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purification of legiobactin and importance of this siderophore in lung infection by legionella pneumophila.when cultured in a low-iron medium, legionella pneumophila secretes a siderophore (legiobactin) that is both reactive in the chrome azurol s (cas) assay and capable of stimulating the growth of iron-starved legionellae. using anion-exchange high-pressure liquid chromatography (hplc), we purified legiobactin from culture supernatants of a virulent strain of l. pneumophila. in the process, we detected the ferrated form of legiobactin as well as other cas-reactive substances. purified legiobactin h ...200919398549
autophagy induced by 2-deoxy-d-glucose suppresses intracellular multiplication of legionella pneumophila in a/j mouse macrophages.legionella pneumophila philadelphia-1 (lp-1) can grow intracellularly in a/j mouse peritoneal macrophages (a/j mphi). we previously reported that 2-deoxy-d-glucose (2dg), when added in macrophage culture medium, inhibited the intracellular multiplication of lp-1 in a/j mphi. we found that 1 mm of 2dg causes lc3-ii-conversion that reflects an induction of autophagy and that 1 and 10 mm of 2dg induced apoptosis associated with caspase-4 activation. we therefore investigated whether 2dg-induced aut ...200919398893
two small ncrnas jointly govern virulence and transmission in legionella pneumophila.to transit from intra- to extracellular environments, legionella pneumophila differentiates from a replicative/non-virulent to a transmissive/virulent form using the two-component system leta/lets and the global repressor protein csra. while investigating how both regulators act co-ordinately we characterized two ncrnas, rsmy and rsmz, that link the leta/lets and csra regulatory networks. we demonstrate that leta directly regulates their expression and show that rsmy and rsmz are functional in e ...200919400772
the leta-rsmyz-csra regulatory cascade, together with rpos and pmra, post-transcriptionally regulates stationary phase activation of legionella pneumophila icm/dot effectors.legionella pneumophila utilize the icm/dot type-iv secretion system to translocate effector proteins into host cells. some of these effectors were shown before to be regulated at the transcriptional level by the pmrab and cpxra two-component systems. in addition, the stationary phase-related regulators leta and csra, which are both members of the same post-transcriptional regulatory cascade, were shown to be involved in l. pneumophila virulence. in this report, we identified two small non-coding ...200919400807
impact of biocide treatments on the bacterial communities of the lascaux cave.the lascaux cave contains a remarkable set of paintings from the upper palaeolithic. shortly after discovery in 1940, the cave was modified for public viewing and, in 2001, was invaded by a fusarium solani species complex. benzalkonium chloride was used from 2001 to 2004 to eliminate the fungal outbreak. in this study, we carried out a sampling in most of the cave halls and galleries. sequence analysis and isolation methods detected that the most abundant genera of bacteria were ralstonia and ps ...200919404600
treatment strategies for legionella infection.given the nonspecific clinical manifestations of legionnaires' disease and the high mortality of untreated legionnaires' disease, we recommend routine use of legionella testing, especially the legionella urinary antigen test, for all patients with community-acquired pneumonia. this includes patients with ambulatory pneumonia and hospitalized children. legionella cultures should be more widely available, especially in hospitals where the drinking water is colonized with legionella. azithromycin o ...200919405787
the coxiella burnetii ankyrin repeat domain-containing protein family is heterogeneous, with c-terminal truncations that influence dot/icm-mediated secretion.coxiella burnetii is an obligate intracellular bacterium that directs biogenesis of a parasitophorous vacuole (pv) for replication. effectors of pv maturation are likely translocated into the host cytosol by a type iv secretion system (t4ss) with homology to the dot/icm apparatus of legionella pneumophila. since secreted bacterial virulence factors often functionally mimic the activities of host proteins, prokaryotic proteins with eukaryotic features are considered candidate t4ss substrates. gen ...200919411324
bdha-patd operon as a virulence determinant, revealed by a novel large-scale approach for identification of legionella pneumophila mutants defective for amoeba infection.legionella pneumophila, the causative agent of legionnaires' disease, is an intracellular parasite of eukaryotic cells. in the environment, it colonizes amoebae. after being inhaled into the human lung, the bacteria infect and damage alveolar cells in a way that is mechanistically similar to the amoeba infection. several l. pneumophila traits, among those the dot/icm type ivb protein secretion machinery, are essential for exploiting host cells. in our search for novel legionella virulence factor ...200919411431
conjugative plasmid pld-tex-kl promotes growth of host bacterium legionella dumoffii at low temperatures.legionella (fluoribacter) dumoffii is a resident of various aquatic environments and occasionally causes pneumonia in humans. we found that l. dumoffii strain tex-kl carries a 66-kb circular plasmid. as predicted by the presence of tra genes similar to those of other transferable plasmids, we showed that pld-tex-kl was actually capable of transferring itself to a plasmid-cured derivative of the original strain. unexpectedly, this plasmid-free derivative turned out to be partially defective in te ...200919415237
evaluation of the oxoid xpect legionella test kit for detection of legionella pneumophila serogroup 1 antigen in urine.we evaluated a new immunochromatographic assay (oxoid xpect legionella test kit) for the ability to detect legionella pneumophila serogroup 1 antigen in urine. the results were compared with those obtained with the binax now urinary antigen test by following the manufacturers' instructions. the sensitivities and specificities were estimated to be 89 and 100%, respectively, for the oxoid xpect legionella test kit and 86 and 100%, respectively, for the binax now test.200919420163
travel-associated legionnaires disease in europe in 2007.nine hundred and forty six cases of travel-associated legionnaires disease were reported to the european surveillance scheme for travel associated legionnaires disease (ewglinet) with onset during 2007; 890 were confirmed and 56 were presumptive. twenty eight cases died, giving a case fatality rate of 3.0%. 8.2% of cases were diagnosed by culture, an important increase from 5.2% in 2006. one hundred and twelve new clusters were identified; the largest involved nine cases. sixteen of these cluste ...200919422777
comparison of the microbial load of incoming and distal outlet waters from dental unit water systems in istanbul.this is a cross-sectional study of the incoming and distal outlet water quality from 41 dental units in istanbul, carried out to compare the total microbial loads using traditional culture method versus epifluorescence microscopy. the possible presence of legionella pneumophila using traditional culture method was also analyzed. one hundred and twenty three samples were taken from the high-speed handpiece lines, air-water syringe lines and source (incoming) water supplies from 41 dental units. t ...200918843542
severe adenovirus community-acquired pneumonia mimicking legionella. 200918850123
legionella pneumophila dna in serum samples during legionnaires' disease in relation to c-reactive protein levels.legionella pneumophila dna can be detected in serum from patients with legionnaires' disease (ld). we explored this observation studying the kinetics of l. pneumophila dna in serum samples in relation to c-reactive protein (crp). eleven hospitalized patients with ld were studied. diagnosis was made by legionella urinary antigen test in 8 patients and seroconversion in 3 patients. a macrophage infectivity potentiator (mip) real-time pcr was performed on 31 serum samples, including 20 follow-up se ...200918855027
the pmra/pmrb two-component system of legionella pneumophila is a global regulator required for intracellular replication within macrophages and protozoa.to examine the role of the pmra/pmrb two-component system (tcs) of legionella pneumophila in global gene regulation and in intracellular infection, we constructed pmra and pmrb isogenic mutants by allelic exchange. genome-wide microarray gene expression analyses of the pmra and pmrb mutants at both the exponential and the postexponential phases have shown that the pmra/pmrb tcs has a global effect on the expression of 279 genes classified into nine groups of genes encoding eukaryotic-like protei ...200918936184
specific detection of viable legionella cells by combined use of photoactivated ethidium monoazide and pcr/real-time pcr.legionella organisms are prevalent in manmade water systems and cause legionellosis in humans. a rapid detection method for viable legionella cells combining ethidium monoazide (ema) and pcr/real-time pcr was assessed. ema could specifically intercalate and cleave the genomic dna of heat- and chlorine-treated dead legionella cells. the ema-pcr assay clearly showed an amplified fragment specific for legionella dna from viable cells, but it could not do so for dna from dead cells. the number of em ...200918978073
proteome analysis of legionella vacuoles purified by magnetic immunoseparation reveals secretory and endosomal gtpases.legionella pneumophila, the causative agent of legionnaires' disease, replicates in macrophages and amoebae within 'legionella-containing vacuoles' (lcvs), which communicate with the early secretory pathway and the endoplasmic reticulum. formation of lcvs requires the bacterial icm/dot type iv secretion system. the icm/dot-translocated effector protein sidc selectively anchors to lcvs by binding the host lipid phosphatidylinositol-4-phosphate (ptdins(4)p). here, we describe a novel and simple ap ...200918980612
a hemidominant naip5 allele in mouse strain molf/ei-derived macrophages restricts legionella pneumophila intracellular growth.mouse-derived macrophages have the unique ability to restrict or permit legionella pneumophila intracellular growth. the common inbred mouse strain c57bl/6j (b6) restricts l. pneumophila growth, whereas macrophages derived from a/j mice allow >10(3)-fold bacterial growth within three days. this phenotypic difference was mapped to the mouse naip5 allele. the b6 restrictive naip5 allele is dominant, and six amino acid changes in its product were predicted to control permissiveness. by using the wi ...200918981241
the legionella pneumophila replication vacuole: making a cosy niche inside host cells.the pathogenesis of legionella pneumophila is derived from its growth within lung macrophages after aerosols are inhaled from contaminated water sources. interest in this bacterium stems from its ability to manipulate host cell vesicular-trafficking pathways and establish a membrane-bound replication vacuole, making it a model for intravacuolar pathogens. establishment of the replication compartment requires a specialized translocation system that transports a large cadre of protein substrates a ...200919011659
large-scale identification of legionella pneumophila dot/icm substrates that modulate host cell vesicle trafficking pathways.the bacterial pathogen legionella pneumophila replicates in a specialized vacuole within host cells. establishment of the replication vacuole depends on the dot/icm translocation system that delivers a large number of protein substrates into the host cell. the functions of most substrates are unknown. here, we analysed a defined set of 127 confirmed or candidate dot/icm substrates for their effect on host cell processes using yeast as a model system. expression of 79 candidates caused significan ...200919016775
modulation of ubiquitin dynamics and suppression of dalis formation by the legionella pneumophila dot/icm system.legionella pneumophila is an intracellular pathogen that uses effector proteins translocated by the dot/icm type iv secretion system to modulate host cellular processes. here we investigate the dynamics of subcellular structures containing ubiquitin during l. pneumophila infection of phagocytic host cells. the dot/icm system mediated the formation of k48 and k63 poly-ubiquitin conjugates to proteins associated with l. pneumophila-containing vacuoles in macrophages and dendritic cells, suggesting ...200919016782
free-living freshwater amoebae differ in their susceptibility to the pathogenic bacterium legionella pneumophila.legionella pneumophila is known as a facultative intracellular parasite of free-living soil and freshwater amoebae, of which several species have been shown to support the growth of the pathogenic bacteria. we report for the first time the behaviour of two strains (c2c and z503) of the amoeba willaertia magna towards different strains of l. pneumophila serogroup 1 and compared it with acanthamoeba castellanii and hartmannella vermiformis, known to be l. pneumophila permissive. in contrast to the ...200919016880
fatal community-acquired pneumonia caused by legionella pneumophila and fluoroquinolone-resistant salmonella enterica serotype choleraesuis bacteraemia. 200918993035
survey of wastewater indicators and human pathogen genomes in biosolids produced by class a and class b stabilization treatments.accurate modeling of the infectious aerosol risk associated with the land application of biosolids requires an in-depth knowledge of the magnitudes and changes in pathogen concentrations for a variety of class a and class b stabilization methods. the following survey used quantitative pcr (qpcr) and culture assays to detect environmentally resistant bacterial and viral pathogens and biosolid indicator organisms for 36 biosolid grab samples. biosolids were collected from 14 u.s. states and includ ...200918997022
the inositol polyphosphate 5-phosphatase ocrl1 restricts intracellular growth of legionella, localizes to the replicative vacuole and binds to the bacterial effector lpne.legionella pneumophila, the causative agent of legionnaires' disease, replicates within a specific vacuole in amoebae and macrophages. to form these 'legionella-containing vacuoles' (lcvs), the bacteria employ the icm/dot type iv secretion system and effector proteins, some of which anchor to the lcv membrane via the host glycolipid phosphatidylinositol 4-phosphate [ptdins(4)p]. here we analysed the role of inositol polyphosphate 5-phosphatases (ip5ps) during l. pneumophila infections. bacterial ...200919021631
spot governs legionella pneumophila differentiation in host macrophages.during its life cycle, legionella pneumophila alternates between a replicative and a transmissive state. to determine their contributions to l. pneumophila differentiation, the two ppgpp synthetases, rela and spot, were disrupted. synthesis of ppgpp was required for transmission, as rela spot mutants were killed during entry to and exit from macrophages. rela, which senses amino acid starvation induced by serine hydroxamate, is dispensable in macrophages, as rela mutants spread efficiently. spot ...200919040633
heterogeneity in chlorine susceptibility for legionella pneumophila released from acanthamoeba and hartmannella.to assess chlorine susceptibility of legionella pneumophila grown from two amoebic hosts, acanthamoeba castellanii and hartmannella vermiformis.200919040705
validation of syto 9/propidium iodide uptake for rapid detection of viable but noncultivable legionella pneumophila.legionella pneumophila is an ubiquitous environmental microorganism that can cause legionnaires' disease or pontiac fever. as a waterborne pathogen, it has been found to be resistant to chlorine disinfection and survive in drinking water systems, leading to potential outbreaks of waterborne disease. in this work, the effect of different concentrations of free chlorine was studied (0.2, 0.7, and 1.2 mg l(-1)), the cultivability of cells assessed by standard culture techniques (buffered charcoal y ...200919043657
deficient mannose-binding lectin-mediated complement activation despite mannose-binding lectin-sufficient genotypes in an outbreak of legionella pneumophila pneumonia.polymorphisms leading to deficiency of mannose-binding lectin (mbl) are associated with predisposition to infection. however, mbl deficiency can be protective against intracellular pathogens that use mbl to enter host cells. the role of mbl genotype and activity in infection with the intracellular pathogen legionella pneumophila was studied in a large outbreak of legionellosis at a dutch flower show. a total of 141 patients, 65 exposed asymptomatic exhibition staff members and 670 unexposed bloo ...200919073229
coxiella type iv secretion and cellular microbiology.coxiella burnetii is a widespread zoonotic bacterial pathogen that causes human q fever. in vivo, coxiella displays a tropism for mononuclear phagocytes where it participates in biogenesis of a lysosome-like replication compartment to conduct its obligate intracellular lifestyle. coxiella actively regulates multiple events during infection, presumably via proteins with effector functions that are delivered to the host cytosol by a dot/icm type iv secretion system. because the organism is current ...200919144560
delta-hemolysin, an update on a membrane-interacting peptide.delta-hemolysin is a hemolytic peptide produced by staphylococcus, and it has been studied for nearly 50 years. therefore, it has become a model in the study of peptides interacting with membranes. in this review, we report some recent findings and compare them with previous works. delta-hemolysin is a 26 amino acid peptide, somewhat hydrophobic and presenting a zero net charge. study of its structure has shown that delta-hemolysin is alpha-helical and amphipathic, such as many antimicrobial pep ...200919150639
respiratory tract infections and pneumonia. 200919152532
clinical predictors for legionella in patients presenting with community-acquired pneumonia to the emergency department.legionella species cause severe forms of pneumonia with high mortality and complication rates. accurate clinical predictors to assess the likelihood of legionella community-acquired pneumonia (cap) in patients presenting to the emergency department are lacking.200919152698
distribution of legionella pneumophila serogroups, monoclonal antibody subgroups and dna sequence types in recent clinical and environmental isolates from england and wales (2000-2008).clinical isolates of legionella pneumophila, obtained from 167 patients, who acquired their illness in the community in england and wales between january 2000 and march 2008, were compared with 276 environmental isolates of l. pneumophila obtained over the same period as part of the routine sampling of 'managed' water systems. the 443 isolates were typed by monoclonal antibody (mab) subgrouping and the internationally standardised, seven-gene loci, sequence-based typing (sbt) scheme of the europ ...200919156453
legionella pneumophila dot/icm translocated substrates: a sum of parts.legionella pneumophila is an intracellular pathogen of freshwater amoeba and of alveolar macrophages in human hosts. after phagocytosis, l. pneumophila establishes a unique intracellular vacuolar niche that avoids entry into the lysosomal network. critical for l. pneumophila intracellular growth is the dot/icm type ivb translocation system. although over 80 substrates of the dot/icm apparatus have been identified, individual substrates are often genetically redundant, complicating their analysis ...200919157961
legionnaires disease in a neonatal unit of a private hospital, cyprus, december 2008: preliminary outbreak report.we report an outbreak of legionnaires disease in neonates, affecting 11 newborn babies. the case fatality rate is currently 27%. the outbreak has been confirmed by detection of legionella pneumophila antigen in eight of the 11 cases. tests are in progress to determine the source of infection.200919161719
a legionella pneumophila effector protein encoded in a region of genomic plasticity binds to dot/icm-modified vacuoles.legionella pneumophila is an opportunistic pathogen that can cause a severe pneumonia called legionnaires' disease. in the environment, l. pneumophila is found in fresh water reservoirs in a large spectrum of environmental conditions, where the bacteria are able to replicate within a variety of protozoan hosts. to survive within eukaryotic cells, l. pneumophila require a type iv secretion system, designated dot/icm, that delivers bacterial effector proteins into the host cell cytoplasm. in recen ...200919165328
pcr-coupled electrochemical sensing of legionella pneumophila.human infections with legionella pneumophila represent a public health problem. current culture assays for surveillance and control of l. pneumophila in water are time-consuming and limited by the sensitivity, especially when samples also contain microorganisms that inhibit legionella growth. in this work, an electrochemical method, different from real-time polymerase chain reaction (pcr) approaches, for semiquantitative evaluation of l. pneumophila is presented. a pcr assay targeting the 16s-rr ...200919167878
an improved protocol for the preparation and restriction enzyme digestion of pulsed-field gel electrophoresis agarose plugs for the analysis of legionella isolates.pulsed-field gel electrophoresis (pfge), which determines the genomic relatedness of isolates, is currently used for the epidemiological investigation of infectious agents such as bacteria. in particular, this method has been used for the epidemiological investigation of legionella outbreaks. however, it takes 4 days to complete a legionella-pfge analysis. due to partial digestion and dna damage, the reproducibility of the obtained fragment digestion patterns is poor for this pathogen. in this s ...200919168960
zn finger-based direct detection system for pcr products of salmonella spp. and the influenza a virus.we have detected pcr products from salmonella spp. and influenza a virus using zn finger protein zif268 and sp1, respectively. previously, we demonstrated a novel method of rapid and specific detection of pcr products from legionella pneumophila genome using zn finger protein sp1. in principle, this methodology might be applied to the detection of most bacteria and viruses using various zn finger proteins. here, to demonstrate the wider applicability of our method, we detected pcr products from ...200919169888
legionella pneumophila couples fatty acid flux to microbial differentiation and virulence.during its life cycle, legionella pneumophila alternates between at least two phenotypes: a resilient, infectious form equipped for transmission and a replicative cell type that grows in amoebae and macrophages. considering its versatility, we postulated that multiple cues regulate l. pneumophila differentiation. beginning with a biolog phenotype microarray screen, we demonstrate that excess short-chain fatty acids (scfas) trigger replicative cells to cease growth and activate their panel of tra ...200919170883
[legionella pneumonia in patients treated with infliximab].therapy with tumour necrosis factor-alfa inhibitors is widely used in various inflammatory disorders, but adverse events from severe infections with intracellular pathogens may occur. we describe two cases of severe pulmonary legionellosis in patients treated with infliximab for crohn's disease and psoriasis, respectively. we conclude that legionella infections are probably more frequent in patients receiving immunosuppressive therapy with tumour necrosis factor-alfa inhibitors than in the backg ...200919174042
comparison of the sensitivity of the legionella urinary antigen eia kits from binax and biotest with urine from patients with infections caused by less common serogroups and subgroups of legionella.the detection of urinary antigen is the most widely used method to diagnose legionnaires' disease (ld), so it is important that these assays have a high sensitivity for the disease. in this study, we compare two kits for their ability to detect urinary antigen in urine samples from patients infected with legionella species and l. pneumophila sero- and subgroups not considered as the most common causes of ld. urine samples (n = 33) from 30 culture-proven cases of l. pneumophila serogroup (sg) 1, ...200919198903
diagnostic strategies for healthcare-associated pneumonia.the first point of a good diagnostic strategy for healthcare-associated pneumonia (hcap) is correct classification of patients with specific criteria, as suggested by the last american thoracic society/ infectious diseases society of america (ats/idsa) guidelines. however, clinical practice and recent literature have suggested new risk factors for multidrug-resistant infection (mri): the presence of permanent indwelling devices, prior antibiotic use in the last 3 months, chronic and advanced pul ...200919199185
healthcare-associated atypical pneumonia.atypical pneumonia was first described in 1938, and over time, mycoplasma, legionella, and chlamydophila were the agents commonly linked with community-associated atypical pneumonia. however, as technology has improved, so has our understanding of this clinical entity. it is now known that there are many agents linked with atypical pneumonia in the community, and many of these agents are also major causes of healthcare-associated pneumonia. this article discusses the history, epidemiology, and p ...200919199189
reciprocal expression of integration host factor and hu in the developmental cycle and infectivity of legionella pneumophila.legionella pneumophila is an intracellular parasite of protozoa that differentiates late in infection into metabolically dormant cysts that are highly infectious. regulation of this process is poorly understood. here we report that the small dna binding regulatory proteins integration host factor (ihf) and hu are reciprocally expressed over the developmental cycle, with hu expressed during exponential phase and ihf expressed postexponentially. to assess the role of these regulatory proteins in d ...200919201975
amoeba co-culture of soil specimens recovered 33 different bacteria, including four new species and streptococcus pneumoniae.amoeba-resistant bacteria (arb), such as legionella spp., are currently regarded as potential human pathogens that live in the natural environment, and thus their habitat is regarded as a reservoir of human pathogens. to detect arb in human and environmental samples, co-culture with amoebae has been demonstrated to be an efficient tool. however, to date, only water samples from cooling towers and hospital water supplies have been investigated as possible reservoirs of arb using this procedure. i ...200919202114
pathogen trafficking pathways and host phosphoinositide metabolism.phosphoinositide (pi) glycerolipids are key regulators of eukaryotic signal transduction, cytoskeleton architecture and membrane dynamics. the host cell pi metabolism is targeted by intracellular bacterial pathogens, which evolved intricate strategies to modulate uptake processes and vesicle trafficking pathways. upon entering eukaryotic host cells, pathogenic bacteria replicate in distinct vacuoles or in the host cytoplasm. vacuolar pathogens manipulate pi levels to mimic or modify membranes of ...200919208094
[pulmonary involvement in the course of cytomegalovirus infection in an immunocompetent adult].cytomegalovirus (cmv) infection in the immunocompetent is generally silent or it may present as a mononucleosis like syndrome but, rarely, it can lead to symptomatic manifestations.200919212290
[nosocomial legionnaires' disease--results from the analysis of germany's surveillance data; 2004-2006].legionella bacteria colonize drinking water systems and can cause severe pneumonia in humans (legionnaires' disease (ld)). the german network for community-acquired pneumonia (capnetz) estimates 15,000-30,000 new cases of ld per year in germany. ld cases are divided into those that were acquired in the context of a stay in a hospital or nursing home (healthcare-associated; hca), in the community (community-acquired (ca)) or during travel (travelassociated (ta)). according to the recommendations ...200919214458
is there a relationship between monthly rainfall and the isolation of legionella in potable water systems in spanish healthcare facilities? 200919215199
severe legionella pneumophila pneumonia following infliximab therapy in a patient with crohn's disease.immunosuppressive therapy with anti-tnf-alpha antibodies is effective in patients with inflammatory bowel disease (ibd). however, there is an increased risk for infections associated with this therapy.200919217020
sigmas controls multiple pathways associated with intracellular multiplication of legionella pneumophila.legionella pneumophila is the causative agent of the severe and potentially fatal pneumonia legionnaires' disease. l. pneumophila is able to replicate within macrophages and protozoa by establishing a replicative compartment in a process that requires the icm/dot type ivb secretion system. the signals and regulatory pathways required for legionella infection and intracellular replication are poorly understood. mutation of the rpos gene, which encodes sigma(s), does not affect growth in rich medi ...200919218380
pharmacokinetics of edp-420 after ascending single oral doses in healthy adult volunteers.edp-420 (ep-013420, s-013420) is a first-in-class bicyclolide (bridged bicyclic macrolide) currently in clinical development for the treatment of respiratory tract infections. it has good preclinical pharmacokinetic properties across multiple species and potent in vitro and in vivo activity against respiratory tract infection pathogens, including haemophilus influenzae, atypical organisms (e.g., chlamydia pneumoniae, mycoplasma pneumoniae, and legionella pneumophila), and multidrug-resistant str ...200919223626
seroepidemiological study after a long-distance industrial outbreak of legionnaires' disease.following a long-distance outbreak of legionnaires' disease from an industrial air scrubber in norway in 2005, a seroepidemiological study measuring levels of immunoglobulin g (igg) and igm antibodies to legionella pneumophila was performed with a polyvalent enzyme-linked immunosorbent assay. one year after the outbreak, igg levels in employees (n = 213) at the industrial plant harboring the scrubber and in blood donors (n = 398) from the outbreak county were low but significantly higher (p < or ...200919225076
evaluation of a nested-pcr-derived sequence-based typing method applied directly to respiratory samples from patients with legionnaires' disease.sequence-based typing (sbt) is a powerful method based on the sequencing of seven genes of legionella pneumophila isolates. sbt performed directly on clinical samples has been used only in a limited number of cases. in our study, its efficiency was tested with 63 legionellosis respiratory samples. sixty-three clinical samples, which included 23 samples from sporadic cases and 40 collected during four french outbreaks, confirmed by culture or urinary antigen testing and all positive by l. pneumop ...200919225096
[legionella contamination risk factors in non-circulating hot spring water].we examined water from 182 non-circulating hot spring bathing facilities in japan for possible legionella occurrence from june 2005 to december 2006, finding legionella-positive cultures in 119 (29.5%) of 403 samples. legionellae occurrence was most prevalent in bathtub water (39.4%), followed by storage tank water (23.8%), water from faucets at the bathtub edge (22.3%), and source-spring water (8.3%), indicating no statistically significant difference, in the number of legionellae, having an ov ...200919227223
cytopathogenicity and molecular subtyping of legionella pneumophila environmental isolates from 17 hospitals.the cytopathogenicity of 22 legionella pneumophila isolates from 17 hospitals was determined by assessing the dose of bacteria necessary to produce 50% cytopathic effect (cped50) in u937 human-derived macrophages. all isolates were able to infect and grow in macrophage-like cells (range log10 cped50: 2.67-6.73 c.f.u./ml). five groups were established and related to the serogroup, the number of pfge patterns coexisting in the same hospital water distribution system, and the possible reporting of ...200918538055
clinical features and outcomes of legionnaires' disease in solid organ transplant recipients.we identified 14 cases of legionnaires' disease occurring in 2946 solid organ transplant recipients from 1985 to 2007. most cases were sporadic and community acquired. the recent introduction of the urinary antigen test has accelerated diagnosis and allows prompt institution of adequate therapy. the overall mortality rate in our series was 14.3%.200918713136
a community outbreak of legionnaires' disease associated with a cooling tower in vic and gurb, catalonia (spain) in 2005.we report the investigation of a community-acquired outbreak of legionnaires' disease. an epidemiological, environmental, and meteorological investigation was undertaken. fifty-five cases were reported in october and november 2005. the exposure occurred in a large area, with 12 cases (21.8%) located between 1,800 and 3,400 metres from the source. water sample cultures showed that legionella pneumophila serogroup 1 (lp-1) was present in five cooling towers in two industrial locations in gurb (pla ...200918752009
cb(1) and cb(2) cannabinoid receptors mediate different aspects of delta-9-tetrahydrocannabinol (thc)-induced t helper cell shift following immune activation by legionella pneumophila infection.legionella pneumophila infection of mice induces proinflammatory cytokines and th1 immunity as well as rapid increases in serum levels of il-12 and ifngamma and splenic il-12rbeta2 expression. delta-9-tetrahydrocannabinol (thc) treatment prior to infection causes a shift from th1 to th2 immunity and here we demonstrate that cb(1) and cb(2) cannabinoid receptors mediate different aspects of the shift. using cannabinoid receptor antagonists and cannabinoid receptor gene deficient mice (cb(1) (-/-) ...200918792785
prognostic value of procalcitonin in legionella pneumonia.the diagnostic reliability and prognostic implications of procalcitonin (pct) (ng/ml) on admission in patients with community-acquired pneumonia (cap) due to legionella pneumophila are unknown. we retrospectively analysed pct values in 29 patients with microbiologically proven legionella-cap admitted to the university hospital basel, switzerland, between 2002 and 2007 and compared them to other markers of infection, namely, c-reactive protein (crp) (mg/l) and leukocyte count (10(9)/l), and two p ...200918677519
multiple myd88-dependent responses contribute to pulmonary clearance of legionella pneumophila.myd88-dependent signalling is important for secretion of early inflammatory cytokines and host protection in response to legionella pneumophila infection. although toll-like receptor (tlr)2 contributes to myd88-dependent clearance of l. pneumophila, tlr-independent functions of myd88 could also be important. to determine why myd88 is critical for host protection to l. pneumophila, the contribution of multiple tlrs and il-18 receptor (il-18r)-dependent interferon-gamma (ifn-gamma) production in a ...200918782351
nlrc4/ipaf: a card carrying member of the nlr family.the nod-like receptor (nlr) family of proteins is involved in the regulation of innate immune responses and cell death pathways. recent findings show that the nlr family member nlrc4 (also known as ipaf) has important roles in innate immune responses to gram-negative bacteria. macrophages infected with legionella pneumophila, salmonella typhimurium, shigella flexneri, or pseudomonas aeruginosa activate caspase-1 in an nlrc4-dependent manner leading to macrophage cell death and the release of pro ...200918819842
detection of respiratory viruses and legionella spp. by real-time polymerase chain reaction in patients with community acquired pneumonia.we conducted a study on throat swabs obtained from a group of hospitalized patients with community acquired pneumonia (cap). throat swab specimens from 242 adults admitted to hospital with cap were tested. in total, 1 or more aetiological agents were identified by real-time pcr in 55 (23%) patients. the most frequently detected pathogens were coronavirus (17%), parainfluenza virus (6%) and influenza virus (4%). overall, viral pathogens were identified by conventional techniques in 7 (2%) patient ...200918821175
severe legionnaires disease complicated by multi-organ dysfunction in a previously healthy patient: a case report.a case of a previously healthy lady with community-acquired pneumonia who progressed to severe acute respiratory distress syndrome, acute renal failure, disseminated intravascular coagulation and sepsis is reported. treatment with antibiotics and various modes of mechanical ventilation in the intensive care unit were successful. a urinary legionella antigen test was positive for legionella pneumophila.200920062668
[modern conception of organization of epidemiological surveillance for legionella infections].evolution of views on legionellosis is analyzed in the review: from extremely dangerous rare infection to sufficiently widespread severe pneumonia emergence of which is determined by features of ecology and prevalence of natural water microorganism in potentially dangerous water systems created by man. epidemiologic features of 3 main groups of legionellosis determined according to place of acquisition are discussed: sporadic (community-acquired) legionellosis; nosocomial legionellosis; legionel ...200920063800
rabgdi displacement by drra from legionella is a consequence of its guanine nucleotide exchange activity.prenylated rab proteins exist in the cytosol as soluble, high-affinity complexes with gdi that need to be disrupted for membrane attachment and targeting of rab proteins. the legionella pneumophila protein drra displaces gdi from rab1:gdi complexes, incorporating rab1 into legionella-containing vacuoles and activating rab1 by exchanging gdp for gtp. here, we present the crystal structure of a complex between the gef domain of drra and rab1 and a detailed kinetic analysis of this exchange. drra e ...200920064470
legionella antibodies in a danish hospital staff with known occupational exposure.although legionnaires' disease frequently is acquired in health care institutions, little is known about the occupational risk of legionella infection among health care workers. the aim of the present cross-sectional study was to analyse antibody levels among exposed hospital workers and to determine the correlation between antibodies to legionella and self-reported symptoms. the study included 258 hospital employees and a reference group of 708 healthy blood donors. hospital workers had a highe ...200920041020
molecular mimicry by an f-box effector of legionella pneumophila hijacks a conserved polyubiquitination machinery within macrophages and protozoa.the ability of legionella pneumophila to proliferate within various protozoa in the aquatic environment and in macrophages indicates a remarkable evolution and microbial exploitation of evolutionarily conserved eukaryotic processes. ankyrin b (ankb) of l. pneumophila is a non-canonical f-box-containing protein, and is the only known dot/icm-translocated effector of l. pneumophila essential for intra-vacuolar proliferation within both macrophages and protozoan hosts. we show that the f-box domain ...200920041211
disinfection of the hospital water supply: a hidden risk to dialysis patients.water suitable for drinking is unsuited for use in the preparation of haemodialysis fluid and undergoes additional treatment. the primary component of the additional treatment is reverse osmosis, which does not remove low-molecular-weight contaminants, and the water treatment system must contain carbon beds or filters to ensure effective removal of such contaminants. the recent article by bek and colleagues highlights an unrecognised issue with respect to chemicals that may be added to the water ...200920053299
[novel model of replicative legionella pneumophila lung infection in dba/2 mice].we present here a new model of legionella pneumophila lung infection in dba/2 mice. by intranasal inoculation with 106 colony-forming units of l. pneumophila strain suzuki serogoup 1, persistent non-lethal lung infection was established as reflected by the detection of more than 10(4) cfu/lung of the organism 14 days after infection. treatment of mice with cyclophosphamide before infection enhanced bacterial replication in the lungs and all cyclophosphamide-treated mice experienced lethal infect ...200920055121
[therapeutic efficacy of levofloxacin against a model of replicable legionella pneumophila lung infection in dba/2 mice].the in vitro and in vivo antibacterial activities of levofloxacin (lvfx), a quinolone antibacterial, against clinically isolated legionella pneumophila were investigated in comparison with those of existing antimicrobial agents approved for legionnaires disease. the minimum inhibitory concentrations (mics) of the agents against 42 strains of l. pneumophila isolated in japan were determined using agar dilution methods with buffered starch yeast extract agar. mic90 of lvfx was 0.03 microg/ml and t ...200920055122
growth in acanthamoeba sp. and antibiotic susceptibility of legionella micdadei isolated from hot spring water samples.as part of an epidemiological study on legionellosis, we attempted to isolate legionella spp. from hot spring water samples, and were able to isolate legionella micdadei from 3 (5.5%) of 55 samples. all of these isolates were able to grow within acanthamoeba sp., suggesting that the isolates will be pathogens. we also confirmed that the k-2 strain from hot spring water grew in guinea pig monocytes. sensitivity tests using 10 drugs showed that the isolates were most sensitive to imipenem, with th ...200920055224
[purpura fulminans (symmetric peripheral gangrene): 7-year consecutive case review in japan].acute infectious purpura fulminans (aipf), a rare syndrome of infection-induced ischemic necrosis of the extremities (symmetric peripheral gangrene), is due most often to neisseria meningitidis in the us and the uk, but is not endemic to japan.200920034317
fulminant legionellosis in two patients treated with infliximab for crohn's disease: case series and literature review.two cases of fulminant pulmonary legionellosis, complicated by prolonged intensive care unit stays and acute respiratory distress syndrome, and who were recently treated with infliximab for crohn's disease, are described. a review of the literature revealed three additional cases in patients with inflammatory bowel disease, and a total of 22 cases of legionella pneumophila pneumonia in the context of treatment with antitumour necrosis (tnf)-alpha medications. the median age of the patients was 4 ...200920011736
rapid diagnostic testing for community-acquired pneumonia: can innovative technology for clinical microbiology be exploited?two nonsynchronous events have affected the management of community-acquired pneumonia (cap): spiraling empiricism for cap and the "golden era" of clinical microbiology. the development of broad-spectrum antibiotics has led to widespread empiric use without ascertaining the etiology of the infecting microbe. unfortunately, this approach clashes with the second event, which is the advent of molecular-based microbiology that can identify the causative pathogen rapidly at the point of care. the uri ...200919995763
[comparative study of the biological properties of various nutrient media used for the isolation of legionella pneumophila].three diagnostic selective media used for the isolation of legionella pneumophila were compared. these included bcyeaalpha (oxoid, a reference medium), bcyeaalpha (hi media), and elective legionellosis medium (elm) developed at the rostov-on-don research institute for plague control. the virulent l. pneumophila strain philadelphia-1 (ld50 was 10(5) cfu for guinea-pigs) was used a test culture. the susceptibility of the media was determined, by culturing 10(-6) and 10(-7) dilutions of the suspens ...200920000116
[extracorporeal membrane oxygenation in legionella pneumonia].we present a case report with a 49-year-old woman with legionella pneumonia and fulminant respiratory failure. despite maximal conventional respirator treatment with positive pressure ventilation, 100% oxygen and pharmacological treatment in an intensive care unit, further deterioration with hypoxemia and multi-organ failure occurred. the patient was referred to ecmo as a last option of treatment. eight days of treatment with ecmo was completed without any complications except critical illness p ...200919944056
c. pneumoniae community-acquired pneumonia (cap) in mimicking mycoplasma pneumoniae meningoencephalitis complicated by asthma.chlamydophila (chlamydia) pneumoniae is a common, non-zoonotic cause of community-acquired pneumonia (cap) in ambulatory young adults. c. pneumoniae clinically presents as a mycoplasma-like illness frequently accompanied by laryngitis. c. pneumoniae cap may also cause nursing home outbreaks in the elderly. similar to mycoplasma pneumoniae in immunocompetent hosts, c. pneumoniae cap usually manifests as a mild/moderately severe cap. in contrast with legionnaire's disease, central nervous system i ...200919944878
lung abscess caused by legionella species: implication of the immune status of hosts.legionella pneumonia typically presents as lobar pneumonia with multiple-lobe involvement, but legionella lung abscess is rare. to identify the predisposing factors for legionella abscess, we analyzed 62 of the 79 case reports on legionella abscess found in literature; 28 (45.2%) were of hospital-acquired infection and 28 (45.2%), community-acquired infection. seventeen patients (27.4%) died. l. pneumophila serogroup 1 was the most common, but other serogroups of l. pneumophila, l. micdadei, l. ...200919952481
water quality in dental chair units. a random sample in the canton of st. gallen.this study aimed to identify the microbial contamination of water from dental chair units (dcus) using the prevalence of pseudomonas aeruginosa, legionella species and heterotrophic bacteria as a marker of pollution in water in the area of st. gallen, switzerland. water (250 ml) from 76 dcus was collected twice (early on a morning before using all the instruments and after using the dcus for at least two hours) either from the high-speed handpiece tube, the 3 in 1 syringe or the micromotor for w ...200919954129
identification of host cytosolic sensors and bacterial factors regulating the type i interferon response to legionella pneumophila.legionella pneumophila is a gram-negative bacterial pathogen that replicates in host macrophages and causes a severe pneumonia called legionnaires' disease. the innate immune response to l. pneumophila remains poorly understood. here we focused on identifying host and bacterial factors involved in the production of type i interferons (ifn) in response to l. pneumophila. it was previously suggested that the delivery of l. pneumophila dna to the host cell cytosol is the primary signal that induces ...200919936053
diagnostic and typing methods for investigating legionella infection.legionella infection is an important cause of community-acquired pneumonia in australia. morbidity and mortality is significant. diagnosis remains a challenge with infection often unrecognised, particularly early in the course of illness. an understanding of available diagnostic methods and their limitations is important to public health practitioners and clinicians alike.200919917208
the metal efflux island of legionella pneumophila is not required for survival in macrophages and amoebas.legionella pneumophila is an intracellular pathogen causing pneumonia-like disease in humans. a 43-kb putative heavy metal efflux gene island was found on the l. pneumophila genome. large legionella deletion strains of the metal efflux genes were tested in human thp-1-derived macrophages and amoebal acanthamoeba castellanii cells and were able to survive and replicate similar to the wild type, suggesting that they do not play a significant role within the intracellular environment. examination o ...200919895645
[nosocomial infections--ecological niches].knowledge of ecological niches of nosocomial pathogens is used in treatment and prevention of nosocomial infections. this article offers an analysis of the ecological niches of three important nosocomial pathogens: clostridium difficile, staphylococcus aureus and legionella pneumophila. relevant terms are explained and examples of deliberate and non-deliberate manipulation of the niches and the following consequences are given. finally, the consequences of climate changes on the pattern of nosoc ...200919857394
the tolc protein of legionella pneumophila plays a major role in multi-drug resistance and the early steps of host invasion.pneumonia associated with iegionnaires's disease is initiated in humans after inhalation of contaminated aerosols. in the environment, legionella pneumophila is thought to survive and multiply as an intracellular parasite within free-living amoeba. in the genome of l. pneumophila lens, we identified a unique gene, tolc, encoding a protein that is highly homologous to the outer membrane protein tolc of escherichia coli. deletion of tolc by allelic exchange in l. pneumophila caused increased sensi ...200919888467
frank kunst, 1943-2009. 200919843231
rab1 guanine nucleotide exchange factor sidm is a major phosphatidylinositol 4-phosphate-binding effector protein of legionella pneumophila.the causative agent of legionnaires disease, legionella pneumophila, forms a replicative vacuole in phagocytes by means of the intracellular multiplication/defective organelle trafficking (icm/dot) type iv secretion system and translocated effector proteins, some of which subvert host gtp and phosphoinositide (pi) metabolism. the icm/dot substrate sidc anchors to the membrane of legionella-containing vacuoles (lcvs) by specifically binding to phosphatidylinositol 4-phosphate (ptdins(4)p). using ...200919095644
non-invasive positive pressure ventilation for a severe legionella pneumonia case.legionella pneumonia has a serious clinical course and requires treatment at intensive care unit. the need for mechanical ventilation is one of the determinants of prognosis. mortality rate is higher in patients treated with mechanical ventilation. non-invasive positive pressure ventilation (nppv) provides mechanical ventilation without endotracheal intubation and decreases the incidence of ventilator associated pneumonia. it is a treatment modality for patients with hypoxia due to community acq ...200919787476
evidence of horizontal gene transfer between amoeba and bacteria. 200919793120
[establishment and application of loop-mediated isothermal amplification method for rapid detection].to develop a loop-mediated isothermal amplification (lamp) method for rapid diagnosing of legionella pneumophila in the pathogen detection department(pdd) or in small-scale laboratory.200919799145
[legionellosis in poland in 2007].in 2007 the 28 cases oflegionellosis were reported in poland, the incidence rate was 0.073/100,000, while 86 cases (incidence rate 0.23/100,000) in 2006. the decrease in number and in incidence rate was due to lower number of examined specimens from patients as the financial support from polish committee of research activity has expired. all the cases were laboratory diagnosed in national institute of hygiene, the only place where laboratory tests are performed. most of them were diagnosed with ...200919799246
detergent-like activity and alpha-helical structure of warnericin rk, an anti-legionella peptide.warnericin rk is the first antimicrobial peptide known to be active against legionella pneumophila, a pathogen bacterium that is responsible for severe pneumonia. strikingly, this peptide displays a very narrow range of antimicrobial activity, almost limited to the legionella genus, and a hemolytic activity. a similar activity has been described for delta-lysin, a well-known hemolytic peptide of staphylococci that has not been described as antimicrobial. in this study we aimed to understand the ...200919804724
opportunistic pathogens enriched in showerhead biofilms.the environments we humans encounter daily are sources of exposure to diverse microbial communities, some of potential concern to human health. in this study, we used culture-independent technology to investigate the microbial composition of biofilms inside showerheads as ecological assemblages in the human indoor environment. showers are an important interface for human interaction with microbes through inhalation of aerosols, and showerhead waters have been implicated in disease. although oppo ...200919805310
the gene history of zebrafish tlr4a and tlr4b is predictive of their divergent functions.mammalian immune responses to lps exposure are typified by the robust induction of nf-kappab and ifn-beta responses largely mediated by tlr4 signal transduction pathways. in contrast to mammals, tlr4 signal transduction pathways in nontetrapods are not well understood. comprehensive syntenic and phylogenetic analyses support our hypothesis that zebrafish tlr4a and tlr4b genes are paralogous rather than orthologous to human tlr4. furthermore, we provide evidence to support our assertion that the ...200919812203
legionella pneumophila secretes an endoglucanase that belongs to the family-5 of glycosyl hydrolases and is dependent upon type ii secretion.examination of cell-free culture supernatants revealed that legionella pneumophila strains secrete an endoglucanase activity. legionella pneumophila lspf mutants were deficient for this activity, indicating that the endoglucanase is secreted by the bacterium's type ii protein secretion (t2s) system. inactivation of cela, encoding a member of the family-5 of glycosyl hydrolases, abolished the endoglucanase activity in l. pneumophila culture supernatants. the cloned cela gene conferred activity up ...200919817866
role of 'atypical pathogens' among adult hospitalized patients with community-acquired pneumonia.agents such as mycoplasma pneumoniae, chlamydophila pneumoniae and legionella pneumophila are recognized as important causes of community-acquired pneumonia (cap) worldwide. this study examined the role of these 'atypical pathogens' (ap) among adult hospitalized patients with cap.200919818051
prevalence of antibodies against legionella spp. in hiv-infected subjects and blood donors. 200919819257
legionnaires' disease cluster linked to a metal product aqueous pre-treatment process, staffordshire, england, may 2008.in may 2008, a report of two workers from the same construction equipment manufacturing plant who were admitted to hospital with legionnaires disease confirmed by urine antigen prompted an outbreak investigation. both cases were middle aged men, smokers, and with no travel, leisure or other common community exposure to legionella sources. there were no wet cooling towers at the plant or in the surrounding area. no increase in respiratory disease or worker absenteeism occurred at the plant during ...200919822119
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