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brain meta-transcriptomics from harbor seals to infer the role of the microbiome and virome in a stranding event.marine diseases are becoming more frequent, and tools for identifying pathogens and disease reservoirs are needed to help prevent and mitigate epizootics. meta-transcriptomics provides insights into disease etiology by cataloguing and comparing sequences from suspected pathogens. this method is a powerful approach to simultaneously evaluate both the viral and bacterial communities, but few studies have applied this technique in marine systems. in 2009 seven harbor seals, phoca vitulina, stranded ...201526630132
active and adaptive legionella crispr-cas reveals a recurrent challenge to the pathogen.clustered regularly interspaced short palindromic repeats with crispr-associated gene (crispr-cas) systems are widely recognized as critical genome defense systems that protect microbes from external threats such as bacteriophage infection. several isolates of the intracellular pathogen legionella pneumophila possess multiple crispr-cas systems (type i-c, type i-f and type ii-b), yet the targets of these systems remain unknown. with the recent observation that at least one of these systems (ii-b ...201626936325
legionella cardiaca sp. nov., isolated from a case of native valve endocarditis in a human heart.a gram-negative, rod-shaped bacterium, designated h63(t), was isolated from aortic valve tissue of a patient with native valve endocarditis. 16s rrna gene sequencing revealed that h63(t) belongs to the genus legionella, with its closest neighbours being the type strains of legionella brunensis (98.8% similarity), l. londiniensis (97.0%), l. jordanis (96.8%), l. erythra (96.2%), l. dresdenensis (96.0%) and l. rubrilucens, l. feeleii, l. pneumophila and l. birminghamensis (95.7%). dna-dna hybridiz ...201222286905
comparative analyses of legionella species identifies genetic features of strains causing legionnaires' disease.the genus legionella comprises over 60 species. however, l. pneumophila and l. longbeachae alone cause over 95% of legionnaires’ disease. to identify the genetic bases underlying the different capacities to cause disease we sequenced and compared the genomes of l. micdadei, l. hackeliae and l. fallonii (llap10), which are all rarely isolated from humans.201425370836
legionella confirmation using real-time pcr and syto9 is an alternative to current methodology.the currently accepted culture techniques for the detection of legionella spp. in water samples (as/nzs 3896:1998 and iso 11731 standard methods) are slow and laborious, requiring from 7 to 14 days for a result. we describe a fully validated rapid confirmation technique that uses real-time pcr incorporating the intercalating dye syto9 for the direct identification of primary cultures, significantly decreasing turnaround time and allowing faster remedial action to be taken by the industry.200516332896
rapid method for enumeration of viable legionella pneumophila and other legionella spp. in water.a sensitive and specific method has been developed to enumerate viable l. pneumophila and other legionella spp. in water by epifluorescence microscopy in a short period of time (a few hours). this method allows the quantification of l. pneumophila or other legionella spp. as well as the discrimination between viable and nonviable legionella. it simultaneously combines the specific detection of legionella cells using antibodies and a bacterial viability marker (chemchrome v6), the enumeration bei ...200516000824
development and evaluation of chlamylege, a new commercial test allowing simultaneous detection and identification of legionella, chlamydophila pneumoniae, and mycoplasma pneumoniae in clinical respiratory specimens by multiplex pcr.this study describes the development and evaluation of a new commercial test, chlamylege (argene inc.), which allows the simultaneous detection in respiratory samples of chlamydophila pneumoniae, mycoplasma pneumoniae, and most legionella species, as well as pcr inhibitors, by using a multiplex pcr and microplate hybridization. the sensitivities of chlamylege were 1 x 10(-3) ifu, 5 x 10(-2) color-changing units, and 1 cfu per reaction tube for c. pneumoniae, m. pneumoniae, and legionella pneumop ...200516000443
the pneumoplex assays, a multiplex pcr-enzyme hybridization assay that allows simultaneous detection of five organisms, mycoplasma pneumoniae, chlamydia (chlamydophila) pneumoniae, legionella pneumophila, legionella micdadei, and bordetella pertussis, and its real-time counterpart.respiratory disease caused by atypical bacteria remains an important cause of morbidity and mortality for adults and children, despite the widespread use of effective antimicrobials agents. culture remains the "gold standard" for the detection of these agents. however, culture is labor-intensive, takes several days to weeks for growth, and can be very insensitive for the detection of some of these organisms. newer singleplex pcr diagnostic tests are sensitive and specific, but multiple assays wo ...200515695646
susceptibility of legionella strains to the chlorinated biocide, monochloramine.members of the legionella genus find suitable conditions for their growth and survival in nuclear power plant cooling circuits. to limit the proliferation of legionella pathogenic bacteria in nuclear power plant cooling circuits, and ensure that levels remain below regulatory thresholds, monochloramine treatment can be used. although the treatment is highly effective, i.e. it reduces legionella numbers by over 99%, legionella bacteria can still be detected at low concentrations and rapid re-colo ...201324005820
mechanistic insights into c-di-gmp-dependent control of the biofilm regulator fleq from pseudomonas aeruginosa.bacterial biofilm formation during chronic infections confers increased fitness, antibiotic tolerance, and cytotoxicity. in many pathogens, the transition from a planktonic lifestyle to collaborative, sessile biofilms represents a regulated process orchestrated by the intracellular second-messenger c-di-gmp. a main effector for c-di-gmp signaling in the opportunistic pathogen pseudomonas aeruginosa is the transcription regulator fleq. fleq is a bacterial enhancer-binding protein (bebp) with a ce ...201626712005
evaluation of the binax and biotest urinary antigen kits for detection of legionnaires' disease due to multiple serogroups and species of legionella.the binax and the biotest urinary antigen kits for the detection of legionnaires' disease caused by organisms other than legionella pneumophila were compared by testing 45 urine samples from non-legionella pneumophila serogroup 1 patients previously positive in a broad-spectrum enzyme-linked immunosorbent assay (elisa). eighteen were positive with the binax kit, and 13 were positive with the biotest. although neither kit is as sensitive as elisa, these results extend the number of serogroups and ...200010878082
mechanistic insights into c-di-gmp-dependent control of the biofilm regulator fleq from pseudomonas aeruginosa.bacterial biofilm formation during chronic infections confers increased fitness, antibiotic tolerance, and cytotoxicity. in many pathogens, the transition from a planktonic lifestyle to collaborative, sessile biofilms represents a regulated process orchestrated by the intracellular second-messenger c-di-gmp. a main effector for c-di-gmp signaling in the opportunistic pathogen pseudomonas aeruginosa is the transcription regulator fleq. fleq is a bacterial enhancer-binding protein (bebp) with a ce ...201626712005
specific detection of legionella pneumophila: construction of a new 16s rrna-targeted oligonucleotide probe.based on comparative sequence analysis, we have designed an oligonucleotide probe complementary to a region of 16s rrna of legionella pneumophila which allows the differentiation of l. pneumophila from other legionella species without cultivation. the specificity of the new probe, legpne1, was tested by in situ hybridization to a total of four serogroups of six strains of l. pneumophila, five different legionella spp. and three nonlegionella species as reference strains. furthermore, l. pneumoph ...19989647849
characterization of the alternative sigma factor sigma54 and the transcriptional regulator fleq of legionella pneumophila, which are both involved in the regulation cascade of flagellar gene expression.we cloned and analyzed legionella pneumophila corby homologs of rpon (encoding sigma(54)) and fleq (encoding sigma(54) activator protein). two other genes (fler and pilr) whose products have a sigma(54) interaction domain were identified in the genome sequence of l. pneumophila. an rpon mutant strain was nonflagellated and expressed very small amounts of the flaa (flagellin) protein. like the rpon mutant, the fleq mutant strain of l. pneumophila was also nonflagellated and expressed only small a ...200415090493
isolation of legionella oakridgensis from two patients with pleural effusion living in the same geographical area.two cases of legionnaire's disease caused by legionella oakridgensis were diagnosed at the university hospital in nantes, france. the two patients' isolates were identified by means of phenotyping and genotyping methods. epidemiological investigations concluded that the first case was hospital acquired while the second case was considered community acquired.200010921997
coevolution between nonhomologous but functionally similar proteins and their conserved partners in the legionella pathogenesis system.legionella pneumophila, the causative agent of legionnaires' disease, and other pathogenic legionella species multiply inside protozoa and human macrophages by using the intracellular multiplication (icm)/defect in organelle trafficking (dot) type-iv secretion system. the icmq protein, which possesses pore-forming activity, and icmr, which regulates the icmq activity, are two essential components of this system. analysis of the region expected to contain these two genes from 29 legionella specie ...200516091472
second serogroup of legionella hackeliae isolated from a patient with pneumonia.a legionella-like organism (strain 798-pa-h, atcc 35999) isolated from a lung aspirate was shown by dna hybridization to belong to the species legionella hackeliae. growth, gas-liquid chromatographic, and physiologic characteristics were consistent with those of the type strain of l. hackeliae, lansing 2 (atcc 35250). however, 798-pa-h was minimally reactive with l. hackeliae direct immunofluorescence assay conjugate or slide agglutination test antiserum. cross-absorption studies with 798-pa-h a ...19854077960
low endotoxic potential of legionella pneumophila lipopolysaccharide due to failure of interaction with the monocyte lipopolysaccharide receptor cd14.legionella pneumophila, a gram-negative bacterium causing legionnaires' disease and pontiac fever, was shown to be highly reactive in in vitro gelation of limulus lysate but not able to induce fever and the local shwartzman reaction in rabbits and mice. we analyzed the capacity of purified l. pneumophila lipopolysaccharide (lps-lp) to induce activation of the human monocytic cell line mono mac 6, as revealed by secretion of proinflammatory cytokines and desensitization to subsequent lps stimulat ...19989712761
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