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respiratory syncytial virus (rsv) community-acquired pneumonia (cap) in a hospitalized adult with human immunodeficiency virus (hiv) mimicking influenza a and pneumocystis (carinii) jiroveci pneumonia (pcp).respiratory syncytial virus (rsv) is an important cause of lower respiratory tract infections in young children, the elderly, and immunocompromised hosts, but rsv is a rare cause of community-acquired pneumonia (cap) in hospitalized adults with human immunodeficiency virus (hiv). in patients with hiv, cap is most frequently attributable to the usual bacterial respiratory pathogens that cause cap in immunocompetent hosts, eg, streptococcuspneumoniae or hemophilus influenzae. adults with hiv are a ...201222005289
Wild-type MIC distribution and epidemiological cut-off values in clinical Legionella pneumophila serogroup 1 isolates.The purpose of this study was to establish wild-type (WT) distributions and determine the epidemiological cut-off values (ECOFF) in clinical L. pneumophila serogroup 1 isolates for 10 antimicrobials commonly used for the treatment of Legionella infections using a method feasible in a routine clinical laboratory.201222100012
Evaluation of the SD Bioline test, a new assay for detecting Legionella pneumophila serogroup 1 antigen in urine. 201222024377
live legionella pneumophila induces muc5ac production by airway epithelial cells independently of intracellular invasion.the airway epithelium is the initial barrier against airborne pathogens, and it plays many roles in host airway defense. legionella pneumophila is an intracellular pathogen that causes rapidly advancing pneumonia and is sometimes life-threatening. here, we evaluated the role of the airway epithelial cells in the defense against l. pneumophila by examining mucus production in vitro. the production of muc5ac, a major mucin protein, was not induced by formalin- or ultraviolet-killed l. pneumophil ...201222260247
Caenorhabditis elegans as an Alternative Model to Study Senescence of Host Defense and the Prevention by Immunonutrition.Whether nutritional control can retard senescence of immune function and decrease mortality from infectious diseases has not yet been established; the difficulty of establishing a model has made this a challenging topic to investigate. Caenorhabditis elegans has been extensively used as an experimental system for biological studies. Particularly for aging studies, the worm has the advantage of a short and reproducible life span. The organism has also been recognized as an alternative to mammalia ...201222127882
domain structure and denaturation of a dimeric mip-like peptidyl prolyl cis-trans isomerase from escherichia coli.fkbp22, a protein expressed by escherichia coli, possesses ppiase (peptidyl-prolyl cis-trans isomerase) activity, binds fk506 (an immunosuppressive drug) and shares homology with legionella mip (a virulence factor) and the related proteins. to understand the domain structure and the folding / unfolding mechanism of mip-like proteins, a recombinant e. coli fkbp22 (his-fkbp22) was investigated here as a model protein. limited proteolysis indicated that his-fkbp22 harbors an n-terminal domain (ntd) ...201222263615
legionella pneumophila secretes a mitochondrial carrier protein during infection.the mitochondrial carrier family (mcf) is a signature group of integral membrane proteins that transport metabolites across the mitochondrial inner membrane in eukaryotes. mcf proteins are characterized by six transmembrane segments that assemble to form a highly-selective channel for metabolite transport. we discovered a novel mcf member, termed legionellanucleotide carrier protein (lncp), encoded in the genome of legionella pneumophila, the causative agent of legionnaire's disease. lncp was se ...201222241989
inhibition of bacterial carbonic anhydrases and zinc proteases: from orphantargets to innovative new antibiotic drugs.zinc-containing enzymes, such as carbonic anhydrases (cas) and metalloproteases (mps) play critical functions in bacteria, being involved in various steps of their life cycle, which are important for survival, colonization, acquisition of nutrients for growth and proliferation, facilitation of dissemination, invasion and pathogenicity. the development of resistance to many classes of clinically used antibiotics emphasizes the need of new antibacterial drug targets to be explored. there is a weal ...201222214451
legionella secreted effectors and innate immune responses.legionella pneumophila is a facultative intracellular pathogen capable of replicating in a wide spectrum of cells. successful infection by legionella requires the dot/icm type iv secretion system, which translocates a large number of effector proteins into infected cells. by co-opting numerous host cellular processes, these proteins function to establish a specialized organelle that allows bacterial survival and proliferation. even within the vacuole, l. pneumophila triggers robust immune respon ...201221985602
eight years of legionnaires' disease transmission in travellers to a condominium complex in las vegas, nevada.summarytravel is a risk factor for legionnaires' disease. in 2008, two cases were reported in condominium guests where we investigated a 2001 outbreak. we reinvestigated to identify additional cases and determine whether ongoing transmission resulted from persistent colonization of potable water. exposures were assessed by matched case-control analyses (2001) and case-series interviews (2008). we sampled potable water and other water sources. isolates were compared using sequence-based typing. f ...201222214820
an outbreak of legionnaires disease associated with a decorative water wall fountain in a hospital.objective. to detect an outbreak-related source of legionella, control the outbreak, and prevent additional legionella infections from occurring. design and setting. epidemiologic investigation of an acute outbreak of hospital-associated legionnaires disease among outpatients and visitors to a wisconsin hospital. patients. patients with laboratory-confirmed legionnaires disease who resided in southeastern wisconsin and had illness onsets during february and march 2010. methods. patients with ...201222227989
legionella longbeachae and endocarditis.we report a case of infectious endocarditis attributable to legionella longbeachae. l. longbeachae is usually associated with lung infections. it is commonly found in composted waste wood products. l. longbeachae should be regarded as an agent of infectious endocarditis, notably in the context of gardening involving handling of potting soils.201222261182
legionella pneumophila lida affects nucleotide binding and activity of the host gtpase rab1.legionella pneumophila, the causative agent of a severe pneumonia known as legionnaires' disease, intercepts material from host cell membrane transport pathways to create a specialized vacuolar compartment that supports bacterial replication. delivery of bacterial effector proteins into the host cell requires the dot/icm type iv secretion system. several effectors, including sidm, sidd, and lepb, were shown to target the early secretory pathway by manipulating the activity of the host guanosine ...201222228731
legionella micdadei prosthetic valve endocarditis complicated by brain abscess: case report and review of the literature.legionella endocarditis is extremely uncommon, and embolic phenomena have never been reported. we report the first case of legionella micdadei prosthetic valve endocarditis complicated by brain abscess. a 57-y-old immunocompromised woman with a history of mitral valve replacement developed confusion and left-sided weakness. brain magnetic resonance imaging showed a 3-cm peripheral-enhancing mass. transoesophageal echocardiography suggested a perivalvular abscess. blood cultures and valve culture ...201222235842
innate immune pathways triggered by listeria monocytogenes and their role in the induction of cell-mediated immunity.acquired cell-mediated immunity to listeria monocytogenes is induced by infection with live, replicating bacteria that grow in the host cell cytosol, whereas killed bacteria, or those trapped in a phagosome, fail to induce protective immunity. in this chapter, we focus on how l. monocytogenes is sensed by the innate immune system, with the presumption that innate immunity affects the development of acquired immunity. infection by l. monocytogenes induces three innate immune pathways: an myd88-de ...201222244582
[a case of legionnaires' pneumonia accompanied by clinically mild encephalitis/encephalopathy with a reversible splenial lesion (mers) with transient altered mental status and cerebellar symptoms, which responded to treatment by antibiotics and corticosteroid].a 60-year-old man was admitted because of fever, headache, and difficulty in walking. respiratory symptoms included only mild cough, but crackles were present on auscultation at the right lung base, the chest roentgenogram and computed tomography scans showed consolidation in the right lower lobe. laboratory findings revealed hyponatremia, elevated liver function test values and creatine phosphokinase, and legionella pneumophila antigen in urine. neurological examination revealed mild mental sta ...201122073610
The rhizome of life: the sympatric Rickettsia felis paradigm demonstrates the random transfer of DNA sequences.The intracellular flea symbiont, Rickettsia felis, may meet other organisms intracellularly such as R. typhi. We used a single-gene phylogenetic approach of the 1375 R. felis genes to look for horizontal transfers that occurred as a result of the bacterial promiscuity with other organisms. Our results showed that besides genes that are linked to the Spotted Fever Group, 165 genes have a different history and are linked to other Rickettsia such as R. bellii (107 genes), R. typhi (15 genes), or to ...201122024628
co-existence of legionella and other gram-negative bacteria in potable water from various rural and urban sources. 201122216808
Making hospital water safe, examined.What are the best methods for monitoring hospital water systems to prevent contamination by waterborne pathogens such as Pseudomonas aeruginosa and Legionella? How can hospital staff determine whether a Pseudomonas outbreak is due to cross-contamination between patients and staff, or to the contamination of a systemic water supply, and how can we best protect our most vulnerable patients from infection with the array of pathogenic organisms lurking in hospitals? As Susan Pearson reports, these w ...201122049621
[Legionellosis in Poland in 2009].In 2009--10 cases of legionellosis were reported in Poland, the incidence rate was 0.026/100 000 (in 2008--15 cases, incidence rate 0.039). All cases were laboratory confirmed. Most of them were diagnosed with serological tests--determination with ELISA test the anti-legionella antibodies in IgM fraction of serum gamma globulins, as the most recent reaction for Legionella infection. Four cases were diagnosed by detection of legionella antigen in urine. In 2005-2009 27 cases were associated with ...201121913463
Faster Legionella testing on horizon.While the "traditional" way to measure Legionella quantitatively in water is based on a complex culture method where results can take up to 14 days, the last few years have seen the availability of very rapid real-time monitoring of the bacterium in water systems, with the development of quantitative polymerase chain reaction (qPCR), a process which gives results "within hours". To date, however, a lack of consensus on how to interpret such results in relation to those from culture has been a st ...201121859065
empyema caused by legionella pneumophila. 201122153580
Respiratory failure presenting in H1N1 influenza with Legionnaires disease: two case reports.ABSTRACT:201122018019
[Revision of the drinking water regulations].The revision the Drinking Water Regulations will come into effect on 01.11.2011. Surveillance authorities and owners of drinking water supply systems had hoped for simplifications and reductions because of the new arrangements. According to the official statement for the revision the legislature intended to create more clarity, consider new scientific findings, to change regulations that have not been proved to close regulatory gaps, to deregulate and to increase the high quality standards. A de ...201122113379
aminoacyl-trna-charged eukaryotic elongation factor 1a is the bona fide substrate for legionella pneumophila effector glucosyltransferases.legionella pneumophila, which is the causative organism of legionnaireś disease, translocates numerous effector proteins into the host cell cytosol by a type iv secretion system during infection. among the most potent effector proteins of legionella are glucosyltransferases (lgt's), which selectively modify eukaryotic elongation factor (eef) 1a at ser-53 in the gtp binding domain. glucosylation results in inhibition of protein synthesis. here we show that in vitro glucosylation of yeast and mous ...201122216304
[hygienic assessment of the characteristics of centralized hot water supply in case of moscow].the paper considers the characteristics of domestic hot water consumption by moscow dwellers. it gives the results of questionnaire surveys in 100 respondents aged 20-80 years about the modes and intensity of hot water use, by indicating the time and frequency of contact with hot water complaints about hot water supply. according to the authors'studies, the daily consumption of hot water per capita was 1.1-2 times greater than that of cold water; at the same time the total water use remained to ...201122250387
[when to ask a microbiological diagnostic test in pneumonia and how to interpret the results].pneumonia is a leading cause of death in adults in the industrialised countries and in the rest of the world in infants. most of the time the pathogens stay unkown and the current recommendations for the treatment of pneumonia are mainly based on a severity score to adapt the treatement to the risk. nonethless new pathogens have recently been identified, coronavirus for srass, h5n1 for avian flu, n1n1 for pandemic flu, 35 years after the identification of legionella pneumophila. these exemples s ...201122135970
the major facilitator superfamily-type protein lbtc promotes the utilization of the legiobactin siderophore by legionella pneumophila.the gram-negative bacterium legionella pneumophila elaborates the siderophore legiobactin. we previously showed that cytoplasmic lbta helps mediate legiobactin synthesis, inner membrane lbtb promotes export of legiobactin, and outer membrane lbtu acts as the ferrisiderophore receptor. rt-pcr analyses now identified lbtc as an iron-repressed gene that is the final gene in an operon containing lbta and lbtb. in silico analysis predicted that lbtc is an inner membrane protein that belongs to the ...201122160401
Tsunami lung.We encountered three cases of lung disorders caused by drowning in the recent large tsunami that struck following the Great East Japan Earthquake. All three were females, and two of them were old elderly. All segments of both lungs were involved in all the three patients, necessitating ICU admission and endotracheal intubation and mechanical ventilation. All three died within 3 weeks. In at least two cases, misswallowing of oil was suspected from the features noted at the time of the detection. ...201122057370
insight into cross-talk between intra-amoebal pathogens.amoebae are phagocytic protists where genetic exchanges might take place between amoeba-resistant bacteria. these amoebal pathogens are able to escape the phagocytic behaviour of their host. they belong to different bacterial phyla and often show a larger genome size than human-infecting pathogens. this characteristic is proposed to be the result of frequent gene exchanges with other bacteria that share a sympatric lifestyle and contrasts with the genome reduction observed among strict human pat ...201122047552
Diary of the "mad" med-lab techs. 201121936417
[Distribution and diversity of Legionella spp. in Lake Taihu in the winter].The Legionella spp. are ubiquitous in aquatic environment and could cause certain risks on human health. In order to investigate the distribution and diversity of Legionella spp. in Lake Taihu during winter time, water samples were collected from 32 sites of the whole lake in February 2010. The presence of Legionella spp. was screened by nested-PCR and their phylogenetic diversity was determined by denaturing gradient gel electrophorese (DGGE) and sequencing analysis of excised DGGE bands. The L ...201121922841
Identification of Anaplasma marginale Type IV Secretion System Effector Proteins.Anaplasma marginale, an obligate intracellular alphaproteobacterium in the order Rickettsiales, is a tick-borne pathogen and the leading cause of anaplasmosis in cattle worldwide. Complete genome sequencing of A. marginale revealed that it has a type IV secretion system (T4SS). The T4SS is one of seven known types of secretion systems utilized by bacteria, with the type III and IV secretion systems particularly prevalent among pathogenic Gram-negative bacteria. The T4SS is predicted to play an i ...201122140462
population variation in naip functional copy number confers increased cell death upon legionella pneumophila infection.the naip gene encodes an intracellular innate immunity receptor that senses flagellin. the genomic region containing naip presents a complex genomic organization and includes various naip paralogs. here, we assessed the degree of copy number variation of the complete naip gene (naipfull) in various human populations and studied the functional impact of such variation on host cell fate using legionella pneumophila as an infection model. we determined that african populations have a naipfull dupli ...201122067212
Legionella wadsworthii pneumonia: Gram stain usefulness. 201122036520
Passage through Tetrahymena tropicalis enhances the resistance to stress and the infectivity of Legionella pneumophila.Legionella pneumophila is a gram-negative bacterium prevalent in fresh water which accidentally infects humans and is responsible for the disease called legionellosis. Intracellular growth of L. pneumophila in Tetrahymena is inconsistent; in the species Tetrahymena tropicalis stationary-phase forms (SPFs) of L. pneumophila differentiate into mature intracellular forms (MIFs) without apparent bacterial replication and are expelled from the ciliate as pellets containing numerous MIFS. In the prese ...201122092856
Legionella pneumophila regulates the small GTPase Rab1 activity by reversible phosphorylcholination.Effectors delivered into host cells by the Legionella pneumophila Dot/Icm type IV transporter are essential for the biogenesis of the specialized vacuole that permits its intracellular growth. The biochemical function of most of these effectors is unknown, making it difficult to assign their roles in the establishment of successful infection. We found that several yeast genes involved in membrane trafficking, including the small GTPase Ypt1, strongly suppress the cytotoxicity of Lpg0695(AnkX), a ...201122158903
Two signal models in innate immunity.Two-signal models have a rich history in immunology. In the classic two-signal model of T-cell activation, signal one consists of engagement of the T-cell receptor by antigen/major histocompatibility complex, whereas signal two arises from costimulatory ligands on antigen-presenting cells. A requirement for two independent signals helps to ensure that T-cell responses are initiated only in response to bona fide infectious threats. Our studies have led us to conclude that initiation of innate imm ...201121884165
Electrochemically amplified molecular beacon biosensor for ultrasensitive DNA sequence-specific detection of Legionella sp.An electrochemically amplified molecular beacon (EAMB) biosensor is constructed using thiolated hairpin DNA-ferrocene probes on gold electrode. The switching from "on" to "off" states of individual probes in the presence of complementary DNA target influences the electrode potential, besides the current, owing to changes in surface density of the electroactive hairpin DNA-ferrocene probes. The EAMB biosensor demonstrates linear range over 8 orders of magnitude with ultrasensitive detection limit ...201122196877
the overlapping host responses to bacterial cyclic dinucleotides.macrophages respond to infection with legionella pneumophila by the induction of inflammatory mediators, including type i interferons (ifn-is). to explore whether the bacterial second messenger cyclic 3'-5' diguanylate (c-digmp) activates some of these mediators, macrophages were infected with l. pneumophila strains in which the levels of bacterial c-digmp had been altered. intriguingly, there was a positive correlation between c-digmp levels and ifn-i expression. subsequent studies with synthet ...201121933720
[A case of legionellesis pneumonia verified by isolation of Legionella pneumophila serogroup 1 from bronchoalveolar lavage fluid treated with levofloxacine and tigecycline].A male patient received non-chemotherapeutic drugs which induced deep neutropenia complicated with sepsis, bilateral pneumonia, acute respiratory insufficiency. Artificial pulmonary ventilation was applied. The examination of bronchoalveolar lavage showed the presence of the culture L. pneumophila (serogroup 1) in a concentration 2 x 10(3) CFU/ml. Antibacterial therapy with levofloxacin in a dose 1000 mg/day was conducted. In a week not only L.pneumophila but also Acinetobacter baumanii was isol ...201121894754
Evaluation of empirical antibiotherapy for acute community-acquired pneumonia prescribed in emergency departments.OBJECTIVE: The authors assessed the management of community-acquired pneumonia (CAP) and empirical antibiotic prescription in a primary care center. METHOD: A retrospective study was made on medical charts of patients admitted to the emergency department for CAP. RESULTS: Seventy-six patients were included. Their mean age was 65years for a sex ratio of 1.81. Fever (83%) and cough (72%) were the most common symptoms. Chest X-ray was abnormal in 86%. The median CRP value was 138mg/L (58-235). The ...201122154524
opportunistic pathogens relative to physicochemical factors in water storage tanks.household water in oman, as well as in other countries in the region, is stored in tanks placed on house roofs that can be subjected to physicochemical factors which can promote microbial growth, including pathogens and opportunistic pathogens which pose health risks. water samples were collected from 30 houses in a heavily populated suburb of muscat. the tanks used were either glass reinforced plastic (grp), polyethylene or galvanised iron (gi). heterotrophic bacteria, coliforms, faecal colifor ...201121942202
Comparative and functional genomics of legionella identified eukaryotic like proteins as key players in host-pathogen interactions.Although best known for its ability to cause severe pneumonia in people whose immune defenses are weakened, Legionella pneumophila and Legionella longbeachae are two species of a large genus of bacteria that are ubiquitous in nature, where they parasitize protozoa. Adaptation to the host environment and exploitation of host cell functions are critical for the success of these intracellular pathogens. The establishment and publication of the complete genome sequences of L. pneumophila and L. long ...201122059087
legionella pneumophila serogroup 3 pneumonia in a patient with low-grade 4 non-hodgkin lymphoma: a case report.abstract:201121849075
rpka, a highly conserved gpcr with a lipid kinase domain, has a role in phagocytosis and anti-bacterial defense.rpka (receptor phosphatidylinositol kinase a) is an unusual seven-helix transmembrane protein of dictyostelium discoideum with a g protein coupled receptor (gpcr) signature and a c-terminal lipid kinase domain (gpcr-pipk) predicted as a phosphatidylinositol-4-phosphate 5-kinase. rpka-homologs are present in all so far sequenced dictyostelidae as well as in several other lower eukaryotes like the oomycete phytophthora, and in the legionella host acanthamoeba castellani. here we show by immunofluo ...201122073313
the occurrence of legionella species other than legionella pneumophila in clinical and environmental samples in denmark identified by mip gene sequencing and matrix-assisted laser desorption ionization time-of-flight mass spectrometry.clin microbiol infect abstract: in denmark, several laboratories use pcr as a routine diagnostic method for legionnaires' disease, and almost all pcr-positive samples are investigated by culture. from 1993 to 2010, isolates of legionella species other than legionella pneumophila were obtained from respiratory samples from 33 patients, and from 1997 to 2010, 42 isolates of legionella non-pneumophila species were obtained and saved from water samples from 39 different sites in denmark. macrophage ...201122070605
The NLRC4 inflammasome receptors for bacterial flagellin and type III secretion apparatus.Inflammasomes are large cytoplasmic complexes that sense microbial infections/danger molecules and induce caspase-1 activation-dependent cytokine production and macrophage inflammatory death. The inflammasome assembled by the NOD-like receptor (NLR) protein NLRC4 responds to bacterial flagellin and a conserved type III secretion system (TTSS) rod component. How the NLRC4 inflammasome detects the two bacterial products and the molecular mechanism of NLRC4 inflammasome activation are not understoo ...201121918512
combined legionella and escherichia coli lung infection after a tsunami disaster.pulmonary infection after a tsunami is often polymicrobial and tends to form chronic pyogenic lung disease, necrotizing pneumonia, and empyemas. we report a combined pulmonary infection of legionella and multiple antibiotic-resistant escherichia coli in a previously well 75-year-old woman following immersion in tsunami waters 1 km inland from the pacific coastline following the tohoku region pacific coast earthquake of 2011. she needed drainage several times and the long-term use of multiple ant ...201121963747
Reprint of: Effective high-throughput overproduction of membrane proteins in Escherichia coli.Structural biology is increasingly reliant on elevated throughput methods for protein production. In particular, development of efficient methods of heterologous production of membrane proteins is essential. Here, we describe the heterologous overproduction of 24 membrane proteins from the human pathogen Legionella pneumophila in Escherichia coli. Protein production was performed in 0.5ml cultures in standard 24-well plates, allowing increased throughput with minimal effort. The effect of the lo ...201121893197
[Demographic characteristics of reported cases of legionellosis in years 2005-2009 in Poland in comparison to EWGLI data].In Poland, all forms of legionellosis are obligatory reported: Legionella pneumonia and extrapulmonary legionellosis (such as Pontiac fever). Total 210 cases caused by Legionella sp. were reported in years 2003-2010. In our study analysis of age, sex, place of residence of 163 patients with legionellosis reported in 2005-2009 were done. The majority (74.2%) cases were reported in Region Mazowieckie. Age and sex structure of patients in Poland in years 2005-2009 differ from the data of EWGLI. In ...201122184944
legionellae in engineered systems and use of quantitative microbial risk assessment to predict exposure.while it is well-established that legionella are able to colonize engineered water systems, the number of interacting factors contributing to their occurrence, proliferation, and persistence are unclear. this review summarizes current methods used to detect and quantify legionellae as well as the current knowledge of engineered water system characteristics that both favour and promote legionellae growth. furthermore, the use of quantitative microbial risk assessment (qmra) models to predict pote ...201122209280
decreasing trend of legionella isolation in a long-term microbial monitoring program in greek hospitals.legionnaires' disease is a known cause of severe pneumonia in a nosocomial setting. this study examined legionella isolation in greek hospitals. water samples and swabs of showerheads from 41 hospitals were collected over a four-year period (2004-2007) from hot and cold water systems and cooling towers in greece. in total, 1058 samples were examined for the presence of legionella. from the hot water samples examined, 166 out of 607 (27.3%) were positive for legionella, including 111 (18.3%) posi ...201122017573
legionellosis --- united states, 2000-2009.legionnaires disease (ld), a serious, sometimes lethal pneumonia, and pontiac fever (pf), an influenza-like, self-limited illness, are the two most common forms of legionellosis, which is caused by legionella bacteria. legionellosis cases are reported to cdc through the national notifiable disease surveillance system (nndss) and a supplemental legionnaires disease surveillance system (sldss) designed to manage surveillance data on travel-related cases and enhance outbreak detection. for this rep ...201121849965
Legionella pneumonia presenting with bilateral flank pain, hyponatraemia and acute renal failure.Legionnaires' disease (LD) is an often overlooked but a possible cause of sporadic community acquired pneumonia. High fever, cough and gastrointestinal symptoms are non-specific symptoms. Hyponatremia is more common in LD than pneumonia linked with other causes. A definitive diagnosis is usually confirmed by culture, urinary antigen testing for Legionella species. Macolide or quinolone antibiotic is the treatment of choice. We describe a case of Legionella pneumonia presenting with high fever, b ...201122154178
activation of nlrc4 by flagellated bacteria triggers caspase-1-dependent and -independent responses to restrict legionella pneumophila replication in macrophages and in vivo.although nlrc4/ipaf activation by flagellin has been extensively investigated, the downstream signaling pathways and the mechanisms responsible for infection clearance remain unclear. in this study, we used mice deficient for the inflammasome components in addition to wild-type (wt) legionella pneumophila or bacteria deficient for flagellin (flaa) or motility (flii) to assess the pathways responsible for nlrc4-dependent growth restriction in vivo and ex vivo. by comparing infections with wt l. p ...201122079982
[the lethiferous journey of a bacterium--the research progress of secretion systems and effectors in legionella pneumophila].legionella pneumophila is the intracellular bacterial pathogen that causes severe legionnaires' disease and flu-like pontiac fever. to accomplish successful aggression against hosts, l. pneumophila secrets more than 150 kinds of substrate effector proteins into host cells via its type ivb secretion system. with the multiple functions of effectors, l. pneumophila evades effectively the defense systems of hosts, converts or adjusts intracellular vesicular transport of hosts, modifies or disguises ...201121993284
roles of il-17 in an experimental legionella pneumonia model.interleukin (il)-17 is a key factor in t helper type (th) 17 lineage host responses and plays critical roles in immunological control of a variety of infectious diseases. although legionella pneumophila, an intracellular bacterium found widely in the environment, often causes a serious and life-threatening pneumonia in humans, the contribution of il-17 to immune function during legionella pneumonia is unknown. in the present study, we used an experimental legionella pneumonia infection to clarif ...201122144493
an in-premise model for legionella exposure during showering events.an exposure model was constructed to predict the critical legionella densities in an engineered water system that result in infection from inhalation of aerosols containing the pathogen while showering. the model predicted the legionella densities in the shower air, water and in-premise plumbing biofilm that might result in a deposited dose of legionella in the alveolar region of the lungs associated with infection for a routine showering event. processes modeled included the detachment of biofi ...201121924754
kinetic, mutagenic, and structural homology analysis of l-serine dehydratase from legionella pneumophila.a structural database search has revealed that the same fold found in the allosteric substrate binding (asb) domain of mycobacterium tuberculosis d-3-phosphoglycerate dehydrogenase (pgdh) is found in l-serine dehydratase from legionella pneumophila. the m. tuberculosis pgdh asb domain functions in the control of catalytic activity. bacterial l-serine dehydratases are 4fe-4s proteins that convert l-serine to pyruvate and ammonia. sequence homology reveals two types depending on whether their α an ...201121878319
[legionella contamination of hospital hot water supply systems in the light of research conducted in 2008-2010 as part of supervision by the country sanitary inspector in bydgoszcz].the aim of the study was to assess the level of legionella sp. contamination in the hot water supply systems at the premises of inpatient healthcare facilities. in the years 2008-2010 the state poviat sanitary inspector in bydgoszcz tested the hot water supply systems in 8 hospitals. a total of 88 samples of hot water were collected in the years 2008-2010. the analysis involved temperature measurements and microbiological testing of the hot water. contamination levels exceeding the applicable st ...201122184945
diagnosis of fulminant pneumonia caused by legionella pneumophila serogroup 8 with the sequence analysis of the 16s rrna gene.pneumonia is the fourth leading cause of death in japan. accurate and rapid detection of the causative pathogen(s) is necessary and important for appropriate antimicrobial treatment, especially in patients with rapidly progressive pneumonia or immunocompromised patients. conventional methods, such as cultivations, detection of urinary antigens or pcr amplification of specific genes, inevitably require the precise presumption of potential pathogens in each case, and pneumonia caused by unanticipa ...201121878746
performance on a multipathogen external quality assessment (eqa) panel by different mono- and multiplex nucleic acid amplification tests.an external quality assessment (eqa) panel consisting of a total of 48 samples in broncho alveolar lavage (bal) or transport medium was prepared in collaboration with quality control for molecular diagnostics (qcmd) (www.qcmd.org). the panel was used to assess the proficiency of the 3 laboratories that would be responsible to examine the 6000 samples to be collected in the grace network of excellence (www.grace-lrti.org). the main objective was to decide on the best performing testing approach f ...201122170925
protein lida from legionella is a rab gtpase supereffector.the causative agent of legionnaires disease, legionella pneumophila, injects several hundred proteins into the cell it infects, many of which interfere with or exploit vesicular transport processes. one of these proteins, lida, has been described as a rab effector (i.e., a molecule that interacts preferentially with the gtp-bound form of rab). we describe here the structure and biochemistry of a complex between the rab-binding domain of lida and active rab8a. lida displays structural peculiariti ...201122011575
chemical disinfection of legionella in hot water systems biofilm: a pilot-scale 1 study.legionella bacteria encounter optimum growing conditions in hot water systems and cooling towers. a pilot-scale 1 unit was built in order to study the biofilm disinfection. it consisted of two identical loops, one used as a control and the other as a 'test loop'. a combination of a bio-detergent and a biocide (hydrogen peroxide + peracetic acid) was applied in the test loop three times under the same conditions at 100 and 1,000 mg/l with a contact time of 24 and 3-6 hours, respectively. each tre ...201122097051
legionella: from protozoa to humans. 201122016745
legionella pneumophila st1/paris-pulsotype subtyping by spoligotyping.endemic strains of legionella pneumophila st1, in particular the st1/paris-pulsotype, are dispersed worldwide and represent about 10% of culture-proven clinical cases of ld in france. the high isolation rate of this strain, in both clinical and environmental samples, makes identification of the source of infection difficult during epidemiological investigations. the full-length genome sequence of this strain was recently determined and it revealed the presence of a crispr/cas complex. the aim of ...201122205819
enhanced isolation of legionella species from composted material.legionella pneumophila and legionella species were isolated from composted material when freshly prepared buffered charcoal yeast extract (bcye) was supplemented with glycine (1.5 g/l), polymyxin b sulfate (40 000 iu/l), vancomycin hydrochloride (0.5 mg/l) and cycloheximide (40 mg/l) (gvpc medium) and modified wadowsky-yee (mwy) (oxoid, cambridge, uk) plates were used for cultivation, but not with commercially sourced pre-poured gvpc and mwy plates (oxoid). legionella cincinnatiensis and pathoge ...201121848971
cluster of travel-associated legionnaires disease in lazise, italy, july to august 2011. 201121996379
minimization of the legionella pneumophila genome reveals chromosomal regions involved in host range expansion.legionella pneumophila is a bacterial pathogen of amoebae and humans. intracellular growth requires a type ivb secretion system that translocates at least 200 different proteins into host cells. to distinguish between proteins necessary for growth in culture and those specifically required for intracellular replication, a screen was performed to identify genes necessary for optimal growth in nutrient-rich medium. mapping of these genes revealed that the l. pneumophila chromosome has a modular ar ...201121873199
prevalence of legionella spp. in water systems of hospitals and hotels in south western greece.the aim of the present study was to determine the prevalence of legionella spp. in water systems of hospitals and hotels located in south western greece, to study the molecular epidemiology of the isolated strains and their possible association with bacterial contamination (total count and pseudomonas aeruginosa), the water ph, and temperature. a prevalence survey for legionella spp. by culturing techniques in water distribution systems of eight hospitals and nine hotels occurred in south wester ...201122149148
legionella pneumophila urinary antigen subtyping using monoclonal antibodies as a tool for epidemiological investigations.legionnaires' disease is diagnosed predominantly by urinary antigen detection, and patient isolates are rarely available. the lipopolysaccharide (lps) epitope pattern of isolates detected by monoclonal antibodies is an accepted marker for the phenotyping of l. pneumophila serogroup 1 strains into monoclonal subgroups. l. pneumophila lps is the dominant antigen in patients' urinary specimens. by using commercially available microtiter wells coated with rabbit anti-legionella serogroup 1 igg as th ...201122120420
de-ampylation unmasked: modulation of host membrane trafficking.ampylation, a posttranslational modification in which adenosine monophosphate (amp) is added to hydroxyl side chains of protein substrates, is employed by many bacterial pathogens to subvert host signaling pathways during infection. the legionella pneumophila effector protein sidm is a multifunctional enzyme that targets the guanosine triphosphatase (gtpase) rab1 to manipulate intracellular vesicular trafficking in the host cell. sidm recruits rab1 to the membranes of legionella-containing vacuo ...201121990428
Anchoring of bacterial effectors to host membranes through host-mediated lipidation by prenylation: a common paradigm.Post-translational lipidation by prenylation of the CaaX-box C-terminal motif in eukaryotic proteins facilitates anchoring of hydrophilic proteins, such as Ras and Rab, to membranes. A large cadre of bacterial effectors injected into host cells is anchored to host membranes by unknown mechanisms. As already documented for Legionella and Salmonella, we propose a common paradigm of microbial exploitation of the host prenylation machinery for anchoring of injected effectors to host membranes. This ...201121983544
legionella species in year-round vs. seasonal accommodation water supply systems.the purpose of this study was to compare the quality of hot water between eleven hotels in the split-dalmatia county, croatia that are open year round and 10 summer season hotels and retirement homes with irregular use of water. we took 122 samples between may and december 2009. water temperature and free residual chlorine were measured in situ. physical and chemical analysis included ph, electrical conductivity, and concentrations of iron, manganese, copper, zinc, calcium, and magnesium that we ...201122202467
Molecular evolution of key genes for type II secretion in Legionella pneumophila.Given the role of type II protein secretion system (T2S) in the ecology and pathogenesis of Legionella pneumophila, it is possible that this system is a target for adaptive evolution. The population genetic structure of L. pneumophila was inferred from the partial sequences of rpoB and from the complete sequence of three T2S structural components (lspD, lspE and pilD) and from two T2S effectors critical for intracellular infection of protozoa (proA and srnA) of 37 strains isolated from natural a ...201122118294
Diagnostic Challenges and Opportunities in Older Adults With Infectious Diseases.Infections remain a major threat to the well-being of our growing aged population. The correct and timely diagnosis of infections in older adults is increasingly important in the current age of antimicrobial resistance. Urinary tract infection, pneumonia, and bacteremia present particular challenges. In older patients with bacteremia, blood cultures have comparable yield as compared with younger patients. However, the routine triggers for ordering blood cultures may not be appropriate in older a ...201122186775
How often is a work-up for Legionella pursued in patients with pneumonia? a retrospective study.It is unclear how often patients with pneumonia are assessed for Legionella in endemic areas. Additionally, the sensitivity of the IDSA/ATS criteria for recommended Legionella testing is undefined.201121899763
extensive recombination events and horizontal gene transfer shaped the legionella pneumophila genomes.legionella pneumophila is an intracellular pathogen of environmental protozoa. when humans inhale contaminated aerosols this bacterium may cause a severe pneumonia called legionnaires' disease. despite the abundance of dozens of legionella species in aquatic reservoirs, the vast majority of human disease is caused by a single serogroup (sg) of a single species, namely l. pneumophila sg1. to get further insights into genome dynamics and evolution of sg1 strains, we sequenced strains lorraine and ...201122044686
Legionella steelei sp. nov. isolated from human respiratory specimens in California and South Australia.Legionella-like bacteria were isolated from the respiratory tract of two humans in California and South Australia, but not thought to cause disease. These bacteria, strains F2632 and IMVS-3376, were found to have identical Legionella macrophage infectivity potentiator (mip) sequences, and were therefore further characterized to determine their genetic and phenotypic relatedness and properties. Both of these Gram-negative bacterial strains grew on buffered charcoal yeast extract medium, were cyst ...201121948093
the surfactant of legionella pneumophila is secreted in a tolc-dependent manner and is antagonistic toward other legionella species.when legionella pneumophila grows on agar plates, it secretes a surfactant that promotes flagellum- and pilus-independent "sliding" motility. we isolated three mutants that were defective for surfactant. the first two had mutations in genes predicted to encode cytoplasmic enzymes involved in lipid metabolism. these genes mapped to two adjacent operons that we designated bbcabcdef and bbcghijk. backcrossing and complementation confirmed the importance of the bbc genes and suggested that the legio ...201121890700
surveillance for waterborne disease outbreaks associated with drinking water---united states, 2007--2008.since 1971, cdc, the environmental protection agency (epa), and the council of state and territorial epidemiologists have collaborated on the waterborne disease and outbreak surveillance system (wbdoss) for collecting and reporting data related to occurrences and causes of waterborne disease outbreaks associated with drinking water. this surveillance system is the primary source of data concerning the scope and health effects of waterborne disease outbreaks in the united states.201121937977
Detection of Legionella by quantitative-Polymerase Chain Reaction (qPCR) for monitoring and risk assessment.ABSTRACT: Background Culture and quantitative polymerase chain reaction (qPCR) assays for the detection of Legionella were compared on samples from a residential area before and after two interventions. A total of 84 samples were collected from shower hoses and taps as first flush samples and at constant temperature. Samples were grouped according to the origin of the sample, a) circulation water b) water from empty apartments c) water from shower hoses. The aims were to investigate the usefulne ...201122103438
death or survival from invasive pneumococcal disease in scotland: associations with serogroups and multilocus sequence types.we describe associations between death from invasive pneumococcal disease (ipd) and particular serogroups and sequence types (sts) determined by multilocus sequence typing (mlst) using data from scotland. all ipd episodes where blood or cerebrospinal fluid (csf) culture isolates were referred to the scottish haemophilus, legionella, meningococcal and pneumococcal reference laboratory (shlmprl) from january 1992 to february 2007 were matched to death certification records by the general register ...201121393453
retraction. inhibition of akt/gsk3ß signalling pathway by legionella pneumophila is involved in induction of t-cell apoptosis. 201121348858
[bacterial community structure and diversity in a cold sulfur spring in xinjiang faulting zone].in order to investigated composition and diversity of bacterial in a cold sulfur spring in xinjiang faulting zone.201121800620
elderly patients with community-acquired pneumonia: optimal treatment strategies.community-acquired pneumonia (cap) is a common infectious disease that still causes substantial morbidity and mortality. elderly people are frequently affected, and several issues related to care of this condition in the elderly have to be considered. this article reviews current recommendations of guidelines with a special focus on aspects of the care of elderly patients with cap. the most common pathogen in cap is still streptococcus pneumoniae, followed by other pathogens such as haemophilus ...201121721597
legionella pneumophilarequires polyamines for optimal intracellular growth.the gram-negative intracellular pathogen legionella pneumophilareplicates in a membrane-bound compartment known as the legionella-containing vacuole (lcv), into which it abundantly releases its chaperonin, htpb. to determine whether htpb remains within the lcv or reaches the host cell cytoplasm, we infected u937 human macrophages and cho cells with l. pneumophilaexpressing a translocation reporter consisting of the bordetella pertussisadenylate cyclase fused to htpb. these infections led to incr ...201121742865
anchors for effectors: subversion of phosphoinositide lipids by legionella.the facultative intracellular pathogen legionella pneumophila replicates in free-living amoebae and macrophages within a distinct compartment, the "legionella-containing vacuole" (lcv). lcv formation involves phosphoinositide (pi) glycerolipids, which are key factors controlling vesicle trafficking pathways and membrane dynamics of eukaryotic cells. to govern the interactions with host cells, l. pneumophila employs the icm/dot type iv secretion system and more than 250 translocated "effector pro ...201121833330
[contemporary clinical diagnostics of respiratory tract infections].the patient population at risk pulmonary infections has increased during the last decade. the spectrum of organisms causing infections has also grown, most of them are viruses baseline diagnostic assessment include history, clinical examination, radiography and measurements of procalcitonin (pct), highly sensitive c-reactive protein (hscrp) and leukocyte count. pct represents a good biological marker for difficult diagnoses in critically ill patients and is superior to crp. chest x-rays seldom g ...201121675131
de-ampylation of the small gtpase rab1 by the pathogen legionella pneumophila.the bacterial pathogen legionella pneumophila exploits host cell vesicle transport by transiently manipulating the activity of the small guanosine triphosphatase (gtpase) rab1. the effector protein sidm recruits rab1 to the legionella-containing vacuole (lcv), where it activates rab1 and then ampylates it by covalently adding adenosine monophosphate (amp). l. pneumophila gtpase-activating protein lepb inactivates rab1 before its removal from lcvs. because lepb cannot bind ampylated rab1, the mol ...201121680813
a new twist in the regulation of legionella replication through asc and caspase-1. 201121833313
legionella pneumophila sidd is a deampylase that modifies rab1.legionella pneumophila actively modulates host vesicle trafficking pathways to facilitate its intracellular replication with effectors translocated by the dot/icm type iv secretion system (t4ss). the sidm/drra protein functions by locking the small gtpase rab1 into an active form by its guanine nucleotide exchange factor (gef) and ampylation activity. here we demonstrate that the l. pneumophila protein sidd preferably deampylates rab1. we found that the deampylation activity of sidd could suppre ...201121734656
detection of legionella species in potting mixes using fluorescent in situ hybridisation (fish).this study used fluorescent in situ hybridisation (fish) with rrna targeted oligonucleotide probes combined with scanning confocal laser microscopy to successfully detect legionella spp. in commercially available potting mix. a range of techniques were explored to optimise the fish method by reducing background fluorescence and preventing non-specific binding of probes. these techniques included the use of a blocking agent, uv light treatment, image subtraction of a nonsense probe and spectral u ...201121683098
Electrochemical inactivation kinetics of boron-doped diamond electrode on waterborne pathogens.A boron-doped diamond (BDD) electrode was constructed as a water disinfector for the inactivation of water borne pathogens. The bactericidal effect of the disinfector was evaluated on artificially contaminated waters containing, respectively, Escherichia coli, Pseudomonas aeruginosa and Legionella pneumophila at high density. By treating the bacterial suspensions with 4 V of constant voltage between the BDD and the counter-electrode for 50 min, the population of E. coli and P. aeruginosa decreas ...201121976200
the neisseria meningitidis macrophage infectivity potentiator protein induces cross-strain serum bactericidal activity and is a potential serogroup b vaccine candidate.a gene encoding a 29-kda protein from neisseria meningitidis serogroup b strain mc58 with homology to the macrophage infectivity potentiator (mip) protein of legionella pneumophila was cloned and expressed in escherichia coli, and the purified soluble recombinant protein (rmip) was used for immunization studies. analysis of the predicted amino acid sequences of mip from 13 well-characterized meningococcal strains, isolated from carriers or patients and differing in serogroup, serotype, and subty ...201121708989
effector glycosyltransferases in legionella.legionella causes severe pneumonia in humans. the pathogen produces an array of effectors, which interfere with host cell functions. among them are the glucosyltransferases lgt1, lgt2 and lgt3 from l. pneumophila. lgt1 and lgt2 are produced predominately in the post-exponential phase of bacterial growth, while synthesis of lgt3 is induced mainly in the lag-phase before intracellular replication of bacteria starts. lgt glucosyltransferases are structurally similar to clostridial glucosylating tox ...201121833323
[a case of repeated upper gastrointestinal bleeding secondary to legionella pneumonia].a 70-year-old woman admitted for nausea and diarrhea was diagnosed with legionella pneumonia based on chest x-ray and urinary antigen testing. despite severe complications, she recovered thanks to ciprofloxacin administration. on hospital day 8, she went into hypovolemic shock necessitating emergency gastrointestinal (gi) fiberscopy, which showed active lower gastric bleeding. the exposed artery was clipped endoscopically and proton pump inhibitor was started. at hospital day 16, the woman's act ...201121706851
crystal structure of a copper-transporting pib-type atpase.heavy-metal homeostasis and detoxification is crucial for cell viability. p-type atpases of the class ib (pib) are essential in these processes, actively extruding heavy metals from the cytoplasm of cells. here we present the structure of a pib-atpase, a legionella pneumophila copa cu(+)-atpase, in a copper-free form, as determined by x-ray crystallography at 3.2 +à resolution. the structure indicates a three-stage copper transport pathway involving several conserved residues. a pib-specific tra ...201121716286
the nlrc4 inflammasome contributes to restriction of pulmonary infection by flagellated legionella spp. that trigger pyroptosis.the nlrc4 inflammasome is triggered in response to contamination of the host cell cytoplasm with bacterial flagellin, which induces pyroptosis, a form of cell death that accounts for restriction of bacterial infections. although induction of pyroptosis has been extensively investigated in response to salmonella typhimurium and legionella pneumophila, little is known regarding the role of the inflammasome for restriction of non-pneumophila legionella species. here, we used five species of the leg ...201121687424
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