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functional characterization of lcpa, a surface-exposed protein of leptospira spp. that binds the human complement regulator c4bp.we have previously shown that pathogenic leptospiral strains are able to bind c4b binding protein (c4bp). surface-bound c4bp retains its cofactor activity, indicating that acquisition of this complement regulator may contribute to leptospiral serum resistance. in the present study, the abilities of seven recombinant putative leptospiral outer membrane proteins to interact with c4bp were evaluated. the protein encoded by lic11947 interacted with this human complement regulator in a dose-dependent ...201020404075
high-resolution melt-curve analysis of random-amplified-polymorphic-dna markers, for the characterisation of pathogenic leptospira.a new test for pathogenic leptospira isolates, based on rapd-pcr and high-resolution melt (hrm) analysis (which measures the melting temperature of amplicons in real time, using a fluorescent dna-binding dye), has recently been developed. a characteristic profile of the amplicons can be used to define serovars or detect genotypes. ten serovars, of leptospires from the species leptospira interrogans (serovars australis, robinsoni, hardjo, pomona, zanoni, copenhageni and szwajizak), l. borgpeterse ...201020406582
first isolation of human leptospira strains, azores, portugal.the aim of this study was the first identification of leptospira isolates from azorean inpatients.201020413339
serologic and molecular studies of leptospira and leptospirosis among rats in the philippines.rats are known to be the most important reservoirs and transmission sources of leptospirosis. however, the status of leptospirosis in the philippines regarding reservoirs and transmission remains unknown. a survey was conducted in metro manila and laguna that analyzed samples obtained from 106 rats. using the microscopic agglutination test, we found that 92% of rat serum samples were positive for anti-leptospira antibodies; the most common infecting serovars were manilae, hebdomadis, and losbano ...201020439972
molecular epidemiology of leptospirosis in northern iran by nested polymerase chain reaction/restriction fragment length polymorphism and sequencing methods.this study was conducted to investigate the prevalence of leptospira species in mazandaran province of iran by using nested polymerase chain reaction (pcr)/restriction fragment length polymorphism (rflp) methods and sequencing analysis. blood samples (n = 119) were collected from humans suspected of having leptospirosis from different parts of the province in 2007. by using an indirect immunofluorescent antibody test (ifat), we determined that 35 (29.4%) of 119 suspected cases had leptospiral an ...201020439973
refolding of the recombinant protein ompa70 from leptospira interrogans from inclusion bodies using high hydrostatic pressure and partial characterization of its immunological properties.leptospira is the etiological agent of leptospirosis, a life-threatening disease that affects human populations worldwide. available vaccines have demonstrated limited effectiveness, and therapeutic interventions are complicated by the difficulty of establishing an early diagnosis. the genome of leptospira strains was sequenced, and bioinformatic analyses revealed potential vaccine and serodiagnosis candidates. the present work studied ompa70, a putative outer membrane protein from leptospira in ...201020450943
[rare acute hepatitis in a female patient with hemochromatosis: a zoonosis?].a 58-year-old female patient was transferred by her general practitioner with fatigue, nausea and icterus which had begun 2 weeks prior to admission. laboratory results revealed acute hepatitis (alat [alanine aminotransferase] 3,871 u/l, asat [aspartate aminotransferase] 2,004 u/l, bilirubin 6.7 mg/dl, gamma-gt [gamma-glutamyl transferase] 503 u/l). the patient's medical history included genetic hemochromatosis (without cirrhosis). hepatitis a to c, infection with herpesviruses or leptospira int ...201020455055
[feasibility to use of recombinant domains of immunoglobulin-like protein liga as a promising marker for serological testing of patients with leptospirosis].to clone the dna fragment encoding conservative domain of liga protein of leptospira interrogans into escherichia coli and to investigate antigenic properties of constructed chimeric protein.201020465007
[construction and expression of recombinant mycobacterium bovis bcg with the ompa-like membrane protein gene loa22 of leptospira interrogans serovar].to study the immunity of loa22 from leptospira interrogans serovar lai strain 56601 by expressing its protein in bcg.201020506632
effect of leptospira interrogans outer membrane proteins lipl32 on huvec.leptospira cause disease through a toxin-mediated process by inducing vascular injury, particularly a small-vessel vasculitis. breakdown of vessel endothelial cell integrity may increase vessel permeability which is correlated with the changes of tight junction and/or apoptosis in vessel endothelial cells. the specific toxin responsible remains unidentified. in this study, we amplified outer membrane protein lipl32 from the genome of leptospira interrogans serovar lai, and it was subcloned in pe ...201020510346
peptidoglycan crosslinking relaxation promotes helicobacter pylori's helical shape and stomach colonization.the mechanisms by which bacterial cells generate helical cell shape and its functional role are poorly understood. helical shape of the human pathogen helicobacter pylori may facilitate penetration of the thick gastric mucus where it replicates. we identified four genes required for helical shape: three lytm peptidoglycan endopeptidase homologs (csd1-3) and a ccma homolog. surrounding the cytoplasmic membrane of most bacteria, the peptidoglycan (murein) sacculus is a meshwork of glycan strands j ...201020510929
[molecular typing on leptospira interrogans isolates from jiangxi province, by pulsed-field gel electrophoresis.].to perform a molecular epidemiological investigation on the types of leptospira interrogans isolates from leptospirosis patients and animal hosts in jiangxi province, using a pulsed-field gel electrophoresis (pfge).201020513291
herd- and animal-level risk factors for bovine leptospirosis in tanga region of tanzania.leptospirosis is the zoonosis of worldwide distribution and common cause of economic loss and ill health among animals and human populations. a cross-sectional seroprevalence study, using a microscopic agglutination test (mat) with a threshold titre of >or=1:160, to elucidate disease magnitude, distribution and associated risk factors in cattle in tanga, tanzania was conducted from may 2003 to january 2004. serum (n = 655) samples collected from randomly selected herds (n = 130) were tested for ...201020517645
detection of "candidatus neoehrlichia mikurensis" in two patients with severe febrile illnesses: evidence for a european sequence variant.recently, a new genus of anaplasmataceae termed "candidatus neoehrlichia" was discovered in ticks and rodents. here, we report on two patients who suffered from febrile bacteremia due to "candidatus neoehrlichia mikurensis" associated with thrombotic or hemorrhagic events. 16s rrna and groel gene sequencing provided evidence of three groups of sequence variants.201020519481
current concepts in biofilm formation of staphylococcus epidermidis.staphylococcus epidermidis is a highly significant nosocomial pathogen mediating infections primarily associated with indwelling biomaterials (e.g., catheters and prostheses). in contrast to staphylococcus aureus, virulence properties associated with s. epidermidis are few and biofilm formation is the defining virulence factor associated with disease, as demonstrated by animal models of biomaterial-related infections. however, other virulence factors, such as phenol-soluble modulins and poly-gam ...201020521936
characterization of leptospiral proteins that afford partial protection in hamsters against lethal challenge with leptospira interrogans.leptospirosis is a worldwide zoonosis caused by pathogenic leptospira. the whole-genome sequence of leptospira interrogans serovar copenhageni together with bioinformatic tools allow us to search for novel antigen candidates suitable for improved vaccines against leptospirosis. this study focused on three genes encoding conserved hypothetical proteins predicted to be exported to the outer membrane. the genes were amplified by pcr from six predominant pathogenic serovars in brazil. the genes were ...201020558583
different outcomes of experimental leptospiral infection in mouse strains with distinct genotypes.the mouse disease model has the advantage of a broad array of immunological and genetic tools available for basic research. some studies on transgenic and/or mutant mouse strains as models for experimental leptospirosis have been reported; however, the wider use of such models is hampered by a poor understanding of the outcome of experimental leptospiral infection among the different mouse strains available. here, the outcome of infection by a virulent strain of leptospira interrogans serogroup ...201020558584
structural insights into the catalytic mechanism of bacterial guanosine-diphospho-d-mannose pyrophosphorylase and its regulation by divalent ions.gmp catalyzes the formation of gdp-man, a fundamental precursor for protein glycosylation and bacterial cell wall and capsular polysaccharide biosynthesis. crystal structures of gmp from the thermophilic bacterium thermotoga maritima in the apo form, in complex with the substrates mannose-1-phosphate or gtp and bound with the end product gdp-man in the presence of the essential divalent cation mg(2+), were solved in the 2.1-2.8 a resolution range. the t. maritima gmp molecule is organized in two ...201020573954
in vitro identification of novel plasminogen-binding receptors of the pathogen leptospira interrogans.leptospirosis is a multisystem disease caused by pathogenic strains of the genus leptospira. we have reported that leptospira are able to bind plasminogen (plg), to generate active plasmin in the presence of activator, and to degrade purified extracellular matrix fibronectin.201020582320
characterization of a lipopolysaccharide mutant of leptospira derived by growth in the presence of an anti-lipopolysaccharide monoclonal antibody.a lipopolysaccharide mutant of leptospira interrogans (laimut) was obtained by growth in the presence of an agglutinating monoclonal antibody (mab) against lipopolysaccharide. agglutination reactions with anti-lipopolysaccharide mabs and polyclonal antibodies showed that laimut had lost some serogroup icterohaemorrhagiae agglutinating epitopes. however, laimut displayed an increased reactivity to antisera against related serogroups, suggesting that the disruption of some lipopolysaccharide epito ...201020584080
the yellow fever vaccine: a history.after failed attempts at producing bacteria-based vaccines, the discovery of a viral agent causing yellow fever and its isolation in monkeys opened new avenues of research. subsequent advances were the attenuation of the virus in mice and later in tissue culture; the creation of the seed lot system to avoid spontaneous mutations; the ability to produce the vaccine on a large scale in eggs; and the removal of dangerous contaminants. an important person in the story is max theiler, who was profess ...201020589188
isolation of leptospira interrogans from suburban rats in tandil, buenos aires, argentina.the main objective of this study was to investigate the role of wild rodents as leptospira spp. reservoirs in a suburban area of tandil city, buenos aires province (argentina), where a person had died due to pulmonary leptospirosis. the specific objectives were: to estimate the rodent density near the patient's home, to determine the serological prevalence and isolation of leptospirosis from wild rodents, and to identify the isolated strains. the area examined was a suburban neighbourhood in tan ...201020589335
prevalence of leptospira interrogans antibodies in free-ranging tayassu pecari of the southern pantanal, brazil, an ecosystem where wildlife and cattle interact.we surveyed a wild population of white-lipped peccaries (tayassu pecari) in the brazilian pantanal for evidence of leptospira interrogans. serum samples from 71 free-ranging t. pecari were obtained between 2003 and 2005 in the southern pantanal of mato grosso do sul state. we used microscopic microagglutination to test for antibodies against 14 l. interrogans serovars (antibody titers ≥ 1:100 were considered seropositive). seventy percent of captured animals tested positive for leptospirosis ant ...201020596776
an alternative route for udp-diacylglucosamine hydrolysis in bacterial lipid a biosynthesis.the outer leaflet of the outer membranes of gram-negative bacteria is composed primarily of lipid a, the hydrophobic anchor of lipopolysaccharide. like escherichia coli, most gram-negative bacteria encode one copy of each of the nine genes required for lipid a biosynthesis. an important exception exists in the case of the fourth enzyme, lpxh, a peripheral membrane protein that hydrolyzes udp-2,3-diacylglucosamine to form 2,3-diacylglucosamine 1-phosphate and ump by catalyzing the attack of water ...201020608695
the hpk2-rrp2 two-component regulatory system of treponema denticola: a potential regulator of environmental and adaptive responses.treponema denticola levels in the gingival crevice become elevated as periodontal disease develops. oral treponemes may account for as much as 40% of the total bacterial population in the periodontal pocket. the stimuli that trigger enhanced growth of t. denticola, and the mechanisms associated with the transmission of these signals, remain to be defined. we hypothesize that the t. denticola open reading frames tde1970 (histidine kinase) and tde1969 (response regulator) constitute a functional t ...201020618698
experimental leptospira interrogans serovar kennewicki infection of horses.little information is available about experimental induction of leptospirosis in horses.201020649749
leptospira serovar as prognostic factor. 201020678345
preliminary characterization of mus musculus-derived pathogenic strains of leptospira borgpetersenii serogroup ballum in a hamster model.human and animal leptospirosis caused by leptospira spp. belonging to serogroup ballum has increased worldwide in the past decade. we report the isolation and serologic and molecular characterization of four l. borgpetersenii serogroup ballum isolates obtained from mus musculus, and preliminary virulence studies. these isolates are useful for diagnosis of leptospirosis and for epidemiologic studies of its virulence and pathogenic mechanisms.201020682877
pathogen dynamics and morbidity of striped skunks in the absence of rabies.parasites have the potential to influence the population dynamics of mammalian hosts, either as a single devastating pathogen or as a community effect. striped skunks (mephitis mephitis) are typically host to rabies, which often regulates population numbers. we assessed micro- and macroparasite dynamics in striped skunk populations in the absence of rabies, to determine if a single pathogen, or community, was responsible for a majority of skunk deaths. we monitored mortality due to pathogens, an ...201020688627
serosurvey for canine distemper virus, canine adenovirus, leptospira interrogans, and toxoplasma gondii in free-ranging canids in scandinavia and svalbard.prevalence of antibodies reactive to canine distemper virus (cdv), canine adenovirus type 1 (cav-1), leptospira interrogans serovars canicola and icterohaemorrhagiae, and toxoplasma gondii were examined in free-ranging scandinavian canids. sampling included 275 red foxes (vulpes vulpes) from mainland norway, 60 arctic foxes (vulpes lagopus) from the high-arctic islands of svalbard, and 98 wolves (canis lupus) from the joint swedish-norwegian population. methods used included virus neutralization ...201020688639
cross-reactivity of antibodies against leptospiral recurrent uveitis-associated proteins a and b (lrua and lrub) with eye proteins.infection by leptospira interrogans has been causally associated with human and equine uveitis. studies in our laboratories have demonstrated that leptospiral lipoprotein lrua and lrub are expressed in the eyes of uveitic horses, and that antibodies directed against lrua and lrub react with equine lenticular and retinal extracts, respectively. these reactivities were investigated further by performing immunofluorescent assays on lenticular and retinal tissue sections. incubation of lens tissue s ...201020689825
expanding the diagnostic use of pcr in leptospirosis: improved method for dna extraction from blood cultures.leptospirosis is a neglected zoonosis of ubiquitous distribution. symptoms are often non-specific and may range from flu-like symptoms to multi-organ failure. diagnosis can only be made by specific diagnostic tests like serology and pcr. in non-endemic countries, leptospirosis is often not suspected before antibiotic treatment has been initiated and consequently, relevant samples for diagnostic pcr are difficult to obtain. blood cultures are obtained from most hospitalized patients before antibi ...201020711446
the ompl37 surface-exposed protein is expressed by pathogenic leptospira during infection and binds skin and vascular elastin.pathogenic leptospira spp. shed in the urine of reservoir hosts into freshwater can be transmitted to a susceptible host through skin abrasions or mucous membranes causing leptospirosis. the infection process involves the ability of leptospires to adhere to cell surface and extracellular matrix components, a crucial step for dissemination and colonization of host tissues. therefore, the elucidation of novel mediators of host-pathogen interaction is important in the discovery of virulence factors ...201020844573
evidence for a novel marine harmful algal bloom: cyanotoxin (microcystin) transfer from land to sea otters."super-blooms" of cyanobacteria that produce potent and environmentally persistent biotoxins (microcystins) are an emerging global health issue in freshwater habitats. monitoring of the marine environment for secondary impacts has been minimal, although microcystin-contaminated freshwater is known to be entering marine ecosystems. here we confirm deaths of marine mammals from microcystin intoxication and provide evidence implicating land-sea flow with trophic transfer through marine invertebrate ...201020844747
serum lipoproteins attenuate macrophage activation and toll-like receptor stimulation by bacterial lipoproteins.chlamydia trachomatis was previously shown to express a lipoprotein, the macrophage infectivity potentiator (mip), exposed at the bacterial surface, and able to stimulate human primary monocytes/macrophages through toll like receptor (tlr)2/tlr1/tlr6, and cd14. in pma-differentiated thp-1 cells the proinflammatory activity of mip was significantly higher in the absence than in the presence of serum. the present study aims to investigate the ability of different serum factors to attenuate mip pro ...201020846396
cellular architecture of treponema pallidum: novel flagellum, periplasmic cone, and cell envelope as revealed by cryo electron tomography.high-resolution cryo electron tomography (cryo-et) was utilized to visualize treponema pallidum, the causative agent of syphilis, at the molecular level. three-dimensional (3d) reconstructions from 304 infectious organisms revealed unprecedented cellular structures of this unusual member of the spirochetal family. high-resolution cryo-et reconstructions provided detailed structures of the cell envelope, which is significantly different from that of gram-negative bacteria. the 4-nm lipid bilayer ...201020850455
in vitro sensitivity and resistance of 46 leptospira strains isolated from rats in the philippines to 14 antimicrobial agents.the in vitro susceptibilities of 46 leptospira isolates from rats to 14 antimicrobial agents were tested. all of the strains were found to be sensitive to ampicillin, cefotaxime, ciprofloxacin, norfloxacin, doxycycline, erythromycin, and streptomycin. in contrast, the tested isolates showed resistance to amphotericin b, 5-fluorouracil, fosfomycin, trimethoprim, sulfamethoxazole, neomycin, and vancomycin. these findings will help in selecting effective and ineffective antimicrobials for treatment ...201020855741
leptospira as an emerging pathogen: a review of its biology, pathogenesis and host immune responses.leptospirosis, the most widespread zoonosis in the world, is an emerging public health problem, particularly in large urban centers of developing countries. several pathogenic species of the genus leptospira can cause a wide range of clinical manifestations, from a mild, flu-like illness to a severe disease form characterized by multiorgan system complications leading to death. however, the mechanisms of pathogenesis of leptospira are largely unknown. this article will address the animal models ...201020860485
a phenomenological model for predicting melting temperatures of dna sequences.we report here a novel method for predicting melting temperatures of dna sequences based on a molecular-level hypothesis on the phenomena underlying the thermal denaturation of dna. the model presented here attempts to quantify the energetic components stabilizing the structure of dna such as base pairing, stacking, and ionic environment which are partially disrupted during the process of thermal denaturation. the model gives a pearson product-moment correlation coefficient (r) of approximately ...201020865157
visual proteomics.visual proteomics attempts to generate molecular atlases by providing the position and angular orientation of protein complexes inside of cells. this is accomplished by template matching (pattern recognition), a cross-correlation-based process that matches the structure of a specific protein complex to the densities of the whole volume or subvolume of a cell, that is typically acquired by cryoelectron tomography. thereby, a search is performed that scans the entire volume for structural template ...201020888477
a low molecular weight lipopolysaccharide antigen preparation reactive to acute leptospirosis heterologous sera.there is a need for identification of new infection markers against common leptospira isolates in malaysia. to achieve this goal, seven-day-old cultures of leptospira interrogans serogroup icterohemorrhagiae (l44) and leptospira interrogans serogroup javanica (l55) were used for antigen preparation by sequential extraction method using 40 mm tris, 8m urea and 2m thiourea. immunoblot analysis of the antigens were performed using serum samples from 46 local patients with confirmed acute leptospiro ...201020962722
leptospirosis in free-ranging endangered european mink (mustela lutreola) and other small carnivores (mustelidae, viverridae) from southwestern france.to study the possible role of disease in the decline of endangered european mink (mustela lutreola), we conducted a survey of antibody prevalence and renal carriage of pathogenic leptospira (leptospira interrogans sensu lato) using serum and kidney samples collected from 1990 to 2007 from several free-ranging small carnivores and farmed american mink (mustela vison) in southwestern france. an indirect microscopic agglutination test using a panel of 16 serovars belonging to 6 serogroups (australi ...201020966265
serologic evaluation of new zealand sea lions for exposure to brucella and leptospira spp.a serologic survey of anti-brucella and antileptospiral antibodies was conducted on 147 adult, female new zealand sea lions (phocarctos hookeri). most sea lions (n=138) were sampled at sandy bay, enderby island, auckland islands (50°30's, 166°17'e), january 2000-march 2005. nine were sampled at otago, new zealand (46°0's, 170°40'e); four in april 2008 and five in march 2009. serum from one of the enderby island females was weakly positive for antibodies to brucella abortus using the competitive ...201020966283
the crystal structure of the leptospiral hypothetical protein lic12922 reveals homology with the periplasmic chaperone sura.leptospirosis is a world spread zoonosis caused by members of the genus leptospira. although leptospires were identified as the causal agent of leptospirosis almost 100 years ago, little is known about their biology, which hinders the development of new treatment and prevention strategies. one of the several aspects of the leptospiral biology not yet elucidated is the process by which outer membrane proteins (omps) traverse the periplasm and are inserted into the outer membrane. the crystal stru ...201020970503
leptospirosis: an unusual cause of ards.severe leptospirosis usually associates shock, jaundice, renal failure, and thrombocytopenia. massive hemoptysis due to diffuse alveolar haemorrhage may rarely occur leading to an acute respiratory failure and multiple organ failure. we present the case of an acute respiratory distress syndrome caused by a severe leptospirosis. the severity of the respiratory failure contrasted with the absence of significant liver or renal dysfunction. bedside open lung biopsy was only consistent with a postinf ...201020981324
expanding the genetic toolbox for leptospira species by generation of fluorescent bacteria.our knowledge of the genetics and molecular basis of the pathogenesis associated with leptospira, in comparison to those of other bacterial species, is very limited. an improved understanding of pathogenic mechanisms requires reliable genetic tools for functional genetic analysis. here, we report the expression of gfp and mrfp1 genes under the control of constitutive spirochetal promoters in both saprophytic and pathogenic leptospira strains. we were able to reliably measure the fluorescence of ...201021037299
transcriptional responses of leptospira interrogans to host innate immunity: significant changes in metabolism, oxygen tolerance, and outer membrane.leptospira interrogans is the major causative agent of leptospirosis. phagocytosis plays important roles in the innate immune responses to l. interrogans infection, and l. interrogans can evade the killing of phagocytes. however, little is known about the adaptation of l. interrogans during this process.201021049008
characterization of novel bovine gastrointestinal tract treponema isolates and comparison with bovine digital dermatitis treponemes.this study aimed to isolate and characterize treponemes present in the bovine gastrointestinal (gi) tract and compare them with bovine digital dermatitis (bdd) treponemes. seven spirochete isolates were obtained from the bovine gi tract, which, on the basis of 16s rrna gene comparisons, clustered within the genus treponema as four novel phylotypes. one phylotype was isolated from several different gi tract regions, including the omasum, colon, rumen, and rectum. these four phylotypes could be di ...201021057019
characterization of novel bovine gastrointestinal tract treponema isolates and comparison with bovine digital dermatitis treponemes.this study aimed to isolate and characterize treponemes present in the bovine gastrointestinal (gi) tract and compare them with bovine digital dermatitis (bdd) treponemes. seven spirochete isolates were obtained from the bovine gi tract, which, on the basis of 16s rrna gene comparisons, clustered within the genus treponema as four novel phylotypes. one phylotype was isolated from several different gi tract regions, including the omasum, colon, rumen, and rectum. these four phylotypes could be di ...201021057019
the photosensor protein ppr of rhodocista centenaria is linked to the chemotaxis signalling pathway.rhodocista centenaria is a phototrophic α-proteobacterium exhibiting a phototactic behaviour visible as colony movement on agar plates directed to red light. as many phototrophic purple bacteria r. centenaria possesses a soluble photoactive yellow protein (pyp). it exists as a long fusion protein, designated ppr, consisting of three domains, the pyp domain, a putative bilin binding domain (bbd) and a histidine kinase domain (pph). the ppr protein is involved in the regulation of polyketide synth ...201021062468
manganese binds to clostridium difficile fbp68 and is essential for fibronectin binding.clostridium difficile is an etiological agent of pseudomembranous colitis and antibiotic-associated diarrhea. adhesion is the crucial first step in bacterial infection. thus, in addition to toxins, the importance of colonization factors in c. difficile-associated disease is recognized. in this study, we identified fbp68, one of the colonization factors that bind to fibronectin (fn), as a manganese-binding protein (k(d) = 52.70 ± 1.97 nm). furthermore, the conformation of fbp68 changed dramatical ...201021062746
manganese binds to clostridium difficile fbp68 and is essential for fibronectin binding.clostridium difficile is an etiological agent of pseudomembranous colitis and antibiotic-associated diarrhea. adhesion is the crucial first step in bacterial infection. thus, in addition to toxins, the importance of colonization factors in c. difficile-associated disease is recognized. in this study, we identified fbp68, one of the colonization factors that bind to fibronectin (fn), as a manganese-binding protein (k(d) = 52.70 ± 1.97 nm). furthermore, the conformation of fbp68 changed dramatical ...201021062746
comparison of conventional, nested, and real-time quantitative pcr for diagnosis of scrub typhus.orientia tsutsugamushi is the causative agent of scrub typhus. for the diagnosis of scrub typhus, we investigated the performances of conventional pcr (c-pcr), nested pcr (n-pcr), and real-time quantitative pcr (q-pcr) targeting the o. tsutsugamushi-specific 47-kda gene. to compare the detection sensitivities of the three techniques, we used two template systems that used plasmid dna (plasmid detection sensitivity), including a partial region of the 47-kda gene, and genomic dna (genomic detectio ...201021068287
acute parvovirus b19 infection causes nonspecificity frequently in borrelia and less often in salmonella and campylobacter serology, posing a problem in diagnosis of infectious arthropathy.several infectious agents may cause arthritis or arthropathy. for example, infection with borrelia burgdorferi, the etiologic agent of lyme disease, may in the late phase manifest as arthropathy. infections with campylobacter, salmonella, or yersinia may result in a postinfectious reactive arthritis. acute infection with parvovirus b19 (b19v) may likewise initiate transient or chronic arthropathy. all these conditions may be clinically indistinguishable from rheumatoid arthritis. here, we presen ...201021106777
acute parvovirus b19 infection causes nonspecificity frequently in borrelia and less often in salmonella and campylobacter serology, posing a problem in diagnosis of infectious arthropathy.several infectious agents may cause arthritis or arthropathy. for example, infection with borrelia burgdorferi, the etiologic agent of lyme disease, may in the late phase manifest as arthropathy. infections with campylobacter, salmonella, or yersinia may result in a postinfectious reactive arthritis. acute infection with parvovirus b19 (b19v) may likewise initiate transient or chronic arthropathy. all these conditions may be clinically indistinguishable from rheumatoid arthritis. here, we presen ...201021106777
first isolation and direct evidence for the existence of large small-mammal reservoirs of leptospira sp. in madagascar.leptospirosis has long been a major public health concern in the southwestern indian ocean. however, in madagascar, only a few, old studies have provided indirect serological evidence of the disease in humans or animals.201021124843
high yield expression of leptospirosis vaccine candidates liga and lipl32 in the methylotrophic yeast pichia pastoris.leptospirosis, a zoonosis caused by leptospira spp., is recognized as an emergent infectious disease. due to the lack of adequate diagnostic tools, vaccines are an attractive intervention strategy. recombinant proteins produced in escherichia coli have demonstrated promising results, albeit with variable efficacy. pichia pastoris is an alternative host with several advantages for the production of recombinant proteins.201021134266
investigation of localisation of leptospira spp. in uterine and fetal tissues of non-pregnant and pregnant farmed deer.to find evidence for localisation in the uterus, and fetal infection, of leptospira spp. in farmed deer in the lower north island of new zealand during and shortly after the breeding season.201021151213
leptospira interrogans associated with hydrallantois in 2 pluriparous thoroughbred mares. 201021155889
2010 acvim small animal consensus statement on leptospirosis: diagnosis, epidemiology, treatment, and prevention.this report offers a consensus opinion on the diagnosis, epidemiology, treatment, and prevention of leptospirosis in dogs, an important zoonosis. clinical signs of leptospirosis in dogs relate to development of renal disease, hepatic disease, uveitis, and pulmonary hemorrhage. disease may follow periods of high rainfall, and can occur in dogs roaming in proximity to water sources, farm animals, or wildlife, or dogs residing in suburban environments. diagnosis is based on acute and convalescent p ...201021155890
stable expression of leptospira interrogans antigens in auxotrophic mycobacterium bovis bcg.mycobacterium bovis bcg has been proposed as an effective live vector for multivalent vaccines. the development of mycobacterial genetic systems to express foreign antigens and the adjuvanticity of bcg are the basis for the potential use of this attenuated mycobacterium as a recombinant vaccine vector. stable plasmid vectors without antibiotic resistance markers are needed for heterologous antigen expression in bcg. our group recently described the construction of a bcg expression system using a ...201021157628
methylthioadenosine/s-adenosylhomocysteine nucleosidase, a critical enzyme for bacterial metabolism.the importance of methylthioadenosine/s-adenosylhomocysteine (mta/sah) nucleosidase in bacteria has started to be appreciated only in the past decade. a comprehensive analysis of its various roles here demonstrates that it is an integral component of the activated methyl cycle, which recycles adenine and methionine through s-adenosylmethionine (sam)-mediated methylation reactions, and also produces the universal quorum-sensing signal, autoinducer-2 (ai-2). sam is also essential for synthesis of ...201021166890
methylthioadenosine/s-adenosylhomocysteine nucleosidase, a critical enzyme for bacterial metabolism.the importance of methylthioadenosine/s-adenosylhomocysteine (mta/sah) nucleosidase in bacteria has started to be appreciated only in the past decade. a comprehensive analysis of its various roles here demonstrates that it is an integral component of the activated methyl cycle, which recycles adenine and methionine through s-adenosylmethionine (sam)-mediated methylation reactions, and also produces the universal quorum-sensing signal, autoinducer-2 (ai-2). sam is also essential for synthesis of ...201021166890
responses of human endothelial cells to pathogenic and non-pathogenic leptospira species.leptospirosis is a widespread zoonotic infection that primarily affects residents of tropical regions, but causes infections in animals and humans in temperate regions as well. the agents of leptospirosis comprise several members of the genus leptospira, which also includes non-pathogenic, saprophytic species. leptospirosis can vary in severity from a mild, non-specific illness to severe disease that includes multi-organ failure and widespread endothelial damage and hemorrhage. to begin to inves ...201021179504
leptospirosis: a toll road from b lymphocytes.leptospirosis is a widespread zoonosis caused by leptospira interrogans, a pathogen transmitted by asymptomatic infected rodents. leptospiral lipoproteins and lipopolysaccharide (lps) have been shown to stimulate murine cells via toll-like receptors (tlrs) 2 and 4. host defense mechanisms remain obscure, although tlr4 has been associated with clearing leptospira. in a recent study, we showed that in response to leptospira infection, double (tlr2 and tlr4) knock-out (dko) mice unexpectedly develo ...201021199604
self-mating in the definitive host potentiates clonal outbreaks of the apicomplexan parasites sarcocystis neurona and toxoplasma gondii.tissue-encysting coccidia, including toxoplasma gondii and sarcocystis neurona, are heterogamous parasites with sexual and asexual life stages in definitive and intermediate hosts, respectively. during its sexual life stage, t. gondii reproduces either by genetic out-crossing or via clonal amplification of a single strain through self-mating. out-crossing has been experimentally verified as a potent mechanism capable of producing offspring possessing a range of adaptive and virulence potentials. ...201021203443
big domains are novel ca²+-binding modules: evidences from big domains of leptospira immunoglobulin-like (lig) proteins.many bacterial surface exposed proteins mediate the host-pathogen interaction more effectively in the presence of ca²+. leptospiral immunoglobulin-like (lig) proteins, liga and ligb, are surface exposed proteins containing bacterial immunoglobulin like (big) domains. the function of proteins which contain big fold is not known. based on the possible similarities of immunoglobulin and βγ-crystallin folds, we here explore the important question whether ca²+ binds to a big domains, which would prov ...201021206924
burkholderia cenocepacia creates an intramacrophage replication niche in zebrafish embryos, followed by bacterial dissemination and establishment of systemic infection.bacteria belonging to the "burkholderia cepacia complex" (bcc) often cause fatal pulmonary infections in cystic fibrosis patients, yet little is know about the underlying molecular mechanisms. these gram-negative bacteria can adopt an intracellular lifestyle, although their ability to replicate intracellularly has been difficult to demonstrate. here we show that bcc bacteria survive and multiply in macrophages of zebrafish embryos. local dissemination by nonlytic release from infected cells was ...201020086083
surveys for disease agents in introduced elk in arkansas and kentucky.surveys for disease agents were conducted in introduced free-ranging elk (cervus elaphus nelsoni) in arkansas and kentucky. elk had been captured in colorado and nebraska and released in arkansas during 1981-1985. from 1997 through 2002 elk were captured in arizona, kansas, north dakota, new mexico, oregon, and utah and released in southeastern kentucky. specimens were collected from 170 hunter-killed elk in arkansas during 1998-2006, and 44 elk in kentucky during 2001-2004. significant findings ...201020090032
serological patterns of brucellosis, leptospirosis and q fever in bos indicus cattle in cameroon.brucellosis, leptospirosis and q fever are important infections of livestock causing a range of clinical conditions including abortions and reduced fertility. in addition, they are all important zoonotic infections infecting those who work with livestock and those who consume livestock related products such as milk, producing non-specific symptoms including fever, that are often misdiagnosed and that can lead to severe chronic disease. this study used banked sera from the adamawa region of camer ...201020098670
global transcriptomic response of leptospira interrogans serovar copenhageni upon exposure to serum.leptospirosis is a zoonosis of worldwide distribution caused by infection with pathogenic serovars of leptospira spp. the most common species, l. interrogans, can survive in the environment for lengthy periods of time in between infection of mammalian hosts. transmission of pathogenic leptospira to humans mostly occurs through abraded skin or mucosal surfaces after direct or indirect contact with infected animals or contaminated soil or water. the spirochete then spreads hematogenously, resultin ...201020113507
severe leptospirosis in hospitalized patients, guadeloupe.we evaluated prognostic factors for leptospirosis in 168 consecutive hospitalized patients in guadeloupe. factors independently associated with severity included chronic hypertension or chronic alcoholism, late initiation of antibacterial therapy, abnormal chest auscultation results, icterus, oligoanuria, disorders of consciousness, elevated aspartate aminotransferase levels, hyperamylasemia, and leptospira interrogans serovar icterohemorrhagiae.201020113574
the contribution of bats to leptospirosis transmission in sao paulo city, brazil.the biodiversity of potential leptospiral reservoir hosts is lower in urban than in rural environments. previous data indicate the potential for bats to act as carriers of leptospira in regions such as the amazon of south america and in australia. yet, little is known about the contribution of bats to leptospirosis in urban environments in south america. this study aimed to test the hypothesis that bats infected with leptospira are sources of leptospirosis transmission to humans in são paulo cit ...201020134010
leptospiral endostatin-like protein a is a bacterial cell surface receptor for human plasminogen.the spirochete leptospira interrogans is a highly invasive pathogen of worldwide public health importance. studies from our laboratories and another have demonstrated that l. interrogans can acquire host plasminogen on its surface. exogenous plasminogen activators can then convert bound plasminogen into the functionally active protease plasmin. in this study, we extend upon those observations and report that leptospiral endostatin-like protein a (lena) binds human plasminogen in a dose-dependent ...201020160016
decrease of plasma platelet-activating factor acetylhydrolase activity in lipopolysaccharide induced mongolian gerbil sepsis model.platelet-activating factor (paf) plays an important role in the pathogenesis of sepsis, and the level of plasma paf acetylhydrolase (ppaf-ah), which inactivates paf, decreases in sepsis patients except for the sepsis caused by severe leptospirosis. usually, increase of ppaf-ah activity was observed in lipopolysaccharide (lps)-induced syrian hamster and rat sepsis models, while contradictory effects were reported for mouse model in different studies. here, we demonstrated the in vivo effects of l ...201020169191
[a case of severe leptospirosis infection (weil's disease) in tokyo].we report a case of severe leptospirosis infection (weil's disease) in tokyo. a 54-year-old man admitted on september 14, 2006, for a 5-day inability to walk due to severe progressive bilateral leg pain, shoulder pain, and fever exhibited jaundice, conjunctival suffusion, hypoxia, and grasping pain in the bilateral leg muscles. laboratory findings showed severe liver damage, renal failure, leukocytosis, anemia, thrombocytopenia, elevated crp, hyponatremia, and hypokalemia. chest x-ray imaging sh ...201020170016
analysis of 16s rdna sequences from pathogenic leptospira serovars and use of single nucleotide polymorphisms for rapid speciation by d-hplc.leptospira have a worldwide distribution and include important zoonotic pathogens yet diagnosis and differentiation still tend to rely on traditional bacteriological and serological approaches. in this study a 1.3 kb fragment of the rrs gene (16s rdna) was sequenced from a panel of 22 control strains, representing serovars within the pathogenic species leptospira interrogans, leptospiraborgpetersenii, and leptospirakirschneri, to identify single nucleotide polymorphisms (snps). these were identi ...201020172572
inactivation of a putative flagellar motor switch protein flig1 prevents borrelia burgdorferi from swimming in highly viscous media and blocks its infectivity.the flagellar motor switch complex protein flig plays an essential role in flagella biosynthesis and motility. in most motile bacteria, only one flig homologue is present in the genome. however, several spirochete species have two putative flig genes (referred to as flig1 and flig2) and their roles in flagella assembly and motility remain unknown. in this report, the lyme disease spirochete borrelia burgdorferi was used as a genetic model to investigate the roles of these two flig homologues. it ...201020180908
asymptomatic renal colonization of humans in the peruvian amazon by leptospira.renal carriage and shedding of leptospires is characteristic of carrier or maintenance animal hosts. sporadic reports indicate that after infection, humans may excrete leptospires for extended periods. we hypothesized that, like mammalian reservoir hosts, humans develop asymptomatic leptospiruria in settings of high disease transmission such as the peruvian amazon.201020186328
leptospira interrogans icterohaemorrhagiae in a patient with crohn's disease. 201020186939
a trk/hkt-type k+ transporter from trypanosoma brucei.the molecular mechanisms of k(+) homeostasis are only poorly understood for protozoan parasites. trypanosoma brucei subsp. parasites, the causative agents of human sleeping sickness and nagana, are strictly extracellular and need to actively concentrate k(+) from their hosts' body fluids. the t. brucei genome contains two putative k(+) channel genes, yet the trypanosomes are insensitive to k(+) antagonists and k(+) channel-blocking agents, and they do not spontaneously depolarize in response to ...201020190075
killing of treponema denticola by mouse peritoneal macrophages.treponema denticola has been identified as an important cause of periodontal disease and hypothesized to be involved in extra-oral infections. the objective of this study was to investigate the role of t. denticola cell length and motility during mouse peritoneal macrophages in vitro uptake. macrophages, incubated under aerobic and anaerobic conditions, produced a similar amount of tnf-alpha when stimulated with escherichia coli lps. the uptake of flge- and cfpa-deficient mutants of t. denticola ...201020200417
cloning and characterization of three cheb genes in leptospira interrogans.motility and chemotaxis systems are critical for the virulence of leptospires. there were multiple copies of putative chemotaxis homologs located at leptospires large chromosome. cheb1 and cheb3 from leptospira interrogans strain lai are predicted to have a global cheb-like domain, but cheb2 is predicted to have a c-terminal effector domain only. in order to verify the function of three putative cheb genes, they were cloned into pqe31 vector and then expressed, respectively, in wild-type escheri ...201020213047
functional characterization of gdp-mannose pyrophosphorylase from leptospira interrogans serovar copenhageni.leptospira interrogans synthesizes a range of mannose-containing glycoconjugates relevant for its virulence. a prerequisite in the synthesis is the availability of the gdp-mannose, produced from mannose-1-phosphate and gtp in a reaction catalyzed by gdp-mannose pyrophosphorylase. the gene coding for a putative enzyme in l. interrogans was expressed in escherichia coli bl21(de3). the identity of this enzyme was confirmed by electrospray-mass spectroscopy, edman sequencing and immunological assays ...201020035319
ompa-like protein loa22 from leptospira interrogans serovar lai is cytotoxic to cultured rat renal cells and promotes inflammatory responses.leptospirosis renal disease is one of the common clinical manifestations of leptospirosis, including acute renal failure and tubulointerstitial nephritis. outer membrane protein a-like protein loa22 is a lipoprotein from leptospira interrogans and has been suggested to be a corresponding virulence factor. however, the role of loa22 in leptospiral nephropathy is not yet understood. in the present study, we constructed a vector and artificially expressed loa22 in escherichia coli bl21(de)plyss cel ...201020043049
lack of demonstrable memory t cell responses in humans who have spontaneously recovered from leptospirosis in the peruvian amazon.background. we tested the hypothesis that patients who have recovered from leptospirosis have peripheral blood memory t cells that are specific for leptospira or leptospira protein antigens. methods. peripheral blood mononuclear cells (pbmcs) were obtained from patients who had recovered from leptospirosis, as well as from control individuals. pbmcs were assessed for in vitro proliferation, phenotyping, and cytokine production after stimulation with different strains of leptospira, recombinant l ...201020053135
evaluation of a recombinant ligb protein of leptospira interrogans serovar canicola in an enzyme-linked immunosorbent assay for the serodiagnosis of bovine leptospirosis.a recombinant leptospiral lipoprotein, ligb, was evaluated for use in the diagnosis of bovine leptospirosis by enzyme-linked immunosorbent assay (rligb igg elisa). the standard reference test (microscopic agglutination test, mat) of 200 serum samples from cattle suspected of leptospirosis showed that 95 (47.5%) samples had positive agglutination titres, which ranged from 100 to 1600. in rligb igg elisa, 49% of the samples were positive. sensitivity of igg elisa for 95 bovine sera, which had mat ...201020022618
lipl53, a temperature regulated protein from leptospira interrogans that binds to extracellular matrix molecules.the regulation of gene expression by environmental signals, such as temperature and osmolarity, has been correlated with virulence. in this study, we characterize the protein lipl53 from leptospira interrogans, previously shown to react with serum sample of individual diagnosed with leptospirosis and to be up-regulated by shift to physiological osmolarity. the recombinant protein was expressed in escherichia coli system, in insoluble form, recovered by urea solubilization and further refolded by ...201020026283
mechanism of substrate recognition and insight into feedback inhibition of homocitrate synthase from thermus thermophilus.homocitrate synthase (hcs) catalyzes aldol-type condensation of acetyl coenzyme a (acetyl-coa) and alpha-ketoglutarate (alpha-kg) to synthesize homocitrate (hc), which is the first and committed step in the lysine biosynthetic pathway through alpha-aminoadipate. as known in most enzymes catalyzing the first reactions in amino acid biosynthetic pathways, hcs is regulated via feedback inhibition by the end product, lysine. here, we determined the crystal structures of hcs from thermus thermophilus ...201019996101
mechanism of substrate recognition and insight into feedback inhibition of homocitrate synthase from thermus thermophilus.homocitrate synthase (hcs) catalyzes aldol-type condensation of acetyl coenzyme a (acetyl-coa) and alpha-ketoglutarate (alpha-kg) to synthesize homocitrate (hc), which is the first and committed step in the lysine biosynthetic pathway through alpha-aminoadipate. as known in most enzymes catalyzing the first reactions in amino acid biosynthetic pathways, hcs is regulated via feedback inhibition by the end product, lysine. here, we determined the crystal structures of hcs from thermus thermophilus ...201019996101
multilocus sequence analysis for typing leptospira interrogans and leptospira kirschneri.fifty-three strains belonging to the pathogenic species leptospira interrogans and leptospira kirschneri were analyzed by multilocus sequence analysis. the species formed two distinct branches. in the l. interrogans branch, the phylogenetic tree clustered the strains into three subgroups. genogroups and serogroups were superimposed but not strictly.201019955271
the crystal structure of the novobiocin biosynthetic enzyme novp: the first representative structure for the tylf o-methyltransferase superfamily.novp is an s-adenosyl-l-methionine-dependent o-methyltransferase that catalyzes the penultimate step in the biosynthesis of the aminocoumarin antibiotic novobiocin. specifically, it methylates at 4-oh of the noviose moiety, and the resultant methoxy group is important for the potency of the mature antibiotic: previous crystallographic studies have shown that this group interacts directly with the target enzyme dna gyrase, which is a validated drug target. we have determined the high-resolution c ...201019857499
the crystal structure of the novobiocin biosynthetic enzyme novp: the first representative structure for the tylf o-methyltransferase superfamily.novp is an s-adenosyl-l-methionine-dependent o-methyltransferase that catalyzes the penultimate step in the biosynthesis of the aminocoumarin antibiotic novobiocin. specifically, it methylates at 4-oh of the noviose moiety, and the resultant methoxy group is important for the potency of the mature antibiotic: previous crystallographic studies have shown that this group interacts directly with the target enzyme dna gyrase, which is a validated drug target. we have determined the high-resolution c ...201019857499
functional characterization of borrelia spielmanii outer surface proteins that interact with distinct members of the human factor h protein family and with plasminogen.acquisition of complement regulator factor h (cfh) and factor h-like protein 1 (cfhl1) from human serum enables borrelia spielmanii, one of the etiological agents of lyme disease, to evade complement-mediated killing by the human host. up to three distinct complement regulator-acquiring surface proteins (crasps) may be expressed by serum-resistant b. spielmanii, each exhibiting an affinity for cfh and/or cfhl1. here, we describe the functional characterization of the 15-kda crasps of b. spielman ...201019858303
functional characterization of borrelia spielmanii outer surface proteins that interact with distinct members of the human factor h protein family and with plasminogen.acquisition of complement regulator factor h (cfh) and factor h-like protein 1 (cfhl1) from human serum enables borrelia spielmanii, one of the etiological agents of lyme disease, to evade complement-mediated killing by the human host. up to three distinct complement regulator-acquiring surface proteins (crasps) may be expressed by serum-resistant b. spielmanii, each exhibiting an affinity for cfh and/or cfhl1. here, we describe the functional characterization of the 15-kda crasps of b. spielman ...201019858303
replication or death: distinct fates of pathogenic leptospira strain lai within macrophages of human or mouse origin.pathogenic leptospires evoke severe diseases in humans but only cause mild chronic or asymptomatic infection in many host animals. the reasons for this diversity of infection remain unclear. here, we demonstrated that leptospira interrogans serovar lai strain lai had a similar ability to adhere to and enter primary and immortal (thp-1 and j774a.1) macrophages from human and mouse, but its intracellular fate in human macrophages differed markedly from that in mouse. the leptospires resided within ...201019587003
expression of tnf-alpha, tgf-beta, ip-10 and il-10 mrna in kidneys of hamsters infected with pathogenic leptospira.leptospirosis is a worldwide zoonosis caused by pathogenic leptospira. although several components of this organism have been identified, the molecular mechanisms underlying pathogenesis of this infectious disease are still poorly understood. besides, direct injury by microbial factors, cytokines produced in response to infection have been proposed to be involved in pathogenesis of leptospirosis. in this study, cytokine gene expression in kidneys was investigated. hamsters were injected with pat ...201019559480
lsa63, a newly identified surface protein of leptospira interrogans binds laminin and collagen iv.leptospira interrogans is the etiological agent of leptospirosis, a zoonotic disease that affects populations worldwide. we have identified in proteomic studies a protein that is encoded by the gene lic10314 and expressed in virulent strain of l. interrogans serovar pomona. this protein was predicted to be surface exposed by psort program and contains a p83/100 domain identified by blast analysis that is conserved in protein antigens of several strains of borrelia and treponema spp. the proteins ...201019879894
high-coverage proteome analysis reveals the first insight of protein modification systems in the pathogenic spirochete leptospira interrogans.leptospirosis is a widespread zoonotic disease caused by pathogenic spirochetes of the genus leptospira that infects humans and a wide range of animals. by combining computational prediction and high-accuracy tandem mass spectra, we revised the genome annotation of leptospira interrogans serovar lai, a free-living pathogenic spirochete responsible for leptospirosis, providing substantial peptide evidence for novel genes and new gene boundaries. subsequently, we presented a high-coverage proteome ...201019918266
a microbiological and serological study of leptospirosis among pigs in the morogoro municipality, tanzania.serological and microbiological studies on leptospirosis in pigs from morogoro municipality, tanzania were carried out between october 2007 and may 2008. serum samples (n = 385) from apparently healthy pigs were tested by microscopic agglutination test for antibodies against live cultures of six known leptospira interrogans serovars: pomona, icterohaemorrhagiae, ballum, tarassovi, grippotyphosa and hardjo. significant positive titres were detected in 4.42% (17/385) of all the tested serum sample ...201019763865
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