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characteristics of reoffending accommodation sites in europe with clusters of legionnaires disease, 2003-2007.between 2003 and 2007, 21% (n=100/477) of accommodation sites linked to clusters of two or more cases of legionnaires’ disease that were investigated by the european surveillance scheme for travel-associated legionnaires’ disease (ewglinet) went on to be associated with at least one further case, despite reporting that satisfactory control measures had been implemented at the time the cluster was first detected. this paper examines these sites (termed reoffenders) in order to determine whether t ...201020946756
crystal structure of legionella dotd: insights into the relationship between type ivb and type ii/iii secretion systems.the dot/icm type ivb secretion system (t4bss) is a pivotal determinant of legionella pneumophila pathogenesis. l. pneumophila translocate more than 100 effector proteins into host cytoplasm using dot/icm t4bss, modulating host cellular functions to establish a replicative niche within host cells. the t4bss core complex spanning the inner and outer membranes is thought to be made up of at least five proteins: dotc, dotd, dotf, dotg and doth. doth is the outer membrane protein; its targeting depen ...201020949065
alternative routes for dissemination of legionella pneumophila causing three outbreaks in norway.three outbreaks of legionnaires' disease were reported in the fredrikstad/sarpsborg community, norway, in 2005 and 2008 caused by the l. pneumophila st15 and st462 strains determined by sequence based typing. in this retrospective study, we suggest that the aeration ponds, a part of the biological treatment plant at borregaard ind. ltd., are the main amplifiers and primary disseminators of the outbreak l. pneumophila strains. this result is supported by the finding that the st15 and st462 strain ...201020949911
travel-associated legionnaires disease in europe in 2009.a total of 818 cases of legionnaires' disease with onset of illness in 2009 were reported from 22 european and two non-european countries to the european surveillance scheme for travel-associated legionnaires' disease (ewglinet). this is a decrease of 52 cases compared with 2008 and 129 fewer than in 2007 - the peak year of reporting to date. a total of 794 (97.1%) cases were reported as confirmed and 24 as presumptive cases. outcome of illness was reported for 561 (68.6%) cases. of these cases ...201020961516
quantifying nonvertical inheritance in the evolution of legionella pneumophila.the exchange of genetic material among bacterial strains and species is recognized as an important factor determining their evolutionary, population genetic, and epidemiological features. we present a detailed analysis of nonvertical inheritance in legionella pneumophila, a human pathogen and facultative intracellular parasite of amoebas. we have analyzed the exchange of l. pneumophila genetic material with other bacteria at three different levels: population genetics, population genomics, and p ...201020961962
gama is a eukaryotic-like glucoamylase responsible for glycogen- and starch-degrading activity of legionella pneumophila.legionella pneumophila (lp) is the causative agent of legionnaires' disease, an atypical pneumonia. lp is found in freshwater habitats and replicates within different protozoa (amoebae). it is known that lp uses amino acids as primary energy and carbon sources for replication. however, very recently it was reported that lp is able to metabolize also carbohydrates (glucose). here, we present for the first time experimental evidence that the lpp0489 [gama] gene encodes a eukaryotic-like glucoamyla ...201020965781
a new gravity-driven microfluidic-based electrochemical assay coupled to magnetic beads for nucleic acid detection.in this work, the characterisation and the optimisation of hybridisation assays based on a novel, rapid and sensitive micro-analytical, gravity-driven, flow device is reported. this device combines a special chip containing eight polymer microchannels, with a portable, computer-controlled instrument. the device is used as a platform for affinity experiments using oligonucleotide-modified paramagnetic particles. in our approach, both hybridisation and labelling events are performed on streptavidi ...201020967776
high diversity and abundance of legionella spp. in a pristine river and impact of seasonal and anthropogenic effects.the diversity and dynamics of legionella species along a french river watershed subject to different thermal and wastewater discharges during an annual cycle were assessed by 16s rrna gene sequencing and by a fingerprint technique, single-strand conformation polymorphism. a high diversity of legionella spp. was observed at all the sampling sites, and the dominant legionella clusters identified were most closely related to uncultured bacteria. the monthly monitoring revealed that legionella sp. d ...201020971864
enzymatic synthesis and properties of glycoconjugates with legionaminic acid as a replacement for neuraminic acid.in addition to sialic acid, bacteria produce several other nonulosonic acids, including legionaminic acid (leg). this has exactly the same stereochemistry as sialic acid, with the added features of 9-deoxy and 7-amino groups. in order to explore the biological effects of replacing sialic acid residues (neu5ac) in glycoconjugates with leg in its diacetylated form, diacetyllegionaminic acid (leg5ac7ac), we tested cmp-leg5ac7ac as a donor substrate with a selection of bacterial and mammalian sialyl ...201020978010
insertion sequences as highly resolutive genomic markers for sequence type 1 legionella pneumophila paris.the causative agent of legionellosis, legionella pneumophila, colonizes all natural and human-made water networks, thus constituting the source of contaminated aerosols responsible for airborne human infections. efficient control of infections, especially during epidemics, necessitates the fastest and most resolutive identification possible of the bacterial source for subsequent disinfection of reservoirs. we thus compared recognized typing approaches for legionella with a method based on charac ...201020980561
a community outbreak of legionnaires' disease in south wales, august-september 2010.during august and september 2010, an outbreak comprising 22 cases of legionnaires' disease was identified by the public health service in wales. the cases are distributed over a wide geographical area in south east wales. there are two space-time clusters centred on the upper rhymney valley and the lower cynon valley respectively. epidemiological investigations are compatible with cooling towers in each location as the potential source, but environmental inspections were satisfactory and microbi ...201021034723
comparison of commercial systems for extraction of nucleic acids from dna/rna respiratory pathogens.this study compared six automated nucleic acid extraction systems and one manual kit for their ability to recover nucleic acids from human nasal wash specimens spiked with five respiratory pathogens, representing gram-positive bacteria (streptococcus pyogenes), gram-negative bacteria (legionella pneumophila), dna viruses (adenovirus), segmented rna viruses (human influenza virus a), and non-segmented rna viruses (respiratory syncytial virus). the robots and kit evaluated represent major commerci ...201021034773
assessment of real-time pcr for quantification of legionella spp. in spa water.legionella bacteria ubiquitously colonize natural freshwater and are responsible for legionellosis in humans. several cases of legionellosis have been associated in particular with the use of whirlpool spas. the objective of this study was to verify whether real-time pcr is applicable for the quantification of legionella spp. in spa water.201021039668
legionella spp. and legionellosis in southeastern italy: disease epidemiology and environmental surveillance in community and health care facilities.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.201021044294
phosphoinositides differentially regulate bacterial uptake and nramp1-induced resistance to legionella infection in dictyostelium.membrane phosphatidylinositides recruit cytosolic proteins to regulate phagocytosis, macropinocytosis and endolysosomal vesicle maturation. here, we describe effects of inactivation of pi3k, pten or plc on escherichia coli and legionella pneumophila uptake by the professional phagocyte dictyostelium discoideum. we show that l. pneumophila is engulfed by macropinocytosis, a process that is partially sensitive to pi3k inactivation, unlike phagocytosis of e. coli. both processes are blocked by plc ...201021045112
genomic diversity of legionella pneumophila serogroup 1 from environmental water sources and clinical specimens using pulsed-field gel electrophoresis (pfge) from 1985 to 2007, korea.the molecular typing of 202 legionella pneumophila sg 1 isolates obtained from environmental water sources and clinical specimens from 1985 to 2007 was conducted using pulsed-field gel electrophoresis (pfge). in this study, a total of 212 isolates were grouped into 35 different pfge types and type 1 was the predominant type, accounting for 28.7% in pfge types. type 1 and type 8 were observed continuously from 1985 to 2007. in the analysis of the distribution of pfge types in six geographic regio ...201021046330
antibodies protect against intracellular bacteria by fc receptor-mediated lysosomal targeting.the protective effect of antibodies (abs) is generally attributed to neutralization or complement activation. using legionella pneumophila and mycobacterium bovis bacillus calmette-guérin as a model, we discovered an additional mechanism of ab-mediated protection effective against intracellular pathogens that normally evade lysosomal fusion. we show that fc receptor (fcr) engagement by abs, which can be temporally and spatially separated from bacterial infection, renders the host cell nonpermiss ...201021048081
caspase-1-induced pyroptosis is an innate immune effector mechanism against intracellular bacteria.macrophages mediate crucial innate immune responses via caspase-1-dependent processing and secretion of interleukin 1β (il-1β) and il-18. although infection with wild-type salmonella typhimurium is lethal to mice, we show here that a strain that persistently expresses flagellin was cleared by the cytosolic flagellin-detection pathway through the activation of caspase-1 by the nlrc4 inflammasome; however, this clearance was independent of il-1β and il-18. instead, caspase-1-induced pyroptotic cel ...201021057511
lipopolysaccharide of legionella pneumophila shed in a liquid culture as a nonvesicular fraction arrests phagosome maturation in amoeba and monocytic host cells.after uptake by susceptible host cells, legionella pneumophila displays the ability to arrest phagolysosome fusion. to elucidate the role of lipopolysaccharide (lps) in this mechanism, we investigated its influence on acanthamoeba castellanii, a/j mouse macrophages and human monocytes. for this, legionellae were cultured in broth to the replicative, noninfectious phase or to the infectious phase expressing virulence traits. shed lps-enriched outer membrane vesicles (omv) and lps species <300 kda ...201020636972
effective environmental sampling strategies for monitoring legionella spp contamination in hot water systems.the prevention and control of legionellosis in hospital settings involves environmental sampling, among other measures. the data yielded by sampling constitute an important means of risk assessment and provide a valid basis on which to plan remedial (cleansing and disinfection) and preventive (maintenance) interventions. this retrospective study had 2 objectives: (1) to evaluate the utility of biofilm sampling at distal sites and (2) to identify an efficient environmental sampling strategy.201020083326
could insect phagocytic avoidance by entomogenous fungi have evolved via selection against soil amoeboid predators?the entomopathogenic fungi metarhizium anisopliae and beauveria bassiana are ubiquitously distributed in soils. as insect pathogens they adhere to the insect cuticle and penetrate through to the insect haemocoel using a variety of cuticle-hydrolysing enzymes. once in the insect haemocoel they are able to survive and replicate within, and/or evade, phagocytic haemocyte cells circulating in the haemolymph. the mechanism by which these soil fungi acquire virulence factors for insect infection and i ...201020338910
the legionella pneumophila f-box protein lpp2082 (ankb) modulates ubiquitination of the host protein parvin b and promotes intracellular replication.the environmental pathogen legionella pneumophila encodes three proteins containing f-box domains and additional protein-protein interaction domains, reminiscent of eukaryotic scf ubiquitin-protein ligases. here we show that the f-box proteins of l. pneumophila strain paris are dot/icm effectors involved in the accumulation of ubiquitinated proteins associated with the legionella-containing vacuole. single, double and triple mutants of the f-box protein encoding genes were impaired in infection ...201020345489
variable genetic element typing: a quick method for epidemiological subtyping of legionella pneumophila.a total of 57 isolates of legionella pneumophila were randomly selected from the german national legionella strain collection and typed by monoclonal antibody subgrouping, seven-gene locus sequence-based typing (sbt) scheme and a newly developed variable element typing (vet) system based on the presence or absence of ten variable genetic elements. these elements were detected while screening a genomic library of strain corby, as well as being taken from published data for pai-1 (pathogenicity is ...201020119676
characterization of a spontaneous avirulent mutant of legionella pneumophila serogroup 6: evidence of dota and flagellin involvement in the loss of virulence.the pathogenesis of legionella pneumophila mainly resides in its ability to inhibit the phagosome-lysosome fusion, which normally prevents the killing of the host cells. in order to characterize the molecular alterations that occurred in a spontaneous avirulent mutant of legionella pneumophila serogroup 6, named vir-, we investigated the ability of the mutant to adhere to and multiply in the wi26va4 alveolar epithelial cell line and in human macrophages, when compared to its parental strain, vir ...201020127472
genome analysis of microorganisms living in amoebae reveals a melting pot of evolution.abstract amoebae-resistant microorganisms exhibit a specific lifestyle. unlike allopatric specialized intracellular pathogens, they have not specialized because they infect the amoebae via amoebal attack and present a sympatric lifestyle with species from different phyla. in this review, we compare the genomes from bacteria (legionella pneumophila, legionella drancourtii, candidatus'protochlamydia amoebophila,'rickettsia bellii, candidatus'amoebophilus asiaticus') and a virus (mimivirus) that mu ...201020132312
[real-time pcr for early detection and monitoring of legionella pneumophila in clinical specimens]. 201020138688
definite, probable, and possible bacterial aetiologies of community-acquired pneumonia at different crb-65 scores.according to the recommendations of the swedish community-acquired pneumonia (cap) guidelines, the selection of empirical antibiotic therapy should be based on the crb-65 rule. the guidelines recommend empirical therapy directed predominantly against streptococcus pneumoniae for patients with low crb-65 scores and broad-spectrum therapy for patients with high crb-65 scores. in order to study the utility of the recommendations, we analyzed the data from an aetiological study previously performed ...201020141490
comparison of ethidium monoazide and propidium monoazide for the selective detection of viable legionella cells.ethidium monoazide (ema) and propidium monoazide (pma) have been utilized for selective pcr amplification of dna from viable bacterial cells. in this study, we compared the abilities of ema and pma, together with real-time pcr, to specifically distinguish dead legionella cells from viable cells. several experiments showed that pma or ema treatment could specifically prevent the pcr amplification of dna from dead legionella cells in water samples. however, a 4-fold higher concentration of pma tha ...201020332575
inhibition of host vacuolar h+-atpase activity by a legionella pneumophila effector.legionella pneumophila is an intracellular pathogen responsible for legionnaires' disease. this bacterium uses the dot/icm type iv secretion system to inject a large number of bacterial proteins into host cells to facilitate the biogenesis of a phagosome permissive for its intracellular growth. like many highly adapted intravacuolar pathogens, l. pneumophila is able to maintain a neutral ph in the lumen of its phagosome, particularly in the early phase of infection. however, in all cases, the mo ...201020333253
[construction of the eukaryotic expression plasmid containing lvga gene flanked with cpg motifs of legionella pneumophila and its expression in nih3t3 cells].to construct the eukaryotic expression plasmid containing lvga gene flanked with cpg motifs of legionella pneumophila for its expression in nih3t3 cells.201020335111
hospital-acquired pneumonia and bacteremia caused by legionella pneumophila in an immunocompromised patient.the legionella species is an important cause of communityand hospital-acquired pneumonia. bacteremic pneumonia caused by l. pneumophila is rarely reported. we describe the first reported case of hospital-acquired pneumonia and bacteremia caused by l. pneumophila from taiwan in a patient with idiopathic thrombocytopenic purpura who received steroid treatment. the patient was successfully treated with ceftazidime and clindamycin initially, followed by ciprofloxacin for 14 days. the blood isolate w ...201020349106
the legionella pneumophila leta/lets two-component system exhibits rheostat-like behavior.when confronted with metabolic stress, replicative legionella pneumophila bacteria convert to resilient, infectious cells equipped for transmission. differentiation is promoted by the leta/lets two-component system, which belongs to a family of signal-transducing proteins that employ a four-step phosphorelay to regulate gene expression. histidine 307 of lets was essential to switch on the transmission profile, but a threonine substitution at position 311 (t311m) suggested a rheostat-like functio ...201020351136
cooperation between multiple microbial pattern recognition systems is important for host protection against the intracellular pathogen legionella pneumophila.multiple pattern recognition systems have been shown to initiate innate immune responses to microbial pathogens. the degree to which these detection systems cooperate with each other to provide host protection is unknown. here, we investigated the importance of several immune surveillance pathways in protecting mice against lethal infection by the intracellular pathogen legionella pneumophila, the causative agent of a severe pneumonia called legionnaires' disease. rip2 and naip5/nlrc4 signaling ...201020351139
effects of chemically and electrochemically dosed chlorine on escherichia coli and legionella beliardensis assessed by flow cytometry.the present study reports the disinfection effects of chemically and electrochemically dosed chlorine on two models for typical water-borne bacteria (escherichia coli and legionella beliardensis) by plating and flow cytometry (fcm) in combination with different fluorescence dyes. the residual effect on various cell functions, including cultivability, esterase activity, membrane polarization, and integrity, was tested at different free chlorine concentrations. in comparison, chemical disinfection ...201020352423
legionella feeleii serotype 2 pneumonia in a man with chronic lymphocytic leukemia: a challenging diagnosis.legionella feeleii has rarely been reported as causing pneumonia in patients with hematologic malignancies. we present a case of legionella feeleii serotype 2 pneumonia with empyema in a man with chronic lymphocytic leukemia and describe the methods of identifying this organism using both standard methods and newer diagnostic techniques.201020357216
glucose metabolism in legionella pneumophila: dependence on the entner-doudoroff pathway and connection with intracellular bacterial growth.glucose metabolism in legionella pneumophila was studied by focusing on the entner-doudoroff (ed) pathway with a combined genetic and biochemical approach. the bacterium utilized exogenous glucose for synthesis of acid-insoluble cell components but manifested no discernible increase in the growth rate. assays with permeabilized cell preparations revealed the activities of three enzymes involved in the pathway, i.e., glucokinase, phosphogluconate dehydratase, and 2-dehydro-3-deoxy-phosphogluconat ...201020363943
unexplained increased incidence of legionnaires disease during the "herald wave" of the h1n1 influenza pandemic. 201020367323
legionella pneumophila 6s rna optimizes intracellular multiplication.legionella pneumophila is a gram-negative opportunistic human pathogen that infects and multiplies in a broad range of phagocytic protozoan and mammalian phagocytes. based on the observation that small regulatory rnas (srnas) play an important role in controlling virulence-related genes in several pathogenic bacteria, we attempted to identify srnas expressed by l. pneumophila. we used computational prediction followed by experimental verification to identify and characterize srnas encoded in the ...201020368425
a legionella pneumophila collagen-like protein encoded by a gene with a variable number of tandem repeats is involved in the adherence and invasion of host cells.legionella pneumophila is a gram-negative, facultative intracellular pathogen and the causative agent of legionnaires' disease, a severe pneumonia in humans. analysis of the legionella sequenced genomes revealed a gene with a variable number of tandem repeats (vntrs), whose number varies between strains. we examined the strain distribution of this gene among a collection of 108 clinical, environmental and hot spring serotype i strains. twelve variants were identified, but no correlation was obse ...201020370832
harvested rainwater quality: the importance of appropriate design.this paper summarises the physicochemical and microbiological quality of water from a rainwater harvesting (rwh) system in a uk-based office building. 7 microbiological and 34 physicochemical parameters were analysed during an 8 month period. physicochemically, harvested rainwater quality posed little health risk; most parameters showed concentrations below widely used guideline levels for drinking water. however, rwh system components (e.g. fittings and down pipes) appear to be affected soft wa ...201020371928
immunology taught by bacteria.it has been proposed that the innate immune system might discriminate living and virulent pathogens from dead or harmless microbes, but the molecular mechanisms by which this discrimination could occur remain unclear. although studies of model antigens and adjuvants have illuminated important principles underlying immune responses, the specific immune responses made to living, virulent pathogens can only be discovered by studies of the living, virulent pathogens themselves.201020373001
molecular pathogenesis of infections caused by legionella pneumophila.the genus legionella contains more than 50 species, of which at least 24 have been associated with human infection. the best-characterized member of the genus, legionella pneumophila, is the major causative agent of legionnaires' disease, a severe form of acute pneumonia. l. pneumophila is an intracellular pathogen, and as part of its pathogenesis, the bacteria avoid phagolysosome fusion and replicate within alveolar macrophages and epithelial cells in a vacuole that exhibits many characteristic ...201020375353
bacterial gene regulation by alpha-hydroxyketone signaling.bacteria produce diffusible, small signaling molecules termed autoinducers to promote cell-cell communication. recently, a novel class of signaling molecules, the alpha-hydroxyketones (ahks), was discovered in the facultative human pathogens legionella pneumophila and vibrio cholerae. in this review, we summarize and compare findings on ahk signaling in these bacteria. the l. pneumophila lqs (legionella quorum sensing) and v. cholerae cqs (cholera quorum sensing) gene clusters synthesize and det ...201020382022
cellular pharmacodynamics of the novel biaryloxazolidinone radezolid: studies with infected phagocytic and nonphagocytic cells, using staphylococcus aureus, staphylococcus epidermidis, listeria monocytogenes, and legionella pneumophila.radezolid is a novel biaryloxazolidinone in clinical development which shows improved activity, including against linezolid-resistant strains. in a companion paper (29), we showed that radezolid accumulates about 11-fold in phagocytic cells, with approximately 60% of the drug localized in the cytosol and approximately 40% in the lysosomes of the cells. the present study examines its activity against (i) bacteria infecting human thp-1 macrophages and located in different subcellular compartments ...201020385852
nursing home-acquired pneumonia: a 10 year single-centre experience.pneumonia among nursing home (nh) residents has increased considerably in recent years, but it remains unclear whether it should be considered as community-acquired pneumonia (cap) or a new category of infection.201020388763
outbreak of legionnaires' disease associated with a supermarket mist machine.an outbreak of legionnaires' disease affected 12 customers of a supermarket in a town in catalonia, spain, between august and november 2006. an epidemiological and environmental investigation was undertaken. preliminary investigation showed that all patients had visited the same supermarket in this town where a mist machine was found in the fish section. water samples were collected from the machine and from the supermarket's water distribution system when high-risk samples were excluded. enviro ...201020392306
legionella colonization of powder paint pretreatment tunnels. 201020392815
cutting edge: pulmonary legionella pneumophila is controlled by plasmacytoid dendritic cells but not type i ifn.plasmacytoid dendritic cells (pdcs) are well known as the major cell type that secretes type i ifn in response to viral infections. their role in combating other classes of infectious organisms, including bacteria, and their mechanisms of action are poorly understood. we have found that pdcs play a significant role in the acute response to the intracellular bacterial pathogen legionella pneumophila. pdcs were rapidly recruited to the lungs of l. pneumophila-infected mice, and depletion of pdcs r ...201020400697
bacterial proteases from the intracellular vacuole niche; protease conservation and adaptation for pathogenic advantage.proteases with important roles for bacterial pathogens that specifically reside within intracellular vacuoles are frequently homologous to those that have important virulence functions for other bacteria. research has identified that some of these conserved proteases have evolved specialized functions for intracellular vacuole-residing bacteria. unique proteases with pathogenic functions have also been described from chlamydia, mycobacteria, and legionella. these findings suggest that there are ...201020402770
caenorhabditis elegans as an alternative model host for legionella pneumophila, and protective effects of bifidobacterium infantis.the survival times of caenorhabditis elegans worms infected with legionella pneumophila from day 7.5 or later after hatching were shorter than those of uninfected worms. however, nematodes fed bifidobacteria prior to legionella infection were resistant to legionella. these nematodes may act as a unique alternative host for legionella research.201020418445
identification of legionella londiniensis isolated from hot spring water samples in shizuoka, japan, and cytotoxicity of isolates.as part of an epidemiological study on legionellosis, we attempted to isolate legionella spp. from hot spring water and were able to isolate l. londiniensis hykf-90505 (=jcm 16338), confirming that l. londiniensis inhabits hot spring water in japan. to investigate the disease potential of l. londiniensis, we examined its ability to grow intracellularly within acanthamoeba sp. jac/e1 strain. the isolated hykf-90505 was able to grow within acanthamoeba sp. jac/e1 strain, and we confirmed also that ...201020419328
antibiotic resistance in invasive streptococcus pneumoniae isolates identified in scotland between 1999 and 2007.data from 4727 invasive isolates of streptococcus pneumoniae submitted to the scottish haemophilus, legionella, meningococcus and pneumococcus reference laboratory between 1999 and 2007 were analysed to establish susceptibility profiles to penicillin, erythromycin and cefotaxime. pneumococcal resistance to penicillin over the study period remained low, with only 0.2 % (n=7/4727) of isolates falling into this category (mic ≥2 mg l(-1)). these isolates have been sporadic, and have mainly represent ...201020651042
the legionella effector protein drra ampylates the membrane traffic regulator rab1b.in the course of legionnaires' disease, the bacterium legionella pneumophila affects the intracellular vesicular trafficking of infected eukaryotic cells by recruiting the small guanosine triphosphatase (gtpase) rab1 to the cytosolic face of the legionella-containing vacuole. in order to accomplish this, the legionella protein drra contains a specific guanine nucleotide exchange activity for rab1 activation that exchanges guanosine triphosphate (gtp) for guanosine diphosphate on rab1. we found t ...201020651120
extremely elevated erythrocyte sedimentation rates (esrs) in legionnaires' disease. 201020652345
phosphatidylcholine biosynthesis and its significance in bacteria interacting with eukaryotic cells.phosphatidylcholine (pc), a typical eukaryotic membrane phospholipid, is present in only about 10% of all bacterial species, in particular in bacteria interacting with eukaryotes. a number of studies revealed that pc plays a fundamental role in symbiotic and pathogenic microbe-host interactions. agrobacterium tumefaciens mutants lacking pc are unable to elicit plant tumors. the human pathogens brucella abortus and legionella pneumophila require pc for full virulence. the plant symbionts bradyrhi ...201020656373
legionella pneumophila carrying the virulence-associated lipopolysaccharide epitope possesses two functionally different lps components.phase-variable expression of legionella pneumophila lipopolysaccharide (lps) has not been described in detail for strains possessing the virulence-associated epitope recognized by the monoclonal antibody (mab) 3/1 of the dresden panel. about 75 % of cases of community-acquired legionellosis are caused by mab 3/1-positive strains. in this study, the lps architecture of the mab 3/1-positive corby strain was investigated during its life cycle in broth culture and inside monocytic host cells. during ...201020656784
high-resolution in situ genotyping of legionella pneumophila populations in drinking water by multiple-locus variable-number tandem-repeat analysis using environmental dna.central to the understanding of infections by the waterborne pathogen legionella pneumophila is its detection at the clonal level. currently, multiple-locus variable-number tandem-repeat (vntr) analysis (mlva) of l. pneumophila isolates can be used as a tool for high-resolution genotyping. since l. pneumophila is difficult to isolate, the isolation of outbreak strains often fails due to a viable but nonculturable (vbnc) state of the respective environmental population. therefore, we developed a ...201020656879
implications of faecal indicator bacteria for the microbiological assessment of roof-harvested rainwater quality in southeast queensland, australia.the study aimed to evaluate the suitability of escherichia coli, enterococci, and clostridium perfringens for assessing the microbiological quality of roof-harvested rainwater and assessing whether the concentrations of these faecal indicators can be used to predict the presence or absence of specific zoonotic bacterial or protozoan pathogens. from a total of 100 samples tested, 58%, 83%, and 46% of samples were found to be positive for, respectively, e. coli, enterococci, and clostridium perfri ...201020657617
exploitation of conserved eukaryotic host cell farnesylation machinery by an f-box effector of legionella pneumophila.farnesylation involves covalent linkage of eukaryotic proteins to a lipid moiety to anchor them into membranes, which is essential for the biological function of ras and other proteins. a large cadre of bacterial effectors is injected into host cells by intravacuolar pathogens through elaborate type iii-vii translocation machineries, and many of these effectors are incorporated into the pathogen-containing vacuolar membrane by unknown mechanisms. the dot/icm type iv secretion system of legionell ...201020660614
proteomic analysis of growth phase-dependent expression of legionella pneumophila proteins which involves regulation of bacterial virulence traits.legionella pneumophila, which is a causative pathogen of legionnaires' disease, expresses its virulent traits in response to growth conditions. in particular, it is known to become virulent at a post-exponential phase in vitro culture. in this study, we performed a proteomic analysis of differences in expression between the exponential phase and post-exponential phase to identify candidates associated with l. pneumophila virulence using 2-dimentional fluorescence difference gel electrophoresis ( ...201020661449
comparison of two mice strains, a/j and c57bl/6, in caspase-1 activity and il-1beta secretion of macrophage to mycobacterium leprae infection.a/j mice were found to have amino acid differences in naip5, one of the nod-like receptors (nlrs) involved in the cytosolic recognition of pathogen-associated molecular patterns and one of the adaptor proteins for caspase-1 activation. this defect was associated with a susceptibility to legionella infection, suggesting an important role for naip5 in the immune response also to other intracellular pathogens, such as mycobacterium leprae. in this study, the immune responses of macrophages from a/j ...201020671924
investigation of plasma-functionalized multiwalled carbon nanotube film and its application of dna sensor for legionella pneumophila detection.a novel multiwall carbon nanotube (mwcnt) electrode functionalized with oxygen plasma treatment was prepared and characterized, and its dna sensing ability for legionella pneumophila (l. pneumophila) detection was examined using electrochemical measurement. a well-patterned mwcnt working electrode (we) on a pt track was fabricated using photolithography, transfer methods and an etching technique. the mwcnt we was functionalized by oxygen plasma treatment prior to applying for dna sensor. the sur ...201020678644
synthesis and biological evaluation of (+/-)-dinemasone c and analogues.dinemasone c was prepared in three steps (8% overall yield) from cis-tetrahydro-4-hydroxy-6-methyl-2-pyrone by aldol reaction with 2,4-hexadienal, epoxidation followed by cyclization, and epimerization of the ring fusion. dinemasone c, epi-dinemasone c, anhydrodinemasone bc, and nor-dinemasone b are active against bacteria, including legionella pneumophila corby, algae, and fungi.201020684519
the pattern recognition receptors nod1 and nod2 account for neutrophil recruitment to the lungs of mice infected with legionella pneumophila.the intracellular bacterium legionella pneumophila induces a severe form of pneumonia called legionnaires diseases, which is characterized by a strong neutrophil (ne) infiltrate to the lungs of infected individuals. although the participation of pattern recognition receptors, such as toll-like receptors, was recently demonstrated, there is no information on the role of nod-like receptors (nlrs) for bacterial recognition in vivo and for ne recruitment to the lungs. here, we employed a murine mode ...201020685341
clinical efficacy of moxifloxacin versus comparator therapies for community-acquired pneumonia caused by legionella spp.the aim of this study was to compare outcomes for patients with community-acquired pneumonia (cap) caused by legionella spp. following treatment with moxifloxacin or a range of comparator antimicrobial agents. data were pooled from four sequential i.v./p.o. trials of moxifloxacin in the treatment of cap. comparators were ceftriaxone +/- erythromycin, amoxicillin/clavulanate +/- clarithromycin, trovafloxacin, levofloxacin, or ceftriaxone + levofloxacin. legionella infection was diagnosed by cultu ...201020685631
distribution of legionella species from environmental water sources of public facilities and genetic diversity of l. pneumophila serogroup 1 in south korea.a total of 560 legionella species were isolated from environmental water sources from public facilities from june to september 2008 throughout south korea. the distribution of legionella isolates was investigated according to geographical region, facility type, and sample type. the genetic diversity of 104 isolates of legionella pneumophila serogroup 1 (sg 1) was analyzed by sequence-based typing (sbt). l. pneumophila was distributed broadly throughout korea, accounting for 85.0% of the isolates ...201020693456
[possible daptomycin-induced organizing pneumonia].we report a possible and rare case of drug-induced organizing pneumonia in a patient receiving daptomycin. a 75-year-old man with acute infective aorta valve endocarditis due to enterococcus faecalis developed organizing pneumonia following treatment with intravenous daptomycin and ceftriaxone. the patient could have acquired an infectious agent which was resistant to ceftriaxone, such as legionella, and he was thus treated with ciprofloxacin and rifampicin. however, no antigen was found in the ...201020696120
consolidation therapy with subcutaneous alemtuzumab after fludarabine and rituximab induction therapy for previously untreated chronic lymphocytic leukemia: final analysis of calgb 10101.to determine if alemtuzumab consolidation improves response rate and progression-free survival (pfs) after induction chemoimmunotherapy in previously untreated symptomatic patients with chronic lymphocytic leukemia.201020697069
eosinophilic infiltrate in a patient with severe legionella pneumonia as a levofloxacin-related complication: a case report.abstract:201021070648
nod1 and nod2 regulation of pulmonary innate immunity to legionella pneumophila.the role of nucleotide-binding oligomerization domain-1 (nod1) and nucleotide-binding oligomerization domain-2 (nod2), cytoplasmic receptors which detect bacterial cell wall molecules, in pulmonary innate immune responses is poorly understood. we determined that both nod1 and nod2 detect heat-killed legionella and stimulate nf-κb and ifn-β promoter activity using an in vitro luciferase reporter system. we next infected nod1- and nod2-deficient animals with aerosolized legionella pneumophila. at ...201021072876
[legionellosis in a site with low risk of proliferation].after three cases of legionellosis associated with a spa were identified, an investigation was conducted to confirm the source of infection, determine the risk factors, and establish control measures. between november 26, 2008 and september 16, 2009, six inspections were carried out, samples were collected for legionella pneumophila isolation, and water temperature was determined at all the sampling points of the hot water system and at the spa pools. the presence of l. pneumophila serogroup 1 w ...201021074903
legionella pneumophila induces cathepsin b-dependent necrotic cell death with releasing high mobility group box1 in macrophages.legionella pneumophila (lpn) can cause a lethal infectious disease with a marked inflammatory response in humans. however, the mechanism of this severe inflammation remains poorly understood. since necrosis is known to induce inflammation, we investigated whether lpn induces necrosis in macrophages. we also analyzed the involvement of lysosomal cathepsin b in lpn-induced cell death.201021092200
[atypical pathogens in adult patients admitted with community-acquired pneumonia].to investigate the current status of atypical pathogen associated infections in community-acquired pneumonia (cap) in adults, and their clinical attributes.201021092629
efficiency of water disinfectants against legionella pneumophila and acanthamoeba.free-living amoebae might be pathogenic by themselves and be a reservoir for bacterial pathogens, such as legionella pneumophila. not only could amoebae protect intra-cellular legionella but legionella grown within amoebae could undergo physiological modifications and become more resistant and more virulent. therefore, it is important to study the efficiency of treatments on amoebae and legionella grown within these amoebae to improve their application and to limit their impact on the environmen ...201021093012
apoptosis-associated speck-like protein (asc) controls legionella pneumophila infection in human monocytes.the ability of legionella pneumophila to cause pneumonia is determined by its capability to evade the immune system and grow within human monocytes and their derived macrophages. human monocytes efficiently activate caspase-1 in response to salmonella but not to l. pneumophila. the molecular mechanism for the lack of inflammasome activation during l. pneumophila infection is unknown. evaluation of the expression of several inflammasome components in human monocytes during l. pneumophila infectio ...201021097506
concentration and diversity of uncultured legionella spp. in two unchlorinated drinking water supplies with different concentrations of natural organic matter.two unchlorinated drinking water supplies were investigated to assess the potential of water treatment and distribution systems to support the growth of legionella spp. the treatment plant for supply a distributed treated groundwater with a low concentration (<0.5 ppm of c) of natural organic matter (nom), and the treatment plant for supply b distributed treated groundwater with a high nom concentration (8 ppm of c). in both supplies, the water temperature ranged from about 10°c after treatment ...201021097586
large-scale identification and translocation of type iv secretion substrates by coxiella burnetii.coxiella burnetii is an obligate intracellular bacterial pathogen responsible for acute and chronic q fever. this bacterium harbors a type iv secretion system (t4ss) highly similar to the dot/icm of legionella pneumophila that is believed to be essential for its infectivity. protein substrates of the coxiella t4ss are predicted to facilitate the biogenesis of a phagosome permissive for its intracellular growth. however, due to the lack of genetic systems, protein transfer by the c. burnetii dot/ ...201021098666
septic arthritis caused by legionella dumoffii in a patient with systemic lupus erythematosus-like disease.we describe a patient with systemic lupus erythematosus (sle)-like disease on immunosuppressive treatment who developed septic arthritis of the knee involving legionella dumoffii. cultures initially remained negative. a broad-range 16s pcr using synovial fluid revealed l. dumoffii rrna genes, a finding that was subsequently confirmed by positive legionella culture results.201021106784
nod1 and nod2 regulation of pulmonary innate immunity to legionella pneumophila.the role of nucleotide-binding oligomerization domain-1 (nod1) and nucleotide-binding oligomerization domain-2 (nod2), cytoplasmic receptors which detect bacterial cell wall molecules, in pulmonary innate immune responses is poorly understood. we determined that both nod1 and nod2 detect heat-killed legionella and stimulate nf-κb and ifn-β promoter activity using an in vitro luciferase reporter system. we next infected nod1- and nod2-deficient animals with aerosolized legionella pneumophila. at ...201021108472
pathogen-host interactions in dictyostelium, legionella, mycobacterium and other pathogens.dictyostelium discoideum is a haploid social soil amoeba that is an established host model for several human pathogens. the research areas presently pursued include the use of d. discoideum to identify genetic host factors determining the outcome of infections and the use as screening system for identifying bacterial virulence factors. here we report about the legionella pneumophila directed phagosome biogenesis and the cell-to-cell spread of mycobacterium species. moreover, we highlight recent ...201021109012
progress in the surveillance and control of legionella infection in france, 1998-2008.in france, the notification of legionnaires' disease (ld) has been mandatory since 1987. following a study showing an important under-reporting of the disease, the surveillance system was strengthened in 1997: the urinary antigen detection test was introduced as a new diagnostic tool and guidelines for prevention and control of the disease were implemented. after these measures, the incidence of ld increased gradually, reaching 2.5 per 100,000 in 2005, and then slightly decreased (2.0 per 100,00 ...201021109475
the risk does exist. 201021109784
c-reactive protein for discriminating treatment failure from slow responding pneumonia.the management of patients with community-acquired pneumonia (cap) who fail to improve constitutes a challenge for clinicians. this study investigated the usefulness of c-reactive protein (crp) changes in discriminating true treatment failure from slow response to treatment.201021111942
legionella pneumophila pneumonia in a pregnant woman treated with anti-tnf-α antibodies for crohn's disease: a case report.anti-tnf-α antibodies are widely used. the indications for their usage are still increasing. with their emerging use, their infectious complications are seen more often. we describe the first case of a pneumonia with legionella pneumophila in a pregnant women with crohn's disease, during treatment with anti-tnf-α antibodies. she was treated with erythromycin and made a full recovery.201021122583
two legionnaires' disease cases associated with industrial waste water treatment plants: a case report.finnish and swedish waste water systems used by the forest industry were found to be exceptionally heavily contaminated with legionellae in 2005.201021126333
the dictyostelium model for mitochondrial disease.mitochondrial diseases are a diverse family of genetic disorders caused by mutations affecting mitochondrial proteins encoded in either the nuclear or the mitochondrial genome. by impairing mitochondrial oxidative phosphorylation, they compromise cellular energy production and the downstream consequences in humans are a bewilderingly complex array of signs and symptoms that can affect any of the major organ systems in unpredictable combinations. this complexity and unpredictability has limited o ...201021129494
effectiveness of different methods to control legionella in the water supply: ten-year experience in an italian university hospital.we report our ten-year experience of hyperchlorination, thermal shock, chlorine dioxide, monochloramine, boilers and point-of-use filters for controlling legionella contamination in a hospital hot water distribution system. shock disinfections were associated with a return to pre-treatment contamination levels within one or two months. we found that chlorine dioxide successfully maintained levels at <100 cfu/l, whilst preliminary experiments gave satisfactory results with monochloramine. no cont ...201021131100
a severe complication of anti-tnf alfa treatment.the antitumor necrosis factor (tnf-alpha) drugs are increasingly used in treating skin diseases such as psoriasis. tnf-alpha is a proinflammatory cytokine with a key role in the pathogenesis of psoriasis but also in host defence against bacterial pathogens, especially against those that multiply inside host cells. the effectiveness of anti-tnf-alpha in the treatment of psoriasis is now widely recognized and has led to their increasingly wide use. although these drugs are considered relatively sa ...201021139554
pipecolic acid derivatives as small-molecule inhibitors of the legionella mip protein.the macrophage infectivity potentiator (mip) protein is a major virulence factor of legionella pneumophila, the causative agent of legionnaires' disease. mip belongs to the fk506-binding proteins (fkbp) and is necessary for optimal intracellular survival and lung tissue dissemination of l. pneumophila. we aimed to identify new small-molecule inhibitors of mip by starting from known fkbp12 ligands. computational analysis, synthesis, and biological testing of pipecolic acid derivatives revealed a ...201021142106
specific real-time pcr for simultaneous detection and identification of legionella pneumophila serogroup 1 in water and clinical samples.legionella pneumophila, a bacterium that replicates within aquatic amoebae and persists in the environment as a free-living microbe, is the causative agent of legionnaires' disease. among the many legionella species described, l. pneumophila is associated with 90% of human disease, and within the 15 serogroups (sg), l. pneumophila sg1 causes more than 84% of legionnaires' disease worldwide. thus, rapid and specific identification of l. pneumophila sg1 is of the utmost importance for evaluation o ...201021193672
do free-living amoebae in treated drinking water systems present an emerging health risk?there is an expanding body of evidence that free-living amoebae (fla) increase both the numbers and virulence of water-based, human-pathogenic, amoeba-resisting microorganisms (arm). legionella spp., mycobacterium spp., and other opportunistic human pathogens are known to be both arm and also the etiologic agents of potentially fatal human lung infections. however, comparatively little is known about the fla that may facilitate arm growth in drinking water. this review examines the available lit ...201021194220
methodologies for quantifying culturable, viable, and total legionella pneumophila in indoor air.abstract  legionella pneumophila, aerosolized from numerous indoor facilities (e.g., shower heads, hot tubs, spas), may cause pontiac fever (pf) and lethal pneumonia named legionnaires' disease (ld) in humans. reliable methods on quantitative exposure assessment of this bioaerosol are essential for the prevention of pf and ld. coupled with culture, ethidium monoazide with qpcr, and qpcr assays, the collection efficiency for culturable, viable, and total l. pneumophila was assessed by means of fi ...201021198889
can technical, functional and structural characteristics of dental units predict legionella pneumophila and pseudomonas aeruginosa contamination?legionella pneumophila and pseudomonas aeruginosa are common colonizers of water environments, particularly dental unit waterlines. the aim of this study was to assess whether the technical, functional and structural characteristics of dental units can influence the presence and the levels of opportunistic pathogens. overall, 42 water samples were collected from dental units in a teaching hospital in palermo, italy, including 21 samples from the 21 taps supplied by the municipal water distributi ...201021206168
[genotypic variability and persistence of legionella pulsed-field gel electrophoresis patterns in 16 cooling towers in shanghai, china.]objective: 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. methods: 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 culster results of pf ...201021162841
antibiotics and uv radiation induce competence for natural transformation in legionella pneumophila.natural transformation by competence is a major mechanism of horizontal gene transfer in bacteria. competence is defined as the genetically programmed physiological state that enables bacteria to actively take up dna from the environment. the conditions that signal competence development are multiple and elusive, complicating the understanding of its evolutionary significance. we used expression of the competence gene comea as a reporter of competence development and screened several hundred mol ...201021169481
dioxygenases in burkholderia ambifaria and yersinia pestis that hydroxylate the outer kdo unit of lipopolysaccharide.several gram-negative pathogens, including yersinia pestis, burkholderia cepacia, and acinetobacter haemolyticus, synthesize an isosteric analog of 3-deoxy-d-manno-oct-2-ulosonic acid (kdo), known as d-glycero-d-talo-oct-2-ulosonic acid (ko), in which the axial hydrogen atom at the kdo 3-position is replaced with oh. here we report a unique kdo 3-hydroxylase (kdoo) from burkholderia ambifaria and yersinia pestis, encoded by the bamb_0774 (bakdoo) and the y1812 (ypkdoo) genes, respectively. when ...201021178073
cytochrome c4 is required for siderophore expression by legionella pneumophila, whereas cytochromes c1 and c5 promote intracellular infection.a panel of cytochrome c maturation (ccm) mutants of legionella pneumophila displayed a loss of siderophore (legiobactin) expression, as measured by both the chrome azurol s assay and a legionella-specific bioassay. these data, coupled with the finding that ccm transcripts are expressed by wild-type bacteria grown in deferrated medium, indicate that the ccm system promotes siderophore expression by l. pneumophila. to determine the basis of this newfound role for ccm, we constructed and tested a s ...201021178169
a method for generation of bone marrow-derived macrophages from cryopreserved mouse bone marrow cells.the broad use of transgenic and gene-targeted mice has established bone marrow-derived macrophages (bmdm) as important mammalian host cells for investigation of the macrophages biology. over the last decade, extensive research has been done to determine how to freeze and store viable hematopoietic human cells; however, there is no information regarding generation of bmdm from frozen murine bone marrow (bm) cells. here, we establish a highly efficient protocol to freeze murine bm cells and furthe ...201021179419
fatty acid composition modulates sensitivity of legionella pneumophila to warnericin rk, an antimicrobial peptide.warnericin rk is an antimicrobial peptide, produced by a staphyloccocus warneri strain, described to be specifically active against legionella, the pathogenic bacteria responsible for legionnaires' disease. warnericin rk is an amphiphilic alpha-helical peptide, which possesses a detergent-like mode of action. two others peptides, δ-hemolysin i and ii, produced by the same s. warneri strain, are highly similar to s. aureus δ-hemolysin and also display anti-legionella activity. it has been recentl ...201021182824
case of legionella pneumonia complicated with pulmonary thromboembolism.we report a patient with community acquired legionella pneumonia, complicated with pulmonary embolism. the patient was cured by levofloxacin and anticoagulant therapy. we performed laboratorial control and we excluded the thrombophilia and antiphospholipid syndrome. our case report draws attention to the possible association between legionella infection and pulmonary embolism.201021183425
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