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isolation of antigenic variants from leptospiras grown in vitro and from heart blood of guinea pigs inoculated with a clonized strain of leptospira.a clonized culture of leptospira interrogans serovar copenhageni strain shibaura (cl-shibaura) was inoculated into guinea pigs. the heart blood of the guinea pigs, obtained at the febrile stage and inoculated onto the solid serum medium containing the homologous immune serum, produced large and small colonies. the serological examinations revealed that the large colonies were found mainly to be the antigenic variants, while the small colonies were mostly the parent. the antigenic variants accoun ...197944789
experimental lethal infection of leptospira interrogans in mice treated with cyclophosphamide.after preadministration of cyclophosphamide (300 mg/kg), balb/c mice were lethally infected with leptospira interrogans serovar lai and a virulent strain of leptospira interrogans serovar copenhageni, and leptospiral cells were detected in both kidneys of infected mice by indirect immunofluorescent assay. nonpathogenic leptospirae, leptospira biflexa serovar patoc, leptonema illini, and an avirulent strain of l. interrogans serovar copenhageni, were not parasitic to the mice treated with cycloph ...19911913341
reaction of monoclonal antibodies with species specific determinants in leptospira interrogans outer envelope.a set of 24 monoclonal antibodies (mabs) was produced against an outer envelope preparation from leptospira interrogans serovar copenhageni. the mabs reacted in enzyme immunoassay with species-specific determinants of an antigen in the leptospiral outer envelope (oe) of pathogenic but not of saprophytic species of leptospira. the mabs did not agglutinate whole leptospires, nor could they opsonise homologous leptospires for phagocytosis by mouse macrophages or protect new-born guinea-pigs against ...19882459387
molecular comparison of antigens and proteins of virulent and avirulent clones of leptospira interrogans serovar copenhageni, strain shibaura.the antigens and the protein profiles of virulent and avirulent clones of leptospira interrogans serovar copenhageni, strain shibaura were compared by sds-polyacrylamide gel electrophoresis (sds-page), western blotting and radioimmunoprecipitation. an antigen specific to the virulent clone was detectable only in the virulent clone by western blotting using anti-virulent clone but not anti-avirulent clone antisera. the molecular weight of the antigen was estimated to be approximately 32000 by sds ...19873439384
biological activities of leptospiral lipopolysaccharide.lipopolysaccharide extracted with phenol-water from leptospira interrogans serovar copenhageni strain shibaura (l-lps) showed various biological activities. in lethality for mice, l-lps was active (ld 50, 3.4 mg/mouse) but about 12 times less potent than escherichia coli lps (e-lps) per weight basis. l-lps had pyrogenicity for rabbits, and the fever curves showed no evidence of the classical biphasic fever produced by e-lps. in the bone marrow of mice, l-lps caused hemorrhages and necrosis but l ...19863518294
phagocytosis of virulent and avirulent leptospires by guinea-pig and human polymorphonuclear leukocytes in vitro.chemiluminescence (cl) and electron microscopy were used to study the phagocytosis of both virulent and avirulent strains of leptospira interrogans serovar copenhageni by guinea-pig and human polymorphonuclear leukocytes (pmn). a significant cl response was observed when guinea-pig pmn were incubated with virulent leptospires in the presence but not in the absence of specific immune serum. this response was markedly enhanced by the addition of guinea-pig complement. phagocytosis was confirmed by ...19846514391
analyses for neutralizing activities of immunoglobulin fractions in anti-leptospiral horse antiserum.the 7s and 19s fraction isolated from hyperimmunized antileptospiral horse sera by sephadex g-200 gel filtration and gamma- and t-globulin fractions from the antisera by starch block electrophoresis were studied for neutralizing (leptospiricidal) activities against infection with leptospira. the activity was determined by the intracutaneous method with virulent shibaura strain of leptospira interrogans serovar copenhageni. no significant difference in regression coefficient was observed between ...19807265554
molecular analysis of the hsp (groe) operon of leptospira interrogans serovar copenhageni.a chromosomal gene library of leptospira interrogans serovar copenhageni strain wijnberg was constructed in phage lambda gt11. plaque immunoassay with r alpha p64 antiserum identified one clone expressing a putative groel homologue. dna sequence analysis of the 2.4 kb ecori-bam hi cloned fragment from strain wijnberg revealed two open reading frames encoding polypeptides of 10.5 kda (hsp10) and 58 kda (hsp58). sequence comparison of the deduced amino acid sequences of these orfs confirmed the op ...19938101351
[leptospira infected rat population as probable cause of a fatal case of weil's disease].in the summer of 1992 a patient died of a leptospiral infection which he probably had contracted while he was swimming in an artificial lake in the region of tübingen/reutlingen. regarding the epidemiological role of leptospirosis the rodent population was investigated, because rats and mice were often seen in the surrounding area. 11 rats and 20 mice could be trapped. from their urine or kidneys two leptospiral serovars were isolated: serovar copenhageni from rattus norvegicus and serovar saxko ...19958593131
intestinal spirochetosis: first cases reported in brazil and the use of immunohistochemistry as an aid in histopathological diagnosis.colonization of the colon and rectum by intestinal spirochetes is detected for the first time in brazil in 4 of 282 (1.41%) patients who had undergone sigmoidoscopy and/or colonoscopy with a histopathological diagnosis of chronic non specific-colitis. this frequency is probably underestimated, since surgically obtained specimens were not considered in the present study. histopathological diagnosis was performed using routine stains like hematoxylin-eosin which showed the typical, of 3-microns th ...19968762639
chemotaxis of leptospires to hemoglobin in relation to virulence.a guinea pig-lethal line of leptospira interrogans serovar copenhageni strain shibaura, but not an avirulent line of the same strain, moved in larger numbers toward hemoglobin than toward distilled water (control) in a u-shaped polypropylene tube. l. interrogans serovar lai strains 017 and kh-1, which were also guinea pig lethal, showed a similar move to hemoglobin. no such move toward hemoglobin was shown by 14 avirulent strains of l. interrogans (with one exception) or any of the 8 strains of ...19938478123
protective effects of serum thymic factor to leptospira interrogans serovar copenhageni infection in mongolian gerbils.the susceptibility to leptospira interrogans serovar copenhageni in mongolian gerbils treated with 10 micrograms of serum thymic factor (fts) 1 day before infection was examined. susceptibility of gerbils treated 5 times with 10 micrograms of fts was also investigated. mortality of fts-treated gerbils was significantly lower than that of controls when small challenge doses were used. to analyse the fts-induced resistance to leptospiral infection, natural killer (nk) cell activity and macrophage ...19947801529
urban epidemic of severe leptospirosis in brazil. salvador leptospirosis study group.leptospirosis has, traditionally, been considered a sporadic rural disease. we describe a large urban outbreak of leptospirosis.199910485724
the hemorrhagic syndrome of leptospirosis: an experimental study in guinea pigs.the hemorrhagic syndrome of leptospirosis was studied in guinea pigs. the study correlates hematological, histopathological and immunohistochemical alterations in sixty animals inoculated by the intraperitoneal route with 1ml of the culture of virulent strain of leptospira interrogans serovar copenhageni. leptospirae antigens were detected by immunoperoxidase, chiefly in liver, kidney and heart muscle capillaries. possible pathogenic mechanisms responsible for hemorrhagic syndrome are discussed ...19957480909
serological survey of leptospirosis in sows with premature birth and stillbirth in chiba and gunma prefectures of japan.in 1996 and 1997, the seroprevalence against leptospira in parturient sows with premature birth or stillbirth from two herds was investigated. in three out of four sow serum samples obtained in gunma prefecture, the antibody titers to leptospira interrogans serovar copenhageni (m20) were higher than 10,000 (the reciprocal of the serum dilution). furthermore, the antibody titers to l. interrogans serovar canicola (hond utrecht iv) were significantly high in the three sows and the titers ranged fr ...200212237523
isolation of revertants from antigenic variants of leptospiras.the revertants were isolated from the antigenic variants of leptospira interrogans serovar copenhageni shibaura by plating the variants on the solid medium containing the homologous immune serum, and by noting the growth of small colonies. the revertants which produced the small colonies were antigenically identical with the parents. the variants which retained their antigenicity for 2 to 3 years produced only a small number of revertants. on the other hand, the variants which phenotypically cha ...19807424250
cross antigenicities of leptospira interrogans serovar copenhageni shibaura strain for preparing biological products in japan.cross protective antigenicities of leptospira were studied with 16 antisera to 13 serovars of leptospira interrogans and a virulent strains "shibaura (v)", which is now considered to belong to serovar copenhageni, for challenge. the antisera of the rabbits highly immunized with various serovar live antigens were examined for leptospiricidal activity; cross immunity was recognized only in the same serogroup, icterohaemorrhagiae. serovar icterohaemorrhagiae lacks a prt of the antigenic components ...19807218577
[screening for antibodies against zoonotic agents among employees of the zoological garden of vienna, schönbrunn, austria].the aim of this study was to investigate the prevalence of antibodies against zoonotic agents in employees of the zoological garden of vienna, schönbrunn, austria. sixty out of 120 employees participated in the study. in 97% of them antibodies to at least one zoonotic agent were identified. only two participants were free of antibodies to the zoonotic agents tested. the following seroprevalences (in brackets) were obtained: viral zoonotic (and potentially zoonotic) agents: influenzavirus a/h1n1 ...200415495931
correlation of virulence, susceptibility to leptospiricidal activity test mediated by antiserum plus complement and colonial morphology of five lines of a strain of leptospira interrogans serovar copenhageni.correlation of virulence, susceptibility to leptospiricidal activity test mediated by antiserum plus complement (lat) and colonial morphology was investigated using five lines of leptospira interrogans serovar copenhageni shibaura. line no. 2, a moderately virulent strain, passaged in guinea pigs for 24 successive times caused occasional death of guinea pigs. leptospiras recovered from deceased animals were characterized by decreased susceptibility to lat and predominance of hazy colonies upon c ...19817200304
the role of macrophages in the protection of mice against leptospirosis: in vitro and in vivo studies.balb/c mice are naturally resistant to infection with leptospira interrogans serovar copenhageni, but leptospires were not phagocytosed by mouse peritoneal macrophages in vitro without added specific antibody. similar results were obtained irrespective of whether leptospires were viable or killed, virulent or avirulent, or whether macrophages were obtained from normal mice, immunized mice or mice previously infected with bcg. suppression or stimulation of macrophage function in vivo did not affe ...19826760092
adhesion of leptospires to mouse fibroblasts (l929) and its enhancement by specific antibody.the adhesion of leptospires (leptospira interrogans serovar. copenhageni l45) to mouse l-cells was studied by microscopic observations. within 3 h of infection of monolayers many leptospires adhered to 95-100% of the cells, and intracellular leptospires were demonstrated by electron microscopy. no specific site of attachment on the cells or the leptospires was observed. avirulent or dead leptospires adhered poorly but attachment of the saprophytic leptospire l. biflexa serovar. patoc occurred on ...19846379182
antigenic variants of leptospiras detected in peritoneal cavity in early stage of infection in immunized guinea pigs.antigenic variants were detected firstly 7 h following intraperitoneal challenge with leptospira interrogans serovar copenhageni shibaura in the peritoneal cavity of guinea pigs which had been previously immunized with the homologous strain. the variants appeared at a rate of 63% of the leptospiras which survived in the peritoneal cavity, and the survivors' rate was 0.00005% of the inoculated organisms. the antigenicity of these variants reversed to that of the parent after 3-5 passages in liqui ...19826187138
glycolipoprotein cytotoxin from leptospira interrogans serovar copenhageni.lipopolysaccharide (lps), glycolipoprotein (glp) and lipid extract were prepared from leptospira interrogans serovar copenhageni. glp, lipid extract or purified fatty acids from lipid extract produced cytotoxic effects seen as cell enzyme leakage followed by cytotoxic death when tested in mouse fibroblast l929 cells in tissue culture. all extracts also agglutinated mouse erythrocytes but purified lps was not cytotoxic. neither glp nor lps were pyrogenic but both gelled limulus amoebocyte lysate. ...19863711858
ultrastructure and chemical composition of lipopolysaccharide extracted from leptospira interrogans serovar copenhageni.lipopolysaccharide (lps) from leptospira interrogans serovar copenhageni was prepared from the aqueous phase of a phenol/water extract. electron microscopic examination of negatively stained lps showed a mixture of ribbon-like, round and ring structures. carbohydrate analysis of the preparations revealed pentoses, hexoses, heptoses, hexosamines, and a 2-keto-3-deoxyonic acid which was chromatographically different from authentic 2-keto-3-deoxyoctonic acid (kdo). the major fatty acids of the lps ...19863711857
leptospiral attachment to extracellular matrix of mouse fibroblast (l929) cells.the attachment of leptospires to the extracellular matrix (ecm) remaining after mouse fibroblast (l929) cells on coverslips had been solubilized with triton x-100 was examined. each highly virulent line of leptospira interrogans serovar copenhageni, canicola and pomona attached to ecm more effectively than intermediately virulent and avirulent lines of the same strains, suggesting a correlation between virulence and attachment to ecm. inhibition of the attachment of highly virulent copenhageni t ...19873439019
opsonic effect of monoclonal antibodies against leptospira interrogans serovar copenhageni.the opsonic effect of monoclonal antibodies (mcabs) against leptospira interrogans serovar copenhageni strain shibaura was examined in vitro using radiolabeled organisms and mouse peritoneal exudate macrophages. four igg mcabs (all igg3) and 2 igm mcabs were used, all showed different reactivities and were bound to homologous lipopolysaccharide (lps). igg3 mcabs at the sub-agglutinating concentration were opsonic, but the degree of the opsonic effect varied among igg3 mcabs. opsonization with ig ...19883376416
an immunoprotective monoclonal antibody directed against leptospira interrogans serovar copenhageni.a monoclonal antibody (mab) was prepared by hybridoma technology in balb/c mice immunized to leptospira interrogans serovar copenhageni. this mab agglutinated serovars copenhageni and icterohaemorrhagiae to high titres and protected hamsters, dogs and monkeys against challenge with a virulent strain of serovar copenhageni. the mab gave protection to hamsters at dilutions up to 1 in 1000; at a 1 in 10 dilution the protective effect lasted for at least two weeks. biochemical analysis by sds-page a ...19892778433
effects of leptospiral lipopolysaccharide on rabbit platelets.leptospiral lipopolysaccharides (lpss) extracted from leptospira interrogans serovar copenhageni virulent strain shibaura, serovar canicola virulent strain moulton, and serovar hebdomadis strain hebdomadis, were tested for their ability to induce platelet aggregation and/or lysis in rabbit platelet-rich plasma (prp). all showed positive reactions with a release of adenosine triphosphate (atp) and serotonin. the values, however, were different from each other. the ability of leptospiral lps extra ...19892775427
experimental immunisation of hamsters with lipopolysaccharide antigens of leptospira interrogans.hamsters were immunised with leptospiral lipopolysaccharide (lps) or the polysaccharide (ps) fraction of lps from leptospira interrogans serovar copenhageni and the antibody responses were measured by agglutination tests. maximum titres were observed approximately 6 weeks after immunisation and protection against lethal challenge with the homologous strain was afforded by immunisation with as little as 2.5 micrograms of lps or ps. all animals produced igm agglutinins but a higher proportion of-a ...19892733021
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.200818673473
skin reaction to lipids from avirulent strain shibaura of leptospira interrogans serovar copenhageni.sonically disrupted cells from avirulent strain shibaura of leptospira interrogans serovar copenhageni induced a skin reaction characterized by infiltration of polymorphonuclear leukocytes (pmn) associated with some edema in guinea pigs. to determine the substance inducing infiltration of pmn, lipids of avirulent strain shibaura were extracted with chloroform--methanol--water after washing with acetone. the lipids comprised 28% of the dry weight of the cell. when the lipids were further separate ...19892611731
differential susceptibility of two stocks of mongolian gerbils (meriones unguiculatus) to leptospira.mongolian gerbils (meriones unguiculatus) of tumble blook (tum) and japan medical science (jms) stocks were compared with regard to susceptibility to leptospira interrogans serovar copenhageni. the tum gerbil died 6 to 9 d after intraperitoneal inoculation with 10 organisms, showing jaundice and systemic hemorrhage. however, 25% of the jms gerbils survived infection with 10(3) or 10(4) organisms and there was no fatal case after infection with 10(2) organisms.19912025654
lipids and fatty acids of leptospira interrogans serovar copenhageni virulent strain shibaura.lipids and fatty acids of leptospira interrogans serovar copenhageni virulent strain shibaura were analyzed by thin-layer chromatography, gas-liquid chromatography, gas-mass spectrometry and infrared absorption spectrometry. the virulent cells possessed a characteristic lipid pattern consisting of free fatty acid (ffa) (41.8%), one major unidentified phospholipid (14.8%), phosphatidylethanolamine (pe) (12.9%), cholesteryl ester (ce) (9.3%), lysophosphatidylethanolamine (lpe) (4.9%) and diphospha ...19911784083
antigens involved in the human antibody response to natural infections with leptospira interrogans serovar copenhageni.serum samples from patients with leptospirosis were screened by the microscopic agglutination test (mat), elisa and by immunoblotting. the latter two tests were performed with l. interrogans serovar copenhageni isolated from human blood culture. immunoblotting with patients' sera revealed antibodies recognizing several leptospiral components in the molecular weight range 14.5-105 kda of both igm and igg response. all patients' serum samples presented igm antibodies reacting with a diffuse band o ...19921495119
identification and characterization of the dtdp-rhamnose biosynthesis and transfer genes of the lipopolysaccharide-related rfb locus in leptospira interrogans serovar copenhageni.immunity to leptospirosis is principally humorally mediated and involves opsonization of leptospires for phagocytosis by macrophages and neutrophils. the only protective antigen identified to date is the leptospiral lipopolysaccharide (lps), which biochemically resembles typical gram-negative lps but has greatly reduced endotoxic activity. little is known about the structure of leptospiral lps. a 2.1-kb ecori fragment from the chromosome of serovar copenhageni was cloned in puc18 in escherichia ...19979023210
molecular analysis of the dnak locus of leptospira interrogans serovar copenhageni.analysis of the dnak locus of leptospira interrogans serovar copenhageni identified four genes in the order hrca, grpe, dnak and dnaj. this is the first time a homologue of hrca has been identified in a spirochete. the hrca gene and a regulatory sequence, designated circe, play a significant role in the regulation of the dnak locus of several gram+ organisms. their presence upstream of dnak in leptospira suggested a similiar regulatory mechanism. transcriptional analysis using reverse transcript ...19989714717
comparative genomics of two leptospira interrogans serovars reveals novel insights into physiology and pathogenesis.leptospira species colonize a significant proportion of rodent populations worldwide and produce life-threatening infections in accidental hosts, including humans. complete genome sequencing of leptospira interrogans serovar copenhageni and comparative analysis with the available leptospira interrogans serovar lai genome reveal that despite overall genetic similarity there are significant structural differences, including a large chromosomal inversion and extensive variation in the number and di ...200415028702
radiometric method for the rapid detection of leptospira organisms.a rapid and sensitive radiometric method for detection of leptospira interrogans serovar pomona and leptospira interrogans serovar copenhageni is described. stuart's medium and middlebrook tb (12a) medium supplemented with bovine serum albumin, catalase, and casein hydrolysate and labeled with 14c-fatty acids were used. the radioactivity was measured in a bactec 460 (johnston laboratories). with this system, leptospira organisms were detected in human blood in 2 to 5 days, a notably shorter time ...19863700624
in vitro evaluation of combined usage of fosfomycin and 5-fluorouracil for selective isolation of leptospira species.the combined usage of fosfomycin (fom) and 5-fluorouracil (5-fu) as selective agents for the isolation of leptospires from contaminated materials was investigated. additive or synergistic antibacterial activity was apparent with the combination compared with each agent used separately. of 54 bacterial strains tested, 52 were inhibited, while all 5 leptospira strains tested were unaffected by the combined addition of fom (400 micrograms/ml) and 5-fu (100 micrograms/ml) to korthof medium. furtherm ...19863519669
a monoclonal antibody reacting with a determinant on leptospiral lipopolysaccharide protects guinea pigs against leptospirosis.an iga monoclonal antibody (mum/f1-1/copenhageni) was produced from a mouse immunised with leptospira interrogans serovar copenhageni. the antibody showed partial serogroup specificity by agglutination and by reaction in enzyme immunoassay, and opsonised homologous leptospires for phagocytosis by cultured mouse macrophages. immunodiffusion and western-blotting experiments indicated that mum/f1-1/copenhageni reacted with a carbohydrate determinant in the leptospiral lipopolysaccharide. daily admi ...19862430103
global transcriptomic response of leptospira interrogans serovar copenhageni upon exposure to serum.leptospirosis is a zoonosis of worldwide distribution caused by infection with pathogenic serovars of leptospira spp. the most common species, l. interrogans, can survive in the environment for lengthy periods of time in between infection of mammalian hosts. transmission of pathogenic leptospira to humans mostly occurs through abraded skin or mucosal surfaces after direct or indirect contact with infected animals or contaminated soil or water. the spirochete then spreads hematogenously, resultin ...201020113507
first isolation of human leptospira strains, azores, portugal.the aim of this study was the first identification of leptospira isolates from azorean inpatients.201020413339
expression and characterization of hlyx hemolysin from leptospira interrogans serovar copenhageni: potentiation of hemolytic activity by lipl32.the hlyx, a putative hemolysin identified from the leptospira genomes, was cloned, expressed in escherichia coli, purified, and its hemolytic activity was confirmed. mouse polyclonal antiserum against the recombinant hlyx recognized hlyx-related antigens in a panel of leptospira species extracts and it was also able to abolish the hemolytic activity of hlyx. a mixture of hlyx and lipl32, a known hemolysin from leptospira, induced hemolysis in a synergistic way that was fully inhibited by antiser ...200515990088
human leptospirosis cases and the prevalence of rats harbouring leptospira interrogans in urban areas of tokyo, japan.thirteen patients with leptospirosis were identified, as confirmed by laboratory analysis during the last 5 years in our laboratory, who came from urban areas of tokyo, japan. all of the patients came into contact with rats before the onset of illness. seventeen per cent of norway rats captured in the inner cities of tokyo carried leptospires in their kidneys. most of these rat isolates were leptospira interrogans serovar copenhageni/icterohaemorrhagiae. antibodies against these serovars and the ...200919528143
genome features of leptospira interrogans serovar copenhageni.we report novel features of the genome sequence of leptospira interrogans serovar copenhageni, a highly invasive spirochete. leptospira species colonize a significant proportion of rodent populations worldwide and produce life-threatening infections in mammals. genomic sequence analysis reveals the presence of a competent transport system with 13 families of genes encoding for major transporters including a three-member component efflux system compatible with the long-term survival of this organ ...200415064809
molecular typing of leptospira spp. based on putative o-antigen polymerase gene (wzy), the benefit over 16s rrna gene sequence.molecular typing of leptospiral strains based on variation within putative o-antigen polymerase gene (wzy) was determined among reference strains and those isolated from patients. using the pcr primers designed from the flanking gene of wzy derived from leptospira interrogans serovar copenhageni, all l. interrogans serovars as well as human and rodent leptospiral isolates from thailand could be amplified. the size of pcr product ranged from 1 to 1.5 kb. the limitation of these primer pairs was t ...200717403048
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 ...200717629368
passive immunization with leptospira lps-specific agglutinating but not non-agglutinating monoclonal antibodies protect guinea pigs from fatal pulmonary hemorrhages induced by serovar copenhageni challenge.leptospira interrogans serovar copenhageni causes pulmonary hemorrhages with respiratory failure, a major cause of death in leptospirosis patients. protective immunity to leptospira is known to correlate with the production of leptospiral lipopolysaccharide (l-lps)-specific agglutinating antibodies. we generated l-lps-specific mouse monoclonal antibodies (mabs) and investigated if these mabs can protect guinea pigs against fatal pulmonary hemorrhages caused by serovar copenhageni. the mabs l8h4 ...201121549788
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 ...200817991451
leptospira interrogans stably infects zebrafish embryos, altering phagocyte behavior and homing to specific tissues.leptospirosis is an extremely widespread zoonotic infection with outcomes ranging from subclinical infection to fatal weil's syndrome. despite the global impact of the disease, key aspects of its pathogenesis remain unclear. to examine in detail the earliest steps in the host response to leptospires, we used fluorescently labelled leptospira interrogans serovar copenhageni to infect 30 hour post fertilization zebrafish embryos by either the caudal vein or hindbrain ventricle. these embryos have ...200919547748
identification of new repetitive element in leptospira interrogans serovar copenhageni and its application to pcr-based differentiation of leptospira serogroups.a new repetitive dna element was identified in an isolate of leptospira interrogans serovar copenhageni from a patient in salvador, brazil. a sau3a genomic library from this strain was constructed and screened for repetitive dna elements. an insert of 438 bp (rep1) from one library clone hybridized to multiple chromosomal dna fragments resolved electrophoretically after digestion with bamhi, hindiii, and mfei. a single oligonucleotide primer, designated irepl, was designed to generate multiple p ...200111136769
global proteome analysis of leptospira interrogans.comparative global proteome analyses were performed on leptospira interrogans serovar copenhageni grown under conventional in vitro conditions and those mimicking in vivo conditions (iron limitation and serum presence). proteomic analyses were conducted using itraq and lc-esi-tandem mass spectrometry complemented with two-dimensional gel electrophoresis and maldi-tof mass spectrometry. a total of 563 proteins were identified in this study. altered expression of 65 proteins, including upregulatio ...200919663501
purification and proteomic analysis of outer membrane vesicles from a clinical isolate of leptospira interrogans serovar copenhageni.the severe pulmonary form of leptospirosis (spfl) is an especially serious and rapid disease process characterized by alveolar hemorrhage and acute respiratory failure. the outer membrane of leptospira facilitates direct interactions with the environs and likely contains important constituents involved during infection, transmission, survival, and adaptation to environmental conditions, including putative vaccinogen and diagnostic candidates. outer membrane vesicles (omvs) were purified by incub ...200515672460
experimental leptospirosis in marmoset monkeys (callithrix jacchus): a new model for studies of severe pulmonary leptospirosis.experimental infection of marmoset monkeys (callithrix jacchus) with leptospira interrogans serovar copenhageni showed microscopic patterns of tissue reactions comparable to those seen in the severe forms of human leptospirosis, including intra-alveolar hemorrhage. the most impressive microscopic changes were seen in the lung and kidney of animals killed at days 6 and 12 after inoculation. there were extensive and irregular areas of hemorrhage predominating around main bronchial branches or diff ...200515728860
whole-genome analysis of leptospira interrogans to identify potential vaccine candidates against leptospirosis.leptospirosis is an important global human and veterinary health problem. humans can be infected by exposure to chronically infected animals and their environment. an important focus of the current leptospiral research is the identification of outer membrane proteins (omps). due to their location, leptospiral omps are likely to be relevant in host-pathogen interactions, hence their potential ability to stimulate heterologous immunity. the existing whole-genome sequence of leptospira interrogans ...200515766783
characterization of leptospiral proteins that afford partial protection in hamsters against lethal challenge with leptospira interrogans.leptospirosis is a worldwide zoonosis caused by pathogenic leptospira. the whole-genome sequence of leptospira interrogans serovar copenhageni together with bioinformatic tools allow us to search for novel antigen candidates suitable for improved vaccines against leptospirosis. this study focused on three genes encoding conserved hypothetical proteins predicted to be exported to the outer membrane. the genes were amplified by pcr from six predominant pathogenic serovars in brazil. the genes were ...201020558583
lethal infection of c3h/hej and c3h/scid mice with an isolate of leptospira interrogans serovar copenhageni.leptospira interrogans serovar copenhageni strain rj16441, a blood isolate from humans with the severe pulmonary form of leptospirosis, has previously been shown to cause fatal pulmonary hemorrhage in guinea pigs and asymptomatic chronic renal tubular colonization with urinary shedding in rats. in this study, rj16441 caused lethal infection of both c3h/hej and c3h/scid mice, but no hemorrhagic phenomena were observed.200516177383
unstable antigenic variation of leptospiras.the antigenic variants which were found in leptospiras, leptospira interrogans serovar copenhageni shibaura grown in a liquid medium containing a homologous antiserum were found to be unstable. the unstable variants showed decreased agglutinability against the homologous antiserum. the decreased agglutinability of the unstable variants reverted to the parent's level of agglutinability after 1 or 2 passages through the normal serum medium. the unstable variants differed antigenically from the par ...19816168141
a newly identified leptospiral adhesin mediates attachment to laminin.pathogenic leptospires have the ability to survive and disseminate to multiple organs after penetrating the host. several pathogens, including spirochetes, have been shown to express surface proteins that interact with the extracellular matrix (ecm). this adhesin-mediated binding process seems to be a crucial step in the colonization of host tissues. this study examined the interaction of putative leptospiral outer membrane proteins with laminin, collagen type i, collagen type iv, cellular fibro ...200616954400
an imprint method for detecting leptospires in the hamster model of vaccine-mediated immunity for leptospirosis.in determining the efficacy of new vaccine candidates for leptospirosis, the primary end point is death and an important secondary end point is sterilizing immunity. however, evaluation of this end point is often hampered by the time-consuming demands and complexity of methods such as culture isolation (ci). in this study, we evaluated the use of an imprint (or touch preparation) method (im) in detecting the presence of leptospires in tissues of hamsters infected with leptospira interrogans sero ...200919679685
functional characterization of gdp-mannose pyrophosphorylase from leptospira interrogans serovar copenhageni.leptospira interrogans synthesizes a range of mannose-containing glycoconjugates relevant for its virulence. a prerequisite in the synthesis is the availability of the gdp-mannose, produced from mannose-1-phosphate and gtp in a reaction catalyzed by gdp-mannose pyrophosphorylase. the gene coding for a putative enzyme in l. interrogans was expressed in escherichia coli bl21(de3). the identity of this enzyme was confirmed by electrospray-mass spectroscopy, edman sequencing and immunological assays ...201020035319
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 ...200717996544
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 ...200818093568
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 ...200818721789
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 ...200818799647
refolding of the recombinant protein ompa70 from leptospira interrogans from inclusion bodies using high hydrostatic pressure and partial characterization of its immunological properties.leptospira is the etiological agent of leptospirosis, a life-threatening disease that affects human populations worldwide. available vaccines have demonstrated limited effectiveness, and therapeutic interventions are complicated by the difficulty of establishing an early diagnosis. the genome of leptospira strains was sequenced, and bioinformatic analyses revealed potential vaccine and serodiagnosis candidates. the present work studied ompa70, a putative outer membrane protein from leptospira in ...201020450943
predictors of lethality in severe leptospirosis in urban brazil.to ascertain prognostic factors associated with fatal outcomes in severe leptospirosis, a retrospective case-control study was done using population-based surveillance data. centralized death certificate reporting of leptospirosis mortality was combined with details of patients' hospitalizations, which were obtained from hospitals representing all sectors of são paulo city. among identified leptospirosis cases, 89 lethal cases and 281 survivor cases were analyzed. predictors of death included ag ...200819052303
crystallization and preliminary x-ray analysis of lipl32 from leptospira interrogans serovar copenhageni.lipl32 is a major surface protein that is expressed during infection by pathogenic leptospira. here, the crystallization of recombinant lipl32(21-272), which corresponds to the mature lipl32 protein minus its n-terminal lipid-anchored cysteine residue, is described. selenomethionine-labelled lipl32(21-272) crystals diffracted to 2.25 a resolution at a synchrotron source. the space group was p3(1)21 or p3(2)21 and the unit-cell parameters were a = b = 126.7, c = 96.0 a.200919255491
chemokines expression during leptospira interrogans serovar copenhageni infection in resistant balb/c and susceptible c3h/hej mice.the role of innate immune responses in protection against leptospirosis remains unclear. we examined the expression of the chemokines ccl2/je (mcp-1), ccl3/mip-1 alpha (mip-1 alpha) and cxcl1/kc (il-8) regarding resistance and susceptibility to leptospirosis in experimental mice models balb/c and c3h/hej, respectively. a virulent strain of leptospira interrogans serovar copenhageni was used in this study. twenty-five animals of each mouse strain of c3h/hej and balb/c, were infected intraperitone ...200919460427
role of inducible nitric oxide synthase in the pathogenesis of experimental leptospirosis.nitric oxide (no) produced by inducible nitric oxide synthase (inos) is a radical effector molecule of the innate immune system that can directly inhibit pathogen replication. in order to study subsequent inos kidney expression in experimental leptospirosis, golden syrian hamsters and c3h/hej mice were infected intraperitoneally with 10(2) or 10(7) virulent leptospira interrogans serovar copenhageni (lic) strain fiocruz l1-130. results showed increased levels of inos mrna and protein in kidneys ...201121497651
characterization of the immunogenic and antigenic potential of putative lipoproteins from leptospira interrogans.the search for a vaccine capable of conferring heterologous protection, through the identification of conserved and cross-protective antigens, remains an ongoing priority in leptospirosis research. in the present study, an in silico analysis was used to identify potentially protective lipoproteins from leptospira interrogans serovar copenhageni. eight putative lipoproteins were selected (lic10009, lic10054, lic10091, lic11058, lic11567, lic13059, lic13305, and lic20172), cloned and expressed in ...201121221970
attenuated nephritis in inducible nitric oxide synthase-knockout c57bl/6 mice and pulmonary haemorrhage in cb17 scid and recombination activating gene 1-knockout c57bl/6 mice infected with leptospira interrogans.the aims of this study were to investigate the frequency of pulmonary haemorrhage (ph) in mice unable to produce functional b- and t-lymphocytes and to explore the effect of an inducible nitric oxide synthase (inos) knockout (ko) on the frequency/severity of interstitial nephritis in vivo. we studied the outcome of infection by the virulent leptospira interrogans serovar copenhageni strain cop. the animals used were inos-ko mice; recombination activating gene 1 ko (rag1-ko); cb17 severe combined ...201121576342
a liga three-domain region protects hamsters from lethal infection by leptospira interrogans.the leptospiral liga protein consists of 13 bacterial immunoglobulin-like (big) domains and is the only purified recombinant subunit vaccine that has been demonstrated to protect against lethal challenge by a clinical isolate of leptospira interrogans in the hamster model of leptospirosis. we determined the minimum number and location of liga domains required for immunoprotection. immunization with domains 11 and 12 was found to be required but insufficient for protection. inclusion of a third d ...201122180800
leptospirosis serodiagnosis by elisa based on recombinant outer membrane protein.the outer membrane protein lipl21, lipl32, lipl41 and loa22 of leptospira interrogans serovar copenhageni were previously revealed by immunoproteomic analysis, using sera from acute phase infection in a guinea pig. the full-length dna of each protein was then cloned from the same serovar and expressed in prset vector. the obtained molecular weight (mw) of recombinant proteins rlipl21, rlipl32 and rloa22 were slightly higher than the mw predicted from nucleotide sequences of each inserted gene, w ...201121353274
methylation and in vivo expression of the surface-exposed leptospira interrogans outer membrane protein ompl32.recent studies have revealed that bacterial protein methylation is a widespread post-translational modification that is required for virulence in selected pathogenic bacteria. in particular, altered methylation of outer membrane proteins has been shown to modulate the effectiveness of the host immune response. in this study, two-dimensional gel electrophoresis combined with matrix-assisted laser desorption/ionization-time of flight mass spectrometry identified a leptospira interrogans serovar c ...201122174381
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