados. El cultivo de la bacteria es el método de referencia para la detección de Legionella en muestras de agua y existen varios ensayos normalizados, como los estándares ISO 11731/98 y 2004 y NF T 90- 431/2003 (AFNOR. Para ayudar a la interpretación de los resultados, los ensayos deben reflejar el estándar en el que se basan y el límite de detección del método, que no debe ser superior a 100 ufc/L. Además, los laboratorios que realizan estos ensayos deben estar acreditados por nuestra entidad de acreditación ENAC. En los últimos años se han desarrollado métodos rápidos de detección de la bacteria basados en la amplificación de ADN cromosómico en muestras de agua mediante reacciones de PCR. El desarrollo científico de estos métodos va por delante del desarrollo reglamentario, y los ensayos de PCR no deben desplazar a los ensayos de cultivo en cumplimiento de las normativas vigentes, sino que deben complementarlo.

Viability qPCR, a new tool for Legionella risk management.

Science.gov (United States)

Lizana, X; López, A; Benito, S; Agustí, G; Ríos, M; Piqué, N; Marqués, A M; Codony, F

2017-11-01

Viability quantitative Polymerase Chain Reaction (v-qPCR) is a recent analytical approach for only detecting live microorganisms by DNA amplification-based methods This approach is based on the use of a reagent that irreversibly fixes dead cells DNA. In this study, we evaluate the utility of v-qPCR versus culture method for Legionellosis risk management. The present study was performed using 116 real samples. Water samples were simultaneously analysed by culture, v-qPCR and qPCR methods. Results were compared by means of a non-parametric test. In 11.6% of samples using both methods (culture method and v-qPCR) results were positive, in 50.0% of samples both methods gave rise to negative results. As expected, equivalence between methods was not observed in all cases, as in 32.1% of samples positive results were obtained by v-qPCR and all of them gave rise to negative results by culture. Only in 6.3% of samples, with very low Legionella levels, was culture positive and v-qPCR negative. In 3.5% of samples, overgrowth of other bacteria did not allow performing the culture. When comparing both methods, significant differences between culture and v-qPCR were in the samples belonging to the cooling towers-evaporative condensers group. The v-qPCR method detected greater presence and obtained higher concentrations of Legionella spp. (p<0.001). Otherwise, no significant differences between methods were found in the rest of the groups. The v-qPCR method can be used as a quick tool to evaluate Legionellosis risk, especially in cooling towers-evaporative condensers, where this technique can detect higher levels than culture. The combined interpretation of PCR results along with the ratio of live cells is proposed as a tool for understanding the sample context and estimating the Legionellosis risk potential according to 4 levels of hierarchy. Copyright © 2017 Elsevier GmbH. All rights reserved.

Comparative analysis of virulence traits between a Legionella feeleii strain implicated in Pontiac fever and a strain that caused Legionnaires' disease.

Science.gov (United States)

Wang, Changle; Saito, Mitsumasa; Tanaka, Tamami; Amako, Kazunobu; Yoshida, Shin-ichi

2015-12-01

Legionella strains of the same species and serogroup are known to cause Legionnaires' disease (a potentially fatal atypical pneumonia) or Pontiac fever (a mild, flu-like disease), but the bacterial factors that define these dramatic differences in pathology have not been elucidated. To gain a better understanding of these factors, we compared the characteristics of Legionella feeleii strains that were isolated from either a sample of freshwater implicated in an outbreak of Pontiac fever (ATCC 35072, serogroup 1, LfPF), or a patient with Legionnaires' disease (ATCC 38549, serogroup 2, LfLD). Growth of LfPF and LfLD in BYE broth was slower than the positive control, Legionella pneumophila strain JR32. However, LfLD grew faster than LfPF at 42 °C. After in vitro infection to J774 murine or U937 human macrophage cell lines and A549 human lung epithelial cell line, LfLD showed a higher cell infection rate, stronger internalization by host cells, and greater cytotoxicity than that of LfPF. Large amounts of IL-6 and IL-8 were secreted by human host cells after infection with LfLD, but not with LfPF. LfLD possessed mono-polar flagellum while LfPF was unflagellated. When LfLD was cultured at 25, 30 and 37 °C, the bacteria had higher motility rate at lower temperatures. Based on our results, this is the first study that showed distinct characteristics between LfPF and LfLD, which may give important leads in elucidating differences in their virulence. Copyright © 2015 Elsevier Ltd. All rights reserved.

Crystallization and preliminary crystallographic analysis of an aminoglycoside kinase from Legionella pneumophila

International Nuclear Information System (INIS)

Lemke, Christopher T.; Hwang, Jiyoung; Xiong, Bing; Cianciotto, Nicholas P.; Berghuis, Albert M.

2005-01-01

Two crystal forms of the antibiotic resistance enzyme APH(9)-Ia from L. pneumophila are reported. 9-Aminoglycoside phosphotransferase type Ia [APH(9)-Ia] is a resistance factor in Legionella pneuemophila, the causative agent of legionnaires’ disease. It is responsible for providing intrinsic resistance to the antibiotic spectinomycin. APH(9)-Ia phosphorylates one of the hydroxyl moieties of spectinomycin in an ATP-dependent manner, abolishing the antibiotic properties of this drug. Here, the crystallization and preliminary X-ray studies of this enzyme in two crystal forms is reported. One of the these crystal forms provides diffraction data to a resolution of 1.7 Å

A multicenter evaluation of the Biotest legionella urinary antigen EIA

DEFF Research Database (Denmark)

Harrison, Timothy; Uldum, Søren; Alexiou-Daniel, Stella

1998-01-01

OBJECTIVES: To undertake a multicenter study to evaluate the Biotest legionella urinary antigen enzyme immunoassay (EIA) performance against those EIAs already in use in 14 European laboratories. METHODS: Each laboratory examined urine specimens from appropriate patients using both their current...... assay and the Biotest EIA. Each examined: a standard panel of 12 coded urine samples (distributed by Biotest); a panel of 10 coded urine samples provided as part of a European external quality assurance (EQA) scheme; urine samples from patients with proven legionnaires' disease (LD); urine samples from...... patients with pneumonia of microbiologically proven cause other than LD; and urine samples submitted for routine examination. Thus, the performance of the Biotest assay (in comparison with current EIAs), its specificity and utility, and the inter-laboratory agreement were assessed. RESULTS: Inter...

Topology of Legionella pneumophila DotA: an inner membrane protein required for replication in macrophages.

OpenAIRE

Roy, C R; Isberg, R R

1997-01-01

The Legionella pneumophila dotA gene is required for intracellular growth of the bacterium in macrophages. In this study, a structure-function analysis of the DotA protein was conducted to elucidate the role of this protein in L. pneumophila pathogenesis. Translational fusions of dotA to the Escherichia coli phoA and lacZ genes indicated that DotA is an integral cytoplasmic membrane protein with eight membrane-spanning domains. DotA contains two large periplasmic domains of approximately 503 ...

CT features of legionella pneumonia, compared with streptococcal pneumonia. A collaborative study

International Nuclear Information System (INIS)

Tokuda, Hitoshi; Sakai, Fumikazu; Goto, Hajime

2007-01-01

Legionella pneumophila pneumonia (LPP) is of serious concern for chest physicians for its potential lethality and difficulty of diagnosis. In spite of widespread use of urine antigen detection method, it remains one of the most difficult-to-treat disease among community acquired pneumonia. We investigated CT images of 38 cases of LPP, comparing them with wide spread Streptococcus pneumoniae pneumonia (SPP). We find that sharply demarcated consolidation scattered in ground-glass opacity is the most striking and pathognomonic feature of LPP, which is rarely found in SPP. Bronchiolitis was not found in LPP, while it is a relatively common finding in SPP, which could be the second clue of differentiation of these two diseases. (author)

Short-Term and Long-Term Survival and Virulence of Legionella pneumophila in the Defined Freshwater Medium Fraquil.

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Nilmini Mendis

Full Text Available Legionella pneumophila (Lp is the etiological agent responsible for Legionnaires' disease, a potentially fatal pulmonary infection. Lp lives and multiplies inside protozoa in a variety of natural and man-made water systems prior to human infection. Fraquil, a defined freshwater medium, was used as a highly reproducible medium to study the behaviour of Lp in water. Adopting a reductionist approach, Fraquil was used to study the impact of temperature, pH and trace metal levels on the survival and subsequent intracellular multiplication of Lp in Acanthamoeba castellanii, a freshwater protozoan and a natural host of Legionella. We show that temperature has a significant impact on the short- and long-term survival of Lp, but that the bacterium retains intracellular multiplication potential for over six months in Fraquil. Moreover, incubation in Fraquil at pH 4.0 resulted in a rapid decline in colony forming units, but was not detrimental to intracellular multiplication. In contrast, variations in trace metal concentrations had no impact on either survival or intracellular multiplication in amoeba. Our data show that Lp is a resilient bacterium in the water environment, remaining infectious to host cells after six months under the nutrient-deprived conditions of Fraquil.

Promotion and Rescue of Intracellular Brucella neotomae Replication during Coinfection with Legionella pneumophila.

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Kang, Yoon-Suk; Kirby, James E

2017-05-01

We established a new Brucella neotomae in vitro model system for study of type IV secretion system-dependent (T4SS) pathogenesis in the Brucella genus. Importantly, B. neotomae is a rodent pathogen, and unlike B. abortus , B. melitensis , and B. suis , B. neotomae has not been observed to infect humans. It therefore can be handled more facilely using biosafety level 2 practices. More particularly, using a series of novel fluorescent protein and lux operon reporter systems to differentially label pathogens and track intracellular replication, we confirmed T4SS-dependent intracellular growth of B. neotomae in macrophage cell lines. Furthermore, B. neotomae exhibited early endosomal (LAMP-1) and late endoplasmic reticulum (calreticulin)-associated phagosome maturation. These findings recapitulate prior observations for human-pathogenic Brucella spp. In addition, during coinfection experiments with Legionella pneumophila , we found that defective intracellular replication of a B. neotomae T4SS virB4 mutant was rescued and baseline levels of intracellular replication of wild-type B. neotomae were significantly stimulated by coinfection with wild-type but not T4SS mutant L. pneumophila Using confocal microscopy, it was determined that intracellular colocalization of B. neotomae and L. pneumophila was required for rescue and that colocalization came at a cost to L. pneumophila fitness. These findings were not completely expected based on known temporal and qualitative differences in the intracellular life cycles of these two pathogens. Taken together, we have developed a new system for studying in vitro Brucella pathogenesis and found a remarkable T4SS-dependent interplay between Brucella and Legionella during macrophage coinfection. Copyright © 2017 American Society for Microbiology.

The Legionella pneumophila kai operon is implicated in stress response and confers fitness in competitive environments

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Loza-Correa, Maria; Sahr, Tobias; Rolando, Monica; Daniels, Craig; Petit, Pierre; Skarina, Tania; Valero, Laura Gomez; Dervins-Ravault, Delphine; Honoré, Nadine; Savchenko, Aleksey; Buchrieser, Carmen

2014-01-01

Summary Legionella pneumophila uses aquatic protozoa as replication niche and protection from harsh environments. Although L. pneumophila is not known to have a circadian clock, it encodes homologues of the KaiBC proteins of Cyanobacteria that regulate circadian gene expression. We show that L. pneumophila kaiB, kaiC and the downstream gene lpp1114, are transcribed as a unit under the control of the stress sigma factor RpoS. KaiC and KaiB of L. pneumophila do not interact as evidenced by yeast and bacterial two-hybrid analyses. Fusion of the C-terminal residues of cyanobacterial KaiB to Legionella KaiB restores their interaction. In contrast, KaiC of L. pneumophila conserved autophosphorylation activity, but KaiB does not trigger the dephosphorylation of KaiC like in Cyanobacteria. The crystal structure of L. pneumophila KaiB suggests that it is an oxidoreductase-like protein with a typical thioredoxin fold. Indeed, mutant analyses revealed that the kai operon-encoded proteins increase fitness of L. pneumophila in competitive environments, and confer higher resistance to oxidative and sodium stress. The phylogenetic analysis indicates that L. pneumophila KaiBC resemble Synechosystis KaiC2B2 and not circadian KaiB1C1. Thus, the L. pneumophila Kai proteins do not encode a circadian clock, but enhance stress resistance and adaption to changes in the environments. PMID:23957615

The Legionella pneumophila GIG operon responds to gold and copper in planktonic and biofilm cultures.

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Jwanoswki, Kathleen; Wells, Christina; Bruce, Terri; Rutt, Jennifer; Banks, Tabitha; McNealy, Tamara L

2017-01-01

Legionella pneumophila contaminates man-made water systems and creates numerous exposure risks for Legionnaires' Disease. Because copper/silver ionization is commonly used to control L. pneumophila, its mechanisms of metal response and detoxification are of significant interest. Here we describe an L. pneumophila operon with significant similarity to the GIG operon of Cupriavidus metallidurans. The Legionella GIG operon is present in a subset of strains and has been acquired as part of the ICE-βox 65-kB integrative conjugative element. We assessed GIG promoter activity following exposure of L. pneumophila to multiple concentrations of HAuCl4, CuSO4 and AgNO3. At 37°C, control stationary phase cultures exhibited GIG promoter activity. This activity increased significantly in response to 20 and 50uM HAuCl4 and CuSO4 but not in response to AgNO3. Conversely, at 26°C, cultures exhibited decreased promoter response to copper. GIG promoter activity was also induced by HAuCl4 or CuSO4 during early biofilm establishment at both temperatures. When an L. pneumophila GIG promoter construct was transformed into E. coli DH5α, cultures showed baseline expression levels that did not increase following metal addition. Analysis of L. pneumophila transcriptional regulatory mutants suggested that GIG up-regulation in the presence of metal ions may be influenced by the stationary phase sigma factor, RpoS.

The Legionella pneumophila GIG operon responds to gold and copper in planktonic and biofilm cultures.

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Kathleen Jwanoswki

Full Text Available Legionella pneumophila contaminates man-made water systems and creates numerous exposure risks for Legionnaires' Disease. Because copper/silver ionization is commonly used to control L. pneumophila, its mechanisms of metal response and detoxification are of significant interest. Here we describe an L. pneumophila operon with significant similarity to the GIG operon of Cupriavidus metallidurans. The Legionella GIG operon is present in a subset of strains and has been acquired as part of the ICE-βox 65-kB integrative conjugative element. We assessed GIG promoter activity following exposure of L. pneumophila to multiple concentrations of HAuCl4, CuSO4 and AgNO3. At 37°C, control stationary phase cultures exhibited GIG promoter activity. This activity increased significantly in response to 20 and 50uM HAuCl4 and CuSO4 but not in response to AgNO3. Conversely, at 26°C, cultures exhibited decreased promoter response to copper. GIG promoter activity was also induced by HAuCl4 or CuSO4 during early biofilm establishment at both temperatures. When an L. pneumophila GIG promoter construct was transformed into E. coli DH5α, cultures showed baseline expression levels that did not increase following metal addition. Analysis of L. pneumophila transcriptional regulatory mutants suggested that GIG up-regulation in the presence of metal ions may be influenced by the stationary phase sigma factor, RpoS.

SPR based immunosensor for detection of Legionella pneumophila in water samples

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Enrico, De Lorenzis; Manera, Maria G.; Montagna, Giovanni; Cimaglia, Fabio; Chiesa, Maurizio; Poltronieri, Palmiro; Santino, Angelo; Rella, Roberto

2013-05-01

Detection of legionellae by water sampling is an important factor in epidemiological investigations of Legionnaires' disease and its prevention. To avoid labor-intensive problems with conventional methods, an alternative, highly sensitive and simple method is proposed for detecting L. pneumophila in aqueous samples. A compact Surface Plasmon Resonance (SPR) instrumentation prototype, provided with proper microfluidics tools, is built. The developed immunosensor is capable of dynamically following the binding between antigens and the corresponding antibody molecules immobilized on the SPR sensor surface. A proper immobilization strategy is used in this work that makes use of an important efficient step aimed at the orientation of antibodies onto the sensor surface. The feasibility of the integration of SPR-based biosensing setups with microfluidic technologies, resulting in a low-cost and portable biosensor is demonstrated.

Silencing the SpMPK1, SpMPK2, and SpMPK3 Genes in Tomato Reduces Abscisic Acid—Mediated Drought Tolerance

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Yan Liang

2013-11-01

Full Text Available Drought is a major threat to agriculture production worldwide. Mitogen-activated protein kinases (MAPKs play a pivotal role in sensing and converting stress signals into appropriate responses so that plants can adapt and survive. To examine the function of MAPKs in the drought tolerance of tomato plants, we silenced the SpMPK1, SpMPK2, and SpMPK3 genes in wild-type plants using the virus-induced gene silencing (VIGS method. The results indicate that silencing the individual genes or co-silencing SpMPK1, SpMPK2, and SpMPK3 reduced the drought tolerance of tomato plants by varying degrees. Co-silencing SpMPK1 and SpMPK2 impaired abscisic acid (ABA-induced and hydrogen peroxide (H2O2-induced stomatal closure and enhanced ABA-induced H2O2 production. Similar results were observed when silencing SpMPK3 alone, but not when SpMPK1 and SpMPK2 were individually silenced. These data suggest that the functions of SpMPK1 and SpMPK2 are redundant, and they overlap with that of SpMPK3 in drought stress signaling pathways. In addition, we found that SpMPK3 may regulate H2O2 levels by mediating the expression of CAT1. Hence, SpMPK1, SpMPK2, and SpMPK3 may play crucial roles in enhancing tomato plants’ drought tolerance by influencing stomatal activity and H2O2 production via the ABA-H2O2 pathway.

Incubation of premise plumbing water samples on Buffered Charcoal Yeast Extract agar at elevated temperature and pH selects for Legionella pneumophila.

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Veenendaal, Harm R; Brouwer-Hanzens, Anke J; van der Kooij, Dick

2017-10-15

Worldwide, over 90% of the notified cases of Legionnaires' disease are caused by Legionella pneumophila. However, the standard culture medium for the detection of Legionella in environmental water samples, Buffered Charcoal Yeast Extract (BCYE) agar of pH 6.9 ± 0.4 with or without antimicrobial agents incubated at 36 ± 1 °C, supports the growth of a large diversity of Legionella species. BCYE agar of elevated pH or/and incubation at elevated temperature gave strongly reduced recoveries of most of 26 L. non-pneumophila spp. tested, but not of L. pneumophila. BCYE agar of pH 7.3 ± 0.1, incubated at 40 ± 0.5 °C (BCYE pH 7.3/40 °C) was tested for selective enumeration of L. pneumophila. Of the L. non-pneumophila spp. tested, only L. adelaidensis and L. londiniensis multiplied under these conditions. The colony counts on BCYE pH 7.3/40 °C of a L. pneumophila serogroup 1 strain cultured in tap water did not differ significantly from those on BCYE pH 6.9/36 °C when directly plated and after membrane filtration and showed repeatability's of 13-14%. By using membrane filtration L. pneumophila was detected in 58 (54%) of 107 Legionella-positive water samples from premise plumbing systems under one or both of these culture conditions. The L. pneumophila colony counts (log-transformed) on BCYE pH 7.3/40 °C were strongly related (r 2  = 0.87) to those on BCYE pH 6.9/36 °C, but differed significantly (p < 0.05) by a mean of - 0.12 ± 0.30 logs. L. non-pneumophila spp. were detected only on BCYE pH 6.9/36 °C in 49 (46%) of the samples. Hence, BCYE pH 7.3/40 °C can facilitate the enumeration of L. pneumophila and their isolation from premise plumbing systems with culturable L. non-pneumophila spp., some of which, e.g. L. anisa, can be present in high numbers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Monitoring of Legionella pneumophila viability after chlorine dioxide treatment using flow cytometry.

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Mustapha, Pascale; Epalle, Thibaut; Allegra, Séverine; Girardot, Françoise; Garraud, Olivier; Riffard, Serge

2015-04-01

The viability of three Legionella pneumophila strains was monitored after chlorine dioxide (ClO2) treatment using a flow cytometric assay. Suspensions of L. pneumophila cells were submitted to increasing concentrations of ClO2. Culturable cells were still detected when using 4 mg/L, but could no longer be detected after exposure to 6 mg/L of ClO2, although viable but not culturable (VBNC) cells were found after exposure to 4-5 mg/L of ClO2. When testing whether these VBNC were infective, two of the strains were resuscitated after co-culture with Acanthamoeba polyphaga, but neither of them could infect macrophage-like cells. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Ovos de Toxocara sp. e larvas de Ancylostoma sp. em praça pública de Lavras, MG Toxocara sp. eggs and Ancylostoma sp. larva in public parks, Brazil

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Antônio Marcos Guimarães

2005-04-01

Full Text Available Larva migrans visceral e cutânea são zoonoses parasitárias causadas pela infecção da larva de Toxocara sp. e Ancylostoma sp., respectivamente. O objetivo do estudo foi verificar a contaminação por ovos de Toxocara sp. e ovos e larvas de Ancylostoma sp. em amostras de solos coletadas de praças públicas e de áreas de recreação infantil de Lavras, Estado de Minas Gerais, por meio da técnica de centrífugo-flutuação e do método de Baermann. A ocorrência de ovos de Toxocara sp. e, ovos e larvas de Ancylostoma sp. foi observada em 69,6% (16/23 das amostras de solo coletadas de praças públicas. A contaminação somente por ovos de Ancylostoma sp. em amostras de solo coletadas em escolas/creches foi de 22,2% (4/18. A percentagem de amostras de areia coletadas de escolas/creches contaminadas somente com larvas de Ancylostoma sp. foi de 11,1% (2/18. Praças públicas são as áreas com maior risco potencial de infecção por Toxocara sp. e Ancylostoma sp. Exame coproparasitológico realizado em 174 amostras de fezes de cães observou 58% e 23%, respectivamente, com ovos de Ancylostoma sp. e Toxocara sp.Visceral and cutaneous larva migrans are parasitic zoonoses caused by the infection of larval nematodes Toxocara sp. and Ancylostoma sp. respectively. The objective of this study was to investigate the contamination by Toxocara sp. eggs and Ancylostoma sp. eggs and larva of soil samples collected from public parks and children's playground areas in state of Minas Gerais, Brazil, using both Baermann's method and centrifugal flotation technique. Toxocara sp. and Ancylostoma sp. eggs were observed in soil samples collected from public squares in 17.4% (4/23 and 69.6 (16/23 respectively. In schools and child day care settings the contamination by Ancylostoma sp. larva in sand samples was 11.1% (2/18. Public parks are settings of more potential risk of Toxocara sp. eggs and Ancylostoma sp. infection. Stool parasitology testing of 174 stool

Structural analyses of Legionella LepB reveal a new GAP fold that catalytically mimics eukaryotic RasGAP.

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Yu, Qin; Hu, Liyan; Yao, Qing; Zhu, Yongqun; Dong, Na; Wang, Da-Cheng; Shao, Feng

2013-06-01

Rab GTPases are emerging targets of diverse bacterial pathogens. Here, we perform biochemical and structural analyses of LepB, a Rab GTPase-activating protein (GAP) effector from Legionella pneumophila. We map LepB GAP domain to residues 313-618 and show that the GAP domain is Rab1 specific with a catalytic activity higher than the canonical eukaryotic TBC GAP and the newly identified VirA/EspG family of bacterial RabGAP effectors. Exhaustive mutation analyses identify Arg444 as the arginine finger, but no catalytically essential glutamine residues. Crystal structures of LepB313-618 alone and the GAP domain of Legionella drancourtii LepB in complex with Rab1-GDP-AlF3 support the catalytic role of Arg444, and also further reveal a 3D architecture and a GTPase-binding mode distinct from all known GAPs. Glu449, structurally equivalent to TBC RabGAP glutamine finger in apo-LepB, undergoes a drastic movement upon Rab1 binding, which induces Rab1 Gln70 side-chain flipping towards GDP-AlF3 through a strong ionic interaction. This conformationally rearranged Gln70 acts as the catalytic cis-glutamine, therefore uncovering an unexpected RasGAP-like catalytic mechanism for LepB. Our studies highlight an extraordinary structural and catalytic diversity of RabGAPs, particularly those from bacterial pathogens.

Antibacterial Actions and Potential Phototoxic Effects of Volatile oils of Foeniculum sp. (fennel, Salvia sp. (sage, Vitis sp. (grape, Lavandula sp. (lavender

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Elif Ayse Erdogan Eliuz

2016-09-01

Full Text Available In the present study, the volatile compounds of essential oil of Foeniculum vulgare (fennel, Salvia officinalis (sage, Vitis vinifera (grape, Lavandula angustifolia (lavender were analysed by gas chromatography-mass spectrometry (GC-MS using the Nist and Willey libraries. It was determined that the main components of Foeniculum sp. were anethole (41.11%, carvacrol (9.18%. whereas main components of Salvia sp were 1.8 cineole (34.09%, caryophyllene (10.95%, camphor (9.44%, α-pinene (8.42%. Vitis sp. contained linoleic acid (36.98%, 2,4-decadienal (30.79%. Finally, volatile component of Lavandula sp. was linalool (33.57%, linalyl acetate (30.74%. Photoxic antibacterial activity of volatile oil of those plants against Escherichia coli (ATCC 25293, Klebsiella pneumoniae (10031, Salmonella thyphimurium, Bacillus subtilis (ATCC 6633, Staphylococcus aureus (ATCC 25925, Enterococcus feacalis (ATCC 29212 were examined by using disc diffusion method. We demonstrated that volatile oil effectively can be activated by a standard LED light. In vitro, significant phototoxicity was demonstrated by volatile oil of Foeniculum sp. and Vitis sp. (P < 0.05, while minor phototoxicity was induced by Lavandula sp. Therefore, volatile oil of plant can be considered as a potential photosensitizer in the photochemical therapy.

Decentralized substations for low-temperature district heating with no Legionella risk, and low return temperatures

International Nuclear Information System (INIS)

Yang, Xiaochen; Li, Hongwei; Svendsen, Svend

2016-01-01

To improve energy efficiency and give more access to renewable energy sources, low-temperature district heating (LTDH) is a promising concept to be realized in the future. However, concern about Legionella proliferation restricts applying low-temperature district heating in conventional systems with domestic hot water (DHW) circulation. In this study, a system with decentralized substations was analysed as a solution to this problem. Furthermore, a modification for the decentralized substation system were proposed in order to reduce the average return temperature. Models of conventional system with medium-temperature district heating, decentralized substation system with LTDH, and innovative decentralized substation system with LTDH were built based on the information of a case building. The annual distribution heat loss and the operating costs of the three scenarios were calculated and compared. From the results, realizing LTDH by the decentralized substation unit, 30% of the annual distribution heat loss inside the building can be saved compared to a conventional system with medium-temperature district heating. Replacing the bypass pipe with an in-line supply pipe and a heat pump, the innovative decentralized substation system can reduce distribution heat loss by 39% compared to the conventional system and by 12% compared to the normal decentralized substation system with bypass. - Highlights: • The system of decentralized substations can realize low-temperature district heating without running the risk of Legionella. • Decentralized substations help reduce the distribution heat loss inside the building compared to conventional system. • A new concept that can reduce the return temperature for district heating is proposed and analysed.

Bradysia sp. em morangueiro Bradysia sp. in strawberry

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Bernadete Radin

2009-04-01

Full Text Available No trabalho, relatam-se os primeiros registros de Bradysia sp. (Insecta: Diptera: Sciaridae em morangueiro (Fragaria x ananassa Duch., cultivado no Município de Eldorado do Sul, RS. O cultivo foi realizado em sacolas com três metros de comprimento, preenchidas com substrato composto de casca de arroz e turfa, dispostas horizontalmente sobre bancadas de madeira, em ambiente protegido. A presença de Bradysia sp. foi observada na segunda quinzena de agosto de 2005. Neste trabalho, estão descritos os sintomas apresentados no morangueiro pela praga, prováveis conseqüências sobre o aparecimento de doenças e uma breve descrição morfológica da Bradysia sp., adulto e fase larval.This paper describes the first record of Bradysia sp. (Insecta; Diptera; Sciaridae in strawberry (Fragaria x ananassa, cultivated in the city of Eldorado do Sul, RS, Brazil. Strawberry was planted in plastic bags filled with a mixture of burnt rice hulls and peat and cultivated in a greenhouse. The presence of Bradysia sp was noticed in the second fortnight of August, 2005. The symptoms in strawberry and the probable consequences in terms of disease arising were described in the present study, as well as the morphological characterization of Bradysia sp. and its illustrations.

EMA-qPCR to monitor the efficiency of a closed-coupled solar pasteurization system in reducing Legionella contamination of roof-harvested rainwater.

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Reyneke, B; Dobrowsky, P H; Ndlovu, T; Khan, S; Khan, W

2016-05-15

Solar pasteurization is effective in reducing the level of indicator organisms in stored rainwater to within drinking water standards. However, Legionella spp. were detected at temperatures exceeding the recommended pasteurization temperatures using polymerase chain reaction assays. The aim of the current study was thus to apply EMA quantitative polymerase chain reaction (EMA-qPCR) to determine whether the Legionella spp. detected were intact cells and therefore possibly viable at pasteurization temperatures >70°C. The BacTiter-Glo™ Microbial Cell Viability Assay was also used to detect the presence of ATP in the tested samples, as ATP indicates the presence of metabolically active cells. Chemical analysis also indicated that all anions and cations were within the respective drinking water guidelines, with the exception of iron (mean: 186.76 μg/L) and aluminium (mean: 188.13 μg/L), which were detected in the pasteurized tank water samples at levels exceeding recommended guidelines. The BacTiter-Glo™ Microbial Cell Viability Assay indicated the presence of viable cells for all pasteurized temperatures tested, with the percentage of ATP (in the form of relative light units) decreasing with increasing temperature [70-79°C (96.7%); 80- 89°C (99.2%); 90-95°C (99.7%)]. EMA-qPCR then indicated that while solar pasteurization significantly reduced (p0.05) in the mean copy numbers was detected with an increase in the pasteurization temperature, with 6 × 10(3) genomic copies/mL DNA sample obtained at 95°C. As intact Legionella cells were detected in the pasteurized tank water samples, quantitative microbial risk assessment studies need to be conducted to determine the potential health risk associated with using the water for domestic purposes. Copyright © 2016 Elsevier B.V. All rights reserved.

Genomic investigation of a suspected outbreak of legionella pneumophila st82 reveals undetected heterogeneity by the present gold-standard methods, denmark, july to november 2014

DEFF Research Database (Denmark)

Schjørring, Susanne; Stegger, M.; Kjelsø, C.

2017-01-01

Between July and November 2014, 15 communityacquired cases of Legionnaires’ disease (LD), including four with Legionella pneumophila serogroup 1 sequence type (ST) 82, were diagnosed in Northern Zealand, Denmark. An outbreak was suspected. No ST82 isolates were found in environmental samples and ...

INTERAKSI ANTARA Trichoderma Harzianum, Penicillium SP. DAN Pseudomonas SP. SERTA KAPASITAS ANTAGONISMENYA TERHADAP Phytophthora CapsicilN VITRO*[Interaction Among Trichoderma Harzianum, Penicillium SP., Pseudomonas SP. and Antagonism Capacities Against Phy

OpenAIRE

Suharna, Nandang

2003-01-01

A preliminary study has been done to know antagonism capacities of three isolates of Trichoderma harzianum, two isolates of Penicillium sp.and one isolate of Pseudomonas sp.against Phytophthora capsici in vitro and interaction among those six antagonists.The highest antagonism capacity possessed by Penicillium sp. KN1, respectively followed by Penicillium sp.KN2,Pseudomonas sp. GH1 and the three T. harzianum isolates. Except for those three T. harzianum isolates, the two Penicillium sp.isolat...

Differences in nutrient uptake capacity of the benthic filamentous algae Cladophora sp., Klebsormidium sp. and Pseudanabaena sp. under varying N/P conditions.

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Liu, Junzhuo; Vyverman, Wim

2015-03-01

The N/P ratio of wastewater can vary greatly and directly affect algal growth and nutrient removal process. Three benthic filamentous algae species Cladophora sp., Klebsormidium sp. and Pseudanabaena sp. were isolated from a periphyton bioreactor and cultured under laboratory conditions on varying N/P ratios to determine their ability to remove nitrate and phosphorus. The N/P ratio significantly influenced the algal growth and phosphorus uptake process. Appropriate N/P ratios for nitrogen and phosphorus removal were 5-15, 7-10 and 7-20 for Cladophora sp., Klebsormidium sp. and Pseudanabaena sp., respectively. Within these respective ranges, Cladophora sp. had the highest biomass production, while Pseudanabaena sp. had the highest nitrogen and phosphorus contents. This study indicated that Cladophora sp. had a high capacity of removing phosphorus from wastewaters of low N/P ratio, and Pseudanabaena sp. was highly suitable for removing nitrogen from wastewaters with high N/P ratio. Copyright © 2014 Elsevier Ltd. All rights reserved.

Prevalence of Infection-Competent Serogroup 6 Legionella pneumophila within Premise Plumbing in Southeast Michigan

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Brenda G. Byrne

2018-02-01

Full Text Available Coinciding with major changes to its municipal water system, Flint, MI, endured Legionnaires’ disease outbreaks in 2014 and 2015. By sampling premise plumbing in Flint in the fall of 2016, we found that 12% of homes harbored legionellae, a frequency similar to that in residences in neighboring areas. To evaluate the genetic diversity of Legionella pneumophila in Southeast Michigan, we determined the sequence type (ST and serogroup (SG of the 18 residential isolates from Flint and Detroit, MI, and the 33 clinical isolates submitted by hospitals in three area counties in 2013 to 2016. Common to one environmental and four clinical samples were strains of L. pneumophila SG1 and ST1, the most prevalent ST worldwide. Among the Flint premise plumbing isolates, 14 of 16 strains were of ST367 and ST461, two closely related SG6 strain types isolated previously from patients and corresponding environmental samples. Each of the representative SG1 clinical strains and SG6 environmental isolates from Southeast Michigan infected and survived within macrophage cultures at least as well as a virulent laboratory strain, as judged by microscopy and by enumerating CFU. Likewise, 72 h after infection, the yield of viable-cell counts increased >100-fold for each of the representative SG1 clinical isolates, Flint premise plumbing SG6 ST367 and -461 isolates, and two Detroit residential isolates. We verified by immunostaining that SG1-specific antibody does not cross-react with the SG6 L. pneumophila environmental strains. Because the widely used urinary antigen diagnostic test does not readily detect non-SG1 L. pneumophila, Legionnaires’ disease caused by SG6 L. pneumophila is likely underreported worldwide.

Genetic Characterization of Legionella pneumophila Isolated from a Common Watershed in Comunidad Valenciana, Spain.

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Sánchez-Busó, Leonor; Coscollá, Mireia; Pinto-Carbó, Marta; Catalán, Vicente; González-Candelas, Fernando

2013-01-01

Legionella pneumophila infects humans to produce legionellosis and Pontiac fever only from environmental sources. In order to establish control measures and study the sources of outbreaks it is essential to know extent and distribution of strain variants of this bacterium in the environment. Sporadic and outbreak-related cases of legionellosis have been historically frequent in the Comunidad Valenciana region (CV, Spain), with a high prevalence in its Southeastern-most part (BV). Environmental investigations for the detection of Legionella pneumophila are performed in this area routinely. We present a population genetics study of 87 L. pneumophila strains isolated in 13 different localities of the BV area irrigated from the same watershed and compare them to a dataset of 46 strains isolated in different points of the whole CV. Our goal was to compare environmental genetic variation at two different geographic scales, at county and regional levels. Genetic diversity, recombination and population structure were analyzed with Sequence-Based Typing data and three intergenic regions. The results obtained reveal a low, but detectable, level of genetic differentiation between both datasets, mainly, but not only, attributed to the occurrence of unusual variants of the neuA locus present in the BV populations. This differentiation is still detectable when the 10 loci considered are analyzed independently, despite the relatively high incidence of the most common genetic variant in this species, sequence type 1 (ST-1). However, when the genetic data are considered without their associated geographic information, four major groups could be inferred at the genetic level which did not show any correlation with sampling locations. The overall results indicate that the population structure of these environmental samples results from the joint action of a global, widespread ST-1 along with genetic differentiation at shorter geographic distances, which in this case are related to

Molecular survey of occurrence and quantity of Legionella spp., Mycobacterium spp., Pseudomonas aeruginosa and amoeba hosts in municipal drinking water storage tank sediments.

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Lu, J; Struewing, I; Yelton, S; Ashbolt, N

2015-07-01

To examine the occurrence and quantity of potential pathogens and an indicator of microbial contamination in the sediments of municipal drinking water storage tanks (MDWSTs), given the absence of such data across the United States. Sediment samples (87 MDWST) from eighteen locations across ten states of the United States were collected and assayed by qPCR for a range of potential enteric and opportunistic microbial pathogens and a sewage-associated Bacteroides marker. Potential opportunistic pathogens dominated, with the highest detection of occurrence (per cent positive detection; average cell equivalence (CE)) being Mycobacterium spp. (88·9%; 6·7 ± 8·5 × 10(4) CE g(-1) ), followed by Legionella spp. (66·7%; 5·2 ± 5·9 × 10(3) CE g(-1) ), Pseudomonas aeruginosa (22·2%; 250 ± 880 CE g(-1) ) and Acanthamoeba spp. (38·9%; 53 ± 70 CE g(-1) ), with no detected Naegleria fowleri. Most enteric pathogens (Campylobacter jejuni, Escherichia coli 0157:H7, Salmonella enterica, Cryptosporidium parvum and Giardia duodenalis) were not detected, except for a trace signal for Campylobacter spp. There was significant correlation between the qPCR signals of Legionella spp. and Acanthamoeba spp. (R(2) = 0·61, n = 87, P = 0·0001). Diverse Legionella spp. including Leg. pneumophila, Leg. pneumophila sg1 and Leg. anisa were identified, each of which might cause legionellosis. These results imply that potential opportunistic pathogens are common within MDWST sediments and could act as a source of microbial contamination, but need downstream growth to be of potential concern. The results imply that opportunistic pathogen risks may need to be managed by regular tank cleaning or other management practices. 2015 The Society for Applied Microbiology.

Enhanced chlorine resistance of tap water-adapted Legionella pneumophila as compared with agar medium-passaged strains.

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Kuchta, J M; States, S J; McGlaughlin, J E; Overmeyer, J H; Wadowsky, R M; McNamara, A M; Wolford, R S; Yee, R B

1985-07-01

Previous studies have shown that bacteria maintained in a low-nutrient "natural" environment such as swimming pool water are much more resistant to disinfection by various chemical agents than strains maintained on rich media. In the present study a comparison was made of the chlorine (Cl2) susceptibility of hot-water tank isolates of Legionella pneumophila maintained in tap water and strains passaged on either nonselective buffered charcoal-yeast extract or selective differential glycine-vancomycin-polymyxin agar medium. Our earlier work has shown that environmental and clinical isolates of L. pneumophila maintained on agar medium are much more resistant to Cl2 than coliforms are. Under the present experimental conditions (21 degrees C, pH 7.6 to 8.0, and 0.25 mg of free residual Cl2 per liter, we found the tap water-maintained L. pneumophila strains to be even more resistant than the agar-passaged isolates. Under these conditions, 99% kill of tap water-maintained strains of L. pneumophila was usually achieved within 60 to 90 min compared with 10 min for agar-passaged strains. Samples from plumbing fixtures in a hospital yielded legionellae which were "super"-chlorine resistant when assayed under natural conditions. After one agar passage their resistance dropped to levels of comparable strains which had not been previously exposed to additional chlorination. These studies more closely approximate natural conditions than our previous work and show that tap water-maintained L. pneumophila is even more resistant to Cl2 than its already resistant agar medium-passaged counterpart.

First report of Anisakis sp. in Epinephelus sp. in East Indonesia

OpenAIRE

Annytha Ina Rohi Detha; Diana Agustiani Wuri; Julianty Almet; Yuni Riwu; Christin Melky

2018-01-01

Objective: The present research was conducted to identify the prevalence of Anisakis sp. as fish-borne zoonoses in Epinephelus sp. in territorial waters of East Nusa Tenggara, Indonesia. Materials and methods: A total of 50 fish (Epinephelus sp.) were collected from Kupang Fish Market in East Nusa Tenggara. Identification of Anisakis sp. was performed based on morphological observations considering shape of ventriculus, boring tooth, and mucron using binocular microscope. Results: Prev...

Characterization of a fluorescent compound isolated from Legionella pneumophila

International Nuclear Information System (INIS)

Swanson, S.J.

1987-01-01

Legionella pneumophila requires the presence of amino acids for growth and utilizes them for energy. Along with other amino acids, either phenylalanine or tyrosine is essential for the growth of the organism and tyrosine has been identified as an energy source. When L. pneumophila is grown in the presence of tyrosine, a brown melanin-like pigment is produced. A green fluorescent pigment, fg2, was isolated from centrifuged culture fluid after the organism was grown in the presence of tyrosine. Fg2 is water soluble with a molecular weight of 152 as determined by mass spectral analysis. A mutant of L. pneumophila unable to produce fg2 was isolated to assist in elucidation of the biosynthesis of fg2. Radiolabeling experiments were utilized to conclude that neither tyrosine nor any other amino acid was a precursor in the biosynthesis of fg2. Shikimic acid, an intermediate in tyrosine biosynthesis, was found to also be an intermediate in the biosynthesis of fg2. A series of experiments in which L. pneumophila was grown in a chemically defined medium containing various combinations of aromatic amino acids determined that fg2 and the brown pigment always occur in tandem

Severe Community-acquired Pneumonia Due to Legionella pneumophila Serogroup 6

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Chung-Yu Chen

2006-01-01

Full Text Available Legionella pneumophila is a common cause of sporadic community-acquired pneumonia, but culture-proven legionellosis is rarely diagnosed. There is no laboratory test for Legionnaires' disease that can detect all patients with the disease. Culture is the standard diagnostic method and should be initiated as soon as possible in suspected cases. We describe a rare case of community-acquired pneumonia caused by L. pneumophila serogroup 6. A 77-year-old man was admitted to a tertiary care hospital because of high fever, productive cough, and progressive dyspnea. Chest radiography showed bilateral pneumonia, which led to respiratory failure necessitating mechanical ventilatory support. Despite antibiotic therapy, his condition continued to deteriorate and acute renal failure also developed. Urine was negative for L. pneumophila. Culture of the sputum yielded L. pneumophila serogroup 6, although there was no elevation of the serum antibody titer. Pneumonia resolved gradually and he was extubated after treatment with levofloxacin followed by erythromycin. L. pneumophila other than serogroup 1 should be included in the differential diagnosis of patients with suspected atypical community-acquired pneumonia.

Penicillium araracuarense sp. nov., Penicillium elleniae sp. nov., Penicillium penarojense sp. nov., Penicillium vanderhammenii sp. nov. and Penicillium wotroi sp. nov., isolated from leaf litter.

Science.gov (United States)

Houbraken, Jos; López-Quintero, Carlos A; Frisvad, Jens C; Boekhout, Teun; Theelen, Bart; Franco-Molano, Ana Esperanza; Samson, Robert A

2011-06-01

Several species of the genus Penicillium were isolated during a survey of the mycobiota of leaf litter and soil in Colombian Amazon forest. Five species, Penicillium penarojense sp. nov. (type strain CBS 113178(T) = IBT 23262(T)), Penicillium wotroi sp. nov. (type strain CBS 118171(T) = IBT 23253(T)), Penicillium araracuarense sp. nov. (type strain CBS 113149(T) = IBT 23247(T)), Penicillium elleniae sp. nov. (type strain CBS 118135(T) = IBT 23229(T)) and Penicillium vanderhammenii sp. nov. (type strain CBS 126216(T) = IBT 23203(T)) are described here as novel species. Their taxonomic novelty was determined using a polyphasic approach, combining phenotypic, molecular (ITS and partial β-tubulin sequences) and extrolite data. Phylogenetic analyses showed that each novel species formed a unique clade for both loci analysed and that they were most closely related to Penicillium simplicissimum, Penicillium janthinellum, Penicillium daleae and Penicillium brasilianum. An overview of the phylogeny of this taxonomically difficult group is presented, and 33 species are accepted. Each of the five novel species had a unique extrolite profile of known and uncharacterized metabolites and various compounds, such as penicillic acid, andrastin A, pulvilloric acid, paxillin, paspaline and janthitrem, were commonly produced by these phylogenetically related species. The novel species had a high growth rate on agar media, but could be distinguished from each other by several macro- and microscopical characteristics.

The Legionella Kinase LegK2 Targets the ARP2/3 Complex To Inhibit Actin Nucleation on Phagosomes and Allow Bacterial Evasion of the Late Endocytic Pathway

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Michard, Céline; Sperandio, Daniel; Baïlo, Nathalie; Pizarro-Cerdá, Javier; LeClaire, Lawrence; Chadeau-Argaud, Elise; Pombo-Grégoire, Isabel; Hervet, Eva; Vianney, Anne; Gilbert, Christophe; Faure, Mathias; Cossart, Pascale

2015-01-01

ABSTRACT Legionella pneumophila, the etiological agent of legionellosis, replicates within phagocytic cells. Crucial to biogenesis of the replicative vacuole is the Dot/Icm type 4 secretion system, which translocates a large number of effectors into the host cell cytosol. Among them is LegK2, a protein kinase that plays a key role in Legionella infection. Here, we identified the actin nucleator ARP2/3 complex as a target of LegK2. LegK2 phosphorylates the ARPC1B and ARP3 subunits of the ARP2/3 complex. LegK2-dependent ARP2/3 phosphorylation triggers global actin cytoskeleton remodeling in cells, and it impairs actin tail formation by Listeria monocytogenes, a well-known ARP2/3-dependent process. During infection, LegK2 is addressed to the Legionella-containing vacuole surface and inhibits actin polymerization on the phagosome, as revealed by legK2 gene inactivation. Consequently, LegK2 prevents late endosome/lysosome association with the phagosome and finally contributes to remodeling of the bacterium-containing phagosome into a replicative niche. The inhibition of actin polymerization by LegK2 and its effect on endosome trafficking are ARP2/3 dependent since it can be phenocopied by a specific chemical inhibitor of the ARP2/3 complex. Thus, LegK2-ARP2/3 interplay highlights an original mechanism of bacterial virulence with an unexpected role in local actin remodeling that allows bacteria to control vesicle trafficking in order to escape host defenses. PMID:25944859

The DotA protein from Legionella pneumophila is secreted by a novel process that requires the Dot/Icm transporter

OpenAIRE

Nagai, Hiroki; Roy, Craig R.

2001-01-01

Legionella pneumophila requires the dot/icm genes to create an organelle inside eukaryotic host cells that will support bacterial replication. The dot/icm genes are predicted to encode a type IV-related secretion apparatus. However, no proteins have been identified that require the dot/icm genes for secretion. In this study we show that the DotA protein, which was previously found to be a polytopic membrane protein, is secreted by the Dot/Icm transporter into culture supernatants. Secreted Do...

Analysis of the Legionella longbeachae genome and transcriptome uncovers unique strategies to cause Legionnaires' disease.

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Christel Cazalet

2010-02-01

Full Text Available Legionella pneumophila and L. longbeachae are two species of a large genus of bacteria that are ubiquitous in nature. L. pneumophila is mainly found in natural and artificial water circuits while L. longbeachae is mainly present in soil. Under the appropriate conditions both species are human pathogens, capable of causing a severe form of pneumonia termed Legionnaires' disease. Here we report the sequencing and analysis of four L. longbeachae genomes, one complete genome sequence of L. longbeachae strain NSW150 serogroup (Sg 1, and three draft genome sequences another belonging to Sg1 and two to Sg2. The genome organization and gene content of the four L. longbeachae genomes are highly conserved, indicating strong pressure for niche adaptation. Analysis and comparison of L. longbeachae strain NSW150 with L. pneumophila revealed common but also unexpected features specific to this pathogen. The interaction with host cells shows distinct features from L. pneumophila, as L. longbeachae possesses a unique repertoire of putative Dot/Icm type IV secretion system substrates, eukaryotic-like and eukaryotic domain proteins, and encodes additional secretion systems. However, analysis of the ability of a dotA mutant of L. longbeachae NSW150 to replicate in the Acanthamoeba castellanii and in a mouse lung infection model showed that the Dot/Icm type IV secretion system is also essential for the virulence of L. longbeachae. In contrast to L. pneumophila, L. longbeachae does not encode flagella, thereby providing a possible explanation for differences in mouse susceptibility to infection between the two pathogens. Furthermore, transcriptome analysis revealed that L. longbeachae has a less pronounced biphasic life cycle as compared to L. pneumophila, and genome analysis and electron microscopy suggested that L. longbeachae is encapsulated. These species-specific differences may account for the different environmental niches and disease epidemiology of these

Microbiological diagnosis and molecular typing of Legionella strains during an outbreak of legionellosis in Southern Germany.

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Essig, Andreas; von Baum, Heike; Gonser, Theodor; Haerter, Georg; Lück, Christian

2016-02-01

An explosive outbreak of Legionnaires' disease with 64 reported cases occurred in Ulm/Neu-Ulm in the South of Germany in December 2009/January 2010 caused by Legionella (L.) pneumophila serogroup 1, monoclonal (mAb) subtype Knoxville, sequence type (ST) 62. Here we present the clinical microbiological results from 51 patients who were diagnosed at the University hospital of Ulm, the results of the environmental investigations and of molecular typing of patients and environmental strains. All 50 patients from whom urine specimens were available were positive for L. pneumophila antigen when an enzyme-linked immunosorbent assay (EIA) was used following concentration of those urine samples that tested initially negative. The sensitivity of the BinaxNow rapid immunographic assay (ICA), after 15 min reading and after 60 min reading were 70% and 84%, respectively. Direct typing confirmed the monoclonal subtype Knoxville in 5 out of 8 concentrated urine samples. Real time PCR testing of respiratory tract specimens for L. pneumophila was positive in 15 out of 25 (60%) patients. Direct nested sequence based typing (nSBT) in some of these samples allowed partial confirmation of ST62. L. pneumophila serogroup 1, monoclonal subtype Knoxville ST62, defined as the epidemic strain was isolated from 8 out of 31 outbreak patients (26%) and from one cooling tower confirming it as the most likely source of the outbreak. While rapid detection of Legionella antigenuria was crucial for the recognition and management of the outbreak, culture and molecular typing of the strains from patients and environmental specimens was the clue for the rapid identification of the source of infection. Copyright © 2016 Elsevier GmbH. All rights reserved.

Distinct difference of flaA genotypes of Legionella pneumophila between isolates from bath water and cooling tower water.

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Amemura-Maekawa, Junko; Kura, Fumiaki; Chang, Bin; Suzuki-Hashimoto, Atsuko; Ichinose, Masayuki; Endo, Takuro; Watanabe, Haruo

2008-09-01

To investigate the genetic difference of Legionella pneumophila in human-made environments, we collected isolates of L. pneumophila from bath water (n = 167) and cooling tower water (n = 128) primarily in the Kanto region in 2001 and 2005. The environmental isolates were serogrouped and sequenced for a target region of flaA. A total of 14 types of flaA genotypes were found: 10 from cooling tower water and nine from bath water. The flaA genotypes of isolates from cooling tower water were quite different from those of bath water.

Genetic variability in environmental isolates of Legionella pneumophila from Comunidad Valenciana (Spain).

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Coscollá, Mireia; Gosalbes, María José; Catalán, Vicente; González-Candelas, Fernando

2006-06-01

Legionella pneumophila is associated to recurrent outbreaks in several Comunidad Valenciana (Spain) localities, especially in Alcoi, where social and climatic conditions seem to provide an excellent environment for bacterial growth. We have analysed the nucleotide sequences of three loci from 25 environmental isolates from Alcoi and nearby locations sampled over 3 years. The analysis of these isolates has revealed a substantial level of genetic variation, with consistent patterns of variability across loci, and comparable to that found in a large, European-wide sampling of clinical isolates. Among the tree loci studied, fliC showed the highest level of nucleotide diversity. The analysis of isolates sampled in different years revealed a clear differentiation, with samples from 2001 being significantly distinct from those obtained in 2002 and 2003. Furthermore, although linkage disequilibrium measures indicate a clonal nature for population structure in this sample, the presence of some recombination events cannot be ruled out.

Evaluation of the strategy designed to reduce the incidence of cases produced by the bio contaminant (legionella Sero group I) in the city of Cordoba-Spain

Energy Technology Data Exchange (ETDEWEB)

Rubio Garcia, A.; Minarro del Moral, R. M.; Guijarro Rodriguez, J. L.

2009-07-01

Environmental protection is essential to the quality of lifer for present and future generations. The EU lines of priorities for reucing the adverse health effects associated with certain environmental factors, include. To prevent risks associated with the facilities at risk in the transmission of certain diseases such as Legionella. (Author)

Evaluation of the strategy designed to reduce the incidence of cases produced by the bio contaminant (legionella Sero group I) in the city of Cordoba-Spain

International Nuclear Information System (INIS)

Rubio Garcia, A.; Minarro del Moral, R. M.; Guijarro Rodriguez, J. L.

2009-01-01

Environmental protection is essential to the quality of lifer for present and future generations. The EU lines of priorities for reucing the adverse health effects associated with certain environmental factors, include. To prevent risks associated with the facilities at risk in the transmission of certain diseases such as Legionella. (Author)

Fatty acid composition of Spirulina sp., Chlorella sp. and Chaetoceros sp. microalgae and introduction as potential new sources to extinct omega 3 and omega 6

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Homan Gorjzdadeh

2016-05-01

Full Text Available Background: This study was carried out to determine the oil fatty acids from two special species of microalgae; Spirulina sp.,Chlorella sp. and also Chaetoceros sp. collected from Bahmanshir River. Materials and Methods: Sampling of microalgae Chaetoceros sp. from Bahmanshir River was under taken using bottle samplers during spring season of 2013. Microalgae Spirulina sp. and Chlorella sp. were supplied from Shrimp Research Institute of Iran in Bushehr Province. Samples then were cultured under controlled laboratory conditions and mass culture for 100 liters was undertaken. Isolation of microalgae species from water of cultured media was carried out using filtration and centrifugation methods. The fatty acid compositions were determined by Gas – FID chromatography. Results: Results showed that regarding Saturated Fatty Acids (SFA obtained from purified culture of Chaetoceros sp., Spirulina sp. and Chlorella sp. the maximum amount of total fatty acids were belonged to palmitic acids (C16:0 with 15.21%, 30.1% and 25.17% of total fatty acids  respectively. Analysis of Mono Unsaturated Fatty Acids (MUFA showed that in the Oleic acid was maximum amount of 34% in Spirulina sp. In addition the amount of MUFA in Chlorella sp. was 16.37% of total fatty acids. On the other hand the amount of palmeotic acid in purified culture of Chaetoceros sp. was 30.33% from total content of fatty acids. Analysis of Poly Unsaturated Fatty Acids (PUFA, Linoleic acid (C18:2 (Omega 6, revealed maximum percentage in Spirulina sp. with 18.8%. Results of Alpha linoleic acid (C18:3 (Omega3 analysis showed maximum amount of 9.66% in Chlorella sp. compared to other microalgae with lower omega 3 contents. Spirulina sp. contained maximum amount of Linoleic acid (C18:2 with 18.8% of total fatty acids. Therefore, Spirulina sp. can be considered as a rich source of omega 6 for the purpose of fatty acid extractions. The presence of PUFA in Chlorella sp. and Spirulina sp. was

Comparison of pulsed corona plasma and pulsed electric fields for the decontamination of water containing Legionella pneumophila as model organism.

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Banaschik, Robert; Burchhardt, Gerhard; Zocher, Katja; Hammerschmidt, Sven; Kolb, Juergen F; Weltmann, Klaus-Dieter

2016-12-01

Pulsed corona plasma and pulsed electric fields were assessed for their capacity to kill Legionella pneumophila in water. Electrical parameters such as in particular dissipated energy were equal for both treatments. This was accomplished by changing the polarity of the applied high voltage pulses in a coaxial electrode geometry resulting in the generation of corona plasma or an electric field. For corona plasma, generated by high voltage pulses with peak voltages of +80kV, Legionella were completely killed, corresponding to a log-reduction of 5.4 (CFU/ml) after a treatment time of 12.5min. For the application of pulsed electric fields from peak voltages of -80kV a survival of log 2.54 (CFU/ml) was still detectable after this treatment time. Scanning electron microscopy images of L. pneumophila showed rupture of cells after plasma treatment. In contrast, the morphology of bacteria seems to be intact after application of pulsed electric fields. The more efficient killing for the same energy input observed for pulsed corona plasma is likely due to induced chemical processes and the generation of reactive species as indicated by the evolution of hydrogen peroxide. This suggests that the higher efficacy and efficiency of pulsed corona plasma is primarily associated with the combined effect of the applied electric fields and the promoted reaction chemistry. Copyright © 2016 Elsevier B.V. All rights reserved.

Eficiencia de pseudomonas sp, rhodopseudomonas sp, micrococcus sp y bacillus sp empleados como cultivos individuales y en consorcio, en la degradación de petróleo diesel ii

OpenAIRE

Otiniano García, Nélida Milly Esther

2010-01-01

In order to evaluate the efficiency of Pseudomonas sp, Rhodopseudomonas sp, Micrococcus sp, Bacillus sp, and the consortium formed by these four microorganisms in the diesel II petroleum degradation, it was worked in 5 bioreactors of aerated and shaken tank of 1.5 litters of capacity, with speed agitation of 120 rpm, and air flow of 0.5 vvm; in which were placed; 940 mL of Minimum Broth of Davies pH 7.0; 50 mL of diesel II petroleum as source of carbon and 10 mL of a suspension of approx...

Activation of Ran GTPase by a Legionella effector promotes microtubule polymerization, pathogen vacuole motility and infection.

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Eva Rothmeier

2013-09-01

Full Text Available The causative agent of Legionnaires' disease, Legionella pneumophila, uses the Icm/Dot type IV secretion system (T4SS to form in phagocytes a distinct "Legionella-containing vacuole" (LCV, which intercepts endosomal and secretory vesicle trafficking. Proteomics revealed the presence of the small GTPase Ran and its effector RanBP1 on purified LCVs. Here we validate that Ran and RanBP1 localize to LCVs and promote intracellular growth of L. pneumophila. Moreover, the L. pneumophila protein LegG1, which contains putative RCC1 Ran guanine nucleotide exchange factor (GEF domains, accumulates on LCVs in an Icm/Dot-dependent manner. L. pneumophila wild-type bacteria, but not strains lacking LegG1 or a functional Icm/Dot T4SS, activate Ran on LCVs, while purified LegG1 produces active Ran(GTP in cell lysates. L. pneumophila lacking legG1 is compromised for intracellular growth in macrophages and amoebae, yet is as cytotoxic as the wild-type strain. A downstream effect of LegG1 is to stabilize microtubules, as revealed by conventional and stimulated emission depletion (STED fluorescence microscopy, subcellular fractionation and Western blot, or by microbial microinjection through the T3SS of a Yersinia strain lacking endogenous effectors. Real-time fluorescence imaging indicates that LCVs harboring wild-type L. pneumophila rapidly move along microtubules, while LCVs harboring ΔlegG1 mutant bacteria are stalled. Together, our results demonstrate that Ran activation and RanBP1 promote LCV formation, and the Icm/Dot substrate LegG1 functions as a bacterial Ran activator, which localizes to LCVs and promotes microtubule stabilization, LCV motility as well as intracellular replication of L. pneumophila.

Activation of Ran GTPase by a Legionella Effector Promotes Microtubule Polymerization, Pathogen Vacuole Motility and Infection

Science.gov (United States)

Rothmeier, Eva; Pfaffinger, Gudrun; Hoffmann, Christine; Harrison, Christopher F.; Grabmayr, Heinrich; Repnik, Urska; Hannemann, Mandy; Wölke, Stefan; Bausch, Andreas; Griffiths, Gareth; Müller-Taubenberger, Annette; Itzen, Aymelt; Hilbi, Hubert

2013-01-01

The causative agent of Legionnaires' disease, Legionella pneumophila, uses the Icm/Dot type IV secretion system (T4SS) to form in phagocytes a distinct “Legionella-containing vacuole” (LCV), which intercepts endosomal and secretory vesicle trafficking. Proteomics revealed the presence of the small GTPase Ran and its effector RanBP1 on purified LCVs. Here we validate that Ran and RanBP1 localize to LCVs and promote intracellular growth of L. pneumophila. Moreover, the L. pneumophila protein LegG1, which contains putative RCC1 Ran guanine nucleotide exchange factor (GEF) domains, accumulates on LCVs in an Icm/Dot-dependent manner. L. pneumophila wild-type bacteria, but not strains lacking LegG1 or a functional Icm/Dot T4SS, activate Ran on LCVs, while purified LegG1 produces active Ran(GTP) in cell lysates. L. pneumophila lacking legG1 is compromised for intracellular growth in macrophages and amoebae, yet is as cytotoxic as the wild-type strain. A downstream effect of LegG1 is to stabilize microtubules, as revealed by conventional and stimulated emission depletion (STED) fluorescence microscopy, subcellular fractionation and Western blot, or by microbial microinjection through the T3SS of a Yersinia strain lacking endogenous effectors. Real-time fluorescence imaging indicates that LCVs harboring wild-type L. pneumophila rapidly move along microtubules, while LCVs harboring ΔlegG1 mutant bacteria are stalled. Together, our results demonstrate that Ran activation and RanBP1 promote LCV formation, and the Icm/Dot substrate LegG1 functions as a bacterial Ran activator, which localizes to LCVs and promotes microtubule stabilization, LCV motility as well as intracellular replication of L. pneumophila. PMID:24068924

An investigation of virulence factors of Legionella pneumophila environmental isolates

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Elif Özlem Arslan-Aydoğdu

Full Text Available ABSTRACT Nine Legionella pneumophila strains isolated from cooling towers and a standard strain (L. pneumophila serogroup 1, ATCC 33152, Philadelphia 1 were analyzed and compared in terms of motility, flagella structure, ability to form biofilms, enzymatic activities (hemolysin, nucleases, protease, phospholipase A, phospholipase C, acid phosphatase, alkaline phosphatase and lipase, hemagglutination capabilities, and pathogenicity in various host cells (Acanthamoeba castellanii ATCC 30234, mouse peritoneal macrophages and human peripheral monocytes. All the isolates of bacteria appeared to be motile and polar-flagellated and possessed the type-IV fimbria. Upon the evaluation of virulence factors, isolate 4 was found to be the most pathogenic strain, while 6 out of the 9 isolates (the isolates 1, 2, 3, 4, 5, and 7 were more virulent than the ATCC 33152 strain. The different bacterial strains exhibited differences in properties such as adhesion, penetration and reproduction in the hosts, and preferred host type. To our knowledge, this is the first study to compare the virulence of environmental L. pneumophila strains isolated in Turkey, and it provides important information relevant for understanding the epidemiology of L. pneumophila.

New crystal forms of NTPDase1 from the bacterium Legionella pneumophila

International Nuclear Information System (INIS)

Zebisch, Matthias; Schäfer, Petra; Lauble, Peter; Sträter, Norbert

2013-01-01

The soluble NTPDase1 from L. pneumophila was crystallized in six crystal forms and the structure was solved using a sulfur SAD approach. Nucleoside triphosphate diphosphohydrolases (NTPDases) are a large class of nucleotidases that hydrolyze the (γ/β)- and (β/α)-anhydride bonds of nucleoside triphosphates and diphosphates, respectively. NTPDases are found throughout the eukaryotic domain. In addition, a very small number of members can be found in bacteria, most of which live as parasites of eukaryotic hosts. NTPDases of intracellular and extracellular parasites are emerging as important regulators for the survival of the parasite. To deepen the knowledge of the structure and function of this enzyme class, recombinant production of the NTPDase1 from the bacterium Legionella pneumophila has been established. The protein could be crystallized in six crystal forms, of which one has been described previously. The crystals diffracted to resolutions of between 1.4 and 2.5 Å. Experimental phases determined by a sulfur SAD experiment using an orthorhombic crystal form produced an interpretable electron-density map

Pengendalian Hayati Penyakit Layu Fusarium Pisang (Fusarium oxysporum f.sp. cubense dengan Trichoderma sp.

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Albertus Sudirman

2011-07-01

Full Text Available The aim of this research was to study the inhibiting ability of Trichoderma sp. to control fusarium wilt of banana in greenhouse condition. The experiments consisted of the antagonism test between Trichoderma sp. and Fusarium oxysporum f.sp. cubense (Foc in vitro using dual culture method and glass house experiment which was arranged in 3×3 Factorial Complete Randomized Design. First factor of the latter experiment was the dose of Trichoderma sp. culture (0, 25, and 50 g per polybag, second factor was time of Trichoderma culture application (2 weeks before Foc inoculation, at same time with Foc inoculation and 2 weeks after Foc inoculation. Trichoderma sp. was cultured in mixed rice brand and chaff medium. The disease intensity was observed with scoring system of wilting leaves (0–4. The results showed that Trichoderma sp. was antagonistic against Foc in vitro and inhibited 86% of Foc colony development. Mechanism of antagonism between Trichoderma sp. and Foc was hyperparasitism. Trichoderma hyphae coiled around Foc hyphae. Lysis of Foc hyphae was occurred at the attached site of Trichoderma hyphae on Foc hyphae. Added banana seedling with Trichoderma sp. Culture reduced disease intensity of Fusarium wilt. Suggested dose of Trichoderma culture application in glass house was 25 g/polybag, given at the same time with Foc inoculation. Penelitian ini bertujuan untuk mengetahui kemampuan Trichoderma sp. untuk pengendalian penyakit layu fusarium pisang di rumah kaca. Penelitian meliputi pengujian daya hambat Fusarium oxysporum f.sp. cubense (Foc in vitro dan kemampuan menekan intensitas penyakit di rumah kaca. Penelitian in vitro meliputi uji antagonisme dan mekanismenya yang dilakukan secara dual culture. Uji pengaruh Trichoderma sp. terhadap penyakit layu Fusarium dilakukan di rumah kaca dengan Rancangan Acak Lengkap Faktorial. Faktor pertama adalah dosis biakan Trichoderma sp., dengan tiga aras (0, 25, 50 g/per bibit dalam polibag. Faktor kedua

SP140L, an Evolutionarily Recent Member of the SP100 Family, Is an Autoantigen in Primary Biliary Cirrhosis

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Mario Saare

2015-01-01

Full Text Available The SP100 family members comprise a set of closely related genes on chromosome 2q37.1. The widely expressed SP100 and the leukocyte-specific proteins SP110 and SP140 have been associated with transcriptional regulation and various human diseases. Here, we have characterized the SP100 family member SP140L. The genome sequence analysis showed the formation of SP140L gene through rearrangements of the two neighboring genes, SP100 and SP140, during the evolution of higher primates. The SP140L expression is interferon-inducible with high transcript levels in B cells and other peripheral blood mononuclear cells. Subcellularly, SP140L colocalizes with SP100 and SP140 in nuclear structures that are devoid of SP110, PML, or p300 proteins. Similarly to SP100 and SP140 protein, we detected serum autoantibodies to SP140L in patients with primary biliary cirrhosis using luciferase immunoprecipitation system and immunoblotting assays. In conclusion, our results show that SP140L is phylogenetically recent member of SP100 proteins and acts as an autoantigen in primary biliary cirrhosis patients.

Bakteri Legionella pneumophila Terdeteksi pada Air Kolam Renang di Kota Surabaya dengan Nested Polymerase Chain Reaction (LEGIONELLA PNEUMOPHILA BACTERIADETECTED IN SWIMMING POOL WATER OF SURABAYA BY USING NESTED POLYMERASE CHAIN REACTION

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Eduardus Bimo Aksono

2017-06-01

Full Text Available Legionella pneumophila is a Gram-negative bacillus that causes nosocomial and community-acquired pneumonia. The aim of this research was to detect the presence of bacteria of L. pneumophila species in the swimming pools water of Surabaya city by using nested Polymerase Chain Reaction (PCR assay of a specific gene for L. pneumophila (mip gene. This study used purposive sampling method. A total of 10 water samples were collected from five swimming pools consisting of 200 mL water for each swimming pool. The results showed that of 10 samples tested by nested PCR, one sample was positive for L. pneumophila, and nine samples were negative. L. pneumophila were found in pool water samples with a higher temperature (>30ºC.Serogrouping analysis of positive sample that L. pneumophila bacteria detected in the water sample of swimming pool in Surabaya was L. pneumophila serogroup 9 (98% and serogroup 10 (98%. L. pneumophila detection of bacteria is expected to raise the awareness of physician and microbiologists about the transmission of L. pneumophila and will also be useful for controlling the agents. ABSTRAK Legionella pneumophila adalah bakteri Gram-negatif berbentuk batang yang dapat menyebabkan penyakit nosokomial dan pneumonia. Tujuan penelitian ini adalah untuk mendeteksi keberadaan bakteri L. pneumophila pada air kolam renang di Kota Surabaya dengan menggunakan nested Polymerase Chain Reaction (PCR berbasis gen spesifik L. pneumophila (mip gene. Penelitian ini menggunakan metode purposive sampling. Sebanyak sepuluh sampel diambil dari lima kolam renang. Sampel diambil sebanyak 200 mL dari air kolam renang di setiap lokasi. Hasil dari 10 sampel yang diuji menggunakan nested PCR, satu sampel menunjukkan hasil positif untuk L.pneumophila, dan sembilan sampel menunjukkan hasil negatif. Bakteri L. pneumophila ditemukan pada sampel air kolam dengan suhu yang lebih tinggi (>30ºC. Satu sampel positip tersebut ketika dilanjutkan terhadap analisis serogrup

Environmental conditions affecting exopolysaccharide production by Pseudomonas aeruginosa, Micrococcus sp., and Ochrobactrum sp.

Science.gov (United States)

Kiliç, Nur Koçberber; Dönmez, Gönül

2008-06-15

Three different chromium-resistant microorganisms (Pseudomonas aeruginosa, Micrococcus sp., and Ochrobactrum sp.) were tested with regard to their EPS production at different pH levels, temperatures, Cr(VI) concentrations, and incubation periods. The optimum pH level was 7 for P. aeruginosa and Micrococcus sp., while it was 8 for Ochrobactrum sp. according to the highest EPS amount at 100 mg/L Cr(VI) concentration. The highest production of EPSs by the three bacteria was obtained under different environmental conditions. P. aeruginosa produced the highest EPS (863.3 mg/L) after incubation for 96 h on media with 50 mg/L Cr(VI) at 20 degrees C, Micrococcus sp. gave the highest yield (444.6 mg/L) after incubation for 72 h on media with 100 mg/L Cr(VI) at the same temperature, and Ochrobactrum sp. had the highest production (430.5 mg/L) on media with 150 mg/L Cr(VI) at 30 degrees C at the end of 48 h of incubation.

Superhard sp2–sp3 hybrid carbon allotropes with tunable electronic properties

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Meng Hu

2016-05-01

Full Text Available Four sp2–sp3 hybrid carbon allotropes are proposed on the basis of first principles calculations. These four carbon allotropes are energetically more favorable than graphite under suitable pressure conditions. They can be assembled from graphite through intralayer wrinkling and interlayer buckling, which is similar to the formation of diamond from graphite. For one of the sp2–sp3 hybrid carbon allotropes, mC24, the electron diffraction patterns match these of i-carbon, which is synthesized from shock-compressed graphite (H. Hirai and K. Kondo, Science, 1991, 253, 772. The allotropes exhibit tunable electronic characteristics from metallic to semiconductive with band gaps comparable to those of silicon allotropes. They are all superhard materials with Vickers hardness values comparable to that of cubic BN. The sp2–sp3 hybrid carbon allotroes are promising materials for photovoltaic electronic devices, and abrasive and grinding tools.

Selective C(sp2)-C(sp) bond cleavage: the nitrogenation of alkynes to amides.

Science.gov (United States)

Qin, Chong; Feng, Peng; Ou, Yang; Shen, Tao; Wang, Teng; Jiao, Ning

2013-07-22

Breakthrough: A novel catalyzed direct highly selective C(sp2)-C(sp) bond functionalization of alkynes to amides has been developed. Nitrogenation is achieved by the highly selective C(sp2)-C(sp) bond cleavage of aryl-substituted alkynes. The oxidant-free and mild conditions and wide substrate scope make this method very practical. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Isolation and identification of Legionella pneumophila from drinking water in Basra governorate, Iraq.

Science.gov (United States)

Al-Sulami, A A; Al-Taee, A M R; Yehyazarian, A A

2013-11-01

This study in Iraq investigated the occurrence of Legionella. pneumophila in different drinking-water sources in Basra governorate as well as the susceptibility of isolates to several antibiotics. A total of 222 water samples were collected in 2008-2009: 49 samples from water purification plants (at entry points, from precipitation tanks, from filtration tanks and at exit points), 127 samples of tap water; and 46 samples from tankers and plants supplying water by reverse osmosis. The findings confirmed the presence of L. pneumophila in sources of crude water, in general drinking water supplies and drinking water tankers. Of 258 isolates 77.1% were serotype 1 and 22.9% serotypes 2-15. All examined isolates displayed drug resistance, particularly to ampicillin, but were 100% susceptible to doxycycline. The prevalence of L. pneumophila, especially serogroup 1, is a strong indicator of unsuitability of drinking water and requires appropriate action.

Is Venice an ideal habitat for Legionella pneumophila?

Science.gov (United States)

Ziprani, C; Selle, V; Palazzi, B; Capretta, F; Ghio, L; Flora, M E; Baldo, V

2012-09-01

Legionella bacterium manifests itself in Legionnaire's disease and Pontiac fever, it is mainly found and transmitted by aerosol produced in cooling towers, water distribution plants and medical equipment, and it affects mainly elder persons in poor health. The population of Venice Local Health Unit was divided in two areas of study and the incidence of legionellosis in residents of Venice historical centre (Distretto Sanitario 1) and in residents of the mainland and coastal areas (Distretti Sanitari 2, 3, 4) was calculated. The cases were those notified to the Public Health Unit by law, and the population of residents was that of the eligible for health care in the archives of the Local Health Unit. Only cases of legionellosis in residents who had not travelled in the 10 days previous of the onset of disease, and not related to nosocomial clusters were considered. The standardized incidence ratio was then calculated and confidence interval were defined by Poisson distribution. Given the population of the two areas, 59801 in Distretto Sanitario 1 and 237555 in Distretti 2, 3, 4, the raw incidence of disease is respectively 87 per 100000 and 20 per 100000 in time 2002-2010. The standardized incidence ratio for the population of Distretto Sanitario 1 vs the remaining population is 4.3. The difference in risk of getting the disease in this two residential areas geographically very close, is probably related to the different buildings' characteristics, old and difficult to maintain in Venice historical centre.

In vitro cytotoxicity evaluation of nano-carbon particles with different sp{sup 2}/sp{sup 3} ratios

Energy Technology Data Exchange (ETDEWEB)

Li, S.S.; Wu, B.J.; Deng, Q.Y. [Key Laboratory for Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Guo, Y.B. [The Third People' s Hospital of Chengdu, Sichuan 610031 (China); Leng, Y.X., E-mail: yxleng@263.net [Key Laboratory for Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Huang, N. [Key Laboratory for Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)

2017-06-01

Graphitization occurs during the long-term service of a diamond-like carbon (DLC) modified artificial joint. Then, DLC wear debris, which are carbon particles with different sp{sup 2}/sp{sup 3} ratios and sizes ranging from the nano- to micro-meter scale produced. In this paper, to promote the application of DLC coating for artificial joint modification, the cytotoxicity of DLC debris (nano-carbon particles, NCs) with different sp{sup 2}/sp{sup 3} ratios was studied. The microstructure and physical characteristics of NCs with different sp{sup 2}/sp{sup 3} ratios were investigated by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Transmission Electron Microscope (TEM) and Dynamic Light Scattering (DLS). Meanwhile, osteoblasts and macrophages were applied to characterize the cytotoxicity of the NCs. In vitro cytotoxicity assay results indicated that cells incubated with NCs of different sp{sup 2}/sp{sup 3} ratios had greater osteogenic capacity, and these particles caused a weaker immune response in comparison with CoCrMo particles. Taken together, the results indicated that NCs with different sp{sup 2}/sp{sup 3} ratios presented a good cytocompatibility than CoCrMo particles. But no significant differences were observed among NCs with different sp{sup 2}/sp{sup 3} ratios. The better cytocompatibility of NCs is mainly attributable to their surface charge. - Highlights: • NCs with different sp{sup 2}/sp{sup 3} ratios have been successfully prepared by annealing treatment. • NCs with different sp{sup 2}/sp{sup 3} ratios show good osteogenic capacity and lower immune response. • The good cytocompatibility of NCs is mainly dependent on its surface charge.

Xylanolytic enzyme systems in Arthrobacter sp MTCC 5214 and Lactobacillus sp.

Digital Repository Service at National Institute of Oceanography (India)

Khandeparker, R.; Jalal, T.

The production of extracellular xylanolytic enzymes such as xylanase, alfa-L-arabinofuranosidase (alfa-l-AFase), and acetyl xylan esterase (Axe) by marine Arthrobacter sp and Lactobacillus sp was investigated using different carbon sources Induction...

Sp6 and Sp8 Transcription Factors Control AER Formation and Dorsal-Ventral Patterning in Limb Development

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Haro, Endika; Delgado, Irene; Junco, Marisa; Yamada, Yoshihiko; Mansouri, Ahmed; Oberg, Kerby C.; Ros, Marian A.

2014-01-01

The formation and maintenance of the apical ectodermal ridge (AER) is critical for the outgrowth and patterning of the vertebrate limb. The induction of the AER is a complex process that relies on integrated interactions among the Fgf, Wnt, and Bmp signaling pathways that operate within the ectoderm and between the ectoderm and the mesoderm of the early limb bud. The transcription factors Sp6 and Sp8 are expressed in the limb ectoderm and AER during limb development. Sp6 mutant mice display a mild syndactyly phenotype while Sp8 mutants exhibit severe limb truncations. Both mutants show defects in AER maturation and in dorsal-ventral patterning. To gain further insights into the role Sp6 and Sp8 play in limb development, we have produced mice lacking both Sp6 and Sp8 activity in the limb ectoderm. Remarkably, the elimination or significant reduction in Sp6;Sp8 gene dosage leads to tetra-amelia; initial budding occurs, but neither Fgf8 nor En1 are activated. Mutants bearing a single functional allele of Sp8 (Sp6−/−;Sp8+/−) exhibit a split-hand/foot malformation phenotype with double dorsal digit tips probably due to an irregular and immature AER that is not maintained in the center of the bud and on the abnormal expansion of Wnt7a expression to the ventral ectoderm. Our data are compatible with Sp6 and Sp8 working together and in a dose-dependent manner as indispensable mediators of Wnt/βcatenin and Bmp signaling in the limb ectoderm. We suggest that the function of these factors links proximal-distal and dorsal-ventral patterning. PMID:25166858

Molecular Typing of Legionella pneumophila Isolates in the Province of Quebec from 2005 to 2015.

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Simon Lévesque

Full Text Available Legionella is found in natural and man-made aquatic environments, such as cooling towers and hot water plumbing infrastructures. Legionella pneumophila serogroup 1 (Lp1 is the most common etiological agent causing waterborne disease in the United States and Canada. This study reports the molecular characterization of Lp strains during a 10 year period. We conducted sequence-based typing (SBT analysis on a large set of Lp isolates (n = 284 to investigate the province of Quebec sequence types (STs distribution in order to identify dominant clusters. From 2005 to 2015, 181 clinical Lp isolates were typed by SBT (141 sporadic cases and 40 outbreak related cases. From the same period of time, 103 environmental isolates were also typed. Amongst the 108 sporadic cases of Lp1 typed, ST-62 was the most frequent (16.6%, followed by ST-213 (10.2%, ST-1 (8.3% and ST-37 (8.3%. Amongst other serogroups (SG, ST-1327 (SG5 (27.3% and ST-378 (SG10 (12.2% were the most frequent. From the environmental isolates, ST-1 represent the more frequent SBT type (26.5%. Unweighted pair group method with arithmetic mean (UPGMA dendrogram from the 108 sporadic cases of SG1 contains 4 major clusters (A to D of related STs. Cluster B contains the majority of the strains (n = 61 and the three most frequent STs in our database (ST-62, ST-213 and ST-1. During the study period, we observed an important increase in the incidence rate in Quebec. All the community associated outbreaks, potentially or confirmed to be associated with a cooling tower were caused by Lp1 strains, by opposition to hospital associated outbreaks that were caused by serogroups of Lp other than SG1. The recent major Quebec City outbreak caused by ST-62, and the fact that this genotype is the most common in the province supports whole genome sequencing characterization of this particular sequence type in order to understand its evolution and associated virulence factors.

The use of heteroduplex analysis of polymerase chain reaction products to support the possible transmission of Legionella pneumophila from a malfunctioning automobile air conditioner.

Science.gov (United States)

Pinar, Ahmet; Ramirez, Julio A; Schindler, Laura L; Miller, Richard D; Summersgill, James T

2002-03-01

Air conditioner condensates have not been previously associated with cases of Legionnaires' disease. We report the possible transmission of Legionella pneumophila serogroup 1 from a malfunctioning automobile air conditioning system's leaking water onto the floorboard of a car driven for a long distance by the patient. Heteroduplex analysis of polymerase chain reaction products was used to help establish an epidemiologic link between the water specimen and the patient.

Multifaceted effects of synthetic TLR2 ligand and Legionella pneumophilia on Treg-mediated suppression of T cell activation

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Sutmuller Roger PM

2011-03-01

Full Text Available Abstract Background Regulatory T cells (Treg play a crucial role in maintaining immune homeostasis and self-tolerance. The immune suppressive effects of Tregs should however be limited in case effective immunity is required against pathogens or cancer cells. We previously found that the Toll-like receptor 2 (TLR2 agonist, Pam3CysSK4, directly stimulated Tregs to expand and temporarily abrogate their suppressive capabilities. In this study, we evaluate the effect of Pam3CysSK4 and Legionella pneumophila, a natural TLR2 containing infectious agent, on effector T (Teff cells and dendritic cells (DCs individually and in co-cultures with Tregs. Results TLR2 agonists can directly provide a co-stimulatory signal inducing enhanced proliferation and cytokine production of naive CD4+ Teff cells. With respect to cytokine production, DCs appear to be most sensitive to low amounts of TLR agonists. Using wild type and TLR2-deficient cells in Treg suppression assays, we accordingly show that all cells (e.g. Treg, Teff cells and DCs contributed to overcome Treg-mediated suppression of Teff cell proliferation. Furthermore, while TLR2-stimulated Tregs readily lost their ability to suppress Teff cell proliferation, cytokine production by Teff cells was still suppressed. Similar results were obtained upon stimulation with TLR2 ligand containing bacteria, Legionella pneumophila. Conclusions These findings indicate that both synthetic and natural TLR2 agonists affect DCs, Teff cells and Treg directly, resulting in multi-modal modulation of Treg-mediated suppression of Teff cells. Moreover, Treg-mediated suppression of Teff cell proliferation is functionally distinct from suppression of cytokine secretion.

Analysis and research on promising solutions of low temperature district heating without risk of legionella

DEFF Research Database (Denmark)

Yang, Xiaochen; Li, Hongwei; Fog, Jette M.

2014-01-01

Most regulations of domestic hot water supply temperature is around 55-60 oC, which potentially requires higher district heating temperature. However, high supply temperature of district heating causes many problems, such as the high heating loss, and obstacles for applying renewable energy...... resources. The most crucial restriction for applying low temperature district heating is the worry about the breakout of legionella, which exists preferably in low temperature hot water systems. Several novel techniques such as electric tracing and flat station were investigated for such dilemma. The pros...... and cons were compared in this paper. Both the energy and economy saving ratios were analysed comparing with high temperature supply scenario. Furthermore, the viability of the applications in different types of buildings for low temperature district heating (LTDH) was also discussed by using dynamic...

Fresh Water Cyanobacteria Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as an Anticancer Drug Resource

OpenAIRE

Srivastava, Akanksha; Tiwari, Ratnakar; Srivastava, Vikas; Singh, Tej Bali; Asthana, Ravi Kumar

2015-01-01

An increasing number of cancer patients worldwide, especially in third world countries, have raised concern to explore natural drug resources, such as the less explored fresh water filamentous cyanobacteria. Six strains of cyanobacteria (Phormidium sp. CCC727, Geitlerinema sp. CCC728, Arthrospira sp. CCC729, Phormidium sp. CCC731, Phormidium sp. CCC730, and Leptolyngbya sp. CCC732) were isolated (paddy fields and ponds in the Banaras Hindu University, campus) and five strains screened for ant...

Estudio sobre la efectividad para la prevención de la legionelosis del sistema de calentamiento instantáneo, instalado en la red de agua sanitaria de un hospital Effectiveness study of a pasteurization system in controlling contamination with Legionella installed in a hospital's hot water system

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Laura Gavaldà Mestre

2006-12-01

Full Text Available Se ha estudiado la efectividad de un sistema de pasteurización en el control de la contaminación por Legionella en la red de agua caliente de un hospital.El hospital había optado por este sistema debido a que los acumuladores convencionales originales presentaban importantes problemas en la capacidad de producción y en el mantenimiento de las temperaturas de distribución.El estudio fue iniciado después de haberse instalado los pasteurizadores y ha consistido en la realización de controles mensuales de Legionella y temperatura durante un período de 11 meses. De los resultados, se puede valorar que el sistema de pasteurización se considera efectivo, siempre y cuando las condiciones de la red (circulación, material, diseño, etc sean las adecuadas. El sistema no se considera efectivo en redes antiguas y con ramales sin circulación como se ha podido constatar en este estudio en el edificio de servicios, donde las conducciones presentaban un estado de conservación deficiente. En esta zona de servicios los controles de Legionella han mostrado una mejora únicamente después de que se iniciara un programa de purgas junto con la paulatina sustitución de los tramos en mal estado.The effectiveness of a pasteurization system in controlling contamination with Legionella has been evaluated in a hospital’s hot water system.The hospital acquired these equipments because the original system -conventional hot water tanks– had problems in producing and maintaining the distribution temperatures in the hot water circuit.The study started 11 months after the pasteurizers had been installed. The study consisted on Legionella and temperature controls which were conducted monthly during an 11-month period. Results have proved that a pasteurization system method to be an effective system of instantaneous warming provided that there are adequate conditions (circulation, materials, design, etc.. This system has no effectiveness in old nets or nets with

Close genetic relationship between Legionella pneumophila serogroup 1 isolates from sputum specimens and puddles on roads, as determined by sequence-based typing.

Science.gov (United States)

Kanatani, Jun-ichi; Isobe, Junko; Kimata, Keiko; Shima, Tomoko; Shimizu, Miwako; Kura, Fumiaki; Sata, Tetsutaro; Watahiki, Masanori

2013-07-01

We investigated the prevalence of Legionella species isolated from puddles on asphalt roads. In addition, we carried out sequence-based typing (SBT) analysis on the genetic relationship between L. pneumophila serogroup 1 (SG 1) isolates from puddles and from stock strains previously obtained from sputum specimens and public baths. Sixty-nine water samples were collected from puddles on roads at 6 fixed locations. Legionella species were detected in 33 samples (47.8%) regardless of season. Among the 325 isolates from puddles, strains of L. pneumophila SG 1, a major causative agent of Legionnaires' disease, were the most frequently isolated (n = 62, 19.1%). Sixty-two isolates of L. pneumophila SG 1 from puddles were classified into 36 sequence types (STs) by SBT. ST120 and ST48 were identified as major STs. Environmental ST120 strains from puddles were found for the first time in this study. Among the 14 STs of the clinical isolates (n = 19), 4 STs (n = 6, 31.6%), including ST120, were also detected in isolates from puddles on roads, and the sources of infection in these cases remained unclear. The lag-1 gene, a tentative marker for clinical isolates, was prevalent in puddle isolates (61.3%). Our findings suggest that puddles on asphalt roads serve as potential reservoirs for L. pneumophila in the environment.

Pengendalian Hayati Penyakit Layu Fusarium Pisang (Fusarium Oxysporum F.sp. Cubense) dengan Trichoderma SP.

OpenAIRE

Sudirman, Albertus; Sumardiyono, Christanti; Widyastuti, Siti Muslimah

2011-01-01

The aim of this research was to study the inhibiting ability of Trichoderma sp. to control fusarium wilt of banana in greenhouse condition. The experiments consisted of the antagonism test between Trichoderma sp. and Fusarium oxysporum f.sp. cubense (Foc) in vitro using dual culture method and glass house experiment which was arranged in 3×3 Factorial Complete Randomized Design. First factor of the latter experiment was the dose of Trichoderma sp. culture (0, 25, and 50 g per polybag), second...

The Effect of Acupuncture to SP6 on Skin Temperature Changes of SP6 and SP10: An Observation of “Deqi”

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Jia-Min Yang

2014-01-01

Full Text Available Background. Deqi sensation is a complex but an important component for acupuncture effect. In this study, we tried to observe the relationship between Deqi and skin temperature changes and whether there was some relativity between Deqi and needle stimulations on cold congealing and dysmenorrhea rat model. Thirty-two female Sprague Dawley (SD rats were randomly divided into four groups (Saline Control Group, Model Group, Group A with strong stimulation, and Group B with small stimulation. Group A and Group B were performed with different stimulations. We found that, compared with saline control group, model group, and Group B, Group A showed that the skin temperature changes on right acupoint SP6 and SP10 increased significantly at 5 min–10 min interval. The skin temperature changes on left SP6 decreased at instant–5 min interval. The skin temperature changes on right SP10 decreased significantly at instant–5 min interval and 10 min–20 min interval. Thermogenic action along Spleen Meridian of Foot Greater Yin was manifested as simultaneous skin temperature increase on right SP6 and SP10 at 5 min–10 min interval after needling SP6, which was helpful to illustrate the relationship between the characteristic of Deqi and needle stimulations.

The amoebal MAP kinase response to Legionella pneumophila is regulated by DupA.

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Li, Zhiru; Dugan, Aisling S; Bloomfield, Gareth; Skelton, Jason; Ivens, Alasdair; Losick, Vicki; Isberg, Ralph R

2009-09-17

The amoeba Dictyostelium discoideum can support replication of Legionella pneumophila. Here we identify the dupA gene, encoding a putative tyrosine kinase/dual-specificity phosphatase, in a screen for D. discoideum mutants altered in allowing L. pneumophila intracellular replication. Inactivation of dupA resulted in depressed L. pneumophila growth and sustained hyperphosphorylation of the amoebal MAP kinase ERK1, consistent with loss of a phosphatase activity. Bacterial challenge of wild-type amoebae induced dupA expression and resulted in transiently increased ERK1 phosphorylation, suggesting that dupA and ERK1 are part of a response to bacteria. Indeed, over 500 of the genes misregulated in the dupA(-) mutant were regulated in response to L. pneumophila infection, including some thought to have immune-like functions. MAP kinase phosphatases are known to be highly upregulated in macrophages challenged with L. pneumophila. Thus, DupA may regulate a MAP kinase response to bacteria that is conserved from amoebae to mammals.

Interaction of Sp1 zinc finger with transport factor in the nuclear localization of transcription factor Sp1

International Nuclear Information System (INIS)

Ito, Tatsuo; Kitamura, Haruka; Uwatoko, Chisana; Azumano, Makiko; Itoh, Kohji; Kuwahara, Jun

2010-01-01

Research highlights: → Sp1 zinc fingers themselves interact with importin α. → Sp1 zinc finger domains play an essential role as a nuclear localization signal. → Sp1 can be transported into the nucleus in an importin-dependent manner. -- Abstract: Transcription factor Sp1 is localized in the nucleus and regulates the expression of many cellular genes, but the nuclear transport mechanism of Sp1 is not well understood. In this study, we revealed that GST-fused Sp1 protein bound to endogenous importin α in HeLa cells via the Sp1 zinc finger domains, which comprise the DNA binding domain of Sp1. It was found that the Sp1 zinc finger domains directly interacted with a wide range of importin α including the armadillo (arm) repeat domain and the C-terminal acidic domain. Furthermore, it turned out that all three zinc fingers of Sp1 are essential for binding to importin α. Taken together, these results suggest that the Sp1 zinc finger domains play an essential role as a NLS and Sp1 can be transported into the nucleus in an importin-dependent manner even though it possesses no classical NLSs.

Role of surfactant protein A (SP-A)/lipid interactions for SP-A functions in the lung.

Science.gov (United States)

Casals, C

2001-01-01

Surfactant protein A (SP-A), an oligomeric glycoprotein, is a member of a group of proteins named collectins that contain collagen-like and Ca(2+)-dependent carbohydrate recognition domains. SP-A interacts with a broad range of amphipathic lipids (glycerophospholipids, sphingophospholipids, glycosphingolipids, lipid A, and lipoglycans) that are present in surfactant or microbial membranes. This review summarizes SP-A/lipid interaction studies regarding the lipid system used (i.e., phospholipid vesicles, phospholipid monolayers, and lipids immobilized on silica or adsorbed on a solid support). The effect of calcium, ionic strength, and pH on the binding of SP-A to lipids and the subsequent lipid aggregation process is discussed. Current evidence suggests that hydrophobic-binding forces are involved in the peripherical association of SP-A to membranes. It is also proposed that fluid and liquid-ordered phase coexistence in surfactant membranes might favor partition of SP-A into those membranes. The binding of SP-A to surfactant membranes containing hydrophobic surfactant peptides makes possible the formation of a membrane reservoir in the alveolar fluid that is protected by SP-A against inactivation and improves the rate of surfactant film formation. In addition, the interaction of SP-A with membranes might enhance the affinity of SP-A for terminal carbohydrates of glycolipids or glycoproteins on the surface of invading microorganisms.

Plumbing system shock absorbers as a source of Legionella pneumophila.

Science.gov (United States)

Memish, Z A; Oxley, C; Contant, J; Garber, G E

1992-12-01

Water distribution systems have been demonstrated to be a major source of nosocomial legionellosis. We describe an outbreak in our institution in which a novel source of Legionella pneumophila was identified in the plumbing system. After an outbreak of 10 cases of legionellosis in our hospital, recommended measures including superheating of the hot water to 80 degrees C, hyperchlorination to 2 ppm, and flushing resulted in no new cases in the following 5 years. Recently, despite these control measures, three new cases occurred. Surveillance cultures of shower heads and water tanks were negative; cultures of tap water samples remained positive. This prompted a search for another reservoir. Shock absorbers installed within water pipes to decrease noise were suspected. One hundred twenty-five shock absorbers were removed and cultured. A total of 13 (10%) yielded heavy growth of L. pneumophila (serogroup 1). Since their removal, no new cases have been found and the percentage of positive results of random tap water culture has dropped from 20% to 5%. This is the first report that identifies shock absorbers as a possible reservoir for L. pneumophila. We recommend that institutions with endemic legionellosis assess the water system for possible removal of shock absorbers.

Five novel Wickerhamomyces- and Metschnikowia-related yeast species, Wickerhamomyces chaumierensis sp. nov., Candida pseudoflosculorum sp. nov., Candida danieliae sp. nov., Candida robnettiae sp. nov. and Candida eppingiae sp. nov., isolated from plants

NARCIS (Netherlands)

Groenewald, Marizeth; Robert, Vincent; Smith, Maudy Th

On the basis of nucleotide divergences in the D1/D2 domain of the 26S rRNA gene and the internal transcribed spacers (ITS) domain of the rRNA gene, five novel yeast species, Wickerhamomyces chaumierensis sp. nov. (CBS 8565(T)  = JCM 17246(T)), Candida pseudoflosculorum sp. nov. (CBS 8584(T)  = JCM

Truncated recombinant human SP-D attenuates emphysema and type II cell changes in SP-D deficient mice

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Mühlfeld Christian

2007-10-01

Full Text Available Abstract Background Surfactant protein D (SP-D deficient mice develop emphysema-like pathology associated with focal accumulations of foamy alveolar macrophages, an excess of surfactant phospholipids in the alveolar space and both hypertrophy and hyperplasia of alveolar type II cells. These findings are associated with a chronic inflammatory state. Treatment of SP-D deficient mice with a truncated recombinant fragment of human SP-D (rfhSP-D has been shown to decrease the lipidosis and alveolar macrophage accumulation as well as production of proinflammatory chemokines. The aim of this study was to investigate if rfhSP-D treatment reduces the structural abnormalities in parenchymal architecture and type II cells characteristic of SP-D deficiency. Methods SP-D knock-out mice, aged 3 weeks, 6 weeks and 9 weeks were treated with rfhSP-D for 9, 6 and 3 weeks, respectively. All mice were sacrificed at age 12 weeks and compared to both PBS treated SP-D deficient and wild-type groups. Lung structure was quantified by design-based stereology at the light and electron microscopic level. Emphasis was put on quantification of emphysema, type II cell changes and intracellular surfactant. Data were analysed with two sided non-parametric Mann-Whitney U-test. Main Results After 3 weeks of treatment, alveolar number was higher and mean alveolar size was smaller compared to saline-treated SP-D knock-out controls. There was no significant difference concerning these indices of pulmonary emphysema within rfhSP-D treated groups. Type II cell number and size were smaller as a consequence of treatment. The total volume of lamellar bodies per type II cell and per lung was smaller after 6 weeks of treatment. Conclusion Treatment of SP-D deficient mice with rfhSP-D leads to a reduction in the degree of emphysema and a correction of type II cell hyperplasia and hypertrophy. This supports the concept that rfhSP-D might become a therapeutic option in diseases that are

Quality improvement on half-fin anchovy (Setipinna taty) fish sauce by Psychrobacter sp. SP-1 fermentation.

Science.gov (United States)

Zheng, Bin; Liu, Yu; He, Xiaoxia; Hu, Shiwei; Li, Shijie; Chen, Meiling; Jiang, Wei

2017-10-01

A method of improving fish sauce quality during fermentation was investigated. Psychrobacter sp. SP-1, a halophilic protease-producing bacterium, was isolated from fish sauce with flavor-enhancing properties and non-biogenic amine-producing activity. The performance of Psychrobacter sp. SP-1 in Setipinna taty fish sauce fermentation was investigated further. The inoculation of Psychrobacter sp. SP-1 did not significantly affect pH or NaCl concentration changes (P > 0.05), although it significantly increased total moderately halophilic microbial count, protease activity, total soluble nitrogen content and amino acid nitrogen content, and also promoted the umami taste and meaty aroma (P sauce quality by fermentation. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Computed tomographic features of 23 sporadic cases with Legionella pneumophila pneumonia

International Nuclear Information System (INIS)

Yu Hui; Higa, Futoshi; Hibiya, Kenji; Furugen, Makoto; Sato, Yoko; Shinzato, Takashi; Haranaga, Shusaku; Yara, Satomi; Tateyama, Masao; Fujita, Jiro; Li, Huiping

2010-01-01

Objective: To describe the chest computed tomographic (CT) findings of Legionella pneumophila pneumonia. Methods: CT scans obtained from 23 sporadic cases of L. pneumophila pneumonia were retrospectively reviewed. Chest CT findings were analyzed with regard to the patterns and distributions of pulmonary abnormalities. We also analyzed the histopathology of lungs from guinea pigs with experimentally induced L. pneumophila pneumonia. Results: Consolidation and ground-glass opacity (GGO) were the main findings of CT scans in L. pneumophila pneumonia. The distribution of opacities was categorized as non-segmental (n = 20) and segmental (n = 4). Non-segmental distribution may follow an onset of segmental distribution. Pleural effusion was observed in 14 (58.3%) patients, of which 13 were accompanied with non-segmental distribution. Abscess formation was observed in only one immunocompromised patient. In the animal pneumonia model, the lesions comprised of terminal bronchioles, alveolar spaces, and interstitia. Small bacilli were observed to be contained by many macrophages within the alveoli. Conclusion: Non-segmental distribution was significantly more frequent than segmental distribution in L. pneumophila pneumonia. It is possible that L. pneumophila infection initially results in segmental pneumonia, which progresses to typical non-segmental distribution.

Computed tomographic features of 23 sporadic cases with Legionella pneumophila pneumonia

Energy Technology Data Exchange (ETDEWEB)

Yu Hui [Department of Respiratory Diseases, Shanghai Pneumology Hospital, Tongji University, Shanghai (China); Higa, Futoshi; Hibiya, Kenji; Furugen, Makoto [Department of Medicine and Therapeutics, Control and Prevention of Infectious Diseases (First Department of Internal Medicine), Faculty of Medicine, University of the Ryukyus, Okinawa (Japan); Sato, Yoko [Tomishiro Chuo Hospital, Okinawa (Japan); Shinzato, Takashi [Nakagami General Hospital, Okinawa (Japan); Haranaga, Shusaku; Yara, Satomi; Tateyama, Masao [Department of Medicine and Therapeutics, Control and Prevention of Infectious Diseases (First Department of Internal Medicine), Faculty of Medicine, University of the Ryukyus, Okinawa (Japan); Fujita, Jiro, E-mail: fujita@med.u-ryukyu.ac.j [Department of Medicine and Therapeutics, Control and Prevention of Infectious Diseases (First Department of Internal Medicine), Faculty of Medicine, University of the Ryukyus, Okinawa (Japan); Li, Huiping [Department of Respiratory Diseases, Shanghai Pneumology Hospital, Tongji University, Shanghai (China)

2010-06-15

Objective: To describe the chest computed tomographic (CT) findings of Legionella pneumophila pneumonia. Methods: CT scans obtained from 23 sporadic cases of L. pneumophila pneumonia were retrospectively reviewed. Chest CT findings were analyzed with regard to the patterns and distributions of pulmonary abnormalities. We also analyzed the histopathology of lungs from guinea pigs with experimentally induced L. pneumophila pneumonia. Results: Consolidation and ground-glass opacity (GGO) were the main findings of CT scans in L. pneumophila pneumonia. The distribution of opacities was categorized as non-segmental (n = 20) and segmental (n = 4). Non-segmental distribution may follow an onset of segmental distribution. Pleural effusion was observed in 14 (58.3%) patients, of which 13 were accompanied with non-segmental distribution. Abscess formation was observed in only one immunocompromised patient. In the animal pneumonia model, the lesions comprised of terminal bronchioles, alveolar spaces, and interstitia. Small bacilli were observed to be contained by many macrophages within the alveoli. Conclusion: Non-segmental distribution was significantly more frequent than segmental distribution in L. pneumophila pneumonia. It is possible that L. pneumophila infection initially results in segmental pneumonia, which progresses to typical non-segmental distribution.

Synthese und Charakterisierung von potenziellen Inhibitoren des „Macrophage infectivity potentiator“ (Mip) Proteins von Legionella pneumophila - Ein neuer Ansatz in der Legionellose-Therapie

OpenAIRE

Juli, Christina

2012-01-01

Die vorliegende Arbeit beschäftigt sich mit der Synthese und Charakterisierung potenzieller Inhibitoren des Oberflächenproteins Mip von Legionella pneumophila. Der gramnegative Mikroorganismus ist der ursächliche Erreger der Legionellose. Die Erkrankung kann in zwei verschiedenen Formen auftreten, dem Pontiac-Fieber, einer Grippe-ähnlichen Atemwegserkrankung, und der Legionärskrankheit, einer schweren Lungenentzündung mit einer Mortalitätsrate von bis zu 30 %. Natürliche und künstlich geschaf...

From spent graphite to amorphous sp2+sp3 carbon-coated sp2 graphite for high-performance lithium ion batteries

Science.gov (United States)

Ma, Zhen; Zhuang, Yuchan; Deng, Yaoming; Song, Xiaona; Zuo, Xiaoxi; Xiao, Xin; Nan, Junmin

2018-02-01

Today, with the massive application of lithium ion batteries (LIBs) in the portable devices and electric vehicles, to supply the active materials with high-performances and then to recycle their wastes are two core issues for the development of LIBs. In this paper, the spent graphite (SG) in LIBs is used as raw materials to fabricate two comparative high-capacity graphite anode materials. Based on a microsurgery-like physical reconstruction, the reconstructed graphite (RG) with a sp2+sp3 carbon surface is prepared through a microwave exfoliation and subsequent spray drying process. In contrast, the neural-network-like amorphous sp2+sp3 carbon-coated graphite (AC@G) is synthesized using a self-reconfigurable chemical reaction strategy. Compared with SG and commercial graphite (CG), both RG and AC@G have enhanced specific capacities, from 311.2 mAh g-1 and 360.7 mAh g-1 to 409.7 mAh g-1 and 420.0 mAh g-1, at 0.1C after 100 cycles. In addition, they exhibit comparable cycling stability, rate capability, and voltage plateau with CG. Because the synthesis of RG and AC@G represents two typical physical and chemical methods for the recycling of SG, these results on the sp2+sp3 carbon layer coating bulk graphite also reveal an approach for the preparation of high-performance graphite anode materials derived from SG.

Halobacterium sp. SP1(1) as a starter culture for accelerating fish sauce fermentation.

Science.gov (United States)

Akolkar, A V; Durai, D; Desai, A J

2010-07-01

Application of Halobacterium sp. SP1(1) for the acceleration of fish sauce fermentation. Traditional fish sauce fermentation was mimicked using Halobacterium sp. SP1(1) as starter culture. Protease activity, peptide release and α-amino content (parameters used to monitor the progress of the fermentation) were high at day 10 in tests and day 20 in un-inoculated controls. The total protein and nitrogen contents were also high in tests compared with controls. The amino acid profile observed at the end of fermentation in experimental samples, when compared with the commercial sauce preparation, was found to be better with respect to flavour and aroma contributing amino acids as well as essential amino acid lysine. Microflora analysis of the final fish sauce revealed the absence of any nonhalophilic or halotolerant micro-organisms. The protease-producing halophilic isolates obtained from the fish sauce of eviscerated and uneviscerated controls were identified as Halobacterium sp. F1 and F2, respectively, by 16S rDNA sequence analysis. Exogenous augmentation of Halobacterium sp. SP1(1) accelerated the fish sauce fermentation process with an additive effect on the existing natural microflora present in the fish during fermentation. Halobacterium sp SP1(1), therefore, can be used as an important starter culture for accelerating the fish fermentation process, which is attributed to its extracellular protease. The present study is the first report on use of Halobacterium species as a starter culture for accelerating fish sauce fermentation. Use of halobacterial starter cultures may revolutionize the process in fish sauce industries by reducing the fermentation time and making the process more economical with improved nutritive value of product. Journal compilation © 2009 The Society for Applied Microbiology. No claim to Indian Government works.

ExaSP2

Energy Technology Data Exchange (ETDEWEB)

2017-09-08

ExaSP2 is a reference implementation of typical linear algebra algorithms and workloads for a quantum molecular dynamics (QMD) electronic structure code. The algorithm is based on a recursive second-order Fermi-Operator expansion method (SP2) and is tailored for density functional based tight-binding calculations of material systems.

Fresh Water Cyanobacteria Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as an Anticancer Drug Resource.

Directory of Open Access Journals (Sweden)

Akanksha Srivastava

Full Text Available An increasing number of cancer patients worldwide, especially in third world countries, have raised concern to explore natural drug resources, such as the less explored fresh water filamentous cyanobacteria. Six strains of cyanobacteria (Phormidium sp. CCC727, Geitlerinema sp. CCC728, Arthrospira sp. CCC729, Phormidium sp. CCC731, Phormidium sp. CCC730, and Leptolyngbya sp. CCC732 were isolated (paddy fields and ponds in the Banaras Hindu University, campus and five strains screened for anticancer potential using human colon adenocarcinoma (HT29 and human kidney adenocarcinoma (A498 cancer cell lines. Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 were the most potent as determined by examination of morphological features and by inhibition of growth by graded concentrations of crude extracts and thin-layer chromatography (TLC eluates. Cell cycle analysis and multiplex assays using cancer biomarkers also confirmed Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as cancer drug resources. Apoptotic studies in the cells of A498 (cancer and MCF-10A (normal human epithelial exposed to crude extracts and TLC fractions revealed no significant impact on MCF-10A cells emphasizing its importance in the development of anticancer drug. Identification of biomolecules from these extracts are in progress.

Fresh Water Cyanobacteria Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as an Anticancer Drug Resource.

Science.gov (United States)

Srivastava, Akanksha; Tiwari, Ratnakar; Srivastava, Vikas; Singh, Tej Bali; Asthana, Ravi Kumar

2015-01-01

An increasing number of cancer patients worldwide, especially in third world countries, have raised concern to explore natural drug resources, such as the less explored fresh water filamentous cyanobacteria. Six strains of cyanobacteria (Phormidium sp. CCC727, Geitlerinema sp. CCC728, Arthrospira sp. CCC729, Phormidium sp. CCC731, Phormidium sp. CCC730, and Leptolyngbya sp. CCC732) were isolated (paddy fields and ponds in the Banaras Hindu University, campus) and five strains screened for anticancer potential using human colon adenocarcinoma (HT29) and human kidney adenocarcinoma (A498) cancer cell lines. Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 were the most potent as determined by examination of morphological features and by inhibition of growth by graded concentrations of crude extracts and thin-layer chromatography (TLC) eluates. Cell cycle analysis and multiplex assays using cancer biomarkers also confirmed Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as cancer drug resources. Apoptotic studies in the cells of A498 (cancer) and MCF-10A (normal human epithelial) exposed to crude extracts and TLC fractions revealed no significant impact on MCF-10A cells emphasizing its importance in the development of anticancer drug. Identification of biomolecules from these extracts are in progress.

[Comparison and evaluation of the Binax EIA and Biotest EIA urinary antigen kits for detection of Legionella pneumophila antigen in urine samples].

Science.gov (United States)

Rastawicki, Waldemar; Rokosz, Natalia; Jagielski, Marek

2011-01-01

The Binax and the Biotest urinary antigen kits for detection of L. pneumophila antigen were compared by testing of selected 67 urine samples obtained from EWGLI as reference samples in External Quality Assessment Scheme. Thirty nine were positive with the Binax kit (100% of sensitivity), and 33 were positive with the Biotest (84.6% of sensitivity). The test specificities were 100% for the both kits. It was concluded that the Binax kit was more suitable for the routine diagnosis of Legionella infections than the Biotest kit.