Publications

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 ...	2009	20064470
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 ...	2009	20041020
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 ...	2009	20041211
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 ...	2009	20053299
[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 ...	2009	20055121
[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 ...	2009	20055122
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 ...	2009	20055224
[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.	2009	20034317
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 ...	2009	20011736
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 ...	2009	19995763
[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 ...	2009	20000116
[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 ...	2009	19944056
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 ...	2009	19944878
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. ...	2009	19952481
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 ...	2009	19954129
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 ...	2009	19936053
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.	2009	19917208
profiling of environmental legionella pneumophila strains by randomly amplified polymorphic dna method isolated from geographically nearby buildings.	legionella pneumophila (l. pneumophila) which is also known as etiologic agent legionnaires disease lives in natural water and man made water systems. these bacteria belonging to legionellaceae family are divided 15 serogroups. phenotypical methods used for the identification of legionella isolates are not very discriminatory. in this study we investigated genotypic features of eight l. pneumophila serogroup 1 and 18 l. pneumophila serogroup 2-14 strains isolated from different buildings in ista ...	2009	18283549
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 ...	2009	18538055
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%.	2009	18713136
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 ...	2009	18752009
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) (-/-) ...	2009	18792785
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 ...	2009	18677519
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 ...	2009	18782351
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 ...	2009	18819842
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 ...	2009	18821175
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 ...	2009	18843542
severe adenovirus community-acquired pneumonia mimicking legionella.		2009	18850123
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 ...	2009	18855027
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 ...	2009	18936184
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 ...	2009	18978073
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 ...	2009	18980612
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 ...	2009	18981241
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 ...	2009	19011659
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 ...	2009	19016775
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 ...	2009	19016782
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 ...	2009	19016880
fatal community-acquired pneumonia caused by legionella pneumophila and fluoroquinolone-resistant salmonella enterica serotype choleraesuis bacteraemia.		2009	18993035
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 ...	2009	18997022
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 ...	2009	19021631
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 ...	2009	19040633
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.	2009	19040705
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 ...	2009	19043657
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 ...	2009	19073229
identification of viral and atypical bacterial pathogens in children hospitalized with acute respiratory infections in hong kong by multiplex pcr assays.	acute respiratory tract infection is a leading cause of hospital admission of children. this study used a broad capture, rapid and sensitive method (multiplex pcr assay) to detect 20 different respiratory pathogens including influenza a subtypes h1, h3, and h5; influenza b; parainfluenza types 1, 2, 3, and 4; respiratory syncytial virus (rsv) groups a and b; adenoviruses; human rhinoviruses; enteroviruses; human metapneumoviruses; human coronaviruses oc43, 229e, and sars-cov; chlamydophila pneum ...	2009	19031443
screening of virulence traits in legionella pneumophila and analysis of the host susceptibility to infection by using the dictyostelium host model system.	the social soil amoeba dictyostelium discoideum has been established as a host model for several human pathogens including legionella pneumophila. the complete genome sequence, the genetic tractability, and the phagocytic characteristics of dictyostelium generate many opportunities for the study of host-pathogen interactions. important applications of this haploid model organism are (i) the use of dictyostelium cells as a screening system for bacterial virulence, (ii) the use of dictyostelium mu ...	2009	19089374
dynamics of legionella antibody levels during 1 year in a healthy population.	a total of 522 danish blood donors were followed during 2004-2005 to describe the seroepidemiology of legionella infections in healthy individuals from a general population. antibodies to legionella spp. were measured by indirect immunofluorescence antibody test. the prevalence of legionella antibodies (titre 1:128) was 26.8% and remained fairly constant during the year of follow-up. however, 6.9% of the blood donors developed a fourfold or greater rise in antibody titres. a history of visits to ...	2009	19102798
surface translocation by legionella pneumophila: a form of sliding motility that is dependent upon type ii protein secretion.	legionella pneumophila exhibits surface translocation when it is grown on a buffered charcoal yeast extract (bcye) containing 0.5 to 1.0% agar. after 7 to 22 days of incubation, spreading legionellae appear in an amorphous, lobed pattern that is most manifest at 25 to 30 degrees c. all nine l. pneumophila strains examined displayed the phenotype. surface translocation was also exhibited by some, but not all, other legionella species examined. l. pneumophila mutants that were lacking flagella and ...	2009	19114479
legionella pollution in cooling tower water of air-conditioning systems in shanghai, china.	to determine legionella pollution prevalence, describe the amount of legionellae with respect to temperature in shanghai cooling tower water (ctws) in various types of public sites.	2009	19120608
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 ...	2009	19144560
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 ...	2009	19150639
respiratory tract infections and pneumonia.		2009	19152532
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.	2009	19152698
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 ...	2009	19156453
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 ...	2009	19157961
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.	2009	19161719
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 ...	2009	19165328
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 ...	2009	19167878
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 ...	2009	19168960
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 ...	2009	19169888
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 ...	2009	19170883
[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 ...	2009	19174042
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, ...	2009	19198903
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 ...	2009	19199185
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 ...	2009	19199189
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 ...	2009	19201975
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 ...	2009	19202114
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 ...	2009	19208094
[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.	2009	19212290
[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 ...	2009	19214458
is there a relationship between monthly rainfall and the isolation of legionella in potable water systems in spanish healthcare facilities?		2009	19215199
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.	2009	19217020
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 ...	2009	19218380
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 ...	2009	19223626
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 ...	2009	19225076
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 ...	2009	19225096
[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 ...	2009	19227223
asc and ipaf inflammasomes direct distinct pathways for caspase-1 activation in response to legionella pneumophila.	caspase-1 activation is a key feature of the innate immune response of macrophages elicited by pathogens and a variety of toxins. here, we determined the requirement for different adapter proteins involved in regulating host processes mediated by caspase-1 after macrophage infection by legionella pneumophila. the adapter protein asc was found to be important for caspase-1 activation during l. pneumophila infection. activation of caspase-1 through asc did not require the flagellin-sensing pathway ...	2009	19237518
incorporation of natural uncultivable legionella pneumophila into potable water biofilms provides a protective niche against chlorination stress.	legionella pneumophila is a waterborne pathogen that has been isolated sporadically from drinking water distribution systems (dwds). resistance to disinfectants is mainly attributed to the association of cells with amoebae, but biofilms are also thought to provide some degree of protection. in the present work, a two-stage chemostat was used to form heterotrophic biofilms from drinking water to study the influence of chlorine on the presence of naturally occurring l. pneumophila. the pathogen wa ...	2009	19241230
comparison between standard culture and peptide nucleic acid 16s rrna hybridization quantification to study the influence of physico-chemical parameters on legionella pneumophila survival in drinking water biofilms.	legionella pneumophila is a waterborne pathogen that is mainly transmitted by the inhalation of contaminated aerosols. in this article, the influence of several physico-chemical parameters relating to the supply of potable water was studied using a l. pneumophila peptide nucleic acid (pna) specific probe to quantify total l. pneumophila in addition to standard culture methods. a two-stage chemostat was used to form the heterotrophic biofilms, with biofilm generating vessels fed with naturally oc ...	2009	19241231
twitching motility in legionella pneumophila.	twitching motility is a form of bacterial translocation over solid or semi-solid surfaces mediated by the extension, tethering, and subsequent retraction of type iv pili. these pili are also known to be involved in virulence, biofilm formation, formation of fruiting bodies, horizontal gene transfer, and protein secretion. we have characterized the presence of twitching motility on agar plates in legionella pneumophila, the etiological agent of legionnaires' disease. by examining twitching motili ...	2009	19243440
a type ii secreted rnase of legionella pneumophila facilitates optimal intracellular infection of hartmannella vermiformis.	type ii protein secretion plays a role in a wide variety of functions that are important for the ecology and pathogenesis of legionella pneumophila. perhaps most dramatic is the critical role that this secretion pathway has in l. pneumophila intracellular infection of aquatic protozoa. recently, we showed that virulent l. pneumophila strain 130b secretes rnase activity through its type ii secretion system. we now report the cloning and mutational analysis of the gene (srna) encoding that novel t ...	2009	19246759
[comparison of five commercial assays for the detection of legionella pneumophila antigens in urine].	antigenuria detection is the main approach for diagnosing legionella infections. the aim of this study was to compare 5 commercially available methods for detecting legionella pneumophila soluble antigens in urine.	2009	19254639
identification of legionella species by use of an oligonucleotide array.	the genus legionella contains a diverse group of motile, asaccharolytic, nutritionally fastidious gram-negative rods. legionella pneumophila is the most important human pathogen, followed by l. micdadei, l. longbeachae, l. dumoffii, and other rare species. accurate identification of legionella spp. other than l. pneumophila is difficult because of biochemical inertness and phenotypic identity of different species. the feasibility of using an oligonucleotide array for identification of 18 species ...	2009	19261788
determination of legionella pneumophila susceptibility to melaleuca alternifolia cheel (tea tree) oil by an improved broth micro-dilution method under vapour controlled conditions.	the aim of this study was to determine the in vitro activity of melaleuca alternifolia cheel (tea tree) oil (tto) against 22 strains of legionella pneumophila of different serogroup and source of isolation. both a standard broth micro-dilution method, with slight modifications, and a micro-atmosphere diffusion method were used. furthermore, we have established a simple sealing procedure in the micro-dilution method to determine the antibacterial activity of tto against legionella in aqueous phas ...	2009	19264101
respiratory failure at home after coronary artery bypass graft surgery requiring extracorporeal membrane oxygenation.		2009	19264514
[inspection on legionella pollution and the health impact of workers in public places of central air conditioning systems in dalian city].	to inspect the conditions of legionella pollution in cooling towers of central air conditioning systems and the state of legionella potential infection of workers in public places in dalian city in order to study the impact factors related witb legiondlla organism infection.	2009	19267082
the efficacy of biocides and other chemical additives in cooling water systems in the control of amoebae.	in vitro experiments were undertaken to evaluate biocide formulations commonly used in cooling water systems against protozoa previously isolated from cooling towers. the investigations evaluated the efficacy of these formulations against amoebic cysts and trophozoites.	2009	19187130
biofilm problems in dental unit water systems and its practical control.	dental chair units (dcus) contain integrated systems that provide the instruments and services for a wide range of dental procedures. dcus use water to cool and irrigate dcu-supplied instruments and tooth surfaces during dental treatment. water is supplied to these instruments by a network of interconnected narrow-bore (2-3 mm) plastic tubes called dental unit waterlines (duwls). many studies over the last 40 years demonstrated that duwl output water is often contaminated with high densities of ...	2009	19187140
stopping legionella in its tracks.	recent legionella outbreaks have done nothing to reassure the general public and "customers" of the healthcare sector that there is no risk from the disease. here jo welters, microbiologist and sector head of ta-aqua+ at hydronic balancing specialist tour & andersson, discusses the relevance of a new method for tackling legionella prevention and the means of removing the current risks associated with the bacteria.	2009	19192600
factors influencing the case-fatality rate of legionnaires' disease.	the extent of the public health problem posed by legionnaires' disease (ld) is not always well- appreciated.	2009	19275805
an anomalous type iv secretion system in rickettsia is evolutionarily conserved.	bacterial type iv secretion systems (t4sss) comprise a diverse transporter family functioning in conjugation, competence, and effector molecule (dna and/or protein) translocation. thirteen genome sequences from rickettsia, obligate intracellular symbionts/pathogens of a wide range of eukaryotes, have revealed a reduced t4ss relative to the agrobacterium tumefaciens archetype (vir). however, the rickettsia t4ss has not been functionally characterized for its role in symbiosis/virulence, and none ...	2009	19279686
the cmp-legionaminic acid pathway in campylobacter: biosynthesis involving novel gdp-linked precursors.	the sialic acid-like sugar 5,7-diacetamido-3,5,7,9-tetradeoxy-d-glycero-d-galacto-nonulosonic acid, or legion-aminic acid, is found as a virulence-associated cell-surface glycoconjugate in the gram-negative bacteria legionella pneumophila and campylobacter coli. l. pneumophila serogroup 1 strains, causative agents of legionnaire's disease, contain an alpha2,4-linked homopolymer of legionaminic acid within their lipopolysaccharide o-chains, whereas the gastrointestinal pathogen c. coli modifies i ...	2009	19282391
replication of legionella pneumophila in biofilms of water distribution pipes.	biofilms similar to those present in water distribution pipes of anthropogenic aquatic systems were simulated in a rotating annular reactor using a non-legionella community consisting of aeromonas hydrophila, escherichia coli, flavobacterium breve and pseudomonas aeruginosa. the impact of this community and acanthamoeba castellanii on the replication of legionella pneumophila was investigated. despite the presence of 10(7) non-legionella bacteria, culture and real-time polymerase chain reaction ...	2009	17644359
genetic diversity of legionella pneumophila in hospital water systems.	it has been shown that different patients who had acquired legionellosis in a hospital setting were infected with the same strain even years apart. however, there are no longitudinal data describing the molecular epidemiology of legionella pneumophila strains that contaminate a water system. this raised the question if there are any shifts of l. pneumophila strains over time, or after carrying out control measures. using genotyping on a large collection of isolates, we investigated in a retrospe ...	2008	17652025
hospital-acquired legionellosis originating from a cooling tower during a period of thermal inversion.	a case of hospital-acquired legionellosis occurred in a 75-year-old male patient who underwent surgery due to malignant melanoma. legionellosis was proven by culture of legionella pneumophila serogroup 1 from bronchoalveolar lavage (bal) fluid. being a chronic smoker the patient used to visit the sickroom balcony that was located about 90 m to the west of a hospital cooling tower. routine cooling tower water samples drawn during the presumed incubation period revealed 1.0x10(4) cfu/100 ml (l. pn ...	2008	17870669
effect of pipe corrosion scales on chlorine dioxide consumption in drinking water distribution systems.	previous studies showed that temperature and total organic carbon in drinking water would cause chlorine dioxide (clo(2)) loss in a water distribution system and affect the efficiency of clo(2) for legionella control. however, among the various causes of clo(2) loss in a drinking water distribution system, the loss of disinfectant due to the reaction with corrosion scales has not been studied in detail. in this study, the corrosion scales from a galvanized iron pipe and a copper pipe that have b ...	2008	17884130
identification and characterization of a new conjugation/type iva secretion system (trb/tra) of legionella pneumophila corby localized on two mobile genomic islands.	horizontal gene transfer probably contributes to evolution of legionella pneumophila and its adaptation to different environments. although horizontal gene transfer was observed in legionella, the mechanism is still not specified. in this study we identified and analysed a new type of conjugation/type iva secretion system (trb/tra) of l. pneumophila corby, a virulent human isolate. two similar versions of this conjugation system were identified, localized on two different genomic islands (trb-1, ...	2008	17888731
real-time pcr assay for the detection and quantification of legionella pneumophila in environmental water samples: utility for daily practice.	we developed a quantitative real-time pcr assay targeting the mip gene of legionella pneumophila for a prospective study from september 2004 to april 2005. it was compared with a standard culture method (french guideline afnor t90-431), analysing 120 water samples collected to monitor the risk related to legionellae at nantes hospital and to investigate a case of legionellosis acquired from hospital environment. samples from six distinct water distribution systems were analysed by dna extraction ...	2008	17720622
differential 2-d protein gel electrophoresis analysis of legionella pneumophila wild type and tat secretion mutants.	the twin-arginine translocation (tat) pathway is a secretory pathway for translocation of folded proteins with two arginines in their signal peptide across the cytoplasmic membrane. recently, we showed the presence of the tat secretion pathway in legionella pneumophila philadelphia-1 and its role in intracellular replication and biofilm formation. to analyse the importance of the tat pathway in protein export and its role in l. pneumophila virulence, a comparative 2-d protein gel electrophoresis ...	2008	17723319