Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| a genome-wide proteome array reveals a limited set of immunogens in natural infections of humans and white-footed mice with borrelia burgdorferi. | humans and other animals with lyme borreliosis produce antibodies to a number of components of the agent borrelia burgdorferi, but a full accounting of the immunogens during natural infections has not been achieved. employing a protein array produced in vitro from 1,292 dna fragments representing approximately 80% of the genome, we compared the antibody reactivities of sera from patients with early or later lyme borreliosis to the antibody reactivities of sera from controls. overall, approximate ... | 2008 | 18474646 |
| acyl chain specificity of the acyltransferases lpxa and lpxd and substrate availability contribute to lipid a fatty acid heterogeneity in porphyromonas gingivalis. | porphyromonas gingivalis lipid a is heterogeneous with regard to the number, type, and placement of fatty acids. analysis of lipid a by matrix-assisted laser desorption ionization-time of flight mass spectrometry reveals clusters of peaks differing by 14 mass units indicative of an altered distribution of the fatty acids generating different lipid a structures. to examine whether the transfer of hydroxy fatty acids with different chain lengths could account for the clustering of lipid a structur ... | 2008 | 18456814 |
| biology of infection with borrelia burgdorferi. | the spirochete borrelia burgdorferi is a tick-borne obligate parasite whose normal reservoir is a variety of small mammals. although infection of these natural hosts does not lead to disease, infection of humans can result in lyme disease as a consequence of the human immunopathologic response to b burgdorferi. consistent with the pathogenesis of lyme disease, bacterial products that allow b burgdorferi to replicate and survive seem to be primarily what is required for the bacterium to cause dis ... | 2008 | 18452798 |
| lsa21, a novel leptospiral protein binding adhesive matrix molecules and present during human infection. | it has been well documented over past decades that interaction of pathogens with the extracellular matrix (ecm) plays a primary role in host cell attachment and invasion. adherence to host tissues is mediated by surface-exposed proteins expressed by the microorganisms during infection. the mechanisms by which pathogenic leptospires invade and colonize the host remain poorly understood since few virulence factors contributing to the pathogenesis of the disease have been identified. whole-genome s ... | 2008 | 18445272 |
| severe course of rat bite-associated weil's disease in a patient diagnosed with a new leptospira-specific real-time quantitative lux-pcr. | leptospirosis is a zoonotic disease with global distribution, caused by spirochaetes of the genus leptospira. transmission of leptospira interrogans serovar icterohaemorrhagiae, the causative agent of weil's disease, to humans usually results from exposure to the urine of infected, but mostly asymptomatic, rodents, either by direct contact or indirectly through contaminated soil or water. although regarded as a re-emerging infectious disease, human leptospirosis is probably underdiagnosed due to ... | 2008 | 18436602 |
| impact of environment and social gradient on leptospira infection in urban slums. | leptospirosis has become an urban health problem as slum settlements have expanded worldwide. efforts to identify interventions for urban leptospirosis have been hampered by the lack of population-based information on leptospira transmission determinants. the aim of the study was to estimate the prevalence of leptospira infection and identify risk factors for infection in the urban slum setting. | 2008 | 18431445 |
| development and experimental validation of a predictive threshold cycle equation for quantification of virulence and marker genes by high-throughput nanoliter-volume pcr on the openarray platform. | development of quantitative pcr (qpcr) assays typically requires extensive screening within and across a given species to ensure specific detection and lucid identification among various pathogenic and nonpathogenic strains and to generate standard curves. to minimize screening requirements, multiple virulence and marker genes (vmgs) were targeted simultaneously to enhance reliability, and a predictive threshold cycle (c(t)) equation was developed to calculate the number of starting copies based ... | 2008 | 18424532 |
| genome-wide subcellular localization of putative outer membrane and extracellular proteins in leptospira interrogans serovar lai genome using bioinformatics approaches. | in bacterial pathogens, both cell surface-exposed outer membrane proteins and proteins secreted into the extracellular environment play crucial roles in host-pathogen interaction and pathogenesis. considerable efforts have been made to identify outer membrane (om) and extracellular (ex) proteins produced by leptospira interrogans, which may be used as novel targets for the development of infection markers and leptospirosis vaccines. | 2008 | 18423054 |
| antimicrobial susceptibilities of geographically diverse clinical human isolates of leptospira. | although antimicrobial therapy of leptospirosis has been studied in a few randomized controlled clinical studies, those studies were limited to specific regions of the world and few have characterized infecting strains. a broth microdilution technique for the assessment of antibiotic susceptibility has been developed at brooke army medical center. in the present study, we assessed the susceptibilities of 13 leptospira isolates (including recent clinical isolates) from egypt, thailand, nicaragua, ... | 2008 | 18411316 |
| lrua and lrub antibodies in sera of humans with leptospiral uveitis. | uveitis can be a serious complication of leptospirosis. previous studies indicated that the leptospiral lipoproteins lrua and lrub are expressed in the eyes of uveitic horses and that antibodies directed against those proteins show in vitro cross-reactivity with components of equine lens, ciliary body, and/or retina. we now demonstrate that sera from a significant proportion of humans who have leptospiral uveitis also contain antibodies against lrua and lrub. different categories of nonleptospir ... | 2008 | 18400972 |
| in lipl32, the major leptospiral lipoprotein, the c terminus is the primary immunogenic domain and mediates interaction with collagen iv and plasma fibronectin. | lipl32 is the major leptospiral outer membrane lipoprotein expressed during infection and is the immunodominant antigen recognized during the humoral immune response to leptospirosis in humans. in this study, we investigated novel aspects of lipl32. in order to define the immunodominant domains(s) of the molecule, subfragments corresponding to the n-terminal, intermediate, and c-terminal portions of the lipl32 gene were cloned and the proteins were expressed and purified by metal affinity chroma ... | 2008 | 18391007 |
| highly conserved surface proteins of oral spirochetes as adhesins and potent inducers of proinflammatory and osteoclastogenic factors. | oral spirochetes include enormously heterogeneous treponema species, and some have been implicated in the etiology of periodontitis. in this study, we characterized highly conserved surface proteins in four representative oral spirochetes (treponema denticola, t. lecithinolyticum, t. maltophilum, and t. socranskii subsp. socranskii) that are homologs of t. pallidum tp92, with opsonophagocytic potential and protective capacity against syphilis. tp92 homologs of oral spirochetes had predicted sign ... | 2008 | 18390996 |
| human leptospirosis caused by a new, antigenically unique leptospira associated with a rattus species reservoir in the peruvian amazon. | as part of a prospective study of leptospirosis and biodiversity of leptospira in the peruvian amazon, a new leptospira species was isolated from humans with acute febrile illness. field trapping identified this leptospire in peridomestic rats (rattus norvegicus, six isolates; r. rattus, two isolates) obtained in urban, peri-urban, and rural areas of the iquitos region. novelty of this species was proven by serological typing, 16s ribosomal rna gene sequencing, pulsed-field gel electrophoresis, ... | 2008 | 18382606 |
| sodium chloride affects helicobacter pylori growth and gene expression. | epidemiological evidence links high-salt diets and helicobacter pylori infection with increased risk of developing gastric maladies. the mechanism by which elevated sodium chloride content causes these manifestations is unclear. here we characterize the response of h. pylori to temporal changes in sodium chloride concentration and show that growth, cell morphology, survival, and virulence factor expression are all altered by increased salt concentration. | 2008 | 18375562 |
| vitamin k-dependent carboxylation. | vitamin k-dependent (vkd) protein carboxylation uses vitamin k epoxidation to convert glus to carboxylated glus (glas), rendering vkd proteins active in physiologies that include hemostasis, apoptosis, bone mineralization, calcium homeostasis, growth control, and signal transduction. clusters of glus are modified by a processive carboxylase, generating a calcium-binding module that allows binding to either hydroxyapatite in the extracellular matrices or cell surfaces where anionic phospholipids ... | 2008 | 18374193 |
| detection of pathogenic leptospira bacteria in pinniped populations via pcr and identification of a source of transmission for zoonotic leptospirosis in the marine environment. | leptospirosis, caused by the spirochete leptospira, is a geographically widespread disease that affects a broad range of mammals, including marine mammals. among pinniped populations, periodic epizootics of leptospirosis are responsible for significant die-offs. along the west coast of north america, the most recent leptospirosis epizootic occurred in 2004, during which samples were collected from cases ranging from california to british columbia. the primary objective of this study was to use t ... | 2008 | 18367568 |
| identification of a novel prophage-like gene cluster actively expressed in both virulent and avirulent strains of leptospira interrogans serovar lai. | dna microarray analysis was used to compare the differential gene expression profiles between leptospira interrogans serovar lai type strain 56601 and its corresponding attenuated strain ipav. a 22-kb genomic island covering a cluster of 34 genes (i.e., genes la0186 to la0219) was actively expressed in both strains but concomitantly upregulated in strain 56601 in contrast to that of ipav. reverse transcription-pcr assays proved that the gene cluster comprised five transcripts. gene annotation of ... | 2008 | 18362131 |
| household transmission of leptospira infection in urban slum communities. | leptospirosis, a spirochaetal zoonotic disease, is the cause of epidemics associated with high mortality in urban slum communities. infection with pathogenic leptospira occurs during environmental exposures and is traditionally associated with occupational risk activities. however, slum inhabitants reside in close proximity to environmental sources of contamination, suggesting that transmission during urban epidemics occurs in the household environment. | 2008 | 18357340 |
| selection of the internal control gene for real-time quantitative rt-pcr assays in temperature treated leptospira. | analysis of gene expression requires sensitive, precise, and reproducible measurements for specific mrna sequences. to avoid bias, real-time rt-pcr is referred to one or several internal control genes. here, we sought to identify a gene to be used as normalizer by analyzing three functional distinct housekeeping genes (lipl41, flab, and 16s rrna) for their expression level and stability in temperature treated leptospira cultures. leptospira interrogans serovar hardjo subtype hardjoprajitno was c ... | 2008 | 18347854 |
| leptospirosis: clinical presentation and correlation with serovars. | a total of 2400 patients with pyrexia of unknown origin and or suspected leptospirosis were included in this study. dark field microscopy detected leptospira in 690 cases, leptospira serological investigations proved positive in 570 out of these 690 patients. among them 212 had the classical icteric and the other 358 had anicteric type of presentation. notably eptospira interrogans serovar ictero haemorrhagiae infection was encountered in 212 patients. in 30 patients, who had multi organ dysfunc ... | 2007 | 18338689 |
| a novel gdp-dependent pyruvate kinase isozyme from toxoplasma gondii localizes to both the apicoplast and the mitochondrion. | we previously reported a cytosolic pyruvate kinase (ec 2.7.1.40) from toxoplasma gondii (tgpyki) that differs from most eukaryotic pyruvate kinases in being regulated by glucose 6-phosphate rather than fructose 1,6-diphosphate. another putative pyruvate kinase (tgpykii) was identified from parasite genome, which exhibits 32% amino acid sequence identity to tgpyki and retains pyruvate kinase signature motifs and amino acids essential for substrate binding and catalysis. whereas tgpyki is most clo ... | 2008 | 18326043 |
| leptospirosis-associated severe pulmonary hemorrhagic syndrome, salvador, brazil. | we report the emergence of leptospirosis-associated severe pulmonary hemorrhagic syndrome (sphs) in slum communities in salvador, brazil. although active surveillance did not identify sphs before 2003, 47 cases were identified from 2003 through 2005; the case-fatality rate was 74%. by 2005, sphs caused 55% of the deaths due to leptospirosis. | 2008 | 18325275 |
| cohesion group approach for evolutionary analysis of tyra, a protein family with wide-ranging substrate specificities. | many enzymes and other proteins are difficult subjects for bioinformatic analysis because they exhibit variant catalytic, structural, regulatory, and fusion mode features within a protein family whose sequences are not highly conserved. however, such features reflect dynamic and interesting scenarios of evolutionary importance. the value of experimental data obtained from individual organisms is instantly magnified to the extent that given features of the experimental organism can be projected u ... | 2008 | 18322033 |
| cytotoxic activity and probable apoptotic effect of sph2, a sphigomyelinase hemolysin from leptospira interrogans strain lai. | our previous work confirmed that sph2/la1029 was a sphigomyelinase-like hemolyisn of leptospira interrogans serogroup icterohaemorrhagiae serovar lai. characteristics of both hemolytic and cytotoxic activities of sph2 were reported in this paper. sph2 was a heat-labile neutral hemolysin and had similar hemolytic behavior as the typical sphingomyelinase c of staphylococcus aureus upon sheep erythrocytes. the cytotoxic activity of sph2 was shown in mammalian cells such as balb/c mouse lymphocytes ... | 2008 | 18315947 |
| biochemical and phylogenetic characterization of a novel diaminopimelate biosynthesis pathway in prokaryotes identifies a diverged form of ll-diaminopimelate aminotransferase. | a variant of the diaminopimelate (dap)-lysine biosynthesis pathway uses an ll-dap aminotransferase (dapl, ec 2.6.1.83) to catalyze the direct conversion of l-2,3,4,5-tetrahydrodipicolinate to ll-dap. comparative genomic analysis and experimental verification of dapl candidates revealed the existence of two diverged forms of dapl (dapl1 and dapl2). dapl orthologs were identified in eubacteria and archaea. in some species the corresponding dapl gene was found to lie in genomic contiguity with othe ... | 2008 | 18310350 |
| reliability and applications of statistical methods based on oligonucleotide frequencies in bacterial and archaeal genomes. | the increasing number of sequenced prokaryotic genomes contains a wealth of genomic data that needs to be effectively analysed. a set of statistical tools exists for such analysis, but their strengths and weaknesses have not been fully explored. the statistical methods we are concerned with here are mainly used to examine similarities between archaeal and bacterial dna from different genomes. these methods compare observed genomic frequencies of fixed-sized oligonucleotides with expected values, ... | 2008 | 18307761 |
| serological survey of canine leptospirosis in the tropics of yucatan mexico using two different tests. | blood samples were taken from 400 stray dogs. the microscopic agglutination test (mat) and enzyme-linked immunosorbent assay (elisa) test were implemented using leptospira interrogans serogroups canicola, hardjo, pyrogenes, panama, pomona, tarassovi, icterohaemorrhagiae, gryppotyphosa, wolffi and brastislava. for the elisa test, sonicated antigen from above mentioned cultures was used. a conjugate ap-labeled anti-dog igg antibody was used, the optimal cut-off point of elisa was set at 1.34. conc ... | 2008 | 18299115 |
| clocking the lyme spirochete. | in order to clear the body of infecting spirochetes, phagocytic cells must be able to get hold of them. in real-time phase-contrast videomicroscopy we were able to measure the speed of borrelia burgdorferi (bb), the lyme spirochete, moving back and forth across a platelet to which it was tethered. its mean crossing speed was 1,636 microm/min (n = 28), maximum, 2800 microm/min (n = 3). this is the fastest speed recorded for a spirochete, and upward of two orders of magnitude above the speed of a ... | 2008 | 18286190 |
| lipl32 is an extracellular matrix-interacting protein of leptospira spp. and pseudoalteromonas tunicata. | lipl32 is the major outer membrane protein in pathogenic leptospira. it is highly conserved throughout pathogenic species and is expressed in vivo during human infection. while these data suggest a role in pathogenesis, a function for lipl32 has not been defined. outer membrane proteins of gram-negative bacteria are the first line of molecular interaction with the host, and many have been shown to bind host extracellular matrix (ecm). a search for leptospiral ecm-interacting proteins identified ... | 2008 | 18285490 |
| genome sequence of the saprophyte leptospira biflexa provides insights into the evolution of leptospira and the pathogenesis of leptospirosis. | leptospira biflexa is a free-living saprophytic spirochete present in aquatic environments. we determined the genome sequence of l. biflexa, making it the first saprophytic leptospira to be sequenced. the l. biflexa genome has 3,590 protein-coding genes distributed across three circular replicons: the major 3,604 chromosome, a smaller 278-kb replicon that also carries essential genes, and a third 74-kb replicon. comparative sequence analysis provides evidence that l. biflexa is an excellent mode ... | 2008 | 18270594 |
| a scenario on the stepwise evolution of the genetic code. | it is believed that in the rna world the operational (ribozymes) and the informational (riboscripts) rna molecules were created with only three (adenosine, uridine, and guanosine) and two (adenosine and uridine) nucleosides, respectively, so that the genetic code started uncomplicated. ribozymes subsequently evolved to be able to cut and paste themselves and riboscripts were acceptive to rigorous editing (adenosine to inosine); the intensive diversification of rna molecules shaped novel cellular ... | 2008 | 18267295 |
| a scenario on the stepwise evolution of the genetic code. | it is believed that in the rna world the operational (ribozymes) and the informational (riboscripts) rna molecules were created with only three (adenosine, uridine, and guanosine) and two (adenosine and uridine) nucleosides, respectively, so that the genetic code started uncomplicated. ribozymes subsequently evolved to be able to cut and paste themselves and riboscripts were acceptive to rigorous editing (adenosine to inosine); the intensive diversification of rna molecules shaped novel cellular ... | 2008 | 18267295 |
| selenium status and antibodies to selected pathogens in white-tailed deer (odocoileus virginianus) in southern minnesota. | to determine exposure to a variety of infectious diseases potentially important for native ungulates, livestock, and humans, serum samples from 114 (94 adults, 20 fawns) female white-tailed deer (odocoileus virginianus) were collected during january 2000-03 from multiple locations in southeast (se) and southwest (sw) minnesota. antibody prevalence was determined for the following pathogens: mycobacterium avium subsp. paratuberculosis, leptospira interrogans (six serovars), anaplasma marginale, b ... | 2008 | 18263838 |
| lyme borreliosis spirochete erp proteins, their known host ligands, and potential roles in mammalian infection. | lyme borreliae naturally maintain numerous distinct dna elements of the cp32 family, each of which carries a mono- or bicistronic erp locus. the encoded erp proteins are surface-exposed outer membrane lipoproteins that are produced at high levels during mammalian infection but largely repressed during colonization of vector ticks. recent studies have revealed that some erp proteins can serve as bacterial adhesins, binding host proteins such as the complement regulator factor h and the extracellu ... | 2008 | 18248770 |
| novel ultrastructures of treponema primitia and their implications for motility. | members of the bacterial phylum spirochaetes are generally helical cells propelled by periplasmic flagella. the spirochete treponema primitia is interesting because of its mutualistic role in the termite gut, where it is believed to cooperate with protozoa that break down cellulose and produce h(2) as a by-product. here we report the ultrastructure of t. primitia as obtained by electron cryotomography of intact, frozen-hydrated cells. several previously unrecognized external structures were reve ... | 2008 | 18248579 |
| elucidation of an alternate isoleucine biosynthesis pathway in geobacter sulfurreducens. | the central metabolic model for geobacter sulfurreducens included a single pathway for the biosynthesis of isoleucine that was analogous to that of escherichia coli, in which the isoleucine precursor 2-oxobutanoate is generated from threonine. 13c labeling studies performed in g. sulfurreducens indicated that this pathway accounted for a minor fraction of isoleucine biosynthesis and that the majority of isoleucine was instead derived from acetyl-coenzyme a and pyruvate, possibly via the citramal ... | 2008 | 18245290 |
| heme rescues a two-component system leptospira biflexa mutant. | heme is typically a major iron source for bacteria, but little is known about how bacteria of the leptospira genus, composed of both saprophytic and pathogenic species, access heme. | 2008 | 18234085 |
| serosurvey of ex situ giant pandas (ailuropoda melanoleuca) and red pandas (ailurus fulgens) in china with implications for species conservation. | conservation strategies for the giant panda (ailuropoda melanoleuca) include the development of a self-sustaining ex situ population. this study examined the potential significance of infectious pathogens in giant pandas ex situ. serologic antibody titers against canine distemper virus (cdv), canine parvovirus (cpv), canine adenovirus (cav), canine coronavirus (ccv), canine herpesvirus, canine parainfluenza virus (cpiv), toxoplasma gondii, neospora caninum, and leptospira interrogans were measur ... | 2007 | 18229861 |
| rapid serodiagnosis of leptospirosis by latex agglutination test and flow-through assay. | diagnosis of leptospirosis facilitates patient management and initiation of therapy. the microscopic agglutination test (mat) is the serological test used in reference laboratories because of its high degree of sensitivity and specificity. but the results are not available quickly for patient management. in the present study, in order to develop a simple, rapid immunodiagnostic assay, one of the outer membrane proteins (omps), recombinant lipl41 (rlipl41) has been utilised in latex agglutination ... | 2008 | 18227597 |
| virus detection and monitoring of viral load in crimean-congo hemorrhagic fever virus patients. | we developed a real-time reverse transcription--pcr that detected 1,164 copies/ml of crimean-congo hemorrhagic fever virus per milliliter of serum at 95% probability (probit analysis) and was 100% concordant with nested pcr on 63 samples from 31 patients with confirmed infection. infected patients who died appeared to have higher viral loads; low viral loads correlated with igg detection. | 2007 | 18214191 |
| [identification of leptospira interrogans serovar pomona in mice genetically selected for high and low antibody production, by means of the immunoperoxidase technique in renal tissue and bacterial isolation in fletcher medium]. | the present work had the objective of identifying the presence of leptospira interrogans serovar pomona in mice that had been genetically selected for high and low response to antibodies. all the animals were subjected to bacterial isolation, immunohistochemical analysis (immunoperoxidase) in renal tissue sections and hematoxylin-eosin staining. the immunoperoxidase technique was little more sensitive than culturing, but both were good parameters for agent identification. more severe renal lesio ... | 2007 | 18200418 |
| leptospira infections in trappers from ontario. | four trappers presented to the middlesex-london health unit in november, 1997 with similar clinical presentations. all four complained of fever, chills and headache, and three of the four had severe muscle aches. all gave histories of trapping raccoons before the onset of illness. three of the four men exhibited diagnostic seroconversions to leptospira grippotyphosa. | 2000 | 18159265 |
| genome evolution and the emergence of fruiting body development in myxococcus xanthus. | lateral gene transfer (lgt) is thought to promote speciation in bacteria, though well-defined examples have not been put forward. | 2007 | 18159227 |
| measurement of aerobic respiration in leptospira icterohaemorhagiae. | 1949 | 18113779 | |
| rattus norvegicus as a model for persistent renal colonization by pathogenic leptospira interrogans. | leptospirosis continues to be a disease with a poorly understood pathogenesis. the experimental rat model is amenable for the investigation of leptospiral dissemination, tropism, persistence of renal colonization and factors related to disease resistance. in this study, wistar rats were infected intraperitoneally with virulent leptospira interrogans serovar copenhageni strain fiocruz l1-130. the detection of leptospires in tissue samples was based on culture, silver staining and immunofluorescen ... | 2008 | 18093568 |
| sensing gram-negative bacterial lipopolysaccharides: a human disease determinant? | 2008 | 18086818 | |
| sensing gram-negative bacterial lipopolysaccharides: a human disease determinant? | 2008 | 18086818 | |
| characterization of the sos regulon of caulobacter crescentus. | the sos regulon is a paradigm of bacterial responses to dna damage. a wide variety of bacterial species possess homologs of lexa and reca, the central players in the regulation of the sos circuit. nevertheless, the genes actually regulated by the sos have been determined only experimentally in a few bacterial species. in this work, we describe 37 genes regulated in a lexa-dependent manner in the alphaproteobacterium caulobacter crescentus. in agreement with previous results, we have found that t ... | 2008 | 18083815 |
| characterization of the sos regulon of caulobacter crescentus. | the sos regulon is a paradigm of bacterial responses to dna damage. a wide variety of bacterial species possess homologs of lexa and reca, the central players in the regulation of the sos circuit. nevertheless, the genes actually regulated by the sos have been determined only experimentally in a few bacterial species. in this work, we describe 37 genes regulated in a lexa-dependent manner in the alphaproteobacterium caulobacter crescentus. in agreement with previous results, we have found that t ... | 2008 | 18083815 |
| [study on the location of membrane and detection of antibody in the sera of genus-specific antigen lipl41s in patients with leptospira interrogans]. | to determine the location on outer envelope and natural antibody response and types of genus-specific lipoprotein antigen lipl41s in patients with leptospira interrogans. | 2007 | 18080565 |
| [establishment of standardized method for pulsed-field gel electrophoresis on leptospira interrogans and analysis on their patterns]. | to establish a standardized operation procedure for pulsed-field gel electrophoresis (pfge) on leptospira interrogans as well as a figure digital database to develop the chinese representative reference strains. | 2007 | 18080564 |
| leptospirosis vaccines. | abstract: leptospirosis is a serious infection disease caused by pathogenic strains of the leptospira spirochetes, which affects not only humans but also animals. it has long been expected to find an effective vaccine to prevent leptospirosis through immunization of high risk humans or animals. although some leptospirosis vaccines have been obtained, the vaccination is relatively unsuccessful in clinical application despite decades of research and millions of dollars spent. in this review, the r ... | 2007 | 18072968 |
| detection and characterization of leptospira interrogans isolates from pet rats belonging to a human immunodeficiency virus-positive patient with leptospirosis. | 2008 | 18065682 | |
| recombinant mycobacterium bovis bcg expressing the lipl32 antigen of leptospira interrogans protects hamsters from challenge. | the bacillus calmette--guerin (bcg), a live attenuated mycobacterium bovis strain is considered a promising candidate as a vector system for delivery of foreign antigens to the immune system. the gene coding for the leptospira interrogans external membrane protein lipl32, a highly immunogenic antigen found in all pathogenic leptospira, was cloned into several mycobacterial vectors for expression in bcg. hamsters immunized with recombinant bcg (rbcg) expressing lipl32 were protected against morta ... | 2007 | 18063449 |
| sequence-based typing of leptospira: epidemiology in the genomic era. | 2007 | 18060079 | |
| evaluation of protective immunity of leptospira immunoglobulin like protein a (liga) dna vaccine against challenge in hamsters. | we demonstrated earlier that immunization with recombinant leptospira immunoglobulin like protein a (liga) induced significant protection against virulent leptospira interrogans serovar pomona challenge in hamsters. however, the protective immune mechanism remains unclear. in the present study we demonstrated the protective efficacy of a liga dna vaccine and evaluated the immune mechanism underlying the protection against leptospirosis in hamsters. the liga dna vaccine was constructed in two tru ... | 2008 | 18055070 |
| assessing the evolutionary rate of positional orthologous genes in prokaryotes using synteny data. | comparison of completely sequenced microbial genomes has revealed how fluid these genomes are. detecting synteny blocks requires reliable methods to determining the orthologs among the whole set of homologs detected by exhaustive comparisons between each pair of completely sequenced genomes. this is a complex and difficult problem in the field of comparative genomics but will help to better understand the way prokaryotic genomes are evolving. | 2007 | 18047665 |
| periplasmic phosphorylation of lipid a is linked to the synthesis of undecaprenyl phosphate. | one-third of the lipid a found in the escherichia coli outer membrane contains an unsubstituted diphosphate unit at position 1 (lipid a 1-diphosphate). we now report an inner membrane enzyme, lpxt (yeiu), which specifically transfers a phosphate group to lipid a, forming the 1-diphosphate species. (32)p-labelled lipid a obtained from lpxt mutants do not produce lipid a 1-diphosphate. in vitro assays with kdo(2)-[4'-(32)p]lipid a as the acceptor shows that lpxt uses undecaprenyl pyrophosphate as ... | 2008 | 18047581 |
| periplasmic phosphorylation of lipid a is linked to the synthesis of undecaprenyl phosphate. | one-third of the lipid a found in the escherichia coli outer membrane contains an unsubstituted diphosphate unit at position 1 (lipid a 1-diphosphate). we now report an inner membrane enzyme, lpxt (yeiu), which specifically transfers a phosphate group to lipid a, forming the 1-diphosphate species. (32)p-labelled lipid a obtained from lpxt mutants do not produce lipid a 1-diphosphate. in vitro assays with kdo(2)-[4'-(32)p]lipid a as the acceptor shows that lpxt uses undecaprenyl pyrophosphate as ... | 2008 | 18047581 |
| yellow fever and max theiler: the only nobel prize for a virus vaccine. | in 1951, max theiler of the rockefeller foundation received the nobel prize in physiology or medicine for his discovery of an effective vaccine against yellow fever--a discovery first reported in the jem 70 years ago. this was the first, and so far the only, nobel prize given for the development of a virus vaccine. recently released nobel archives now reveal how the advances in the yellow fever vaccine field were evaluated more than 50 years ago, and how this led to a prize for max theiler. | 2007 | 18039952 |
| identification of prophages in bacterial genomes by dinucleotide relative abundance difference. | prophages are integrated viral forms in bacterial genomes that have been found to contribute to interstrain genetic variability. many virulence-associated genes are reported to be prophage encoded. present computational methods to detect prophages are either by identifying possible essential proteins such as integrases or by an extension of this technique, which involves identifying a region containing proteins similar to those occurring in prophages. these methods suffer due to the problem of l ... | 2007 | 18030328 |
| leptospira interrogans endostatin-like outer membrane proteins bind host fibronectin, laminin and regulators of complement. | the pathogenic spirochete leptospira interrogans disseminates throughout its hosts via the bloodstream, then invades and colonizes a variety of host tissues. infectious leptospires are resistant to killing by their hosts' alternative pathway of complement-mediated killing, and interact with various host extracellular matrix (ecm) components. the lena outer surface protein (formerly called lfha and lsa24) was previously shown to bind the host ecm component laminin and the complement regulators fa ... | 2007 | 18000555 |
| detection of leptospira interrogans dna and antigen in fixed equine eyes affected with end-stage equine recurrent uveitis. | equine recurrent uveitis (eru) is the most frequent cause of blindness in horses worldwide. leptospira has been implicated as an etiologic agent in some cases of eru and has been detected in fresh ocular tissues of affected horses. the objective of this study was to determine the presence of leptospira antigen and dna in fixed equine ocular tissues affected with end-stage eru. sections of eyes from 30 horses were obtained. controls included 1) 10 normal equine eyes and 2) 10 equine eyes with a n ... | 2007 | 17998558 |
| morphological alterations in the kidney of rats with natural and experimental leptospira infection. | leptospirosis is a widespread anthropozoonosis, with a broad array of mammalian reservoirs, occurring as rural endemics, urban outbreaks related to floods, and emergent disease associated with water sports and recreational exposure in developed countries. rats are the major source of human infection, particularly in urban areas; however few reports have focused on the pathology of leptospirosis in this host. this study reports pathological changes in 60 kidneys from captured wild rats and compar ... | 2007 | 17996544 |
| leptospirosis in the andaman islands, india. | leptospirosis is an emerging zoonosis. in the andaman islands during the early twentieth century, it occurred in the penal settlements of the british india administration, mostly as weil's disease, an acute febrile illness with hepato-renal complications. it was caused by leptospires belonging to groups akiamy a and andamans a. after the 1930s nothing further is known regarding the disease until the late 1980s, when andaman haemorrhagic fever (ahf), a mysterious illness with the majority of case ... | 2008 | 17991499 |
| experimental infection in tumor necrosis factor alpha receptor, interferon gamma and interleukin 4 deficient mice by pathogenic leptospira interrogans. | only recently, knockout mouse models were applied in studies on the pathogenesis of leptospirosis. current data suggest an important role of innate immunity receptors and interferon gamma dependant cellular response on protection. it is not clear, however, whether t helper cell polarization influences on outcome of leptospiral infection. we report findings of experimental infection of c57bl/6 (interferon gamma or tumor necrosis factor alpha receptor deficient) and balb/c (interleukin 4 deficient ... | 2008 | 17991451 |
| a dominant clone of leptospira interrogans associated with an outbreak of human leptospirosis in thailand. | a sustained outbreak of leptospirosis occurred in northeast thailand between 1999 and 2003, the basis for which was unknown. | 2007 | 17989782 |
| cyclical changes in seroprevalence of leptospirosis in california sea lions: endemic and epidemic disease in one host species? | leptospirosis is a zoonotic disease infecting a broad range of mammalian hosts, and is re-emerging globally. california sea lions (zalophus californianus) have experienced recurrent outbreaks of leptospirosis since 1970, but it is unknown whether the pathogen persists in the sea lion population or is introduced repeatedly from external reservoirs. | 2007 | 17986335 |
| zinc is the metal cofactor of borrelia burgdorferi peptide deformylase. | peptide deformylase (pdf, e.c. 3.5.1.88) catalyzes the removal of n-terminal formyl groups from nascent ribosome-synthesized polypeptides. pdf contains a catalytically essential divalent metal ion, which is tetrahedrally coordinated by three protein ligands (his, his, and cys) and a water molecule. previous studies revealed that the metal cofactor is a fe2+ ion in escherichia coli and many other bacterial pdfs. in this work, we found that pdfs from two iron-deficient bacteria, borrelia burgdorfe ... | 2007 | 17977509 |
| [scale-up of the fermentation of leptospira interrogans canicola canicola for the production of vax-spiral vaccine]. | the operational conditions for the production of vaccine vax-spiral were established at the scale of 100 l. it was concluded that it should be carried out with an air flow of 10 l/min (0.1 vvm) and without mechanical agitation. | 2005 | 17966489 |
| [use of diafiltration in the lavage of cultures of leptospira interrogans canicola canicola for the production of vaccine vax-spiral]. | it was proposed to substitute the present technology of the lavage operation for a tangential microfiltration system at the lavage stages of the culture of leptospira interrogans canicola canicola. it was proved that this system may be applied, since no cellular affectation was observed and high pollutant elimination levels were obtained. | 2005 | 17966488 |
| [evaluation of the vaccine potentiality of 2 strains from leptospira interrogans serogroup ballum]. | two vacine candidate strains from ballum serogroup were characterized and their immunogenicity and protective power were studied in hamster. the monovalent vaccine formulations obtained showed a high immunogenicity and capacity of homologous protection and, in a lesser degree, of cross protection. | 2005 | 17966485 |
| [solubilization of components of outer membrane of leptospira interrogans serovar mozdok by sodium desoxycholate and triton x-100 and evaluation of their immunogenic capacity and homologous and heterologous protection induced in hamsters]. | two detergents (triton x-100 and sodium desoxycholate) were evaluated as solubilizing agents of the components of the outer membrane of leptospira pomona serovar mozdok. it was obtained a greater yielding of proteins on applying the treatment with triton x-100. the variants formulated starting from the extracts obtained showed a high immunogenicity and capacity of homologous protection against the challenge in hamster. | 2005 | 17966480 |
| [evaluation of the transcription of locus rfb for the biosynthesis of lps in leptospira interrogans subtype hardjoprajitno]. | plasmid pgl4w15-96 was constructed from the pgl4w74 vector without promoter for kanamycin and a sequence of 480pb containing the supposed j15 promoter with the objective of confirming the role of j15 sequence as a promoter for leptospira, which restored the transcription of the gene of resistance to kanamycin in escherichia coli and leptospira biflexa, corroborating this way the function of the insertion as a promoter for both organisms. | 2005 | 17966475 |
| [evaluation of an homologous bacterin against bovine leptospirosis]. | 48 adult bovine females dividided into 6 groups were used aimed at characterizing the immune response induced in breastfeeeding cows by an homologous bacterin formulated with different adjuvants. they were intramuscularly administered 2 milliliters of a bacterin formulated with leptospira interrogans serovars uam, wolffi, hardjo, bratislava, grippotyphosa and panama added with different adjuvants, such as aluminum hydroxide, freud's complete adjuvant, freud's incomplete adjuvant, liposoluble vit ... | 2005 | 17966474 |
| crystal structures of leptospira interrogans fad-containing ferredoxin-nadp+ reductase and its complex with nadp+. | ferredoxin-nadp(h) reductases (fnrs) are flavoenzymes that catalyze the electron transfer between nadp(h) and the proteins ferredoxin or flavodoxin. a number of structural features distinguish plant and bacterial fnrs, one of which is the mode of the cofactor fad binding. leptospira interrogans is a spirochaete parasitic bacterium capable of infecting humans and mammals in general. leptospira interrogans fnr (lepfnr) displays low sequence identity with plant (34% with zea mays) and bacterial (31 ... | 2007 | 17958910 |
| a novel leptospiral protein increases icam-1 and e-selectin expression in human umbilical vein endothelial cells. | it has been reported previously that activation of vascular endothelium by outer membrane proteins of the spirochetes borrelia sp. and treponema sp. resulted in enhanced expression of endothelial cell adhesion molecules. to investigate the role of leptospiral proteins in this process, a predicted lipoprotein encoded by the gene lic10365 was selected, which belongs to a paralogous family that presents a domain of unknown function, duf1565. the lic10365 gene was cloned and the protein expressed in ... | 2007 | 17956423 |
| frequency and causes of infectious abortion in a dairy herd in queretaro, mexico. | the objective of this study was to determine the frequency of infectious bovine abortion and to identify some of its causes, specifically brucellosis, leptospirosis, bovine viral diarrhea, infectious bovine rhinotracheitis, and neosporosis. the study was carried out in a dairy herd in the state of queretaro, mexico, between september 2002 and march 2003. at the beginning of the study, blood samples were taken from a random 33% of the 300 lactating or pregnant cows; antibodies against leptospira ... | 2007 | 17955907 |
| molecular detection of leptospira interrogans in human tissues and environmental samples in a lethal case of leptospirosis. | a forensic case of suspected leptospirosis with fatal course was resolved by the molecular detection of leptospira interrogans in postmortem human tissues and in environmental samples. polymerase chain reaction analysis and dna sequencing confirmed the clinical diagnosis of weil syndrome, and the death was considered to be an occupational accident with all the legal implications. | 2008 | 17943302 |
| crystal structure of homoserine o-acetyltransferase from leptospira interrogans. | homoserine o-acetyltransferase (hta, ec 2.3.1.31) initiates methionine biosynthesis pathway by catalyzing the transfer of acetyl group from acetyl-coa to homoserine. this study reports the crystal structure of hta from leptospira interrogans determined at 2.2a resolution using selenomethionyl single-wavelength anomalous diffraction method. hta is modular and consists of two structurally distinct domains--a core alpha/beta domain containing the catalytic site and a helical bundle called the lid d ... | 2007 | 17927957 |
| [reconstruction of leptospira interrogans lipl21 gene and characteristics of its expression product]. | to reconstruct the nucleotide sequence of leptospira interrogans lipl21 gene for increasing the output of prokaryotic expression and to understand the changes on immunogenicity of the expression products before and after reconstruction, and to determine the position of envelope lipoprotein lipl21 on the surface of leptospiral body. | 2007 | 17924464 |
| comparative genomic analysis of tropheryma whipplei strains reveals that diversity among clinical isolates is mainly related to the wisp proteins. | the aim of this study was to analyze the genomic diversity of several tropheryma whipplei strains by microarray-based comparative genomic hybridization. fifteen clinical isolates originating from biopsy samples recovered from different countries were compared with the t. whipplei twist strain. for each isolate, the genes were defined as either present or absent/divergent using the gack analysis software. genomic changes were then further characterized by pcr and sequencing. | 2007 | 17910761 |
| osmotic regulation of expression of two extracellular matrix-binding proteins and a haemolysin of leptospira interrogans: differential effects on liga and sph2 extracellular release. | the life cycle of the pathogen leptospira interrogans involves stages outside and inside the host. entry of l. interrogans from moist environments into the host is likely to be accompanied by the induction of genes encoding virulence determinants and the concomitant repression of genes encoding products required for survival outside of the host. the expression of the adhesin liga, the haemolysin sph2 (lk73.5) and the outer-membrane lipoprotein lipl36 of pathogenic leptospira species have been re ... | 2007 | 17906138 |
| ompl1 dna vaccine cross-protects against heterologous leptospira spp. challenge. | available leptospirosis vaccines made up of inactivated bacteria or their membrane components elicit immunity which is serovar specific and unsatisfactory immunological memory. a vaccine that protects across leptospira serogroups/serovars, i.e. broad spectrum, and induces long-lasting memory is needed for both human and veterinary uses. in this study, a plasmid dna vaccine was constructed from cloning gene encoding a transmembrane porin protein, ompl1, of pathogenic leptospira interrogans, serog ... | 2007 | 17891923 |
| structure and biological activities of beta toxin from staphylococcus aureus. | beta toxin is a neutral sphingomyelinase secreted by certain strains of staphylococcus aureus. this virulence factor lyses erythrocytes in order to evade the host immune system as well as scavenge nutrients. the structure of beta toxin was determined at 2.4-a resolution using crystals that were merohedrally twinned. this structure is similar to that of the sphingomyelinases of listeria ivanovii and bacillus cereus. beta toxin belongs to the dnase i folding superfamily; in addition to sphingomyel ... | 2007 | 17873030 |
| bilateral acute keratouveitis in leptospirosis: a new entity. | 2007 | 17699963 | |
| leptospirosis serology in the common brushtail possum (trichosurus vulpecula) from urban sydney, australia. | the common brushtail possum (trichosurus vulpecula) is indeed a common marsupial in major cities of australia. this species is known to be susceptible to leptospirosis and often lives in close contact with humans, raising concerns about the potential for transmission of this disease in urban areas. a total of 192 brushtail possum blood samples were collected from 136 individuals in suburban areas of metropolitan sydney from november 2002 to november 2004. sera were screened against a reference p ... | 2007 | 17699087 |
| structural basis for the acyl chain selectivity and mechanism of udp-n-acetylglucosamine acyltransferase. | udp-n-acetylglucosamine (udp-glcnac) acyltransferase (lpxa) catalyzes the first step of lipid a biosynthesis, the reversible transfer of the r-3-hydroxyacyl chain from r-3-hydroxyacyl acyl carrier protein to the glucosamine 3-oh group of udp-glcnac. escherichia coli lpxa is highly selective for r-3-hydroxymyristate. the crystal structure of the e. coli lpxa homotrimer, determined previously in the absence of lipid substrates or products, revealed that lpxa contains an unusual, left-handed parall ... | 2007 | 17698807 |
| seroepidemiological survey of rodents collected at a u.s. military installation, yongsan garrison, seoul, republic of korea. | a seroepidemiological study of selected rodent-borne diseases (hantavirus [seoul [seo] virus], scrub typhus [orientia tsutsugamushi], murine typhus [rickettsia typhi], and leptospirosis [leptospira interrogans]), as part of the u.s. military rodent surveillance and control program, was conducted from 2001 through 2005 at yongsan garrison, seoul, republic of korea. rodents were collected to determine the prevalence of rodent-borne diseases at a u.s. military installation in an urban environment. ... | 2007 | 17691691 |
| rasta-bacteria: a web-based tool for identifying toxin-antitoxin loci in prokaryotes. | toxin/antitoxin (ta) systems, viewed as essential regulators of growth arrest and programmed cell death, are widespread among prokaryotes, but remain sparsely annotated. we present rasta-bacteria, an automated method allowing quick and reliable identification of ta loci in sequenced prokaryotic genomes, whether they are annotated open reading frames or not. the tool successfully confirmed all reported ta systems, and spotted new putative loci upon screening of sequenced genomes. rasta-bacteria i ... | 2007 | 17678530 |
| identification of leptospiral isolates by bacterial restriction endonuclease analysis (brenda). | dna samples from 19 reference serovars belonging to 19 different serogroups of leptospira interrogans and two serovars belonging to leptospira biflexa were examined by bacterial restriction endonuclease analysis using ecor i and hae iii enzymes. all the serovars gave unique restriction patterns that differed from each other. dna from 10 local isolates digested with these enzymes produced patterns which on comparison with the standard patterns produced by reference strains could be identified to ... | 2001 | 17664802 |
| human pathogenic borrelia spielmanii sp. nov. resists complement-mediated killing by direct binding of immune regulators factor h and factor h-like protein 1. | borrelia spielmanii sp. nov. has recently been shown to be a novel human pathogenic genospecies that causes lyme disease in europe. in order to elucidate the immune evasion mechanisms of b. spielmanii, we compared the abilities of isolates obtained from lyme disease patients and tick isolate pc-eq17 to escape from complement-mediated bacteriolysis. using a growth inhibition assay, we show that four b. spielmanii isolates, including pc-eq17, are serum resistant, whereas a single isolate, pmew, wa ... | 2007 | 17635869 |
| the ompa-like protein loa22 is essential for leptospiral virulence. | pathogenic mechanisms of leptospira interrogans, the causal agent of leptospirosis, remain largely unknown. this is mainly due to the lack of tools for genetic manipulations of pathogenic species. in this study, we characterized a mutant obtained by insertion of the transposon himar1 into a gene encoding a putative lipoprotein, loa22, which has a predicted ompa domain based on sequence identity. the resulting mutant did not express loa22 and was attenuated in virulence in the guinea pig and hams ... | 2007 | 17630832 |
| the terminal portion of leptospiral immunoglobulin-like protein liga confers protective immunity against lethal infection in the hamster model of leptospirosis. | subunit vaccines are a potential intervention strategy against leptospirosis, which is a major public health problem in developing countries and a veterinary disease in livestock and companion animals worldwide. leptospiral immunoglobulin-like (lig) proteins are a family of surface-exposed determinants that have ig-like repeat domains found in virulence factors such as intimin and invasin. we expressed fragments of the repeat domain regions of liga and ligb from leptospira interrogans serovar co ... | 2007 | 17629368 |
| increased prevalence of borrelia burgdorferi infections in bernese mountain dogs: a possible breed predisposition. | glomerulonephritis in dogs has been associated with b. burgdorferi infections. in bernese mountain dogs with glomerulonephritis antibodies against b. burgdorferi have been found in most dogs, raising the question if the breed is predisposed to infections with b. burgdorferi. the aim of this study was to determine the prevalence of antibodies against b. burgdorferi sensu lato in a well defined population of bernese mountain dogs and to compare this prevalence with data from dogs of other breeds. | 2007 | 17626630 |
| pathology and pathophysiology of pulmonary manifestations in leptospirosis. | leptospirosis is a re-emerging zoonosis occurring as large outbreaks throughout the world caused by leptospira interrogans. the incidence of pulmonary involvement in leptospirosis has been reported to be increasing in the last years, affecting up to 70% of the patients. alveolar hemorrhage presented as dyspnea and hemoptysis is the main pulmonary manifestation. the emergence of massive hemoptysis and acute respiratory distress syndrome has characterized the recent changes reported in the clinica ... | 2007 | 17625743 |
| comparison of invasion of fibroblasts and macrophages by high- and low-virulence leptospira strains: colonization of the host-cell nucleus and induction of necrosis by the virulent strain. | the infection cycle of low- and high-virulence strains of leptospira interrogans was compared in fibroblasts and macrophages. l. interrogans serovar lai strain lai was used as a representative high-virulence strain, while l. interrogans serovars pomona strain luo was used as a low-virulence strain. l. biflexa serovar patoc strain patoc i, a nonparasitic strain of leptospira, was used as a control. both the high- and low-virulence strains could adhere to fibroblasts and macrophages using one or b ... | 2007 | 17622516 |
| identification of a novel potential antigen for early-phase serodiagnosis of leptospirosis. | this study examined four genes encoding for predicted membrane proteins selected from the genome sequences of leptospira interrogans. genes were cloned and the proteins expressed in e. coli. immunoblotting analysis of the recombinants with sera from early and convalescent phases of a leptospirosis patient showed that two proteins, namely lp29 and lp49, were reactive with serum from both phases of the illness. these data were further confirmed in enzyme-linked immunosorbent assay using sera from ... | 2007 | 17609931 |
| bartonella quintana lipopolysaccharide is a natural antagonist of toll-like receptor 4. | bartonella quintana is a gram-negative microorganism that causes trench fever and chronic bacteremia. b. quintana lipopolysaccharide (lps) was unable to induce the production of proinflammatory cytokines in human monocytes. interestingly, b. quintana lps is a potent antagonist of toll-like receptor 4 (tlr4), as it inhibited both mrna transcription and the release of tumor necrosis factor alpha, interleukin 1beta (il-1beta), and il-6 by escherichia coli lps in human monocytes, at ratios ranging f ... | 2007 | 17606598 |
| parallel dimerization of a prrc-anticodon nuclease region implicated in trnalys recognition. | the optional escherichia coli restriction trnase prrc represents a family of potential antiviral devices widespread among bacteria. prrc comprises a functional c-domain of unknown structure and regulatory abc/atpase-like n-domain. the possible involvement of a c-domain sequence in trna(lys) recognition was investigated using a matching end-protected 11-meric peptide. this mimic, termed here larp (lys-anticodon recognizing peptide) uv-cross-linked trna(lys) anticodon stem-loop (asl) analogs and i ... | 2007 | 17604307 |