Publications

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[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
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
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
identification of immunodominant b- and t-cell combined epitopes in outer membrane lipoproteins lipl32 and lipl21 of leptospira interrogans.leptospirosis is a serious infectious disease caused by pathogenic leptospira. b- and t-cell-mediated immune responses contribute to the mechanisms of leptospira interrogans infection and immune intervention. lipl32 and lipl21 are the conserved outer membrane lipoproteins of l. interrogans and are considered vaccine candidates. in this study, we identified b- and t-cell combined epitopes within lipl32 and lipl21 to further develop a novel vaccine. by using a computer prediction algorithm, two b- ...201020237196
altered linkage of hydroxyacyl chains in lipid a of campylobacter jejuni reduces tlr4 activation and antimicrobial resistance.modification of the lipid a moiety of bacterial lipopolysaccharide influences cell wall properties, endotoxic activity, and bacterial resistance to antimicrobial peptides. known modifications are variation in the number or length of acyl chains and/or attached phosphoryl groups. here we identified two genes (gnna and gnnb) in the major foodborne pathogen campylobacter jejuni that enable the synthesis of a glcn3n precursor udp 2-acetamido-3-amino-2,3-dideoxy-alpha-d-glucopyranose (udp-glcnac3n) i ...201020351099
use of luminescent leptospira interrogans for enumeration in biological assays.rapid and reliable in vitro methods for the detection of pathogenic leptospires, such as leptospira interrogans, are lacking. the present study investigated the use of luminescence to replace the existing enumeration techniques. transposon tnsc189 was modified to incorporate the luxcdabe cassette from photorhabdus luminescens and was used to construct luminescent leptospira spp. there was a linear relationship between luminescence and cell number, with the theoretical detection limit being less ...201020375235
the infective causes of hepatitis and jaundice amongst hospitalised patients in vientiane, laos.there is little information on the diverse infectious causes of jaundice and hepatitis in the asiatic tropics. serology (hepatitis a, b, c and e, leptospirosis, dengue, rickettsia), antigen tests (dengue), pcr assays (hepatitis a, c and e) and blood cultures (septicaemia) were performed on samples from 392 patients admitted with jaundice or raised transaminases (> or =x3) to mahosot hospital, vientiane, laos over 3 years. conservative definitions suggested diagnoses of dengue (8.4%), rickettsios ...201020378138
characterization and serologic analysis of the treponema pallidum proteome.treponema pallidum subsp. pallidum is the causative agent of syphilis, a sexually transmitted disease characterized by widespread tissue dissemination and chronic infection. in this study, we analyzed the proteome of t. pallidum by the isoelectric focusing (ief) and nonequilibrating ph gel electrophoresis (nephge) forms of two-dimensional gel electrophoresis (2dge), coupled with matrix-assisted laser desorption ionization-time of flight (maldi-tof) analysis. we determined the identity of 148 t. ...201020385758
translocation of borrelia burgdorferi surface lipoprotein ospa through the outer membrane requires an unfolded conformation and can initiate at the c-terminus.borrelia burgdorferi surface lipoproteins are essential to the pathogenesis of lyme borreliosis, but the mechanisms responsible for their localization are only beginning to emerge. we have previously demonstrated the critical nature of the amino-terminal 'tether' domain of the mature lipoprotein for sorting a fluorescent reporter to the borrelia cell surface. here, we show that individual deletion of four contiguous residues within the tether of major surface lipoprotein ospa results in its inef ...201020398211
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
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
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
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
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
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
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
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
stray dogs as reservoirs of the zoonotic agents leptospira interrogans, trypanosoma cruzi, and aspergillus spp. in an urban area of chiapas in southern mexico.this investigation determined the presence and prevalence of the zoonotic agents leptospira interrogans, trypanosoma cruzi, and aspergillus spp. in the stray dog population (a total of 224 stray dogs) in an urban area of southern mexico. blood serum samples were taken from all dogs, and root hair samples were taken from dogs with skin lesions and partial alopecia. igg antibodies for l. interrogans from 10 serovars were detected using the microscopic agglutination test. immunofluorescence antibod ...201019514808
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
[biological risk prevention in agriculture and animal breeding: immunization strategies].vaccine preventable diseases are, so far, a main focus of public health programmes all over the world since people still die in consequence of dyphteria or tetanus. biological risk is widely represented in agriculture and animal breeding, due to environmental characteristics and to injury typology. moreover, aged people and migrants represent a significant part of the workforce. these two groups are, for instance, more exposed to clostridium tetani infection because not fully immunized. among in ...201021438285
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
virtual screening for potential inhibitors of homology modeled leptospira interrogans murd ligase.the life-threatening infections caused by leptospira serovars remain a global challenge since long time. prevention of infection by controlling environmental factors being difficult to practice in developing countries, there is a need for designing potent anti-leptospirosis drugs. atp-dependent murd involved in biosynthesis of peptidoglycan was identified as common drug target among pathogenic leptospira serovars through subtractive genomic approach. peptidoglycan biosynthesis pathway being uniq ...201021566738
in silico identification of common putative drug targets in leptospira interrogans.infectious diseases are the leading causes of death worldwide. hence, there is a need to develop new antimicrobial agents. traditional method of drug discovery is time consuming and yields a few drug targets with little intracellular information for guiding target selection. thus, focus in drug development has been shifted to computational comparative genomics for identifying novel drug targets. leptospirosis is a worldwide zoonosis of global concern caused by leptospira interrogans. availabilit ...201021572503
an emerging pulmonary haemorrhagic syndrome in dogs: similar to the human leptospiral pulmonary haemorrhagic syndrome?severe pulmonary haemorrhage is a rare necropsy finding in dogs but the leptospiral pulmonary haemorrhagic syndrome (lphs) is a well recognized disease in humans. here we report a pulmonary haemorrhagic syndrome in dogs that closely resembles the human disease. all 15 dogs had massive, pulmonary haemorrhage affecting all lung lobes while haemorrhage in other organs was minimal. histologically, pulmonary lesions were characterized by acute, alveolar haemorrhage without identifiable vascular lesio ...201021274452
infectious causes of stillbirth: a clinical perspective.untreated infection may cause stillbirth by several mechanisms, including direct fetal infection, placental damage, and severe maternal illness. many bacteria, viruses, and protozoa have been associated with stillbirth. in developed countries, up to 24% of stillbirths have been attributed to infection, although with increased availability of sophisticated diagnostics and rigorous screening, it appears likely that higher numbers may actually be associated with infection. in developed countries, a ...201020661048
complement control protein factor h: the good, the bad, and the inadequate.the complement system is an essential component of the innate immune system that participates in elimination of pathogens and altered host cells and comprises an essential link between the innate and adaptive immune system. soluble and membrane-bound complement regulators protect cells and tissues from unintended complement-mediated injury. complement factor h is a soluble complement regulator essential for controlling the alternative pathway in blood and on cell surfaces. normal recognition of ...201020580090
the expression and functions of toll-like receptors in atherosclerosis.inflammation drives atherosclerosis. both immune and resident vascular cell types are involved in the development of atherosclerotic lesions. the phenotype and function of these cells are key in determining the development of lesions. toll-like receptors are the most characterised innate immune receptors and are responsible for the recognition of exogenous conserved motifs on pathogens, and, potentially, some endogenous molecules. both endogenous and exogenous tlr agonists may be present in athe ...201020652007
infection-related stillbirths.infection is an important cause of stillbirths worldwide: in low-income and middle-income countries, 50% of stillbirths or more are probably caused by infection. by contrast, in high-income countries only 10-25% of stillbirths are caused by infection. syphilis, where prevalent, causes most infectious stillbirths, and is the infection most amenable to screening and treatment. ascending bacterial infection is a common cause of stillbirths, but prevention has proven elusive. many viral infections c ...201020223514
leptospirosis induced pulmonary alveolar hemorrhage.leptospirosis, a zoonosis with protean manifestations caused by the spirochete leptospira interrogans, occurs worldwide. we report a case of leptospirosis presenting as pulmonary alveolar hemorrhage in a young immunocompetent male. this organism should be considered as an important infectious cause of pulmonary alveolar hemorrhage in the appropriate epidemiological setting.201021932486
a bacterial ortholog of class ii lysyl-trna synthetase activates lysine.aminoacyl-trna synthetases produce aminoacyl-trnas, essential substrates for accurate protein synthesis. beyond their central role in translation some of these enzymes or their orthologs are recruited for alternative functions, not always related to their primary cellular role. we investigate here the enzymatic properties of genx (also called poxa and yjea), an ortholog of bacterial class ii lysyl-trna synthetase. genx is present in most gram-negative bacteria and is homologous to the catalytic ...201020580719
abundant oligonucleotides common to most bacteria.bacteria show a bias in their genomic oligonucleotide composition far beyond that dictated by g+c content. patterns of over- and underrepresented oligonucleotides carry a phylogenetic signal and are thus diagnostic for individual species. patterns of short oligomers have been investigated by multiple groups in large numbers of bacteria genomes. however, global distributions of the most highly overrepresented mid-sized oligomers have not been assessed across all prokaryotes to date. we surveyed o ...201020352124
a flood of microbial genomes-do we need more? 200919513110
rapid universal identification of bacterial pathogens from clinical cultures by using a novel sloppy molecular beacon melting temperature signature technique.a real-time pcr assay with the ability to rapidly identify all pathogenic bacteria would have widespread medical utility. current real-time pcr technologies cannot accomplish this task due to severe limitations in multiplexing ability. to this end, we developed a new assay system which supports very high degrees of multiplexing. we developed a new class of mismatch-tolerant "sloppy" molecular beacons, modified them to provide an extended hybridization range, and developed a multiprobe, multimelt ...200919923485
rapid universal identification of bacterial pathogens from clinical cultures by using a novel sloppy molecular beacon melting temperature signature technique.a real-time pcr assay with the ability to rapidly identify all pathogenic bacteria would have widespread medical utility. current real-time pcr technologies cannot accomplish this task due to severe limitations in multiplexing ability. to this end, we developed a new assay system which supports very high degrees of multiplexing. we developed a new class of mismatch-tolerant "sloppy" molecular beacons, modified them to provide an extended hybridization range, and developed a multiprobe, multimelt ...200919923485
lateral transfer of genes and gene fragments in prokaryotes.lateral genetic transfer (lgt) involves the movement of genetic material from one lineage into another and its subsequent incorporation into the new host genome via genetic recombination. studies in individual taxa have indicated lateral origins for stretches of dna of greatly varying length, from a few nucleotides to chromosome size. here we analyze 1,462 sets of single-copy, putatively orthologous genes from 144 fully sequenced prokaryote genomes, asking to what extent complete genes and fragm ...200920333212
the farmer who didn't need a wheel barrow.we report the difficulties encountered in diagnosing leptospirosis in an 85-year-old man who presented with non-specific signs and symptoms. initially, a wide haematologic and oncologic work-up without significant results was performed, as symptoms of several organ dysfunctions emerged and the clinical course showed a rapid deterioration. after several days without a definite diagnosis, the infection was finally detected after reviewing all results and considering the patient's profession as a f ...200921687022
proteome analysis of leptospira interrogans virulent strain.leptospirosis is a worldwide zoonotic infection of human and veterinary concern. caused by pathogenic spirochetes of the genus leptospira, the disease presents greater incidence in tropical and subtropical regions. the identification of proteins that could be involved in the bacteria host interactions may facilitate the search for immune protective antigens. we report the proteomic analysis of leptospira interrogans serovar pomona virulent strain lpf cultured from kidney and liver of infected ha ...200919590580
proteome-wide cellular protein concentrations of the human pathogen leptospira interrogans.mass-spectrometry-based methods for relative proteome quantification have broadly affected life science research. however, important research directions, particularly those involving mathematical modelling and simulation of biological processes, also critically depend on absolutely quantitative data--that is, knowledge of the concentration of the expressed proteins as a function of cellular state. until now, absolute protein concentration measurements of a considerable fraction of the proteome ( ...200919606093
leptospirosis research: fast, easy and reliable enumeration of mobile leptospires.leptospirosis caused by leptospira interrogans is the most widespread zoonosis and a major public health problem worldwide. based on light-scattering and absorption, quantification of leptospires using uv-vis spectroscopy was used as an indirect counting technique by measuring the optical density and comparing this to automated direct counting using a counting chamber in combination with imaging and analyzing software. two serovars, bangkok and copenhagenii, from log-phase growth were used for t ...200919621128
bayesian inference for within-herd prevalence of leptospira interrogans serovar hardjo using bulk milk antibody testing.leptospirosis is the most widespread zoonosis throughout the world and human mortality from severe disease forms is high even when optimal treatment is provided. leptospirosis is also one of the most common causes of reproductive losses in cattle worldwide and is associated with significant economic costs to the dairy farming industry. herds are tested for exposure to the causal organism either through serum testing of individual animals or through testing bulk milk samples. using serum results ...200919628639
tlr4- and tlr2-mediated b cell responses control the clearance of the bacterial pathogen, leptospira interrogans.leptospirosis is a widespread zoonosis caused by pathogenic leptospira interrogans that are transmitted by asymptomatic infected rodents. leptospiral lipoproteins and lps have been shown to stimulate murine cells via tlrs 2 and 4. host defense mechanisms remain obscure, although tlr4 has been shown to be involved in clearing leptospira. in this study, we show that double (tlr2 and tlr4) knockout (dko) mice rapidly died from severe hepatic and renal failure following leptospira inoculation. strik ...200919635914
a serological survey of leptospirosis in cattle of rural communities in the province of kwazulu-natal, south africa.a serological survey of leptospirosis in cattle originating from rural communities of the province of kwazulu-natal (kzn) in south africa was carried out between march 2001 and december 2003. the survey was designed as a 2-stage survey, using the local diptank as the primary sampling point. in total, 2021 animals from 379 diptanks in 33 magisterial districts were sampled and tested with the microscopic agglutination test (mat). the apparent prevalence at district level was adjusted for clusterin ...200919653519
crystal structure and acyl chain selectivity of escherichia coli lpxd, the n-acyltransferase of lipid a biosynthesis.lpxd catalyzes the third step of lipid a biosynthesis, the r-3-hydroxyacyl-acp-dependent n-acylation of udp-3-o-(acyl)-alpha-d-glucosamine, and is a target for new antibiotic development. here we report the 2.6 a crystal structure of the escherichia coli lpxd homotrimer (eclpxd). as is the case in chlamydia trachomatis lpxd (ctlxpd), each eclpxd chain consists of an n-terminal uridine-binding region, a left-handed parallel beta-helix (lbetah), and a c-terminal alpha-helical domain. the backbones ...200919655786
global proteome analysis of leptospira interrogans.comparative global proteome analyses were performed on leptospira interrogans serovar copenhageni grown under conventional in vitro conditions and those mimicking in vivo conditions (iron limitation and serum presence). proteomic analyses were conducted using itraq and lc-esi-tandem mass spectrometry complemented with two-dimensional gel electrophoresis and maldi-tof mass spectrometry. a total of 563 proteins were identified in this study. altered expression of 65 proteins, including upregulatio ...200919663501
innovations in host and microbial sialic acid biosynthesis revealed by phylogenomic prediction of nonulosonic acid structure.sialic acids (sias) are nonulosonic acid (nulo) sugars prominently displayed on vertebrate cells and occasionally mimicked by bacterial pathogens using homologous biosynthetic pathways. it has been suggested that sias were an animal innovation and later emerged in pathogens by convergent evolution or horizontal gene transfer. to better illuminate the evolutionary processes underlying the phenomenon of sia molecular mimicry, we performed phylogenomic analyses of biosynthetic pathways for sias and ...200919666579
an imprint method for detecting leptospires in the hamster model of vaccine-mediated immunity for leptospirosis.in determining the efficacy of new vaccine candidates for leptospirosis, the primary end point is death and an important secondary end point is sterilizing immunity. however, evaluation of this end point is often hampered by the time-consuming demands and complexity of methods such as culture isolation (ci). in this study, we evaluated the use of an imprint (or touch preparation) method (im) in detecting the presence of leptospires in tissues of hamsters infected with leptospira interrogans sero ...200919679685
wild boars as sources for infectious diseases in livestock and humans.wild boars (sus scrofa) are indigenous in many countries in the world. these free-living swine are known reservoirs for a number of viruses, bacteria and parasites that are transmissible to domestic animals and humans. changes of human habitation to suburban areas, increased use of lands for agricultural purposes, increased hunting activities and consumption of wild boar meat have increased the chances of exposure of wild boars to domestic animals and humans. wild boars can act as reservoirs for ...200919687039
immunoproteomic analysis of outer membrane proteins and extracellular proteins of actinobacillus pleuropneumoniae jl03 serotype 3.actinobacillus pleuropneumoniae is the causative agent of porcine contagious pleuropneumonia, a highly contagious respiratory infection in pigs, and all the 15 serotypes are able to cause disease. current vaccines including subunit vaccines could not provide satisfactory protection against a. pleuropneumoniae. in this study, the immunoproteomic approach was applied to the analysis of extracellular and outer membrane proteins of a. pleuropneumoniae jl03 serotype 3 for the identification of novel ...200919695095
a novel fibronectin type iii module binding motif identified on c-terminus of leptospira immunoglobulin-like protein, ligb.infection by pathogenic strains of leptospira hinges on the pathogen's ability to adhere to host cells via extracellular matrix such as fibronectin (fn). previously, the immunoglobulin-like domains of leptospira lig proteins were recognized as adhesins binding to n-terminal domain (ntd) and gelatin binding domain (gbd) of fn. in this study, we identified another fn-binding motif on the c-terminus of the leptospira adhesin ligb (ligbctv), residues 1708-1712 containing sequence lipad with a beta-s ...200919699715
immune response and prophylactic efficacy of smegmosomes in a hamster model of leptospirosis.leptospirosis is an important zoonotic disease worldwide. subunit vaccines are an attractive intervention strategy against this disease, but potent, non-toxic adjuvants are necessary components to any effective vaccine. among various adjuvant candidates, liposomes have garnered recent attention for their capacity as carriers of vaccines. in the present study we prepared novel liposomes using total polar lipids from the nonpathogenic bacterium, mycobacterium smegmatis (designated smegmosomes). th ...200919715780
disruption of the bmei0066 gene attenuates the virulence of brucella melitensis and decreases its stress tolerance.brucella melitensis is a facultative intracellular pathogen. an operon composed of bmei0066, which encodes a two-component response regulator cenr, and bmei0067, which encodes a camp-dependent protein kinase regulatory subunit, has been predicted to exist in many bacterial species. however, little is known about the function of this operon. in order to characterize this operon and assess its role in virulence, we constructed a marked deletion mutant of bmei0066. the mutant was less able to withs ...200919742243
development and validation of a real-time pcr for detection of pathogenic leptospira species in clinical materials.available serological diagnostics do not allow the confirmation of clinically suspected leptospirosis at the early acute phase of illness. several conventional and real-time pcrs for the early diagnosis of leptospirosis have been described but these have been incompletely evaluated. we developed a sybr green-based real-time pcr targeting secy and validated it according to international guidelines. to determine the analytical specificity, dna from 56 leptospira strains belonging to pathogenic, no ...200919763264
investigation of carbon metabolism in "dehalococcoides ethenogenes" strain 195 by use of isotopomer and transcriptomic analyses.members of the genus "dehalococcoides" are the only known microorganisms that can completely dechlorinate tetrachloroethene and trichloroethene to the innocuous end product, ethene. this study examines the central metabolism in "dehalococcoides ethenogenes" strain 195 via (13)c-labeled tracer experiments. supported by the genome annotation and the transcript profile, isotopomer analysis of key metabolites clarifies ambiguities in the genome annotation and identifies an unusual biosynthetic pathw ...200919525347
human leptospirosis cases and the prevalence of rats harbouring leptospira interrogans in urban areas of tokyo, japan.thirteen patients with leptospirosis were identified, as confirmed by laboratory analysis during the last 5 years in our laboratory, who came from urban areas of tokyo, japan. all of the patients came into contact with rats before the onset of illness. seventeen per cent of norway rats captured in the inner cities of tokyo carried leptospires in their kidneys. most of these rat isolates were leptospira interrogans serovar copenhageni/icterohaemorrhagiae. antibodies against these serovars and the ...200919528143
distribution of the leptospiral immunoglobulin-like (lig) genes in pathogenic leptospira species and application of ligb to typing leptospiral isolates.the family of leptospiral immunoglobulin-like (lig) genes comprises liga, ligb and ligc. this study used pcr to demonstrate the presence of lig genes among serovars from a collection of leptospiral strains and clinical isolates. whilst liga and ligc appeared to be present in a limited number of pathogenic serovars, the ligb gene was distributed ubiquitously among all pathogenic strains. none of the lig genes were detected among intermediate or saprophytic leptospira species. it was also shown th ...200919528180
a newly identified protein of leptospira interrogans mediates binding to laminin.pathogenic leptospira is the aetiological agent of leptospirosis, a life-threatening disease that affects populations worldwide. the search for novel antigens that could be relevant in host-pathogen interactions is being pursued. these antigens have the potential to elicit several activities, including adhesion. this study focused on a hypothetical predicted lipoprotein of leptospira, encoded by the gene lic12895, thought to mediate attachment to extracellular matrix (ecm) components. the gene w ...200919541787
leptospira interrogans stably infects zebrafish embryos, altering phagocyte behavior and homing to specific tissues.leptospirosis is an extremely widespread zoonotic infection with outcomes ranging from subclinical infection to fatal weil's syndrome. despite the global impact of the disease, key aspects of its pathogenesis remain unclear. to examine in detail the earliest steps in the host response to leptospires, we used fluorescently labelled leptospira interrogans serovar copenhageni to infect 30 hour post fertilization zebrafish embryos by either the caudal vein or hindbrain ventricle. these embryos have ...200919547748
case of fulminant leptospirosis in a renal transplant patient.we present a case of fulminant leptospirosis that was acquired in the suburban area by a 48-year-old male renal transplant recipient. he developed acute renal and hepatic failure with profound jaundice. spirochetes were identified on liver biopsy. weil's disease was suspected, and the diagnosis was further supported by a positive serum leptospira interrogans icterohaemorrhagiae antibody titer. unfortunately, he suffered from recurrent lower gastrointestinal bleeding, had a prolonged hospital cou ...200919558375
serum activity of platelet-activating factor acetylhydrolase is a potential clinical marker for leptospirosis pulmonary hemorrhage.pulmonary hemorrhage has been recognized as a major, often lethal, manifestation of severe leptospirosis albeit the pathogenesis remains unclear. the leptospira interrogans virulent serogroup icterohaemorrhagiae serovar lai encodes a protein (la2144), which exhibited the platelet-activating factor acetylhydrolase (paf-ah) activity in vitro similar to that of human serum with respect to its substrate affinity and specificity and thus designated l-paf-ah. on the other hand, the primary amino acid ...200919145243
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