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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
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
save the tree of life or get lost in the woods.the wealth of prokaryotic genomic data available has revealed that the histories of many genes are inconsistent, leading some to question the value of the tree of life hypothesis. it has been argued that a tree-like representation requires suppressing too much information, and that a more pluralistic approach is necessary for understanding prokaryotic evolution. we argue that trees may still be a useful representation for evolutionary histories in light of new data.201020594329
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
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
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
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
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
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
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
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
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
an outbreak of severe leptospirosis in capuchin (cebus) monkeys.naturally acquired acute leptospirosis in monkeys is uncommon. this study reports an outbreak of severe leptospirosis among 52 capuchin (cebus) monkeys that had been rescued from homes and housed in a wildlife rehabilitation center in colombia in 2007. case confirmation consisted of leptospira isolation followed by a polymerase chain reaction targeting the lipl32 gene. the attack and mortality rates were 71% and 27%, respectively. sixteen cases were confirmed. necropsy revealed diffuse jaundice ...201120554228
unifying vertical and nonvertical evolution: a stochastic arg-based framework.evolutionary biologists have introduced numerous statistical approaches to explore nonvertical evolution, such as horizontal gene transfer, recombination, and genomic reassortment, through collections of markov-dependent gene trees. these tree collections allow for inference of nonvertical evolution, but only indirectly, making findings difficult to interpret and models difficult to generalize. an alternative approach to explore nonvertical evolution relies on phylogenetic networks. these networ ...200920525618
unifying vertical and nonvertical evolution: a stochastic arg-based framework.evolutionary biologists have introduced numerous statistical approaches to explore nonvertical evolution, such as horizontal gene transfer, recombination, and genomic reassortment, through collections of markov-dependent gene trees. these tree collections allow for inference of nonvertical evolution, but only indirectly, making findings difficult to interpret and models difficult to generalize. an alternative approach to explore nonvertical evolution relies on phylogenetic networks. these networ ...200920525618
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
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
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
[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
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
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
[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
the cultivation of spirochaeta icterohaemorrhagiae and the production of a therapeutic anti-spirochaetal serum. 191920474680
[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
[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
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
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
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
first isolation of human leptospira strains, azores, portugal.the aim of this study was the first identification of leptospira isolates from azorean inpatients.201020413339
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
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
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
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
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
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
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
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
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
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
bilateral facial palsy associated with leptospirosis.leptospirosis is a zoonosis of worldwide occurrence caused by the spirochete leptospira interrogans. it is an acute feverish disease with a broad clinical spectrum and follows a characteristic biphasic course. bilateral facial palsy is a rare clinical condition and the differential diagnosis of its causes is extensive. the objective of this exploratory study, presented as a case report, is to describe the occurrence of bilateral facial palsy as an unusual manifestation of leptospirosis. this sug ...200920232000
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
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
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
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
leptospira interrogans icterohaemorrhagiae in a patient with crohn's disease. 201020186939
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
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
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
[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
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
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
host-microbe interactions in the developing zebrafish.the amenability of the zebrafish to in vivo imaging and genetic analysis has fueled expanded use of this vertebrate model to investigate the molecular and cellular foundations of host-microbe relationships. study of microbial encounters in zebrafish hosts has concentrated on developing embryonic and larval stages, when the advantages of the zebrafish model are maximized. a comprehensive understanding of these host-microbe interactions requires appreciation of the developmental context into which ...201020153622
a persistent and diverse airway microbiota present during chronic obstructive pulmonary disease exacerbations.acute exacerbations of chronic obstructive pulmonary disease (copd) are a major source of morbidity and contribute significantly to healthcare costs. although bacterial infections are implicated in nearly 50% of exacerbations, only a handful of pathogens have been consistently identified in copd airways, primarily by culture-based methods, and the bacterial microbiota in acute exacerbations remains largely uncharacterized. the aim of this study was to comprehensively profile airway bacterial com ...201020141328
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
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
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
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
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
the path to next generation biofuels: successes and challenges in the era of synthetic biology.volatility of oil prices along with major concerns about climate change, oil supply security and depleting reserves have sparked renewed interest in the production of fuels from renewable resources. recent advances in synthetic biology provide new tools for metabolic engineers to direct their strategies and construct optimal biocatalysts for the sustainable production of biofuels. metabolic engineering and synthetic biology efforts entailing the engineering of native and de novo pathways for con ...201020089184
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
cytopathic effect in bhk 21 (c13) cells inoculated with leptospira interrogans serovar pomona isolated from a porcine abortion. 200920085192
differential cytokine gene expression according to outcome in a hamster model of leptospirosis.parameters predicting the evolution of leptospirosis would be useful for clinicians, as well as to better understand severe leptospirosis, but are scarce and rarely validated. because severe leptospirosis includes septic shock, similarities with predictors evidenced for sepsis and septic shock were studied in a hamster model.201020076757
leptospira wolffii, a potential new pathogenic leptospira species detected in human, sheep and dog.leptospirosis is the most common zoonotic disease, which is transmitted to humans through contaminated water or direct exposure to the urine of infected animals. in this study, the presence and prevalence of leptospira species in the infected samples of human (n=369) and sheep (n=75) sera and also dogs' urine (n=150), collected from four provinces of iran, were investigated by using nested-pcr/rflp assay followed by sequencing analysis. nested-pcr assay detected that 98/369 (26.5%) human, 13/75 ...201020074666
of guinea pigs and men--an unusual case of jaundice.a 21-year-old male presented at the emergency room with jaundice, itching, dry cough, malaise and weight loss of 10 kg during the preceding four weeks. eighteen months earlier, the patient had suffered an automobile accident leading to polytrauma. serological markers for viral or other causes of hepatitis were absent. for suspected secondary sclerosing cholangitis, ultrasound and ercp were performed but failed to reveal pathological findings. a liver biopsy showed cholestatic liver disease witho ...201020072994
tlr cross-talk mechanism of hemorrhagic shock-primed pulmonary neutrophil infiltration.hemorrhage resulted from severe trauma renders patients susceptible to the development of acute lung injury (ali). the accumulation of polymorphonuclear neutrophils (pmn) in the lung is a critical event in the development of ali. pmn migration is a result of a cascade of cellular events, in which pmn, endothelial cells (ec), and macrophages (mϕ) act in concert. recent studies explored interrelated novel findings indicating that toll-like receptors (tlrs) cross-talk mechanisms occurring in pmn, e ...201020072711
identification and characterization of ompa-like proteins as novel vaccine candidates for leptospirosis.leptospira is an important infectious gram-negative bacterium causing leptospirosis in mammals. outer membrane proteins (omps) are key molecules in the interface between the cell and its environment. a group of putative leptospiral outer membrane proteins with an ompa-like domain, comprising lp0056, lp0222, lp3615, lp3685, lp4337 and lbp328, were identified by bioinformatic methods and expressed as gst-tag fusion proteins. all these recombinant proteins were screened for immune-protective potent ...201020064477
experimental leptospirosis in capybaras (hydrochaeris hydrochaeris) infected with leptospira interrogans serovar pomona.capybara (hydrochaeris hydrochaeris), the largest rodent in the world, is widely distributed in south america. these animals live in areas with abundant water, which makes them a potential reservoir for leptospira. the objective of this study was to investigate seroconversion, leptospiremia, and leptospiruria in capybaras experimentally infected with a virulent strain of leptospira interrogans serovar pomona. seven capybaras were used: one control and six infected. agglutinins against serovar po ...200920063819
retrospective evaluation of idiopathic hematuria and associated pathology in grant's gazelles (gazella granti): 10 cases.ten cases of hematuria in grant's gazelle (gazella granti) (two male and eight female) from five institutions were examined and the clinicopathologic data summarized. five gazelles died spontaneously and five were euthanized. all gazelles had marked hematuria without pyuria. mean age at the onset of clinical signs and time of euthanasia or death was 5.0 +/- 1.4 yr and 8.2 +/- 3.7 yr, respectively. the severity of clinical signs with hematuria ranged from episodes of chronic intermittent hematuri ...200920063809
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
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
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
risk factors associated with the seroprevalence of leptospirosis, amongst at-risk groups in and around tanga city, tanzania.the epidemiological status of human leptospirosis in tanzania has not been well defined because of a general lack of awareness of the disease and difficulties in its diagnosis. a cross-sectional seroprevalence study, using the microscopic agglutination test with a threshold titre of 1 : 160, was therefore conducted, among various occupational groups from tanga city, in november 2005. of the 199 subjects investigated, 30 (15.1%) were found to have antibodies that reacted with antigens from at lea ...200920030995
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
early identification of leptospirosis-associated pulmonary hemorrhage syndrome by use of a validated prediction model.to identify prediction factors for the development of leptospirosis-associated pulmonary hemorrhage syndrome (lphs).201020026189
early identification of leptospirosis-associated pulmonary hemorrhage syndrome by use of a validated prediction model.to identify prediction factors for the development of leptospirosis-associated pulmonary hemorrhage syndrome (lphs).201020026189
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
detection of leptospira in urine using anti-leptospira-coated gold nanoparticles.serological assays for antibody detection have been widely used for leptospirosis diagnosis. however, antibody is usually undetectable during the first week after infection. detection of leptospira dna can be done by pcr but this technique requires special equipments and the cost is still relatively high. here we demonstrate that gold nanoparticles can be used to facilitate leptospira detection. gold nanoparticles were coated with rabbit antibody specific to leptospira interrogans serovar bratis ...201120015548
averaging of electron subtomograms and random conical tilt reconstructions through likelihood optimization.the reference-free averaging of three-dimensional electron microscopy (3d-em) reconstructions with empty regions in fourier space represents a pressing problem in electron tomography and single-particle analysis. we present a maximum likelihood algorithm for the simultaneous alignment and classification of subtomograms or random conical tilt (rct) reconstructions, where the fourier components in the missing data regions are treated as hidden variables. the behavior of this algorithm was explored ...200920004160
inactivation of the fliy gene encoding a flagellar motor switch protein attenuates mobility and virulence of leptospira interrogans strain lai.pathogenic leptospira species cause leptospirosis, a zoonotic disease of global importance. the spirochete displays active rotative mobility which may contribute to invasion and diffusion of the pathogen in hosts. fliy is a flagellar motor switch protein that controls flagellar motor direction in other microbes, but its role in leptospira, and paricularly in pathogenicity remains unknown.200920003186
comparative transcriptional and translational analysis of leptospiral outer membrane protein expression in response to temperature.leptospirosis is a global zoonosis affecting millions of people annually. transcriptional changes in response to temperature were previously investigated using microarrays to identify genes potentially expressed upon host entry. past studies found that various leptospiral outer membrane proteins are differentially expressed at different temperatures. however, our microarray studies highlighted a divergence between protein abundance and transcript levels for some proteins. given the abundance of ...200919997626
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
epidemic dynamics at the human-animal interface.few infectious diseases are entirely human-specific: most human pathogens also circulate in animals or else originated in nonhuman hosts. influenza, plague, and trypanosomiasis are classic examples of zoonotic infections that transmit from animals to humans. the multihost ecology of zoonoses leads to complex dynamics, and analytical tools, such as mathematical modeling, are vital to the development of effective control policies and research agendas. much attention has focused on modeling pathoge ...200919965751
evidence that two atp-dependent (lon) proteases in borrelia burgdorferi serve different functions.the canonical atp-dependent protease lon participates in an assortment of biological processes in bacteria, including the catalysis of damaged or senescent proteins and short-lived regulatory proteins. borrelia spirochetes are unusual in that they code for two putative atp-dependent lon homologs, lon-1 and lon-2. borrelia burgdorferi, the etiologic agent of lyme disease, is transmitted through the blood feeding of ixodes ticks. previous work in our laboratory reported that b. burgdorferi lon-1 i ...200919956677
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
a pair of ligation-independent escherichia coli expression vectors for rapid addition of a polyhistidine affinity tag to the n- or c-termini of recombinant proteins.6x his tag is one of the most widely used affinity fusion tags that facilitates detection and purification of recombinant proteins. however, the location of this tag within a particular type of protein may influence the expression, solubility, and bioactivity of the protein, and the optimal location needs to be determined experimentally. to provide a tool for rapid generation of 6x his tags at the n- or c-terminus of any recombinant protein, we have constructed a pair of escherichia coli express ...200919949695
cohesion group approach for evolutionary analysis of aspartokinase, an enzyme that feeds a branched network of many biochemical pathways.aspartokinase (ask) exists within a variable network that supports the synthesis of 9 amino acids and a number of other important metabolites. lysine, isoleucine, aromatic amino acids, and dipicolinate may arise from the ask network or from alternative pathways. ask proteins were subjected to cohesion group analysis, a methodology that sorts a given protein assemblage into groups in which evolutionary continuity is assured. two subhomology divisions, ask(alpha) and ask(beta), have been recognize ...200919946135
evolutionary implication of outer membrane lipoprotein-encoding genes ompl1, upl32 and lipl41 of pathogenic leptospira species.leptospirosis is recognized as the most widespread zoonosis with a global distribution. in this study, the antigenic variation in leptospira interrogans and leptospira borgpetersenii isolated from human urine and field rat kidney was preliminarily confirmed by microscopic agglutination test using monoclonal antibodies, and was further subjected to amplification and identification of outer membrane lipoproteins with structural gene variation. sequence similarity analysis revealed that these prote ...200919944382
serological and genetic analysis of leptospirosis in patients with acute febrile illness in kandy, sri lanka.leptospirosis has emerged as an important infectious disease in sri lanka and little information is available on circulating leptospiral species and serogroups in this country. therefore, we studied circulating leptospiral species and serogroups in patients with acute febrile illness using polymerase chain reaction and the microscopic agglutination test, respectively. anti-leptospiral antibodies were detected in 26 of 107 serum samples studied (24.3%). the predominant reacting serogroups were se ...200919934544
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
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
comparing cellular proteomes by mass spectrometry.mass spectrometry and cryo-electron tomography together enable the determination of the absolute and relative abundances of proteins and their localization, laying the groundwork for comprehensive systems analyses of cells.200919886975
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
a comparison of the spirochete of yellow fever (leptospira icteroides noguchi) with the leptospira of weil's disease.the most noteworthy point observed in our studies is the extraordinary duration of life and the relatively meagre requirements for sustenance of leptospira icteroides. it is conceivable that under natural conditions opportunities might arise for the prolonged existence of leptospira icteroides, so that possibly after a lapse of years, the disease might reappear without introduction from outside. at any rate, the great viability of leptospira icteroides must be considered in this connection. a de ...192819869411
etiology of yellow fever : xiv. duration of the protective effect of anti-icteroides immune serum after subcutaneous inoculation into animals.analysis of the records of instances in which non-immune persons contracted yellow fever notwithstanding vaccination shows that the onset of disease occurs soon after vaccination, the longest period being 13 days. since the average incubation period in yellow fever is 6 days, it seems that infection must have taken place in some instances during the period while protection was developing. these instances led to a study of the possibility of immediate protection by means of the anti-icteroides se ...192219868677
etiology of yellow fever : xiii. behavior of the heart in the experimental infection of guinea pigs and monkeys with leptospira icteroides and leptospira icterohaemorrhagiae.1. slowing of the heart occurred in monkeys and guinea pigs during the febrile period of the experimental infection due to leptospira icteroides. a similar reaction took place in animals inoculated with leptospira icterohoemorrhagioe. 2. the mechanism of slowing was usually due to slowing of the whole heart. 3. once incomplete heart block was seen. changes in the ventricular complex occurred four times.192119868529
immunology of the peruvian strains of leptospira icteroides.serum from yellow fever convalescents from payta, piura, and morropon gave a positive pfeiffer reaction with the strains of leptospira icteroides isolated in guayaquil and merida. the serum also protected the guinea pigs from these strains in the majority of instances. the pfeiffer reaction was complete with all recent convalescents (7 to 36 days) but slight or partial in some instances with serum derived from individuals who had had the attack of yellow fever 10 months previously. the virulence ...192119868493
experimental studies on yellow fever in northern peru.fourteen typical cases of yellow fever were studied in northern peru during an epidemic occurring in 1920, nine in payta in march and april, and five in morropon and piura in april and may. the method of investigation was similar to that previously employed, but as the laboratory facilities were very meager certain changes were required. although in payta the work was handicapped by the lack of electric light, the scarcity of water and animal food, the unsuitability of the guinea pigs for inocul ...192119868492
immunological studies with a strain of leptospira isolated from a case of yellow fever in merida, yucatan.identification of the leptospira isolated from a case of yellow fever in merida was accomplished by means of an anti-icteroides immune serum prepared in a horse with several guayaquil strains of leptospira icteroides. the immune serum showed a protective action of high titer against the merida strain, thus establishing its efficacy as a therapeutic agent against this strain. polyvalent anti-icteroides immune serum prepared in the horse or monovalent anti-icteroides immune serums prepared in the ...192019868465
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