Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
intra-species and inter-kingdom signaling of legionella pneumophila.the ubiquitous gram-negative bacterium legionella pneumophila parasitizes environ mental amoebae and, upon inhalation, replicates in alveolar macrophages, thus causing a life-threatening pneumonia called "legionnaires' disease." the opportunistic pathogen employs a bi-phasic life cycle, alternating between a replicative, non-virulent phase and a stationary, transmissive/virulent phase. l. pneumophila employs the lqs (legionella quorum sensing) system as a major regulator of the growth phase swit ...201728217110
thioaromatic dna monolayers for target-amplification-free electrochemical sensing of environmental pathogenic bacteria.genosensing technology has mostly based on mixed self-assembled monolayers (sams) of thiol-modified oligonucleotides and alkanethiols on gold surfaces. however, the typical backfilling approach, which incorporates the alkanethiol in a second step, gives rise to a heterogeneous distribution of oligonucleotide probes on the surface, negatively affecting to both hybridization efficiency and surface stability. despite aromatic thiols present a remarkably different behavior from alkanethiols, with hi ...201728213329
the legionella pneumophila genome evolved to accommodate multiple regulatory mechanisms controlled by the csra-system.the carbon storage regulator protein csra regulates cellular processes post-transcriptionally by binding to target-rnas altering translation efficiency and/or their stability. here we identified and analyzed the direct targets of csra in the human pathogen legionella pneumophila. genome wide transcriptome, proteome and rna co-immunoprecipitation followed by deep sequencing of a wild type and a csra mutant strain identified 479 rnas with potential csra interaction sites located in the untranslate ...201728212376
seeding and establishment of legionella pneumophila in hospitals; implications for genomic investigations of nosocomial legionnaires' disease. 201728203790
prevalence of legionella species isolated from shower water in public bath facilities in toyama prefecture, japan.we investigated the prevalence of legionella spp. isolated from shower water in public bath facilities in toyama prefecture, japan. in addition, we analyzed the genetic diversity among legionella pneumophila isolates from shower water as well as the genetic relationship between isolates from shower water and from stock strains previously analyzed from sputum specimens.201728188095
presence of antibodies against legionella pneumophila in patients with pemphigus vulgaris. 201728181230
legionella pneumophila pneumonia possibly due to ustekinumab therapy in a patient with crohn's disease.a case report of legionella pneumophila pneumonia associated with off-label use of ustekinumab in a patient with crohn's disease (cd) is presented.201728179246
expression of flagellin and key regulatory flagellar genes in the non-motile bacterium piscirickettsia salmonis.the piscirickettsia salmonis genome was screened to evaluate potential flagella-related open reading frames, as well as their genomic organization and eventual expression. a complete and organized set of flagellar genes was found for p. salmonis, although no structural flagellum has ever been reported for this bacterium. to gain further understanding, the hierarchical flagellar cascade described for legionella pneumophila was used as a reference model for putative analysis in p. salmonis. specif ...201728177291
legionella prevalence and risk of legionellosis in japanese households.this study determined the occurrence of legionellae in private houses for which there were no available data on aquatic environments other than the water supply system. from june 2013 to november 2014, we collected 138 water and 90 swab samples from aquatic environments in 19 houses. legionella dna was detected via a loop-mediated isothermal amplification assay in 66 (47·8%) water and 17 (18·9%) swab samples. high legionella dna detection rates were observed in water samples from washing machine ...201728166862
approach to determine the diversity of legionella species by nested pcr-dgge in aquatic environments.in this study, we describe a nested pcr-dgge strategy to detect legionella communities from river water samples. the nearly full-length 16s rrna gene was amplified using bacterial primer in the first step. after, the amplicons were employed as dna templates in the second pcr using legionella specific primer. the third round of gene amplification was conducted to gain pcr fragments apposite for dgge analysis. then the total numbers of amplified genes were observed in dgge bands of products gained ...201728166249
temperature-dependent growth modeling of environmental and clinical legionella pneumophila multilocus variable-number tandem-repeat analysis (mlva) genotypes.legionella pneumophila causes waterborne infections resulting in severe pneumonia. high-resolution genotyping of l. pneumophila isolates can be achieved by multiple-locus variable-number tandem-repeat analysis (mlva). recently, we found that different mlva genotypes of l. pneumophila dominated different sites in a small drinking-water network, with a genotype-related temperature and abundance regime. the present study focuses on understanding the temperature-dependent growth kinetics of the geno ...201728159784
microbiology and epidemiology of legionnaire's disease.legionnaire's disease (ld) is the pneumonic form of legionellosis caused by aerobic gram-negative bacilli of the genus legionella. individuals become infected when they inhale aerosolized water droplets contaminated with legionella species. forty years after the identification of legionella pneumophila as the cause of the 1976 pneumonia outbreak in a hotel in philadelphia, we have non-culture-based diagnostic tests, effective antibiotics, and preventive measures to handle ld. with a mortality ra ...201728159177
legionnaire's disease and influenza.legionella pneumophila and influenza types a and b viruses can cause either community-acquired pneumonia with respiratory failure, or legionella infection could attribute to influenza infection with potentially fatal prognosis. copathogenesis between pandemic influenza and bacteria is characterized by complex interactions between coinfecting pathogens and the host. understanding the underlying reason of the emersion of the secondary bacterial infection during an influenza infection is challengin ...201728159173
severe pneumonia caused by legionella pneumophila: differential diagnosis and therapeutic considerations.severe legionella pneumonia poses a diagnostic challenge and requires early intervention. legionnaire's disease can have several presenting signs, symptoms, and laboratory abnormalities that suggest that legionella pneumophila is the pathogen, but none of these are sufficient to distinguish l pneumophila pneumonia from other respiratory pathogens. l pneumophila is primarily an intracellular pathogen and needs treatment with antibiotics that efficiently enter the intracellular space.201728159171
complete genome sequences of legionella pneumophila subsp. fraseri strains detroit-1 and dallas 1e.we report here the complete genome sequences of two of the earliest known strains of legionella pneumophila subsp. fraseri detroit-1 is serogroup 1 and was isolated from a lung biopsy specimen in 1977. dallas 1e is serogroup 5 and was isolated in 1978 from a cooling tower.201728153889
differential proteome between patient-related and non-related environmental isolates of legionella pneumophila.molecular epidemiologic studies of legionella have shown different molecular types coexisting in the same environment, with only one having the ability to trigger an outbreak. we therefore studied the proteome of isolates of these different molecular types in search of the proteins responsible for infection. in this study, we performed a differential proteomic analysis between patient-related and non-patient-related environmental isolates using two-dimensional difference gel electrophoresis (2d- ...201728138785
the type ii secretion system of legionella pneumophila dampens the myd88 and toll-like receptor 2 signaling pathway in infected human macrophages.previously, we reported that mutants of legionella pneumophila lacking a type ii secretion (t2s) system elicit higher levels of cytokines (e.g., interleukin-6 [il-6]) following infection of u937 cells, a human macrophage-like cell line. we now show that this effect of t2s is also manifest upon infection of human thp-1 macrophages and peripheral blood monocytes but does not occur during infection of murine macrophages. supporting the hypothesis that t2s acts to dampen the triggering of an innate ...201728138020
an interactive macrophage signal transduction map facilitates comparative analyses of high-throughput data.macrophages (mϕs) are key players in the coordination of the lifesaving or detrimental immune response against infections. the mechanistic understanding of the functional modulation of mϕs by pathogens and pharmaceutical interventions at the signal transduction level is still far from complete. the complexity of pathways and their cross-talk benefits from holistic computational approaches. in the present study, we reconstructed a comprehensive, validated, and annotated map of signal transduction ...201728137890
a legionella effector disrupts host cytoskeletal structure by cleaving actin.legionella pneumophila, the etiological agent of legionnaires' disease, replicates intracellularly in protozoan and human hosts. successful colonization and replication of this pathogen in host cells requires the dot/icm type ivb secretion system, which translocates approximately 300 effector proteins into the host cell to modulate various cellular processes. in this study, we identified ravk as a dot/icm substrate that targets the host cytoskeleton and reduces actin filament abundance in mammal ...201728129393
rates and predictors of exposure to legionella pneumophila in the united states among dental practitioners: 2002 through 2012.in this study, the authors compared the odds of exposure to legionella pneumophila among currently active dental practitioners with that of nonpractitioners and evaluated demographic and clinical practice predictors of exposure.201728126227
evaluation of a most probable number method for the enumeration of legionella pneumophila from potable and related water samples.this study compared the performance of a novel mpn method (legiolert/quanti-tray) with the iso 11731-2 membrane filtration method for the enumeration of legionella pneumophila from 100 ml potable water and related samples. data from a multi-laboratory study analysed according to iso 17994 showed that legiolert™/quanti-tray® yielded on average higher counts of l. pneumophila. the legiolert medium had a high specificity of 96·4%. the new method represents a significant improvement in the enumerati ...201728117485
acyl histidines: new n-acyl amides from legionella pneumophila.legionella pneumophila, the causative agent of legionnaires' disease, is a gram-negative gammaproteobacterial pathogen that infects and intracellularly replicates in human macrophages and a variety of protozoa. l. pneumophila encodes an orphan biosynthetic gene cluster (bgc) that contains isocyanide-associated biosynthetic genes and is upregulated during infection. because isocyanide-functionalized metabolites are known to harbor invertebrate innate immunosuppressive activities in bacterial path ...201728116768
structural mimicry by a bacterial f box effector hijacks the host ubiquitin-proteasome system.ankyrin b (ankb/legau13) is a translocated f box effector essential for the intracellular replication of the pathogen legionella pneumophila. ankb co-opts a host ubiquitin ligase to decorate the pathogen-containing vacuole with k(48)-linked polyubiquitinated proteins and degrade host proteins as a source of energy. here, we report that ankb commandeers the host ubiquitin-proteasome system through mimicry of two eukaryotic protein domains. using x-ray crystallography, we determined the 3d structu ...201728111017
outbreak of legionnaire's disease caused by legionella pneumophila serogroups 1 and 13.in japan, hot springs and public baths are the major sources of legionellosis. in 2015, an outbreak of legionnaires' disease occurred among 7 patients who had visited a spa house. laboratory investigation indicated that l. pneumophila serogroup 1 and 13 strains caused the outbreak and that these strains were genetically related.201728098535
effect of temperature and colonization of legionella pneumophila and vermamoeba vermiformis on bacterial community composition of copper drinking water biofilms.it is unclear how the water-based pathogen, legionella pneumophila (lp), and associated free-living amoeba (fla) hosts change or are changed by the microbial composition of drinking water (dw) biofilm communities. thus, this study characterized the bacterial community structure over a 7-month period within mature (> 600-day-old) copper dw biofilms in reactors simulating premise plumbing and assessed the impact of temperature and introduction of lp and its fla host, vermamoeba vermiformis (vv), c ...201728097816
methodological approaches for monitoring opportunistic pathogens in premise plumbing: a review.opportunistic premise (i.e., building) plumbing pathogens (oppps, e.g., legionella pneumophila, mycobacterium avium complex, pseudomonas aeruginosa, acanthamoeba, and naegleria fowleri) are a significant and growing source of disease. because oppps establish and grow as part of the native drinking water microbiota, they do not correspond to fecal indicators, presenting a major challenge to standard drinking water monitoring practices. further, different oppps present distinct requirements for sa ...201728390237
structure of the wipa protein reveals a novel tyrosine protein phosphatase effector from legionella pneumophila.legionnaires disease is a severe form of pneumonia caused by the bacterium legionella pneumophila. l. pneumophila pathogenicity relies on secretion of more than 300 effector proteins by a type ivb secretion system. among these legionella effectors, wipa has been primarily studied because of its dependence on a chaperone complex, icmsw, for translocation through the secretion system, but its role in pathogenicity has remained unknown. in this study, we present the crystal structure of a large fra ...201728389563
neutrophils and ly6chi monocytes collaborate in generating an optimal cytokine response that protects against pulmonary legionella pneumophila infection.early responses mounted by both tissue-resident and recruited innate immune cells are essential for host defense against bacterial pathogens. in particular, both neutrophils and ly6chi monocytes are rapidly recruited to sites of infection. while neutrophils and monocytes produce bactericidal molecules, such as reactive nitrogen and oxygen species, both cell types are also capable of synthesizing overlapping sets of cytokines important for host defense. whether neutrophils and monocytes perform r ...201728384349
global analysis of gene expression reveals mrna superinduction is required for the inducible immune response to a bacterial pathogen.the inducible innate immune response to infection requires a concerted process of gene expression that is regulated at multiple levels. most global analyses of the innate immune response have focused on transcription induced by defined immunostimulatory ligands, such as lipopolysaccharide. however, the response to pathogens involves additional complexity, as pathogens interfere with virtually every step of gene expression. how cells respond to pathogen-mediated disruption of gene expression to n ...201728383283
assessment of antibiotic susceptibility of legionella pneumophila isolated from water systems in poland.several studies have reported therapy failures in patients with legionnaires'disease; however, antimicrobial resistance of clinical and environmental isolates of legionella spp. has not yet been documented. routine susceptibility testing of legionella spp. is not recommended because of difficulties in determining standard minimal inhibitory concentration values. the purpose of this study was to analyze the antimicrobial susceptibility of legionella pneumophila. strains isolated from a water supp ...201728378991
evaluation of legionella real-time pcr against traditional culture for routine and public health testing of water samples.to evaluate the usefulness of legionella qpcr alongside traditional culture for enumeration of legionella from water samples as part of both routine and public health investigation testing.201728376265
the legionella pneumophila incomplete phosphotransferase system (pts) is required for optimal intracellular growth and maximal expression of pmra regulated effectors.the nitrogen phosphotransferase system (pts(ntr)) is a regulatory cascade present in many bacteria, where it controls different functions. this system is usually composed of three basic components: ei(ntr), npr and eiia(ntr) (encoded by the ptsp, ptso and ptsn genes, respectively). in legionella pneumophila, as well as in many other legionella species, the eiia(ntr) component is missing. however, we found that deletion mutations in both ptsp and ptso are partially attenuated for intracellular gr ...201728373357
diving deep into hospital-acquired legionella pneumophila with whole-genome sequencing. 201728369254
recombinant mip-pile-flaa dominant epitopes vaccine candidate against legionella pneumophila.legionella pneumophila is the main causative agent of legionnaires' disease, which is a severe multi-system disease with pneumonia as the primary manifestation. we designed a recombinant mip-pile-flaa dominant epitopes vaccine against legionella pneumophila to prevent the disease and evaluated its immunogenicity and protective immunity. the protein structures of mip, pile and flaa were analyzed using a computer, and the gene sequences of the dominant epitopes of the three proteins were selected ...201728366526
the tug-of-war over mtor in legionella infections.a ruptured bacteria-containing organelle within the cytosol of an infected eukaryotic cell frequently initiates host defense responses that restrict pathogen replication. therefore, source for lipids must be found to accommodate the organelle membrane expansion required to support bacterial replication. how host cells are manipulated to provide lipids for the expansion of pathogen-occupied organelles is not well understood. by investigating the interaction between macrophages and the human pulmo ...201728357391
exploring the legionella pneumophila positivity rate in hotel water samples from antalya, turkey.the genus legionella is a fastidious gram-negative bacteria widely distributed in natural waters and man made water supply systems. legionella pneumophila is the aetiological agent of approximately 90% of reported legionellosis cases, and serogroup 1 is the most frequent cause of infections. legionnaires' disease is often associated with travel and continues to be a public health concern at present. the correct water management quality practices and rapid methods for analyzing legionella species ...201728353109
legionella pneumonia associated with severe acute respiratory distress syndrome and diffuse alveolar hemorrhage - a rare association.legionella pneumophila is a common, usually underreported and undiagnosed cause of community acquired pneumonia which can lead to significant morbidity and mortality. diffuse alveolar hemorrhage rarely have been associated with legionella infection. we present a 61-year-old man with hypertension, diabetes mellitus and obesity admitted with severe acute respiratory distress syndrome. he was found to have legionella pneumonia with associated diffuse alveolar hemorrhage diagnosed with bronchoscopic ...201728348947
legionella pneumophila pneumonia in two infants treated with adrenocorticotropic hormone.patients with infantile spasms, an intractable epileptic disorder, often are treated with adrenocorticotropic hormone. legionella pneumophila is a rare cause of pneumonia in children. we describe 2 infants with legionella pneumonia whose infection occurred within 1 month after starting adrenocorticotropic hormone.201728336145
evaluation of the bionexia legionella test including the impact of incubation time extension for the detection of legionella pneumophila serogroup 1 antigen in urine.in this study, we compared the bionexia (biomérieux, marcy-l'étoile, france), a new immunochromatographic assay for the detection of legionella pneumophila serogroup 1 in urine, with the binaxnow urinary antigen test (alere, waltham, massachusetts, usa). after 15 minutes of incubation (in accordance with the manufactures instructions), the sensitivity and specificity were, respectively, 76.5% and 97.2% for the bionexia test and 87.1% and 100% for the binaxnow test. after a prolonged incubation t ...201728330891
pily1 promotes legionella pneumophila infection of human lung tissue explants and contributes to bacterial adhesion, host cell invasion, and twitching motility.legionnaires' disease is an acute fibrinopurulent pneumonia. during infection legionella pneumophila adheres to the alveolar lining and replicates intracellularly within recruited macrophages. here we provide a sequence and domain composition analysis of the l. pneumophila pily1 protein, which has a high homology to pily1 of pseudomonas aeruginosa. pily1 proteins of both pathogens contain a von willebrand factor a (vwfa) and a c-terminal pily domain. using cellular fractionation, we assigned the ...201728326293
host fih-mediated asparaginyl hydroxylation of translocated legionella pneumophila effectors.fih-mediated post-translational modification through asparaginyl hydroxylation of eukaryotic proteins impacts regulation of protein-protein interaction. we have identified the fih recognition motif in 11 legionella pneumophila translocated effectors, yopm of yersinia, ipah4.5 of shigella and an ankyrin protein of rickettsia. mass spectrometry analyses of the ankb and ankh effectors of l. pneumophila confirm their asparaginyl hydroxylation. consistent with localization of the ankb effector to the ...201728321389
legionella pneumophila outer membrane vesicles: isolation and analysis of their pro-inflammatory potential on macrophages.bacteria are able to secrete a variety of molecules via various secretory systems. besides the secretion of molecules into the extracellular space or directly into another cell, gram-negative bacteria can also form outer membrane vesicles (omvs). these membrane vesicles can deliver their cargo over long distances, and the cargo is protected from degradation by proteases and nucleases. legionella pneumophila (l. pneumophila) is an intracellular, gram-negative pathogen that causes a severe form of ...201728287548
detection of legionella pneumophila in urine and serum specimens of neutropenic febrile patients with haematological malignancies.background: legionella pneumophila (l. pneumophila) is a gram-negative bacterium which causes ‎legionnaires' disease as well as pontiac fever. the legionella infections in patients suffering from ‎neutropenia- as a common complication of cancer chemotherapy- can distribute rapidly. we ‎aimed to detect of l. pneumophila in haematological malignancy suffering patients with ‎neutropenic fever by targeting the (macrophage infectivity potentiator) mip gene. subjects andmethods: serum and ‎urine speci ...201728286615
a discussion about public health, lead and legionella pneumophila in drinking water supplies in the united states.lead (pb) in public drinking water supplies has garnered much attention since the outset of the flint water crisis. pb is a known hazard in multiple environmental matrices, exposure from which results in long-term deleterious health effects in humans. this discussion paper aims to provide a succinct account of environmental pb exposures with a focus on water pb levels (wlls) in the united states. it is understood that there is a strong correlation between wlls and blood pb levels (blls), and the ...201728285860
impact of water heater temperature setting and water use frequency on the building plumbing microbiome.hot water plumbing is an important conduit of microbes into the indoor environment and can increase risk of opportunistic pathogens (for example, legionella pneumophila). we examined the combined effects of water heater temperature (39, 42, 48, 51 and 58 °c), pipe orientation (upward/downward), and water use frequency (21, 3 and 1 flush per week) on the microbial composition at the tap using a pilot-scale pipe rig. 16s rrna gene amplicon sequencing indicated that bulk water and corresponding bio ...201728282040
did a patient acquire legionella pneumophila from the cup filler of a dental unit or did a patient infected with l. pneumophila contaminate the cup filler? 201728262432
dipolar relaxation dynamics at the active site of an atpase regulated by membrane lateral pressure.the active transport of ions across biological membranes requires their hydration shell to interact with the interior of membrane proteins. however, the influence of the external lipid phase on internal dielectric dynamics is hard to access by experiment. using the octahelical transmembrane architecture of the copper-transporting p1b -type atpase from legionella pneumophila as a model structure, we have established the site-specific labeling of internal cysteines with a polarity-sensitive fluoro ...201728026092
mams are attractive targets for bacterial repurposing of the host cell: mam-functions might be key for undermining an infected cell.pathogenic bacteria frequently target the endoplasmic reticulum (er) and mitochondria in order to exploit host functions. er-mitochondria inter-organelle communication is topologically sub-compartmentalized at mitochondria-associated er membranes (mams). mams are specific membranous microdomains with unique regulatory functions such as lipid synthesis and trafficking, calcium homeostasis, mitochondrial morphology, inflammasome activation, autophagosome formation, and apoptosis. these important c ...201728026026
inflammasome biology taught by legionella pneumophila.inflammasomes are multimeric protein complexes that assemble in the cytosol of many types of cells, including innate immune cells. the inflammasomes can be activated in response to infection or in response to stress signals that induce damage in the host cell membranes. these platforms trigger inflammatory processes, cell death, and the control of microbial replication. many inflammasomes have been described so far, including nlrp3, naip/nlrc4, caspase-11, and aim2. the ligand for nlrp3 is still ...201727999148
legionnaire's disease and immunosuppressive drugs.immunosuppressive agents predispose patients to legionnaire's disease. patients receiving tumor necrosis factor antagonists are generally not severely immunocompromised by the underlying disease. in patients with malignancy receiving immunosuppressive therapies, it is difficult to balance the underlying disease versus the therapy used. transplant recipients are often on multiple drugs, including immunosuppressants. it seems that immunosuppressive drugs add to the risk for legionella infection. t ...201727979686
laboratory tests for legionnaire's disease.legionella pneumophila is one of the more recently discovered bacterial pathogens of humans. the last 2 decades have seen tremendous progress in the evolution of diagnostic tests, for detection and characterization of this pathogen and for defining the host response to infection. this has generated several diagnostic tools that span the range from simple immunologic assays to modern genome sequencing. this review describes the state of affairs of this continuously evolving field regarding the di ...201727979684
occurrence of legionella in uk household showers.household water systems have been proposed as a source of sporadic, community acquired legionnaires' disease. showers represent a frequently used aerosol generating device in the domestic setting yet little is known about the occurrence of legionella spp. in these systems. this study has investigated the prevalence of legionella spp. by culture and qpcr in uk household showers. ninety nine showers from 82 separate properties in the south of england were sampled. clinically relevant legionella sp ...201727964907
legionella longbeachae is immunologically silent and highly virulent in vivo.legionella longbeachae (llo) and legionella pneumophila (lpn) are the most common pneumonia-causing agents of the genus. although both species can be lethal to humans and are highly prevalent, little is known about the molecular pathogenesis of llo infections. in murine models of infection, lpn infection is self-limited, whereas llo infection is lethal.201727932612
seasonality of pathogens causing community-acquired pneumonia.seasonal distribution of microbial aetiology in patients with community-acquired pneumonia (cap) may add important information both for epidemiologists and clinicians. we investigate the seasonal distribution of microbial aetiology in cap.201728093834
effect of disinfectant exposure on legionella pneumophila associated with simulated drinking water biofilms: release, inactivation, and infectivity.legionella pneumophila, the most commonly identified causative agent in drinking water associated with disease outbreaks, can be harbored by and released from drinking water biofilms. in this study, the release of biofilm-associated l. pneumophila under simulated drinking water flow containing a disinfectant residual was examined. meanwhile, the inactivation and infectivity (to amoebae) of the released l. pneumophila were studied. to simulate drinking water system conditions, biofilms were prepa ...201728085262
a bioinformatics tool for ensuring the backwards compatibility of legionella pneumophila typing in the genomic era.whole genome sequencing (wgs) has revolutionized the subtyping of legionella pneumophila but calling the traditional sequence-based type from genomic data is hampered by multiple copies of the momps locus. we propose a novel bioinformatics solution for rectifying that limitation, ensuring the feasibility of wgs for cluster investigation.201728082190
ribosomal mutations conferring macrolide resistance in legionella pneumophila.monitoring the emergence of antibiotic resistance is a recent issue in the treatment of legionnaires' disease. macrolides are recommended as first-line therapy, but resistance mechanisms have not been studied in legionella species. our aim was to determine the molecular basis of macrolide resistance in l. pneumophila twelve independent lineages from a common susceptible l. pneumophila ancestral strain were propagated under conditions of erythromycin or azithromycin pressure to produce high-level ...201728069647
innate immunity against legionella pneumophila during pulmonary infections in mice.legionella pneumophila is an etiological agent of the severe pneumonia known as legionnaires' disease (ld). this gram-negative bacterium is thought to replicate naturally in various freshwater amoebae, but also replicates in human alveolar macrophages. inside host cells, legionella induce the production of non-endosomal replicative phagosomes by injecting effector proteins into the cytosol. innate immune responses are first line defenses against legionella during early phases of infection, and d ...201728063015
biofilm composition and threshold concentration for growth of legionella pneumophila on surfaces exposed to flowing warm tap water without disinfectant.legionella pneumophila in potable water installations poses a potential health risk, but quantitative information about its replication in biofilms in relation to water quality is scarce. therefore, biofilm formation on the surfaces of glass and chlorinated polyvinyl chloride (cpvc) in contact with tap water at 34 to 39°c was investigated under controlled hydraulic conditions in a model system inoculated with biofilm-grown l. pneumophila the biofilm on glass (average steady-state concentration, ...201728062459
[rapid diagnostic test for respiratory infections].acute respiratory infections are the second cause of morbidity and mortality in children and adults worldwide, being viruses, bacteria and fungi involved in their etiology. the rapid diagnosis allows for a better clinical management of the patient, for adopting public health measures and for controlling possible outbreaks. the main etiologic agents can be diagnosed within the first hours after the onset of symptoms with antigen detection techniques, primarily immunochromatography. results are ob ...201728062161
a single legionella effector catalyzes a multistep ubiquitination pathway to rearrange tubular endoplasmic reticulum for replication.intracellular pathogens manipulate host organelles to support replication within cells. for legionella pneumophila, the bacterium translocates proteins that establish an endoplasmic reticulum (er)-associated replication compartment. we show here that the bacterial sde proteins target host reticulon 4 (rtn4) to control tubular er dynamics, resulting in tubule rearrangements as well as alterations in rtn4 associated with the replication compartment. these rearrangements are triggered via sde-promo ...201728041930
the regulation of acute immune responses to the bacterial lung pathogen legionella pneumophila.legionella pneumophila causes legionnaires' disease, a severe and potentially fatal bacterial pneumonia in immunocompromised individuals. despite the understanding that a robust inflammatory response is important for control of l. pneumophila infection, our understanding of the network of molecular and cellular events within the lung that function to clear the bacterium is not clearly understood. this review compiles our understanding of the various molecular and cellular pathways stimulated upo ...201728034914
strategies for the reduction of legionella in biological treatment systems.a community-wide outbreak of legionnaire's disease occurred in warstein, germany, in august 2013. the epidemic strain, legionella pneumophila serogruppe 1, was isolated from an industrial wastewater stream entering the municipal wastewater treatment plant (wwtp) in wartein, the wwtp itself, the river wäster and air/water samples from an industrial cooling system 3 km downstream of the wwtp. the present study investigated the effect of physical-chemical disinfection methods on the reduction of th ...201727533856
application of real-time quantitative polymerase chain reaction assay to detect legionella pneumophila in patients of community-acquired pneumonia in a tertiary care hospital.legionella pneumophila is one of the important pathogen responsible for community -acquired pneumonia attributing for 1-5% of cases. since early and accurate therapy reduces mortality, rapid and reliable diagnostic methods are needed. a total of 134 samples of blood, urine and respiratory tract fluids were collected. blood was tested for igg, igm and iga antibodies using commercially available kits. a total of 8 (6%) samples were found to be positive for l. pneumophila by quantitative reverse tr ...201727934840
developing an ecologically relevant heterogeneous biofilm model for dental-unit waterlines.this study monitored the biodiversity of microbes cultured from a heterogeneous biofilm which had formed on the lumen of a section of dental waterline tubing over a period of 910 days. by day 2 bacterial counts on the outlet-water showed that contamination of the system had occurred. after 14 days, a biofilm comparable to that of clinical waterlines, consisting of bacteria, fungi and amoebae had formed. this showed that the proprietary silver coating applied to the luminal surface of the commerc ...201727928939
lessons from an outbreak of legionnaires' disease on a hematology-oncology unit.objectives to define the scope of an outbreak of legionnaires' disease (ld), to identify the source, and to stop transmission. design and setting epidemiologic investigation of an ld outbreak among patients and a visitor exposed to a newly constructed hematology-oncology unit. methods an ld case was defined as radiographically confirmed pneumonia in a person with positive urinary antigen testing and/or respiratory culture for legionella and exposure to the hematology-oncology unit after february ...201727919312
rapid detection and evolutionary analysis of legionella pneumophila serogroup 1 sequence type 47.legionella pneumophila serogroup 1 (lp1) sequence type 47 is the leading cause of legionellosis in north-western europe, but, surprisingly, it is rarely isolated from environmental samples. comparative genomics was applied to develop a pcr assay and to better understand the evolution of this strain.201727915212
tnf-α inhibits the growth of legionella pneumophila in airway epithelial cells by inducing apoptosis.tnf-α plays an important role in the pathogenesis of legionella pneumophila (lp)-induced pneumonia. patients undergoing anti-tnf-α therapy are at an increased risk of lp infection. lp infects both phagocytic and non-phagocytic cells such as airway epithelial cells; however, the role of tnf-α in airway epithelial cells is unknown.201727865699
pleuromutilins: potent drugs for resistant bugs-mode of action and resistance.pleuromutilins are antibiotics that selectively inhibit bacterial translation and are semisynthetic derivatives of the naturally occurring tricyclic diterpenoid pleuromutilin, which received its name from the pleuromutilin-producing fungus pleurotus mutilus tiamulin and valnemulin are two established derivatives in veterinary medicine for oral and intramuscular administration. as these early pleuromutilin drugs were developed at a time when companies focused on major antibacterial classes, such ...201727742734
clinical utility of testing for legionella pneumonia in central texas.legionella pneumophila is an uncommon cause of community-acquired pneumonia in the south central region of the united states, and regular testing may not be cost effective in areas of low incidence.201727739904
legionellosis in the occupational setting.legionellosis is the common name for two infections, legionnaires' disease (ld) and pontiac fever (pf), both caused by legionella bacteria. although with low incidence, ld is an important cause of community- and hospital-acquired pneumonia. among community-acquired cases, an increasing number was reported to be linked to the occupational setting, posing the need for better recognition of work activities at risk of legionellosis. in this work, we selected and reviewed relevant literature on cases ...201727717486
detection of legionella-contaminated aerosols in the vicinity of a bio-trickling filter of a breeding sow facility - a pilot study.the urbanization of agricultural areas results in a reduction of distances between residential buildings and livestock farms. in the public debate, livestock farming is increasingly criticized due to environmental disturbance and odor nuisance originating from such facilities. one method to reduce odor and ammonia is by exhaust air treatment, for example, by biological exhaust air purification processes with bio-trickling filters filled with tap water. higher temperatures in the summer time and ...201727692939
pulmonary legionellosis in oncologic patients: findings on chest ct.the purpose of this study was to report the computed tomography (ct) findings of non-pneumophila legionella pneumonia and to compare these ct findings to those caused by legionella pneumophila in oncologic patients.201727454787
travel-associated infections caused by unusual serogroups of legionella pneumophila identified using legionella biochip slides in turkey and iraq.although legionella pneumophila serogroup 1 is the common disease causing serogroup, rare serogroups can also may cause legionellosis. a 54-year-old male patient (index case) reported that he had been on a religious trip (for visiting, tomb of ali, which is important for shias) to iraq with a large group (50 shia pilgrims from kars city of turkey) two weeks prior to admission. due to civil war, the hotel where the patient stayed in iraq lacked proper hygiene. a large number of people in the trav ...201727108684
the 1:2 complex between ravz and lc3 reveals a mechanism for deconjugation of lc3 on the phagophore membrane.hosts utilize macroautophagy/autophagy to clear invading bacteria; however, bacteria have also developed a specific mechanism to survive by manipulating the host cell autophagy mechanism. one pathogen, legionella pneumophila, can hinder host cell autophagy by using the specific effector protein ravz that cleaves phosphatidylethanolamine-conjugated lc3 on the phagophore membrane. however, the detailed molecular mechanisms associated with the function of ravz have hitherto remained unclear. here, ...201727791457
distribution of secretion systems in the genus legionella and its correlation with pathogenicity.the genus legionella comprises over 60 species, which are important human pathogens. secretion systems in legionella pneumophila have been studied extensively because of the essential role of protein secretion in bacterial infection. however, there are few reports describing the secretion systems in non-l. pneumophila species. in this study, we analyzed the distribution of secretion systems in l. pneumophila and 18 species of non-l. pneumophila based on whole genome sequences. a total of 74 whol ...201728352254
annual variations and effects of temperature on legionella spp. and other potential opportunistic pathogens in a bathroom.opportunistic pathogens (ops) in drinking water, like legionella spp., mycobacteria, pseudomonas aeruginosa, and free-living amobae (fla) are a risk to human health, due to their post-treatment growth in water systems. to assess and manage these risks, it is necessary to understand their variations and environmental conditions for the water routinely used. we sampled premise tap (n cold = 26, n hot = 26) and shower (n shower = 26) waters in a bathroom and compared water temperatures to levels of ...201727815848
proq/fino-domain proteins: another ubiquitous family of rna matchmakers?small rnas (srnas), particularly those that act by limited base pairing with mrnas, are part of most regulatory networks in bacteria. in many cases, the base-pairing interaction is facilitated by the rna chaperone hfq. however, not all bacteria encode hfq and some base-pairing srnas do not require hfq raising the possibility of other rna chaperones. candidates are proteins with homology to fino, a factor that promotes base pairing between the finp antisense srna and the traj mrna to control f pl ...201728370625
in situ structure of the legionella dot/icm type iv secretion system by electron cryotomography.type iv secretion systems (t4sss) are large macromolecular machines that translocate protein and dna and are involved in the pathogenesis of multiple human diseases. here, using electron cryotomography (ect), we report the in situ structure of the dot/icm type ivb secretion system (t4bss) utilized by the human pathogen legionella pneumophila this is the first structure of a type ivb secretion system, and also the first structure of any t4ss in situ while the dot/icm system shares almost no seque ...201728336774
characterization of the cryptic plasmid pofk55 from legionella pneumophila and construction of a pofk55-derived shuttle vector.in this study, a cryptic plasmid pofk55 from legionella pneumophila was isolated and characterized. pofk55 comprised 2584bp with a gc content of 37.3% and contained three putative open reading frames (orfs). orf1 encoded a protein of 195 amino acids and the putative protein shared 39% sequence identity with a putative plasmid replication protein repl. orf1 was needed for replication in l. pneumophila but pofk55 did not replicate in escherichia coli. orf2 and orf3 encoded putative hypothetical pr ...201728259635
seeing red; the development of pon.mcherry, a broad-host range constitutive expression plasmid for gram-negative bacteria.the development of plasmid-mediated gene expression control in bacteria revolutionized the field of bacteriology. many of these expression control systems rely on the addition of small molecules, generally metabolites or non-metabolized analogs thereof, to the growth medium to induce expression of the genes of interest. the paradigmatic example of an expression control system is the lac system from escherichia coli, which typically relies on the ptac promoter and the lac repressor, laci. in many ...201728257493
macrolide resistance in legionella pneumophila: the role of lpeab efflux pump.a previous study on 12 in vitro-selected azithromycin-resistant legionella pneumophila lineages showed that ribosomal mutations were major macrolide resistance determinants. in addition to these mechanisms that have been well described in many species, mutations upstream of lpeab operon, homologous to acrab in escherichia coli, were identified in two lineages. in this study, we investigated the role of lpeab and of these mutations in macrolide resistance of l. pneumophila methods: the role of lp ...201728137939
seasonal assessment of opportunistic premise plumbing pathogens in roof-harvested rainwater tanks.a seasonal study on the occurrence of six opportunistic premise plumbing pathogens (oppps) in 24 roof-harvested rainwater (rhrw) tanks repeatedly sampled over six monthly sampling events (n = 144) from august 2015 to march 2016 was conducted using quantitative qpcr. fecal indicator bacteria (fib) escherichia coli (e. coli) and enterococcus spp. were enumerated using culture-based methods. all tank water samples over the six events were positive for at least one oppp (legionella spp., legionella ...201728040888
high prevalence of legionella in non-passenger merchant vessels.there is a paucity of information on the risk from potable water in non-passenger merchant vessels (npmvs) particularly with regard to legionella and other bacteria. this retrospective study examined water samples from 550 npmvs docked in eight uk ports. a total of 1027 samples from 412 npmvs were examined for total aerobic colony counts (acc), coliforms, escherichia coli and enterococci; 41% of samples yielded acc above the action level (>1 × 103 c.f.u./ml) and 4·5% contained actionable levels ...201727890040
comparative proteomics of purified pathogen vacuoles correlates intracellular replication of legionella pneumophila with the small gtpase ras-related protein 1 (rap1).legionella pneumophila is an opportunistic bacterial pathogen that causes a severe lung infection termed "legionnaires' disease." the pathogen replicates in environmental protozoa as well as in macrophages within a unique membrane-bound compartment, the legionella-containing-vacuole (lcv). lcv formation requires the bacterial icm/dot type iv secretion system, which translocates ca. 300 "effector proteins" into host cells, where they target distinct host factors. the l. pneumophila "pentuple" mut ...201728183814
promotion and rescue of intracellular brucella neotomae replication during co-infection with legionella pneumophila.we established a new brucella neotomaein vitro model system for study of type iv secretion system-dependent (t4ss) pathogenesis in the brucella genus. importantly, b. neotomae is a rodent pathogen and, unlike b. abortus, melitensis, and suis, has not been observed to infect humans. it therefore can be handled more facilely using biosafety level 2 practices. more particularly, using a series of novel fluorescent protein and lux operon reporter systems to differentially label pathogens and track i ...201728264909
interferon-inducible guanylate-binding proteins at the interface of cell-autonomous immunity and inflammasome activation.guanylate-binding proteins (gbps) are essential components of cell-autonomous immunity. in response to ifn signaling, gbps are expressed in the cytoplasm of immune and nonimmune cells, where they unleash their antimicrobial activity toward intracellular bacteria, viruses, and parasites. recent studies have revealed that gbps are essential for mediating activation of the caspase-1 inflammasome in response to the gram-negative bacteria salmonella enterica serovar typhimurium, francisella novicida, ...201727418355
fluorocycline tp-271 is potent against complicated community-acquired bacterial pneumonia pathogens.tp-271 is a novel, fully synthetic fluorocycline antibiotic in clinical development for the treatment of respiratory infections caused by susceptible and multidrug-resistant pathogens. tp-271 was active in mic assays against key community respiratory gram-positive and gram-negative pathogens, including streptococcus pneumoniae (mic90 = 0.03 µg/ml), methicillin-sensitive staphylococcus aureus (mssa; mic90 = 0.25 µg/ml), methicillin-resistant s. aureus (mrsa; mic90 = 0.12 µg/ml), streptococcus pyo ...201728251179
the expanding role of type ii secretion in bacterial pathogenesis and beyond.type ii secretion (t2s) is one means by which gram-negative pathogens secrete proteins into the extracellular milieu and/or host organisms. based upon recent genome sequencing, it is clear that t2s is largely restricted to the proteobacteria, occurring in many, but not all genera in the α-, β-, γ-, and δ- classes. prominent human and/or animal pathogens that express a t2s system(s) include acinetobacter baumannii, burkholderia pseudomallei, chlamydia trachomatis, escherichia coli, klebsiella pne ...201728264910
can contaminated water be rendered safe for nasal saline irrigations?to compare sterile water to three methods of sterilization (carbon filtration, boiling, and ultraviolet [uv] light) for preparation of nasal saline irrigants free of bacterial and amebic contaminants.201728224696
Refresh
firstprev
...9192939495969798
nextlast
Displaying items 9701 - 9790 of 9790