| characterization of legionella lipopolysaccharide. | the lipopolysaccharide(lps) of legionella spp. is an immuno-dominant antigen and the basis for legionella pneumophila serogroup classification. the lps shows a peculiar structure composed of a very hydrophobic lipid a acylated by long chain fatty acids and an o-antigen-specific chain consisting of homopolymeric legionaminic acid. in this chapter we describe a method for the isolation of lps from l. pneumophila. in the first part we describe the chemical purification, in the second part we outlin ... | 2013 | 23150410 |
| interactions of legionella effector proteins with host phosphoinositide lipids. | by means of the icm/dot type iv secretion system legionella pneumophila translocates several effector proteins into host cells, where they anchor to the cytoplasmic face of the lcv membrane by binding to phosphoinositide (pi) lipids. thus, phosphatidylinositol-4-phosphate anchors the effector proteins sidc and sidm, which promote the interaction of lcvs with the er and the secretory vesicle trafficking -pathway. in this chapter, we describe protocols to (1) identify pi-binding proteins in legion ... | 2013 | 23150409 |
| legionella phospholipases implicated in infection: determination of enzymatic activities. | the intracellularly replicating lung pathogen legionella pneumophila expresses a multitude of different phospholipases which are important virulence tools during host cell infection. to study the lipolytic properties including substrate specificities of potential l. pneumophila phospholipases a (pla), we used different assays to monitor lipid hydrolysis. here we describe methods for quantitative analysis of liberated fatty acids via a photometric assay and for identification of specific lipids w ... | 2013 | 23150408 |
| subcellular localization of legionella dot/icm effectors. | the translocation of effector proteins by the dot/icm type iv secretion system is central to the ability of legionella pneumophila to persist and replicate within eukaryotic cells. the subcellular localization of translocated dot/icm proteins in host cells provides insight into their function. through co-staining with host cell markers, effector proteins may be localized to specific subcellular compartments and membranes, which frequently reflects their host cell target and mechanism of action. ... | 2013 | 23150406 |
| methods for determining protein translocation by the legionella pneumophila dot/icm type iv secretion system. | legionella pneumophila the causative agent of legionnaires' disease, actively manipulates host cell -processes to establish a membrane-bound replication vacuole permissive for its replication. establishment of such replication niche requires the dot/icm type iv secretion system which translocates a plethora of effectors into host cells. determining whether a particular protein is a substrate of the transporter is a prerequisite for subsequent functional studies. thus, a variety of methods have b ... | 2013 | 23150405 |
| immunofluorescence imaging of legionella infection in vitro. | upon uptake into a host cell, the intracellular bacterium legionella pneumophila is not degraded on the lysosomal pathway but efficiently establishes a highly specialized replicative vacuole in which it readily multiplies. as many icm/dot type 4 secretion translocated bacterial effectors contribute to the establishment of this subcellular compartment in close interaction with host cell trafficking pathways, the analysis of the intracellular localization of this bacterium during infection is of p ... | 2013 | 23150402 |
| analysis of legionella infection by flow cytometry. | legionella pneumophila infects and replicates in environmental protozoa and metazoan macrophages within a specific vacuole. the infection of phagocytes by l. pneumophila can be assessed by an agar plating assay or by fluorescence microscopy. here, we describe the analysis of legionella infection by automated flow cytometry using wild-type and mutant bacteria that constitutively produce the green fluorescent protein (gfp). advantages of the flow cytometry technique include (1) a software-assisted ... | 2013 | 23150400 |
| enrichment of outer membrane vesicles shed by legionella pneumophila. | the production of outer membrane vesicles (omvs) is a widespread phenomenon employed by bacteria to secrete cell envelope components into the environment. a contribution of legionella pneumophila omvs to the pathogenesis of legionnaires' disease is likely due to the high number of virulence-related proteins in the vesicles. omvs are isolated from the supernatant of liquid cultures of l. pneumophila. after low-speed centrifugation, residual bacteria and cell fragments are eliminated by passing th ... | 2013 | 23150399 |
| production of l. pneumophila monospecies biofilms in a low-nutrient-concentration medium. | in aquatic environments such as water distribution systems, legionella pneumophila persistence is -correlated to the presence of a biofilm. the method described here permits the formation of a monospecies l. pneumophila biofilm in microplates, enabling the screening of multiple parameters. the culture medium used has a low nutrient concentration compared to the classical buffered yeast extract culture medium. hence, bacterial growth occurs in the sessile phase, allowing the formation of three-di ... | 2013 | 23150398 |
| natural biofilm formation with legionella pneumophila. | biofilm formation could be studied in various conditions. most of the studies with legionella pneumophila used monospecies biofilm in culture media. in some cases, it is important to study bacteria in conditions more close to environmental conditions. in this paper, we describe protocols to produce natural biofilms from river water that were spiked with l. pneumophila. | 2013 | 23150397 |
| induction of competence for natural transformation in legionella pneumophila and exploitation for mutant construction. | many gram-positive and gram-negative bacteria possess natural competence mechanisms for dna -capture and internalization that play an important role in diversifying adaptation of bacteria through horizontal gene transfer. natural transformation and other mechanisms of horizontal gene transfer are dependent on dna recombination. natural competence can be exploited both for studying adaptation and horizontal gene transfer as well as for genetic engineering of a strain. we report here different app ... | 2013 | 23150395 |
| the intracellular metabolism of legionella by isotopologue profiling. | metabolic pathways and fluxes can be analyzed under in vivo conditions by incorporation experiments using general (13)c-labeled precursors. on the basis of the isotopologue compositions in amino acids or other metabolites, the incorporation rates of the supplied precursors and the pathways of their utilization can be studied in considerable detail. in this chapter, the method of isotopologue profiling is illustrated with recent work on the metabolism of intracellular living legionella pneumophil ... | 2013 | 23150394 |
| culturing, media, and handling of legionella. | this chapter describes methods for culturing legionella pneumophila in both complex and defined media. the first protocol describes the use of buffered charcoal yeast extract (bcye) agar, the solid medium that is most commonly used for culturing l. pneumophila. the next procedure details the cultivation of l. pneumophila in buffered yeast extract (bye) broth, i.e., the liquid medium version of bcye agar. we describe how culturing in bye broth can also be used for investigating proteins that are ... | 2013 | 23150393 |
| typing methods for legionella. | in this chapter we describe the methods currently used for subgrouping legionella pneumophila and other non-pneumophila species. in the first part we describe monoclonal antibody (mab) subgrouping, either by indirect immunofluorescence or indirect elisa methods. these monoclonal antibodies are not commercially available but can be obtained for noncommercial purposes from one of the authors. further, we describe pulsed-field gel electrophoresis (pfge), amplified fragment length polymorphism (aflp ... | 2013 | 23150392 |
| sequence-based typing of legionella pneumophila serogroup 1 clinical isolates from belgium between 2000 and 2010. | sequence-based typing (sbt) is a discriminatory method widely used to genotype legionella pneumophila strains. a total of 86 clinical l. pneumophila serogroup 1 (sg1) isolates, collected between january 2000 and december 2010 in the two belgian national reference centres for legionella pneumophila, were genotyped using the internationally standardised sbt protocol of the european working group for legionella infections (ewgli). the isolates could be classified into 31 different sequence types (s ... | 2012 | 23137466 |
| validation of irs pcr, a molecular typing method, for the study of the diversity and population dynamics of legionella in industrial cooling circuits. | legionella bacteria are ubiquitous in aquatic environments. members of the species legionella pneumophila are responsible for more than 98% of cases of legionnaires' disease in france. our objective was to validate a molecular typing method called infrequent restriction site pcr (irs pcr), applied to the study of the ecology of legionella and to compare this method with reference typing methods, pulsed-field gel electrophoresis (pfge) and sequence-based typing (sbt). pfge and sbt are considered ... | 2013 | 23136984 |
| [legionellosis in poland in 2010]. | the main objective of this article is to assess the epidemiology of legionellosis in poland in 2010, using national surveillance data. in poland, legionellosis is a mandatory notifiable disease based on the european union (probable or confirmed) case definition, however legionella pnemophila of unknown serogroup specific antybody response meets also laboratory criteria for case confirmation. | 2012 | 23101209 |
| humidifier-associated paediatric legionnaires' disease, israel, february 2012. | we report a fatal case of community-acquired legionnaires' disease in an infant aged under six months. epidemiological and microbiological investigations suggested that a free-standing cold water humidifier using domestic tap water contaminated with legionella pneumophila serogroup 1 served as a vehicle for infection. these findings were corroborated by sequence-based typing (sbt). humidifier-associated legionnaires' disease can be prevented by appropriate control measures. this case also illust ... | 2012 | 23078810 |
| quantitative risk estimation for a legionella pneumophila infection due to whirlpool use. | quantitative microbiological risk assessment was used to quantify the risk associated with the exposure to legionella pneumophila in a whirlpool. conceptually, air bubbles ascend to the surface, intercepting legionella from the traversed water. at the surface the bubble bursts into dominantly noninhalable jet drops and inhalable film drops. assuming that film drops carry half of the intercepted legionella, a total of four (95% interval: 1-9) and 4.5×10(4) (4.4×10(4) - 4.7×10(4) ) cfu/min were es ... | 2013 | 23078231 |
| control of biological growth in recirculating cooling systems using treated secondary effluent as makeup water with monochloramine. | secondary-treated municipal wastewater, an abundant and widely distributed impaired water source, is a promising alternative water source for thermoelectric power plant cooling. however, excessive biological growth is a major challenge associated with wastewater reuse in cooling systems as it can interfere with normal system operation as well as enhance corrosion and scaling problems. furthermore, possible emission of biological aerosols (e.g., legionella pneumophila) with the cooling tower drif ... | 2012 | 23063442 |
| effect of disinfectant, water age, and pipe material on occurrence and persistence of legionella, mycobacteria, pseudomonas aeruginosa, and two amoebas. | opportunistic pathogens represent a unique challenge because they establish and grow within drinking water systems, yet the factors stimulating their proliferation are largely unknown. the purpose of this study was to examine the influence of pipe materials, disinfectant type, and water age on occurrence and persistence of three opportunistic pathogens (legionella pneumophila, mycobacterium avium, and pseudomonas aeruginosa), broader genera (legionella and mycobacteria), and two amoeba hosts (ac ... | 2012 | 23046164 |
| colonization of hospital water systems by legionella pneumophila, pseudomonas aeroginosa, and acinetobacter in icu wards of tehran hospitals. | nosocomial infection caused by non-enterobacteriaceae gram negative bacteria (gnb-ne) is increasing in intensive care units (icu). | 2012 | 23032830 |
| structural models of the human copper p-type atpases atp7a and atp7b. | the human copper exporters atp7a and atp7b contain domains common to all p-type atpases as well as class-specific features such as six sequential heavy-metal binding domains (hmbd1-hmbd6) and a type-specific constellation of transmembrane helices. despite the medical significance of atp7a and atp7b related to menkes and wilson diseases, respectively, structural information has only been available for isolated, soluble domains. here we present homology models based on the existing structures of s ... | 2012 | 23029640 |
| photonic crystals on copolymer film for bacteria detection. | the development of two-dimensional photonic crystals (pcs) on a copolymer film is described in connection with fresnel reflection spectroscopy and fluorescence microscopy. label-free detection of legionella pneumophila was performed using a pc platform with a detection limit of 200 cells/ml. l. pneumophila is well known as the cause of legionnaires' disease and a lesser form called pontiac fever. since death by l. pneumophila infection depends on the early anti-microbial treatment, rapid diagnos ... | 2013 | 23021840 |
| influence of temperature, chlorine residual and heavy metals on the presence of legionella pneumophila in hot water distribution systems. | the microbiological colonisation of buildings and man-made structures often occurs on the walls of plumbing systems; therefore, monitoring of opportunistic pathogens such as legionella pneumophila (l. pneumophila), both in water distribution mains and in consumers' plumbing systems, is an important issue according to the international and national guidelines that regulate the quality of drinking water. this paper investigates the presence of l. pneumophila in the dalmatian county of croatia and ... | 2012 | 23020035 |
| [the ethiology structure of community-acquried pneumonia of young adults in closed communities]. | despite of success in ethiology evaluation of community-acquired pneumonia (cap) and instant improvement of diagnostic methods microbiological spectrum of cap is still remaining underestimated and is still the problem for the routine clinical practice. in our study we estimated the role of fastidious bacteria which cause atypical cap such as chlamydophilla pneumoniae, mycoplasma pneumoniae, legionella pneumophila. furthermore we also defined the role of viral pathogens in ethiology of cap. | 2012 | 23013002 |
| flia expression analysis and influence of the regulatory proteins rpon, fleq and flia on virulence and in vivo fitness in legionella pneumophila. | in legionella pneumophila, the regulation of the flagellum and the expression of virulence traits are linked. fleq, rpon and flia are the major regulators of the flagellar regulon. we demonstrated here that all three regulatory proteins mentioned (fleq, rpon and flia) are necessary for full in vivo fitness of l. pneumophila strains corby and paris. in this study, we clarified the role of fleq for flia expression from the level of mrna toward protein translation. fleq enhanced flia expression, bu ... | 2012 | 23011748 |
| evaluation of meridian tru legionella®, a new rapid test for detection of legionella pneumophila serogroup 1 antigen in urine samples. | we evaluated the ability of a new antigen test (tru legionella® assay, meridian bioscience, cincinnati, oh, usa) to detect legionella pneumophila serogroup 1 antigen in urine. the results were compared with those obtained with the binax now® urinary antigen test (binax, portland, me, usa). the sensitivities and specificities were 73 % [95 % confidence interval (ci), 65 to 81 %] and 100 %, respectively, for the meridian tru legionella test and 77 % (95 % ci, 68 to 84 %) and 100 %, respectively, f ... | 2013 | 23010904 |
| an outbreak of legionnaires' disease associated with a display spa pool in retail premises, stoke-on-trent, united kingdom, july 2012. | twenty-one confirmed cases of legionnaires’ disease (legionella pneumophila serogroup 1) were identified in the stoke-on-trent area of england with onsets since 2 july 2012. sequence-based typing results are available for nine cases; all are a unique type (st1268). initial interviews highlighted a number of possible environmental sources. inspection of premises of interest revealed an operating spa pool on display, from which the outbreak strain was identified. all cases had visited the retail p ... | 2012 | 22995431 |
| molecular characterization of clinical and environmental isolates of legionella pneumophila in norway, 2001-2008. | the aims of the study were to determine the molecular characteristics of a collection of legionella pneumophila isolates from 45 cases with legionnaires' disease and from 96 environmental samples, received by the national reference laboratory in norway between 2001 and 2008, to use these characteristics to identify links between cases and suspected sources of infection, and to compare the isolate characteristics with those in other european countries. | 2013 | 22992204 |
| covalent attachment of biomacromolecules to plasma-patterned and functionalized carbon nanotube-based devices for electrochemical biosensing. | the interface between biomacromolecules and carbon nanotubes (cnts) is of critical importance in developing effective techniques that provide cnts with both biomolecular recognition and signal transduction through immobilization. however, the chemical inertness of cnt surfaces poses an obstacle to wider implementation of cnts in bioanalytical applications. in this paper, we present a review of our recent research activities related to the covalent attachment of biomacromolecules to plasma-patter ... | 2012 | 22988883 |
| a practical approach to ensuring safe water. | susan pearson bsc reports on a recent specialist waterborne diseases 'masterclass' held in nottingham, at which leading experts discussed not only the control of pseudomonas, but also other problematic waterborne pathogens such as legionella, the cause of legionnaires' disease. the pall medical-sponsored event provided plenty of 'food for thought' for estates and facilities personnel responsible for hospital water systems, and clearly demonstrated how difficult and persistent a foe organisms suc ... | 2012 | 22984741 |
| hospital acquired pneumonia: comparison of culture and real-time pcr assays for detection of legionella pneumophila from respiratory specimens at tehran hospitals. | legionella pneumophila is an important etiological agent in both hospital and community acquired pneumonia. the sensitivity of culture for isolation of l. pneumophila from clinical specimens is low and time consuming. similar problem also exists when the method of direct immunofluorescence is used. to detect this organism quantitatively from respiratory specimens, a taq man based real-time pcr targeting the mip sequence was developed. both real-time pcr and culture methods were applied on 262 re ... | 2012 | 22982639 |
| phagocytic entry of legionella pneumophila into macrophages through phosphatidylinositol 3,4,5-trisphosphate-independent pathway. | legionella pneumophila, a causative agent of legionnaire's disease, is an intracellular pathogen. it intervenes in the signal transduction of macrophages by secreting effector molecules through the icm/dot type iv secretion system (t4ss). there is a connection between signaling cascades that regulate phagocytosis and the production of reactive oxygen species (ros). class i phosphatidylinositol 3-kinase (pi3-k) and its product phosphatidylinositol 3,4,5-trisphosphate (pi(3,4,5)p3) play key roles ... | 2012 | 22975496 |
| electrochemical nanoporous alumina membrane-based label-free dna biosensor for the detection of legionella sp. | an electrochemical nanoporous alumina membrane-based label free dna biosensor is developed using 5'-aminated dna probes immobilized into the nanochannels of alumina. alumina nanoporous membrane-like structure is carved over platinum wire electrode of 76 μm diameter dimension by electrochemical anodization. the hybridization of complementary target dna with probe dna molecules attached inside the nanochannels influences the pore size and ionic conductivity. electrochemical biosensing signal is de ... | 2012 | 22939135 |
| of mice and men--naip homologues face legionella pneumophila. | | 2012 | 22922068 |
| detection of legionella pneumophila serogroup 1 in blood cultures from a patient treated with tumor necrosis factor-alpha inhibitor. | a 65-year-old man was admitted to our hospital with a temperature of 39.3 °c, cough, sputum, and pharyngeal discomfort that had persisted for 3 days. he had been treated with methotrexate and adalimumab (a tumor necrosis factor-alpha [tnf-α] inhibitor) for rheumatoid arthritis for 2 years, and he had also been treated with s-1 (tegafur, gimeracil, and oteracil potassium) for pancreatic metastasis of gastric cancer for 2 months. regardless of the underlying pathologies, his general condition was ... | 2013 | 22911089 |
| kinetic evidence of a noncatalytic substrate binding site that regulates activity in legionella pneumophila l-serine dehydratase. | the l-serine dehydratase from legionella pneumophila (lplsd) has recently been shown to contain a domain (β domain) that has a high degree of structural homology with the asb domain of d-3-phosphoglycerate dehydrogenase (pgdh) from mycobacterium tuberculosis. furthermore, this domain has been shown by sequence homology to be present in all bacterial l-serine dehydratases that utilize an fe-s catalytic center. in pgdh, l-serine binds to the act domain to inhibit catalytic activity. however, subst ... | 2012 | 22891658 |
| legionella pneumophila serogroup 3 infection: importance of serology. | we present a case of legionella pneumophila serogroup 3 (lp3) infection in a patient with severe community-acquired pneumonia (cap). the diagnosis was complicated by an initial equivocal l. pneumophila urinary antigen test, followed by two negative samples. lp3 was cultured from a sputum sample and the diagnosis was confirmed by serology 15 days into the admission. this case highlights the importance of considering non-lp1 serogroups as causes of cap and the role of serological testing in diagno ... | 2012 | 22859812 |
| community-acquired legionella pneumonia in the intensive care unit: impact on survival of combined antibiotic therapy. | to compare intensive care unit (icu) mortality in patients with severe community-acquired pneumonia (scap) caused by legionella pneumophila receiving combined therapy or monotherapy. | 2016 | 22854618 |
| legionella pneumophila serogroup 1 in a birthing pool. | this report describes a risk assessment and subsequent actions following isolation of legionella pneumophila serogroup 1 in the water supply to a birthing pool during a planned maintenance programme. a literature search for cases of neonatal legionellosis identified 24 reports of cases among babies aged <2 months, two of which were associated with water births. on this basis, the pool was closed until legionella spp. were undetectable. control proved difficult as hyperchlorination failed, and a ... | 2012 | 22854354 |
| detection of legionella pneumophila on clinical samples and susceptibility assessment by flow cytometry. | culture in selective media represents the standard diagnostic method to confirm legionella pneumophila infection, despite requiring a prolonged incubation period; antigen detection by immunofluorescence (ifs) and molecular techniques are also available, but they do not allow antimicrobial susceptibility evaluation. our objective was to optimise flow cytometry (fc) protocols for the detection of l. pneumophila in respiratory samples and for susceptibility evaluation to first-line drugs. in order ... | 2012 | 22843284 |
| [prevalence of glucosyl transferase lgt among legionella pneumophila strains isolated from various sources]. | determine various members of lgt glucosyl transferase family among microorganisms of legionellaceae genus from museum collection and legionellae strains recently isolated in the russian federation and germany. | 2012 | 22830268 |
| [examination of the contamination aetiological agent of legionellosis in the water supply systems of medical treatment facilities]. | this study considers the features of colonization of water distribution systems by legionella in large multi-type health-care facilities in moscow-city, russia. the investigation of 16 pavilions in 5 multi-type health-care facilities had found the hith level of hot water systems contaminated by legionella pneumophila (68%), including the risk units. among the different species of legionella pneumophila, circulating in hot water systems of health-care facilities, the following strains had prevail ... | 2012 | 22830115 |
| [isolation of legionella species from hot springs used for foot-soaking]. | we aimed to investigate the presence of legionella species in hot-spring baths for feet, which have been rapidly increasing in number in japan in recent years. | 2012 | 22816190 |
| [legionella, legionnaires' disease]. | legionella is the causative agent of legionnaires' disease, a severe form of pneumonia. detection of legionella pneumophila serogroup 1 antigen in urine samples has shortened the delay of diagnosis and subsequent treatment initiation resulting in decreased mortality. improved surveillance of potable water system reinforces the community prevention. in france, the national reference center for legionella collects the strains responsible for sporadic or epidemic cases and crosslinks the data inclu ... | 2012 | 22805141 |
| molecular typing of legionella pneumophila strains isolated from environment in morocco. | legionella pneumophila is a common cause of hospital and community-acquired pneumonia, being transmitted by inhalation of aqueous aerosols. most legionellosis outbreaks are linked to contaminated hot water systems or cooling towers. the aim of this study was to determine the genetic diversity of (n= 55) environmental strains of l. pneumophila recovered from the hot water distribution systems of 16 establishments in seven moroccan towns during the period 2009-2011. thirteen chromosomal restrictio ... | 2012 | 22762526 |
| efficacy of the detection of legionella in hot and cold water samples by culture and pcr. ii. examination of native samples from various sources. | a total of 123 water samples were examined in parallel by culture and semi-nested pcr for the presence of legionella. they comprised: 35 samples of hot water distributed by the urban municipal water supply system (mwss) taken in institutions, 45 samples of hot water distributed by urban mwss taken in dwellings, 27 samples of cold water distributed by rural mwss taken in dwellings, and 16 samples of cold well water taken in rural areas. the greatest frequency of the isolation of legionella by cul ... | 2012 | 22742805 |
| efficacy of the detection of legionella in hot and cold water samples by culture and pcr. i. standardization of methods. | the aim of the present study was: - to compare methods for concentration and isolation of legionella dna from water; - to examine the efficacy of various modifications of pcr test (pcr, semi-nested pcr, and real-time pcr) for the detection of known numbers of legionella pneumophila in water samples artificially contaminated with the strain of this bacterium and in randomly selected samples of environmental water, in parallel with examination by culture. it was found that filtration is much more ... | 2012 | 22742804 |
| mechanism of invasion of lung epithelial cells by filamentous legionella pneumophila. | legionella, the aetiological agent responsible for legionellosis, is an opportunistic pathogen that infects humans upon the inhalation of contaminated aerosolized water droplets. legionella is pleomorphic and its different morphotypes exhibit varying degrees of virulence. while the filamentous forms of legionella pneumophila (lp) have been reported in patient samples since the first description of legionellosis, their role in disease has not been studied. our results show that both e-cadherin an ... | 2012 | 22727141 |
| innate instruction of cd4+ t cell immunity in respiratory bacterial infection. | the innate immune system recognizes invading microbes via conserved pattern recognition receptors and uses inflammatory signals to concert adaptive defense mechanisms. however, microbial and host parameters involved in cd4 t cell priming and direction of th1, th2, and th17 differentiation in the context of infections with complex pathogens in vivo are incompletely understood. in this study, we used legionella pneumophila, which triggers membrane-bound and cytosolic pattern recognition receptors, ... | 2012 | 22723524 |
| lapg, required for modulating biofilm formation by pseudomonas fluorescens pf0-1, is a calcium-dependent protease. | biofilm formation by pseudomonas fluorescens pf0-1 requires the cell surface adhesin lapa. we previously reported that lapg, a periplasmic cysteine protease of p. fluorescens, cleaves the n terminus of lapa, thus releasing this adhesin from the cell surface and resulting in loss of the ability to make a biofilm. the activity of lapg is regulated by the inner membrane-localized cyclic-di-gmp receptor lapd via direct protein-protein interactions. here we present chelation and metal add-back studie ... | 2012 | 22707708 |
| lethal legionella infection in an immunocompromised child: first reported case in the middle east. | legionnaires disease continues to be underreported in the middle east--a reflection of underdiagnosis, both clinically and by laboratory investigations. we draw the attention to this unusual cause of occasionally fatal, yet severe, pneumonia by reporting an immunocompromised infant who succumbed to legionella pneumophila pneumonia. the urinary test for legionella antigen was positive, and this was then confirmed by a bronchoalveolar fluid culture. moreover we have reviewed the incidence, pathoph ... | 2012 | 22705619 |
| epidemiological investigation of a legionnaires' disease outbreak in christchurch, new zealand: the value of spatial methods for practical public health. | between april and august 2005 christchurch, new zealand experienced an outbreak of legionnaires' disease. there were 19 laboratory-confirmed case including three deaths. legionella pneumophila serogroup 1 (lpsg1) was identified as the causative agent for all cases. a case-control study indicated a geographical association between the cases but no specific common exposures. rapid spatial epidemiological investigation confirmed the association and identified seven spatially significant case cluste ... | 2013 | 22697112 |
| identification of protective b cell antigens of legionella pneumophila. | abs confer protection from secondary infection with legionella pneumophila, the causative agent of a severe form of pneumonia known as legionnaires' disease. in this study, we demonstrate that ab-mediated protection is effective across l. pneumophila serogroups, suggesting that abs specific for conserved protein ags are sufficient to mediate this protective effect. we used two independent methods to identify immunogenic l. pneumophila protein ags, namely, the screening of a λ phage library repre ... | 2012 | 22696443 |
| [serologic characteristic of legionella pneumophila strains isolated from potentially dangerous water systems in russian federation in 2007 - 2011]. | study serologic diversity of legionella pneumophila strains circulating in potentially dangerous water systems in russian federation by using an international panel of monoclonal antibodies. | 2012 | 22693806 |
| effects of ultraviolet germicidal irradiation and swirling motion on airborne staphylococcus aureus, pseudomonas aeruginosa and legionella pneumophila under various relative humidities. | staphylococcus aureus, pseudomonas aeruginosa, and legionella pneumophila have been detected in indoor air and linked to human infection. it is essential to adopt control methods to inactivate airborne pathogens. by passing bioaerosols horizontally into a uv device at two flow rates (qs) and moving cells around a central uvc lamp at relative humidity (rh) of 12.7-16.7%, 58.7-59.6%, and 87.3-90%, the effects of swirling motion and 254-nm ultraviolet germicidal irradiation (uvgi) against bioaeroso ... | 2013 | 22680348 |
| analysis of population structure among korean and japanese legionella pneumophila isolates using hsp60 sequences. | the population structure of korean (150 strains) and japanese (92 strains) legionella pneumophila isolates along with 18 reference strains were investigated using hsp60 sequence (1647 bp) analysis. twelve clonal subgroups (hsp-i to hsp-x and hsf-i and hsf-ii) were designated on the hsp60 tree, inferred from representative sequences using the neighbor-joining method. some of the isolates showed unique subgroups depending on the source of isolates, including hsp-i, hsf-i, and hsf-ii from cooling t ... | 2012 | 22672106 |
| postantibiotic effect of various antibiotics on legionella pneumophila strains isolated from water systems. | the postantibiotic effects (pae) of azithromycin, clarithromycin, ciprofloxacin, and levofloxacin were investigated against legionella pneumophila (l. pneumophila) strains isolated from several hot water systems of different buildings in istanbul. each strain in logarithmic phase of growth was exposed to concentrations of antibiotics equal to minimum inhibitory concentration (mic) and 4× mic for 1 h. recovery periods of test cultures were evaluated after centrifugation using the viable counting ... | 2012 | 22627604 |
| enabling fiber optic serotyping of pathogenic bacteria through improved anti-fouling functional surfaces. | significant research efforts are continually being directed towards the development of sensitive and accurate surface plasmon resonance biosensors for sequence specific dna detection. these sensors hold great potential for applications in healthcare and diagnostics. however, the performance of these sensors in practical usage scenarios is often limited due to interference from the sample matrix. this work shows how the co-immobilization of glycol(peg) diluents or 'back filling' of the dna sensin ... | 2012 | 22609831 |
| automated dead-end ultrafiltration of large volume water samples to enable detection of low-level targets and reduce sample variability. | a portable multi-use automated concentration system (pmacs) concentrates micro-organisms from large volumes of water through automated dead-end ultrafiltration and backflushing. the ability to detect microbial targets from ground, surface and cooling tower waters collected using standard methods was compared with samples from the pmacs in this study. | 2012 | 22607480 |
| medical treatment failure and complete left pneumonectomy after legionella pneumophila pneumonia in a bone marrow transplant recipient. | legionnaire disease (ld) is infrequently considered in the differential diagnoses for hospital- and community-acquired pneumonia in pediatrics. we report a case of legionnaire disease in a 19-year-old male with aplastic anemia after bone marrow transplant, who was being treated in a children's hospital. severe, refractory pulmonary disease necessitated pneumonectomy to control the infection. | 2012 | 22581222 |
| innate immunity to intracellular pathogens: lessons learned from legionella pneumophila. | intracellular bacterial pathogens have the remarkable ability to manipulate host cell processes in order to establish a replicative niche within the host cell. in response, the host can initiate immune defenses that lead to the eventual restriction and clearance of intracellular infection. the bacterial pathogen legionella pneumophila has evolved elaborate virulence mechanisms that allow for its survival inside protozoa within a specialized membrane-bound organelle. these strategies also enable ... | 2012 | 22569517 |
| deep sequencing defines the transcriptional map of l. pneumophila and identifies growth phase-dependent regulated ncrnas implicated in virulence. | the bacterium legionella pneumophila is found ubiquitously in aquatic environments and can cause a severe pneumonia in humans called legionnaires' disease. how this bacterium switches from intracellular to extracellular life and adapts to different hosts and environmental conditions is only partly understood. here we used rna deep sequencing from exponentially (replicative) and post exponentially (virulent) grown l. pneumophila to analyze the transcriptional landscape of its entire genome. we es ... | 2012 | 22546937 |
| characterization of an acetyltransferase that detoxifies aromatic chemicals in legionella pneumophila. | 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 environments. the molecular mechanisms by which this bacterium detoxifies these chemicals remain poorly understood. in particular, the expression and functions of xmes (xenobiotic-metabolizing enzymes) th ... | 2012 | 22545684 |
| legionella pneumophila found in windscreen washer fluid without added screenwash. | | 2012 | 22543984 |
| genetic speciation of environmental legionella isolates in thailand. | legionella-like organisms were isolated during 2003-2007 from various water resources by culturing on selective media of wadowsky-yee-okuda agar. the 256 isolates were identified as belonging to the legionella genus based on detection of 108 bp pcr product of the 5s rrna gene, while the inclusion as legionella pneumophila were confirmed by pcr detection of a specific mip gene region of 168 bp. the 50 isolates, identified as non-pneumophila, were then subjected to dna tree analysis, based on mip ... | 2012 | 22504352 |
| the human apoptosis inhibitor naip induces pyroptosis in macrophages infected with legionella pneumophila. | human nucleotide oligomerization domain-like receptor family apoptosis inhibitory protein (naip) prevents apoptosis by inhibiting caspase-3, -7, and -9. four functional naip exist in the murine genome, each of which is equally similar to human naip. among them, naip5 induces pyroptosis by promoting caspase-1 activation in response to legionella pneumophila infection in macrophages. however, the contribution of human naip to this response is unclear. to investigate the role of human naip in macro ... | 2012 | 22504023 |
| biologic therapy and risk of infection. | biologic compounds are being used more frequently to treat a multitude of systemic inflammatory conditions. these novel compounds are composed of antibodies or other peptides that act through one of three mechanisms: inhibiting inflammatory cytokine signaling (typically tumor necrosis factor or tnf), inhibiting t-cell activation, or depleting b-cells. the increase in use and ever expanding list of new immune modulating therapies make knowledge of the infectious complications associated with immu ... | 2012 | 22491803 |
| development of a method for oral administration of hydrophobic substances to caenorhabditis elegans: pro-longevity effects of oral supplementation with lipid-soluble antioxidants. | methods for quantitative oral administration of various substances to caenorhabditis elegans are needed. previously, we succeeded in oral administration of hydrophilic substances using liposomes. however, an adequate system for delivery of hydrophobic chemicals was not available. in this study, we developed a method for oral administration of lipid-soluble substances to c. elegans. γ-cyclodextrin (γcd), which delivers hydrophobic chemicals, was used to make micro-particles of inclusion compounds ... | 2012 | 22484623 |
| molecular identification of hartmannella vermiformis and vannella persistens from man-made recreational water environments, tehran, iran. | a survey was conducted on man-made recreational water located in different regions of tehran, iran to detect the free-living amoebae present in ponds and fountains of parks and squares. fifty water samples from 22 municipal districts of tehran were screened for free-living amoebae and identified by morphological characters and polymerase chain reaction amplification. amoebae detected were identified as hartmannella vermiformis (12 %) and vannella persistens (4 %), which are the first reports of ... | 2012 | 22476603 |
| liver cirrhosis as a predisposing condition for legionnaires' disease: a report of four laboratory-confirmed cases from china. | here, we describe four cases of laboratory-confirmed legionella infection. case 1 was a culture-confirmed case of legionella infection in a patient with liver cirrhosis. following this, three other liver cirrhosis cases (cases 2-4) were diagnosed with legionella infection as confirmed by quantitative real-time pcr. the cause of the pneumonia was determined as legionella pneumophila by positive direct fluorescence assay and isolation of the causative agent. the infections were successfully treate ... | 2012 | 22466030 |
| protective immunity against legionnaires' disease in an a/j mouse model using a dna vaccine composed of an outer membrane protein (29 kda) and the pile fusion protein. | in order to assess the protective effects of the dna vaccine (pcdip/pile) against legionella pneumophila, the coding sequences of the 2 proteins were cloned into the pet32a(+) and pcdna3.1(+) vectors. to provide an enhanced immunological response, the proteins were linked together. in this study, the a/j mouse model was used for examine the immunogenicity and protective efficacy of the dna vaccines of pcdip, pcdpile and pcdip/pile. our results showed that the total igg titers were higher level i ... | 2012 | 22465301 |
| detection of free-living amoebae by using multiplex quantitative pcr. | free-living amoebae (fla) are protozoa found worldwide in soil and aquatic environments, which are able to colonize man-made water networks. some fla have the potential to be pathogenic and others might harbour pathogenic bacteria. indeed, fla feed on bacteria, but some bacteria could resist phagocytosis and either survive in fla or even multiply within fla. these bacteria are collectively named amoeba resistant bacteria (arb). the best characterized example is legionella pneumophila, for which ... | 2012 | 22449586 |
| development of a new card-fish protocol for quantification of legionella pneumophila and its application in two hospital cooling towers. | open cooling towers are frequent sources of infections with legionella pneumophila. the gold standard for the detection of leg. pneumophila is based on cultivation lasting up to 10 days and detecting only culturable cells. alternative fluorescence in situ hybridization (fish) protocols have been proposed, but they result in faint fluorescence signals and lack specificity because of cross-hybridization with other legionella species. our aim was thus to develop a new fish protocol for rapid and sp ... | 2012 | 22443397 |
| importance of the icmn gene in the growth of legionella pneumophila in amoebic cells at low temperature. | legionella pneumophila grows in amoebae and has achieved the ability to grow at various temperatures, although the mechanisms controlling this ability remain poorly understood. the icm/dot type ivb secretion system is composed of more than 25 proteins and is known to be essential for intracellular growth. the role of the icmn gene in intracellular multiplication and the effects of culture temperatures on it are not precisely understood. we conducted our investigation using an icmn mutant made by ... | 2012 | 22435730 |
| disposable immunochips for the detection of legionella pneumophila using electrochemical impedance spectroscopy. | the rapid diagnosis of legionellosis is crucial for the effective treatment of this disease. currently, most clinical laboratories utilize rapid immunoassays that are sufficient for the detection of legionella serogroup 1, but not other clinically relevant serogroups. in this report, the development of a disposable immunochip system is described in connection with electrochemical impedance spectroscopy and fluorescence microscopy. the immunochips were prepared by covalently immobilizing fluoroph ... | 2012 | 22424137 |
| the role of the ntpdase enzyme family in parasites: what do we know, and where to from here? | nucleoside triphosphate diphosphohydrolases (ntpdases, gda1_cd39 protein superfamily) play a diverse range of roles in a number of eukaryotic organisms. in humans ntpdases function in regulating the inflammatory and immune responses, control of vascular haemostasis and purine salvage. in yeast ntpdases are thought to function primarily in the golgi, crucially involved in nucleotide sugar transport into the golgi apparatus and subsequent protein glycosylation. although rare in bacteria, in legion ... | 2012 | 22423612 |
| wellness centres: an important but overlooked source of legionnaires disease. eight years of source investigation in the netherlands, 1 august 2002 to 1 august 2010. | visiting wellness centres is considered safe and relaxing and might provide health benefits for visitors with certain cardiovascular, dermatological or respiratory diseases. on the other hand, wellness centres could pose health risks, especially with respect to legionnaires’ disease. we investigated the role of wellness centres in the occurrence of legionnaires’ disease by analysing the data of eight years (2002–2010) of source investigation in the netherlands. there were 15 wellness centres ide ... | 2012 | 22401507 |
| post-translational modifications of host proteins by legionella pneumophila: a sophisticated survival strategy. | eukaryotic proteins are tightly regulated by post-translational modifications, leading to a very subtle degree of regulation in time and space. pathogen-mediated post-translational modifications are key strategies to modulate host factors by targeting central signaling pathways in the host cell. legionella pneumophila, an intracellular pathogen that coevolved with protozoan hosts, encodes a large arsenal of secreted effectors conferring the ability to evade host cellular defenses and to manipula ... | 2012 | 22393890 |
| community-acquired pneumonia in immunocompromised older patients: incidence, causative organisms and outcome. | the number of elderly patients in the community with immunosuppressive conditions has increased progressively over recent decades. we sought to determine the incidence, causative organisms and outcome of community-acquired pneumonia (cap) occurring in immunocompromised older patients. we prospectively compared cases of cap in immunocompromised and non-immunocompromised patients admitted to five public hospitals in three spanish regions. of 320 cases studied, 115 (36%) occurred in immunocompromis ... | 2013 | 22390624 |
| evaluation of dna isolation procedures for detecting and quantifying environmental legionella by real-time quantitative pcr. | six methods, qiaamp dna mini kit (q), q with sepharose 4b gel column (q/g), q with low melting point agarose (q/l), freeze-thaw/phenol-chloroform lysis (ft-pc), ft-pc/g, and ft-pc/l, were evaluated for their ability to isolate dna of sufficient quality to quantify legionella using qpcr. samples of mixing legionella pneumophila (atcc33152) and humic acid (ha, 0-126.8 mg/l) were treated by the six methods. q, q/g, q/l, ft-pc/g, and ft-pc/l removed ha from 1.9-126.8 to <1 mg/l determined by a260 wi ... | 2012 | 22377993 |
| epidemiological investigation of a legionellosis outbreak in a slovenian nursing home, august 2010. | august 2010 marked the beginning of the largest outbreak of legionellosis in a slovenian nursing home. this article presents our experiences with the outbreak investigation. | 2012 | 22339541 |
| application of legionella pneumophila-specific quantitative real-time pcr combined with direct amplification and sequence-based typing in the diagnosis and epidemiological investigation of legionnaires' disease. | the detection of legionella pneumophila dna in clinical specimens using quantitative real-time polymerase chain reaction (qpcr) combined with direct sequence-based typing (sbt) offers rapid confirmation and timely intervention in the investigation of cases of legionnaires' disease (ld). we assessed the utility of a specific l. pneumophila qpcr assay targeting the macrophage infectivity potentiator (mip) gene and internal process control with three clinical specimen types from confirmed ld cases. ... | 2012 | 22278293 |
| legionella pneumophila contamination in a steam towel warmer in a hospital setting. | for prevention of nosocomial legionellosis, environmental investigation to identify possible infectious sources is essential. an environmental study in a ward of our hospital revealed that a steam towel warmer was contaminated with legionella whereas no legionella was detected in tap water supplies and shower heads. water in the apparatus may be a reservoir of legionella. we abandoned the use of all steam towel warmers in our hospital. based on this finding, we recommend that steam towel warmers ... | 2012 | 22266131 |
| plasma-activated carbon nanotube-based high sensitivity immunosensors for monitoring legionella pneumophila by direct detection of maltose binding protein peptidoglycan-associated lipoprotein (mbp-pal). | transferred multi-walled carbon nanotube (mwcnt)-modified platinum thin-film immunosensing electrode material was engineered on a glass substrate and fabricated a fully-integrated electrochemical three-electrode system for monitoring legionella pneumophila. the transferred mwcnt film was treated with oxygen plasma to improve its electrochemical response and electrical conductivity. we voltammetrically characterized and optimized the electrochemical performance of the fabricated electrode for dir ... | 2012 | 22234602 |
| legionellosis presenting as singultus and external ophthalmoplegia. | we report a 71-year-old man with legionellosis, who presented with abducens nerve palsy, singultus, confusion, memory impairment, ataxia, and hyporeflexia. legionella pneumonia was diagnosed on the basis of detection of legionella pneumophila antigen in the urine. the cerebrospinal fluid was negative for the antigen and antibody, but an oligoclonal band was detected, and the igg index was elevated. it was speculated that an undetermined immune-mediated mechanism had contributed to the developmen ... | 2012 | 22234523 |
| temporal and differential regulation of expression of the eukaryotic-like ankyrin effectors of legionella pneumophila. | upon transition from the exponential (e) to the post-exponential phase (pe) of growth, legionella pneumophila undergoes a phenotypic modulation from a replicative to a highly infectious form. this transition requires a delicate regulatory cascade that is triggered to induce expression of various virulence-related genes. we have recently characterized eleven l. pneumophila eukaryotic-like ankyrin effectors (ank) shared between the four sequenced genomes of l. pneumophila. the ankb effector recrui ... | 2010 | 23766255 |
| incorporation of natural uncultivable legionella pneumophila into potable water biofilms provides a protective niche against chlorination stress. | legionella pneumophila is a waterborne pathogen that has been isolated sporadically from drinking water distribution systems (dwds). resistance to disinfectants is mainly attributed to the association of cells with amoebae, but biofilms are also thought to provide some degree of protection. in the present work, a two-stage chemostat was used to form heterotrophic biofilms from drinking water to study the influence of chlorine on the presence of naturally occurring l. pneumophila. the pathogen wa ... | 2009 | 23110528 |
| detection oflegionella antibodies by enzyme-linked immunosorbent assay (elisa) using whole cell and carbohydrate antigens. | the systematic study oflegionella as a human pathogen and a bacterium widely disseminated in the environment requires simplification of present methodology. we describe a highly sensitive enzyme-linked immunosorbent assay (elisa) for the detection of serum antibodies that can also be used for the detection of antigen.legionella pneumophila serogroups 1 and 3 (philadelphia 2 and bloomington 2),l. bozemanii (wiga), andl. micdadei (tatlock) were grown in diphasic medium consisting of charcoal yeast ... | 1982 | 24226047 |