| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| [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 |
| [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 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 |
| [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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| sequence-based typing of leptospira: epidemiology in the genomic era. | | 2007 | 18060079 |
| 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 |
| detection and characterization of leptospira interrogans isolates from pet rats belonging to a human immunodeficiency virus-positive patient with leptospirosis. | | 2008 | 18065682 |
| 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 |
| [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 |
| [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 |
| 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 |
| sensing gram-negative bacterial lipopolysaccharides: a human disease determinant? | | 2008 | 18086818 |
| sensing gram-negative bacterial lipopolysaccharides: a human disease determinant? | | 2008 | 18086818 |
| 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 |
| measurement of aerobic respiration in leptospira icterohaemorhagiae. | | 1949 | 18113779 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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: 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| a 52-kda leucyl aminopeptidase from treponema denticola is a cysteinylglycinase that mediates the second step of glutathione metabolism. | the metabolism of glutathione by the periodontal pathogen treponema denticola produces hydrogen sulfide, which may play a role in the host tissue destruction seen in periodontitis. h2s production in this organism has been proposed to occur via a three enzyme pathway, gamma-glutamyltransferase, cysteinylglycinase (cgase), and cystalysin. in this study, we describe the purification and characterization of t. denticola cgase. standard approaches were used to purify a 52-kda cgase activity from t. d ... | 2008 | 18482986 |
| unraveling the evolutionary history of the phosphoryl-transfer chain of the phosphoenolpyruvate:phosphotransferase system through phylogenetic analyses and genome context. | the phosphoenolpyruvate phosphotransferase system (pts) plays a major role in sugar transport and in the regulation of essential physiological processes in many bacteria. the pts couples solute transport to its phosphorylation at the expense of phosphoenolpyruvate (pep) and it consists of general cytoplasmic phosphoryl transfer proteins and specific enzyme ii complexes which catalyze the uptake and phosphorylation of solutes. previous studies have suggested that the evolution of the constituents ... | 2008 | 18485189 |
| molecular basis of the substrate specificity and the catalytic mechanism of citramalate synthase from leptospira interrogans. | leptospira interrogans is the causative agent for leptospirosis, a zoonotic disease of global importance. in contrast with most other micro-organisms, l. interrogans employs a pyruvate pathway to synthesize isoleucine and licms (l. interrogans citramalate synthase) catalyses the first reaction of the pathway which converts pyruvate and acetyl-coa into citramalate, thus making it an attractive target for the development of antibacterial agents. we report here the crystal structures of the catalyt ... | 2008 | 18498255 |
| serological survey for evidence of leptospira interrogans in free-living platypuses (ornithorhynchus anatinus). | to survey free-living platypuses for evidence of leptospira interrogans. | 2008 | 18498563 |
| functional and structural characterization of a cation-dependent o-methyltransferase from the cyanobacterium synechocystis sp. strain pcc 6803. | the coding sequence of the cyanobacterium synechocystis sp. strain pcc 6803 slr0095 gene was cloned and functionally expressed in escherichia coli. the corresponding enzyme was classified as a cation- and s-adenosyl-l-methionine-dependent o-methyltransferase (synomt), consistent with considerable amino acid sequence identities to eukaryotic o-methyltransferases (omts). the substrate specificity of synomt was similar with those of plant and mammalian ccoaomt-like proteins accepting a variety of h ... | 2008 | 18502765 |
| the leptospiral antigen lp49 is a two-domain protein with putative protein binding function. | pathogenic leptospira is the etiological agent of leptospirosis, a life-threatening disease that affects populations worldwide. currently available vaccines have limited effectiveness and therapeutic interventions are complicated by the difficulty in making an early diagnosis of leptospirosis. the genome of leptospira interrogans was recently sequenced and comparative genomic analysis contributed to the identification of surface antigens, potential candidates for development of new vaccines and ... | 2008 | 18508281 |
| human granulocytic ehrlichiosis complicating early pregnancy. | background: the goal of this case is to review the zoonotic infection, human granulocytic ehrlichiosis, presenting with pyrexia. case. a 22-year-old multigravid female presented to the emergency department with a painful skin rash, high fever, and severe myalgias. the patient underwent a diagnostic evaluation for zoonotic infections due to her geographical and seasonal risk factors. treatment of human granulocytic ehrlichiosis was successful though the patient spontaneously aborted presumably du ... | 2008 | 18509484 |
| leptospira interrogans requires a functional heme oxygenase to scavenge iron from hemoglobin. | the transposon tnsc189 was used to construct a mutant in the putative heme oxygenase gene hemo (lb186) of leptospira interrogans. unlike its parent strain, the mutant grew poorly in medium in which hemoglobin was the sole iron source. the putative heme oxygenase was over expressed in a his-tagged form, purified and was demonstrated to degrade heme in vitro. unexpectedly, it was also found that the l. interrogans growth rate was significantly increased when medium was supplemented with hemoglobin ... | 2008 | 18524663 |
| characterization of the antioxidant enzyme, thioredoxin peroxidase, from the carcinogenic human liver fluke, opisthorchis viverrini. | the human liver fluke, opisthorchis viverrini, induces inflammation of the hepatobiliary system. despite being constantly exposed to inimical oxygen radicals released from inflammatory cells, the parasite survives for many years. the mechanisms by which it avoids oxidative damage are unknown. in this study, thioredoxin peroxidase (tpx), a member of the peroxiredoxin superfamily, was cloned from an o. viverrini cdna library. o. viverrini tpx cdna encoded a polypeptide of 212 amino acid residues, ... | 2008 | 18538872 |
| characterization of virulence of leptospira isolates in a hamster model. | effort has been made to identify protective antigens in order to develop a recombinant vaccine against leptospirosis. several attempts failed to conclusively demonstrate efficacy of vaccine candidates due to the lack of an appropriate model of lethal leptospirosis. the purposes of our study were: (i) to test the virulence of leptospiral isolates from brazil, which are representative of important serogroups that cause disease in humans and animals; and (ii) to standardize the lethal dose 50% (ld( ... | 2008 | 18547690 |
| disease threats to the endangered iberian lynx (lynx pardinus). | the iberian lynx, (lynx pardinus), is the most endangered felid in the world. to determine whether sympatric carnivores are reservoirs of pathogens posing a disease risk for the lynx, evidence of exposure to 17 viral, bacterial and protozoan agents was investigated in 176 carnivores comprising 26 free-living lynx, 53 domestic cats, 28 dogs, 33 red foxes (vulpes vulpes), 24 egyptian mongooses (herpestes ichneumon), 10 common genets (genetta genetta) and 2 eurasian badgers (meles meles) in the are ... | 2009 | 18555712 |
| leptospira interrogans is recognized through dc-sign and induces maturation and cytokine production by human dendritic cells. | leptospirosis is a global zoonotic disease, caused by pathogenic leptospira species including leptospira interrogans, that causes public health and livestock problems. pathogenesis, immune response and cellular receptors for leptospira are not well understood. interaction of dendritic cells (dcs) with l. interrogans serovar autumnalis l-643 and bl-6 isolated from leptospirosis patients, and both virulent and avirulent serovar pyrogenes 2317 strains isolated from animal were investigated. carbohy ... | 2008 | 18564288 |
| real-time high resolution 3d imaging of the lyme disease spirochete adhering to and escaping from the vasculature of a living host. | pathogenic spirochetes are bacteria that cause a number of emerging and re-emerging diseases worldwide, including syphilis, leptospirosis, relapsing fever, and lyme borreliosis. they navigate efficiently through dense extracellular matrix and cross the blood-brain barrier by unknown mechanisms. due to their slender morphology, spirochetes are difficult to visualize by standard light microscopy, impeding studies of their behavior in situ. we engineered a fluorescent infectious strain of borrelia ... | 2008 | 18566656 |
| conservation of the s10-spc-alpha locus within otherwise highly plastic genomes provides phylogenetic insight into the genus leptospira. | s10-spc-alpha is a 17.5 kb cluster of 32 genes encoding ribosomal proteins. this locus has an unusual composition and organization in leptospira interrogans. we demonstrate the highly conserved nature of this region among diverse leptospira and show its utility as a phylogenetically informative region. comparative analyses were performed by pcr using primer sets covering the whole locus. correctly sized fragments were obtained by pcr from all l. interrogans strains tested for each primer set ind ... | 2008 | 18648538 |
| characterization of new is elements and studies of their dispersion in two subspecies of leifsonia xyli. | leifsonia xyli is a xylem-inhabiting bacterial species comprised of two subspecies: l. xyli subsp. xyli (lxx) and l. xyli subsp. cynodontis (lxc). lxx is the causal agent of ratoon stunting disease in sugarcane commercial fields and lxc colonizes the xylem of several grasses causing either mild or no symptoms of disease. the completely sequenced genome of lxx provided insights into its biology and pathogenicity. since is elements are largely reported as an important source of bacterial genome di ... | 2008 | 18655699 |
| cross-sectional study of canine leptospirosis in animal shelter populations in mainland australia. | to measure the prevalence of canine leptospirosis in queensland and to detect infection, if present, in new south wales, victoria, south australia, western australia and the northern territory by measuring the serological titres of dogs held in animal shelters. | 2008 | 18673473 |
| prevalence of pathogenic leptospira spp. in sheep in a sheep-only abattoir in new zealand. | to determine the prevalence of the two most commonly diagnosed pathogenic leptospira spp. serovars, hardjobovis and pomona, in sheep in a sheep-only abattoir in new zealand, and to determine the prevalence of kidneys which were leptospire culture-positive collected from sheep seropositive or seronegative to the microscopic agglutination test (mat). | 2008 | 18690252 |
| diagnostic potential of an iron-regulated hemin-binding protein hbpa that is widely conserved in leptospira interrogans. | like most bacteria, leptospira spp. requires iron for growth. however, they face conditions of iron limitation due to the low solubility of the ferric iron and additionally due to the observation that most of the available iron is held as protein-bound iron by the mammalian host. our experimental observations with pathogenic leptospira showed that they do not elaborate siderophores upon iron limitation. in leptospira interrogans serovar lai, we demonstrated direct acquisition of iron via an iron ... | 2008 | 18692158 |
| bacterial species exhibit diversity in their mechanisms and capacity for protein disulfide bond formation. | protein disulfide bond formation contributes to the folding and activity of many exported proteins in bacteria. however, information about disulfide bond formation is limited to only a few bacterial species. we used a multifaceted bioinformatic approach to assess the capacity for disulfide bond formation across this biologically diverse group of organisms. we combined data from a cysteine counting method, in which a significant bias for even numbers of cysteine in proteins is taken as an indicat ... | 2008 | 18695247 |
| [zoonoses transmitted by mouse and rat maintained as laboratory or pet animals]. | large numbers of mice (mus spp.) and rats (rattus spp.) are maintained for scientific reasons and as pet animals in germany. while laboratory animals are monitored for pathogenic agents, the hygienic status of pet animals is usually completely unknown. despite great efforts, zoonotic infections were reported even in laboratory settings, e.g. with hantavirus (seoul virus), streptobacillus moniliformis, and trichphyton mentagrophytes. however, in current reports, zoonotic infections were transmitt ... | 2008 | 18712260 |
| carriage of leptospira interrogans among domestic rats from an urban setting highly endemic for leptospirosis in brazil. | a survey was conducted to identify reservoirs for urban leptospirosis in the city of salvador, brazil. sampling protocols were performed in the vicinity of households of severe leptospirosis cases identified during active hospital-based surveillance. among a total of 142 captured rattus norvegicus (norwegian brown rat), 80.3% had a positive culture isolate from urine or kidney specimens and 68.1% had a positive serum sample by microscopic agglutination test (mat) titre of > or = 1:100. monoclona ... | 2008 | 18721789 |
| the guinea pig as a model of infectious diseases. | the words 'guinea pig' are synonymous with scientific experimentation, but much less is known about this species than many other laboratory animals. this animal model has been used for approximately 200 y and was the first to be used in the study of infectious diseases such as tuberculosis and diphtheria. today the guinea pig is used as a model for a number of infectious bacterial diseases, including pulmonary, sexually transmitted, ocular and aural, gastrointestinal, and other infections that t ... | 2008 | 18724774 |
| proteomic analysis of leptospira interrogans shed in urine of chronically infected hosts. | leptospirosis is a global zoonotic disease. the causative agent, pathogenic leptospira species, survives in the renal tubules of chronically infected hosts, from where leptospires are shed via urine into the environment. infection of new hosts can present as an array of acute and chronic disease processes reflecting variations in host-pathogen interactions. the present study was designed to reproduce the carrier phase of infection in rattus norvegicus, thus facilitating shedding of leptospires i ... | 2008 | 18765721 |
| hamster model of leptospirosis. | this unit describes the techniques involved in the hamster model of leptospirosis. hamsters are exquisitely susceptible to infection with pathogenic leptospira species. the ld(50) of virulent leptospiral strains by intraperitoneal inoculation of 3- to 4-week-old hamsters is as low as a single organism. the pathogenesis of severe leptospirosis in the hamster is a model of accidental infections observed in nature in many mammals, including humans. animal husbandry issues and the reproducibility of ... | 2006 | 18770576 |
| putative outer membrane proteins of leptospira interrogans stimulate human umbilical vein endothelial cells (huvecs) and express during infection. | cell adhesion molecules (cams) are surface receptors present in eukaryotic cells that mediate cell-cell or cell-extracellular matrix interactions. vascular endothelium stimulation in vitro that lead to the upregulation of cams was reported for the pathogenic spirochaetes, including rlic10365 of leptospira interrogans. in this study, we report the cloning of lic10507, lic10508, lic10509 genes of l. interrogans using escherichia coli as a host system. the rational for selecting these sequences is ... | 2008 | 18778767 |
| evaluation of leptospiral recombinant antigens mpl17 and mpl21 for serological diagnosis of leptospirosis by enzyme-linked immunosorbent assays. | leptospirosis is a zoonosis of multisystem involvement caused by pathogenic strains of the genus leptospira. in the last few years, intensive studies aimed at the development of a vaccine have provided important knowledge about the nature of the immunological mechanisms of the host. the purpose of this study was to analyze the immune responses to two recombinant proteins, mpl17 and mpl21 (encoded by the genes lic10765 and lic13131, respectively) of leptospira interrogans serovar copenhageni in i ... | 2008 | 18799647 |