| presence of putative sphingomyelinase genes among members of the family leptospiraceae. | the presence of multiple dna elements in pathogenic members of the family leptospiraceae, similar to the spha sphingomyelinase gene from leptospira borgpetersenii, was demonstrated by low-stringency hybridization experiments. these dna elements were designated putative sphingomyelinase genes. grouping of strains by similarity of hybridization patterns corresponds to the species subdivision of the family leptospiraceae on the basis of genetic characteristics. therefore, hybridization with the sph ... | 1992 | 1548095 |
| molecular analysis of a leptospira borgpetersenii gene encoding an endoflagellar subunit protein. | a flagellin gene, flab, from leptospira borgpetersenii (formerly l. interrogans) serovar hardjo was cloned and expressed in escherichia coli. expression of the 32 kda flab protein was dependent upon the lacz promoter from puc18. nucleotide sequence data showed an open reading frame encoding 283 amino acid residues, corresponding to a protein of molecular mass 31.3 kda. the g + c content of the flab gene was 54.7 mol%. comparison of the deduced flab amino acid sequence with flagellins from other ... | 1991 | 1955849 |
| cloning of the pfap gene of leptospira borgpetersenii. | a lambda gt11 library constructed with leptospira borgpetersenii dna was screened with monoclonal antibodies (mab) recognizing a periplasmic flagella-associated protein. a plaque expressing a fusion protein (lambda f15) which reacted with the mab was isolated and the nucleotide sequence analyzed. the deduced amino-acid (aa) sequence indicates that the pfap gene belongs to a group of bacterial genes whose products share aa sequence and possibly functional homologies with sppa, an escherichia coli ... | 1995 | 7628708 |
| restriction fragment length polymorphisms distinguish leptospira borgpetersenii serovar hardjo type hardjo-bovis isolates from different geographical locations. | genetic variability among leptospira borgpetersenii serovar hardjo type hardjo-bovis isolates representing several geographical regions was determined by restriction endonuclease analysis. five previously unidentified ecori digestion patterns and one previously unidentified hhai digestion pattern were seen with the various isolates. the copy number and genomic distribution of an l. borgpetersenii insertion sequence (is1533) was determined. hardjo-bovis isolate 033 (the type strain for hardjo-bov ... | 1993 | 7681437 |
| random amplified polymorphic dna fingerprinting for rapid identification of leptospiras of serogroup sejroe. | eight leptospiral and three non-leptospiral primers were examined in the development of a random amplified polymorphic dna (rapd) fingerprinting method for identification of leptospiral serovars within the serogroup sejroe. the strains examined comprised 19 reference strains of serogroup sejroe, five field strains and 17 leptospira borgpetersenii serovar hardjo type hardjobovis strains. unique dna banding patterns were obtained for each of the 17 reference strains with l. hardjo type hardjobovis ... | 1995 | 7752212 |
| detection and identification of leptospira interrogans serovars by pcr coupled with restriction endonuclease analysis of amplified dna. | primers for pcr were selected from a sequenced fragment of clone pl590, which contains a repetitive element present in the genome of leptospira interrogans serovar hardjo type hardjoprajitno (m. l. pacciarini, m. l. savio, s. tagliabue, and c. rossi, j. clin. microbiol. 30:1243-1249, 1992). a specific dna fragment was amplified from the genomic dnas of serovar hardjo type hardjoprajitno and nine serovars also belonging to l. interrogans as a consequence of the spread of the same or a closely rel ... | 1994 | 8027346 |
| nucleotide sequence analysis of is1533 from leptospira borgpetersenii: identification and expression of two is-encoded proteins. | the nucleotide sequence of is1533, an insertion sequence-like element cloned from the spirochete leptospira borgpetersenii, was determined. is1533 contains imperfect terminal inverted repeats (ivr) of 31 bp flanking a 1402-bp internal sequence. a putative target sequence was identified, and insertion may result in duplication of 2 bp. the internal sequence has a single open reading frame (orf). is1533 encodes two proteins (43.5 and 41 kda) initiating alternatively at either the first or the seco ... | 1994 | 8171119 |
| magnetic immuno capture pcr assay (mipa): detection of leptospira borgpetersenii serovar hardjo. | magnetic immuno pcr assay (mipa) was developed for the rapid detection of leptospires excreted in urine samples (n = 59) collected from 35 experimentally infected cattle. the immunomagnetic separation of leptospires from inhibitors in frozen formalin fixed bovine urine prior to pcr detection resulted in a marked improvement on previous detection methods. mipa is a rapid 5 step protocol requiring 70 mins preparation time prior to amplification, which consistently detects 10(1) organisms. mipa det ... | 1997 | 9228689 |
| development of a monoclonal antibody-based competitive enzyme-linked immunosorbent assay for the detection of leptospira borgpetersenii serovar hardjo type hardjobovis antibodies in bovine sera. | a murine monoclonal antibody (designated m553) that binds to an epitope on whole cell antigens prepared from leptospira borgpetersenii serovar hardjo type hardjobovis and leptospira interrogans serovar hardjo type hardjoprajitno, was produced and incorporated into a competitive enzyme-linked immunosorbent assay for the detection of bovine antibodies to serovar hardjo. the epitope recognized by m553 was susceptible to periodate oxidation. the m553 antibody was characterized by western blot with h ... | 1997 | 9342450 |
| [research on the recombinant plasmid pdjh2 of l. interrogans serovar lai: sequencing and alignment with other known bacterial omp sequence]. | the leptospira whole cell vaccine (lwcv) currently used in china is safe and effective, out the immunity following vaccination with two doses of the fluid medium vaccine is of low order. the duration of immunity conferred by this vaccine is rather short, six months or at most one year. therefore, it is necessary to develop new generation vaccines against leptospirosis for the developing world. in this paper we report the sequencing of the insert fragment of pdjh2 from genomic dna of l. interroga ... | 1996 | 9389001 |
| leptospirosis: an ignored cause of acute renal failure in taiwan. | leptospirosis, caused by a spirochete, is the most common zoonosis in domestic or wild animals. animals excrete infected urine in soil or water and may cause human infections through abrased wound, mucosa, conjunctiva, or by swallowing contaminated water. clinical presentations of leptospirosis are mostly subclinical. five to ten percent of leptospirosis are fatal, causing fever, hemorrhage, jaundice, and acute renal failure (weil's syndrome). leptospirosis has been ignored as a cause of acute r ... | 1997 | 9398130 |
| amoxycillin as an alternative to dihydrostreptomycin sulphate for treating cattle infected with leptospira borgpetersenii serovar hardjo. | to assess the effect of amoxycillin treatment on urinary excretion of leptospires from cattle infected with leptospira borgpetersenii serovar hardjo. | 1997 | 9404617 |
| experimental leptospira borgpetersenii serovar hardjo infection of pregnant cattle. | to observe the effect upon the foetus of experimental infection of pregnant cattle with leptospira borgpetersenii serovar hardjo. | 1997 | 9404618 |
| development of an immunomagnetic antigen capture system for detecting leptospires in bovine urine. | a magnetic bead antigen capture system which combined the use of two evolving techniques - immunomagnetic separation (ims) and time-resolved fluoroimmunoassay (tr-fia) - was developed to detect leptospira borgpetersenii serovar hardjo in bovine urine. the assay utilised monoclonal antibody coated magnetic beads to capture leptospiral antigen which was in turn detected using another monoclonal antibody (indicator) labelled with biotin. signal was generated by the binding of europium labelled stre ... | 1998 | 9625467 |
| leptospira borgpetersenii serovar hardjo type hardjobovis in bovine embryos fertilized in vitro. | the association of leptospira borgpetersenii serovar hardjo type hardjobovis with bovine embryos produced by in vitro fertilization was examined by scanning electron microscopy (sem) and transmission electron microscopy (tem). morula stage embryos with an intact zona pellucida (zp) were exposed to this spirochete for 24 h in culture medium, washed by the standard washing procedure as recommended by the international embryo transfer society, and then examined. sem showed typical helicoid leptospi ... | 1998 | 9684055 |
| wound-released chemical signals may elicit multiple responses from an agrobacterium tumefaciens strain containing an octopine-type ti plasmid. | the vir regions of octopine-type and nopaline-type ti plasmids direct the transfer of oncogenic t-dna from agrobacterium tumefaciens to the nuclei of host plant cells. previous studies indicate that at least two genetic loci at the left ends of these two vir regions are sufficiently conserved to form heteroduplexes visible in the electron microscope. to initiate an investigation of these genetic loci, we determined the dna sequences of these regions of both ti plasmids and identified both conser ... | 1998 | 9791116 |
| sanitary status of oocytes and embryos collected from heifers experimentally exposed to leptospira borgpetersenii serovar hardjobovis. | in a preliminary trial and three experiments, a total of 30 holstein heifers were experimentally infected with a culture of leptospira borgpetersenii serovar hardjobovis via one or more routes (uterine, cervical supraconjunctival, intranasal) and oviductal and uterine fluids recovered post-mortem or in vivo following superovulation with fsh. all routes of administration were effective in establishing leptospira infection in the reproductive tract and leptospira were identified in the oviductal a ... | 1998 | 9877053 |
| production and characterization of monoclonal antibodies specific for leptospira borgpetersenii serovar hardjo type hardjobovis and leptospira interrogans serovar hardjo type hardjoprajitno. | murine monoclonal antibodies were produced by immunizing balb/c mice with a killed whole-cell antigen prepared from leptospira borgpetersenii serovar hardjo type hardjobovis. six of these antibodies recognized epitopes on the homologous antigen and on whole-cell antigen prepared from leptospira interrogans serovar hardjo type hardjoprajitno. these antibodies did not cross-react with whole-cell antigens prepared from l. borgpetersenii serovar sejroe, 10 other pathogenic leptospira serovars, or th ... | 1999 | 9918336 |
| further determination of dna relatedness between serogroups and serovars in the family leptospiraceae with a proposal for leptospira alexanderi sp. nov. and four new leptospira genomospecies. | dna relatedness was determined among 303 strains of leptospira and leptonema. included in the analysis were reference strains from 228 well-characterized and recognized serovars. the study included 268 serovars from 29 named and one or more unnamed serogroups. the strains clustered into 17 dna hybridization groups, representing 12 previously described species (292 strains) and five new genomospecies (11 strains). the largest groups included leptospira interrogans (91 strains from 82 serovars), l ... | 1999 | 10319510 |
| use of recombinant flagellin protein as a tracer antigen in a fluorescence polarization assay for diagnosis of leptospirosis. | the objective of the present study was to investigate the usefulness of a recombinant flagellar protein, flab, of leptospira interrogans serovar pomona in the serodiagnosis of leptospirosis by the fluorescence polarization assay (fpa). the recombinant protein flab was purified to homogeneity by a combination of nickel-nitriloacetic acid agarose chromatography, electrophoresis, and electroelution. purified flab was labeled with fluorescein isothiocyanate (fitc). western blotting was performed by ... | 1999 | 10391870 |
| dna relatedness of leptospira strains isolated from beef cattle in zimbabwe. | the dna relatedness of 17 leptospira strains isolated from beef cattle in zimbabwe was determined using the hydroxyapatite method. similarly to previously speciated african strains, all zimbabwe isolates belonged to either leptospira borgpetersenii or leptospira kirschneri. all serovars within serogroups pyrogenes (kwale, mombe and a strain closely related to serovar nigeria), hebdomadis (marondera and mhou), tarassovi (ngavi) and sejroe (balcanica and hardjo) were l. borgpetersenii. l. kirschne ... | 1999 | 10425768 |
| genetic organization of the lipopolysaccharide o-antigen biosynthetic locus of leptospira borgpetersenii serovar hardjobovis. | leptospiral lps plays a critical role in immunity to leptospirosis and forms the basis for serological classification of leptospira. however, neither the structure of leptospiral lps nor the genetics of its biosynthesis have been elucidated. a probe derived from the rhamnose biosynthetic genes of l. interrogans serovar copenhageni was used to identify the rfb locus of l. borgpetersenii serovar hardjobovis. chromosome walking and sequence analysis revealed an rfb locus spanning 36.7 kb, which con ... | 1999 | 10458921 |
| comparative analysis of the lps biosynthetic loci of the genetic subtypes of serovar hardjo: leptospira interrogans subtype hardjoprajitno and leptospira borgpetersenii subtype hardjobovis. | although leptospira borgpetersenii subtype hardjobovis and l. interrogans subtype hardjoprajitno belong to different species, they are serologically indistinguishable and are therefore classified as serovar hardjo. since lps is the major antigen involved in serological classification, this implies that the lps of these subtypes is identical. comparison of the lps biosynthetic loci (rfb) of the subtypes revealed remarkable similarity, with 32 and 31 origins of replication (orfs) in the hardjopraj ... | 1999 | 10474199 |
| genetics of o-antigen biosynthesis in pseudomonas aeruginosa. | pathogenic bacteria produce an elaborate assortment of extracellular and cell-associated bacterial products that enable colonization and establishment of infection within a host. lipopolysaccharide (lps) molecules are cell surface factors that are typically known for their protective role against serum-mediated lysis and their endotoxic properties. the most heterogeneous portion of lps is the o antigen or o polysaccharide, and it is this region which confers serum resistance to the organism. pse ... | 1999 | 10477307 |
| interstrain variation of the polysaccharide b biosynthesis locus of bacteroides fragilis: characterization of the region from strain 638r. | the sequence and analysis of the capsular polysaccharide biosynthesis locus, ps b2, of bacteroides fragilis 638r are described, and the sequence is compared with that of the ps b1 biosynthesis locus of b. fragilis nctc 9343. two genes of the region, wcgd and wcgc, are shown by complementation to encode a udp-n-acetylglucosamine 2-epimerase and a udp-n-acetylmannosamine dehydrogenase, respectively. | 1999 | 10498737 |
| development of an elisa to detect antibodies to a protective lipopolysaccharide fraction of leptospira borgpetersenii serovar hardjo in cattle. | monoclonal antibodies (mabs) were produced against leptospira borgpetersenii serovar hardjo-type bovis antigens. a panel of 28 mabs were characterised. only the nine mabs toward a lipopolysaccharide (lps) fraction of 18, 24 kda bands and a 26-28 kda smear showed agglutinating, leptospiricidal and growth-inhibition activities, and passively protected hamsters against renal infection with hardjo. they also reacted strongly in the ch-elisa, captured killed whole hardjo leptospires, gave good fluore ... | 1999 | 10512042 |
| functional conservation of the polysaccharide biosynthetic protein wbpm and its homologues in pseudomonas aeruginosa and other medically significant bacteria. | wbpm is a highly conserved protein involved in synthesis of the o antigens of pseudomonas aeruginosa. homologues of this protein have been identified in a large number of bacteria, and they can be divided into two subfamilies: subfamily 1, including wbpm, contains large proteins ( approximately 600 amino acids), while subfamily 2, typified by hp0840 (flaa1) of helicobacter pylori, contains smaller proteins ( approximately 350 amino acids) homologous to the c termini of proteins in subfamily 1. a ... | 2000 | 10639466 |
| comparison of polymerase chain reaction assays with bacteriologic culture, immunofluorescence, and nucleic acid hybridization for detection of leptospira borgpetersenii serovar hardjo in urine of cattle. | to compare sensitivity and specificity of various polymerase chain reaction (pcr) assays for detection of leptospira borgpetersenii serovar hardjo in bovine urine and to compare results of the optimal pcr assay with results of immunofluorescence, nucleic acid hybridization, and bacteriologic culture. | 2000 | 10714525 |
| analysis of leptospira isolates from mainland portugal and the azores islands. | from 228 recent leptospira isolates from mainland portugal and azorean wild mammals, 149 were characterized at the serovar level by monoclonal antibodies (mabs), a quick serological method in epidemiological studies. in order to compare this antigenic information with that from new genetic techniques, a sample of isolates was analyzed through pulsed-field agarose gel electrophoresis (pfge) (n=71), mapped restriction site polymorphisms (mrsps) in pcr-amplified rrna genes (n=45, including 13 sapro ... | 2000 | 10754245 |
| rpob gene analysis as a novel strategy for identification of spirochetes from the genera borrelia, treponema, and leptospira. | spirochetes are emerging pathogens for which culture and identification are partly unresolved. in fact, 16s rrna-based sequencing is by far the most widely used pcr methodology that is able to detect such uncultivable pathogens. however, this assay actually has some limitations linked to potential problems of contamination, which hampers diagnosis. to circumvent this, we have devised a simple pcr strategy involving targeting of the gene encoding the rna polymerase beta subunit (rpob), a highly c ... | 2000 | 10834976 |
| functional analysis of genes in the rfb locus of leptospira borgpetersenii serovar hardjo subtype hardjobovis. | lipopolysaccharide (lps) is a key antigen in immunity to leptospirosis. its biosynthesis requires enzymes for the biosynthesis and polymerization of nucleotide sugars and the transport through and attachment to the bacterial membrane. the genes encoding these functions are commonly clustered into loci; for leptospira borgpetersenii serovar hardjo subtype hardjobovis, this locus, named rfb, spans 36.7 kb and contains 31 open reading frames, of which 28 have been assigned putative functions on the ... | 2000 | 10858186 |
| detection of leptospira spp. in the aqueous humor of horses with naturally acquired recurrent uveitis. | leptospiral organisms have long been presumed to be associated with the presence of equine recurrent uveitis. this project was undertaken to determine the presence of leptospira spp. in the aqueous humor of horses with uveitis to determine if there was an association with inflammation. thirty horses were determined to have recurrent uveitis based on clinical evaluation or history. sixteen horses were judged clinically and historically to be free of uveitis and were used as controls. aqueous humo ... | 2000 | 10878072 |
| the spirochete flaa periplasmic flagellar sheath protein impacts flagellar helicity. | spirochete periplasmic flagella (pfs), including those from brachyspira (serpulina), spirochaeta, treponema, and leptospira spp., have a unique structure. in most spirochete species, the periplasmic flagellar filaments consist of a core of at least three proteins (flab1, flab2, and flab3) and a sheath protein (flaa). each of these proteins is encoded by a separate gene. using brachyspira hyodysenteriae as a model system for analyzing pf function by allelic exchange mutagenesis, we analyzed purif ... | 2000 | 11073915 |
| identification of residues involved in catalytic activity of the inverting glycosyl transferase wbbe from salmonella enterica serovar borreze. | synthesis of the o:54 o antigen of salmonella enterica is initiated by the nonprocessive glycosyl transferase wbbe, assigned to family 2 of the glycosyl transferase enzymes (gt2). gt2 enzymes possess a characteristic n-terminal domain, domain a. based on structural data from the gt2 representative spsa (s. j. charnock and g. j. davies, biochemistry 38:6380-6385, 1999), this domain is responsible for nucleotide binding. it possesses two invariant asp residues, the first forming a hydrogen bond to ... | 2001 | 11114903 |
| 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 ... | 2001 | 11136769 |
| competitive enzyme-linked immunosorbent assay for detection of leptospira interrogans serovar pomona antibodies in bovine sera. | a competitive enzyme-linked immunosorbent assay (elisa) using a specific monoclonal antibody (m898) was developed for detection of bovine antibodies to leptospira interrogans serovar pomona. this assay was evaluated using field sera (n = 190) with serovar pomona microscopic agglutination test (mat) titers of > or =100 as the positive population (group a); field sera (n = 1,445) which were negative in the mat (1:100 dilution) for serovar pomona (group b); and sera (from a specific-pathogen-free c ... | 2001 | 11139193 |
| penicillin-binding proteins in leptospira interrogans. | the leptospira interrogans pona and pbpb genes were isolated and characterized. pona and pbpb encode the penicillin-binding proteins (pbps) 1 and 3, respectively. there is little sequence variation between the pbp genes from two l. interrogans strains (serovar icterohaemorrhagiae strain verdun and serovar pomona strain rz11). the deduced l. interrogans pbp 1 and pbp 3 protein sequences from the two strains shared over 50% similarity to homologous proteins from escherichia coli. it was demonstrat ... | 2001 | 11181373 |
| leptospirosis. | leptospirosis is a worldwide zoonotic infection with a much greater incidence in tropical regions and has now been identified as one of the emerging infectious diseases. the epidemiology of leptospirosis has been modified by changes in animal husbandry, climate, and human behavior. resurgent interest in leptospirosis has resulted from large outbreaks that have received significant publicity. the development of simpler, rapid assays for diagnosis has been based largely on the recognition that ear ... | 2001 | 11292640 |
| use of a monovalent leptospiral vaccine to prevent renal colonization and urinary shedding in cattle exposed to leptospira borgpetersenii serovar hardjo. | to determine whether a monovalent leptospira borgpetersenii serovar hardjo (type hardjobovis) vaccine commercially available in australia, new zealand, ireland, and the united kingdom would protect cattle from renal colonization and urinary shedding when exposed to a us strain of leptospira borgpetersenii serovar hardjo. | 2001 | 11453500 |
| genetic differences among the lps biosynthetic loci of serovars of leptospira interrogans and leptospira borgpetersenii. | the gene organization in the lipopolysaccharide biosynthetic (rfb) locus was analyzed in seven leptospira interrogans serovars within serogroup icterohemorrhagiae, seven non-icterohemorrhagiae serovars and one leptospira borgpetersenii serovar. two groups of loci were delineated based on dna hybridization and sequence analysis. group 1 contained the two hardjo subtypes, hardjoprajitno and hardjobovis. group 2 (containing copenhageni, pomona, naam, mwogolo, smithi, lai, canicola, autumnalis, pyro ... | 2001 | 11476985 |
| evaluation of antibiotics for treatment of cattle infected with leptospira borgpetersenii serovar hardjo. | to evaluate antibiotics for treatment of cattle with leptospirosis caused by leptospira borgpetersenii serovar hardjo. | 2001 | 11549093 |
| pcr genome walking identifies a genetic locus comprising two heat shock genes (hslv and hslu) from leptospira borgpetersenii serovar hardjobovis. | pcr walking on genomic dna of leptospira borgpetersenii serovar hardjobovis has identified a genetic locus comprising two heat shock genes (hslv and hslu). this is the first molecular study on hslv and hslu in a leptospira species. the hslv gene has an open reading frame (orf) of 543 bp coding for a 180-amino acid polypeptide (19.476 kd) with 49-62% identity to other bacterial hslv homologs. forty-three nucleotides downstream from the hslv stop codon was found a second heat shock gene hslu with ... | 2001 | 11685516 |
| protective killed leptospira borgpetersenii vaccine induces potent th1 immunity comprising responses by cd4 and gammadelta t lymphocytes. | leptospira borgpetersenii serovar hardjo is the most common cause of bovine leptospirosis and also causes zoonotic infections of humans. a protective killed vaccine against serovar hardjo was shown to induce strong antigen-specific proliferative responses by peripheral blood mononuclear cells (pbmc) from vaccinated cattle by 2 months after the first dose of vaccine. this response was absent from nonvaccinated control cattle. the mean response peaked by 2 months after completion of the two-dose v ... | 2001 | 11705932 |
| novel 45-kilodalton leptospiral protein that is processed to a 31-kilodalton growth-phase-regulated peripheral membrane protein. | leptospiral protein antigens are of interest as potential virulence factors and as candidate serodiagnostic and immunoprotective reagents. we identified leptospiral protein antigens by screening a genomic expression library with serum from a rabbit hyperimmunized with formalin-killed, virulent leptospira kirschneri serovar grippotyphosa. genes expressing known outer membrane lipoproteins lipl32 and lipl41, the heat shock protein groel, and the alpha, beta, and beta' subunits of rna polymerase we ... | 2002 | 11748198 |
| immunological characterization of a gammadelta t-cell stimulatory ligand on autologous monocytes. | bovine gammadelta t cells are stimulated to proliferate by autologous monocytes. this is referred to as the autologous mixed leucocyte reaction (amlr). it has been shown previously that the stimulatory component is constitutively expressed on the monocyte plasma membrane and is a protein or has a protein moiety. here we showed that gammadelta t-cell responses to the monocytes requires interaction with the t-cell receptor because fab1 fragments of a monoclonal antibody (mab) that reacts with the ... | 2002 | 11872093 |
| changing epidemiology of human leptospirosis in new zealand. | the objective was to describe the current epidemiology and trends in new zealand human leptospirosis, using descriptive epidemiology of laboratory surveillance and disease notification data, 1990-8. the annual incidence of human leptospirosis in new zealand 1990-8 was 44 per 100,000. incidence was highest among meat processing workers (163.5/100,000), livestock farm workers (91.7), and forestry-related workers (24.1). the most commonly detected serovars were leptospira borgpetersenii serovar (sv ... | 2002 | 11895088 |
| homologs of the rml enzymes from salmonella enterica are responsible for dtdp-beta-l-rhamnose biosynthesis in the gram-positive thermophile aneurinibacillus thermoaerophilus dsm 10155. | the glycan chains of the surface layer (s-layer) glycoprotein from the gram-positive, thermophilic bacterium aneurinibacillus (formerly bacillus) thermoaerophilus strain dsm 10155 are composed of l-rhamnose- and d-glycero-d-manno-heptose-containing disaccharide repeating units which are linked to the s-layer polypeptide via core structures that have variable lengths and novel o-glycosidic linkages. in this work we investigated the enzymes involved in the biosynthesis of thymidine diphospho-l-rha ... | 2002 | 12147463 |
| evaluation of type 1 immune response in naïve and vaccinated animals following challenge with leptospira borgpetersenii serovar hardjo: involvement of wc1(+) gammadelta and cd4 t cells. | organisms within the hardjo serovar of leptospira species are harbored in cattle throughout the world, causing abortion in pregnant animals as well as being shed in the urine, thereby providing sources of zoonotic infection for humans. we recently showed that sterile immunity in vaccinated cattle is associated with induction of a type 1 (th1) cell-mediated immune response. here naïve and previously vaccinated pregnant cattle were challenged with a virulent strain of serovar hardjo and subsequent ... | 2002 | 12379692 |
| low-stringency single specific primer pcr for identification of leptospira. | thirty-five leptospira serovars from the species leptospira interrogans, leptospira borgpetersenii, leptospira santarosai, leptospira kirschneri, leptospira weilii, leptospira biflexa and leptospira meyeri were characterized by the low-stringency single specific primer pcr (lssp-pcr) technique. lssp-pcr analysis was performed to detect dna polymorphisms in a 285 bp dna fragment amplified from genomic dna with g1 and g2 selected primers. similar lssp-pcr profiles were obtained for serovars from t ... | 2003 | 12543918 |
| interleukin 12 in part regulates gamma interferon release in human whole blood stimulated with leptospira interrogans. | heat-killed pathogenic leptospira interrogans serovar rachmati induced the production of gamma interferon (ifn-gamma) and the ifn-gamma-inducing cytokines interleukin-12p40 (il-12p40) and tumor necrosis factor alpha in human whole blood in vitro. the production of ifn-gamma was largely dependent on il-12. these data establish that pathogenic leptospires can stimulate the production of type i cytokines involved in cellular immunity. | 2003 | 12626464 |
| in vitro susceptibilities of seven leptospira species to traditional and newer antibiotics. | human leptospirosis is generally treated with penicillin or doxycycline. we studied the susceptibilities of 11 serovars (seven species) of leptospira to 14 antibiotics. with the exception of chloramphenicol, all tested agents were at least as potent as penicillin and doxycycline, with the macrolide and ketolide drugs producing the lowest mics (and minimal bactericidal concentrations). | 2003 | 12878533 |
| pathogenic leptospira species express surface-exposed proteins belonging to the bacterial immunoglobulin superfamily. | proteins with bacterial immunoglobulin-like (big) domains, such as the yersinia pseudotuberculosis invasin and escherichia coli intimin, are surface-expressed proteins that mediate host mammalian cell invasion or attachment. here, we report the identification and characterization of a new family of big domain proteins, referred to as lig (leptospiral ig-like) proteins, in pathogenic leptospira. screening of l. interrogans and l. kirschneri expression libraries with sera from leptospirosis patien ... | 2003 | 12890019 |
| a novel is element, is621, of the is110/is492 family transposes to a specific site in repetitive extragenic palindromic sequences in escherichia coli. | an escherichia coli strain, ecor28, was found to have insertions of an identical sequence (1,279 bp in length) at 10 loci in its genome. this insertion sequence (named is621) has one large open reading frame encoding a putative protein that is 326 amino acids in length. a computer-aided homology search using the dna sequence as the query revealed that is621 was homologous to the piv genes, encoding pilin gene invertase (piv). a homology search using the amino acid sequence of the putative protei ... | 2003 | 12897009 |
| comparison of three different leptospiral vaccines for induction of a type 1 immune response to leptospira borgpetersenii serovar hardjo. | leptospira serovar hardjo are bacterial pathogens of cattle that cause zoonotic infections of humans. monovalent serovar hardjo vaccines protect cattle from serovar hardjo while pentavalent vaccines do not even though they contain serovar hardjo organisms. here, cattle vaccinated with either of two monovalent vaccines had lymphocytes that made interferon-gamma (ifn-gamma) and igg(1) and igg(2) antibodies to hardjo antigen while those from cattle vaccinated with a pentavalent leptospira vaccine d ... | 2003 | 14505928 |
| host-inducible immunogenic sphingomyelinase-like protein, lk73.5, of leptospira interrogans. | leptospira interrogans causes a variety of clinical syndromes in animals and humans. although much information has accumulated on the importance of leptospiral lipopolysaccharide in protective antibody responses, relatively little is known about proteins that participate in immune responses. identification of those proteins induced only in the host is particularly difficult. using a novel double-antibody screen designed to identify clones in a gene library of l. interrogans serovar pomona expres ... | 2004 | 14742516 |
| an indirect enzyme linked immunosorbent assay for the detection of bovine antibodies to multiple leptospira serovars. | an indirect enzyme linked immunosorbent assay was developed for the detection of bovine antibodies to multiple pathogenic leptospira serovars, including canicola, copenhageni (represents icterohaemorrhagiae), grippotyphosa, hardjobovis, pomona, and sejroe. the antigen utilized in this assay was a sonicated mixture of equal parts of killed whole cells of each of the 6 serovars named above. a mouse monoclonal antibody against bovine immunoglobulin (ig)g1 that was conjugated with horseradish peroxi ... | 2004 | 14979428 |
| identification of a second flagellin gene and functional characterization of a sigma70-like promoter upstream of a leptospira borgpetersenii flab gene. | leptospira borgpetersenii, one of the causative agents of leptospirosis in both animals and humans, is a bacterial pathogen with characteristic motility that is mediated by the rotation of two periplasmic flagella (pf). the flab gene coding for a core polypeptide subunit of pf was previously characterized by sequence analysis of its open reading frame (orf) (m. lin, j biochem mol biol biophys 2:181-187, 1999). the present study was undertaken to isolate and clone the uncharacterized sequence ups ... | 2004 | 15057484 |
| 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 ... | 2004 | 15064809 |
| leptospiral membrane proteins--variations on a theme? | | 2005 | 15802754 |
| [a case of leptospirosis caused by leptospira borgpetersenii serovar sejroe infected in bali island, indonesia]. | we report a patient with leptospirosis caused by leptospira borgpetersenii serovar sejroe infection on bali island, indonesia. this 33-year-old japanese man had stayed at a resort hotel on the island from july 8 to july 13 2004. at the hotel, he swam in the pool, walked barefoot, and lied down in the grass. he developed a high fever and headache 7 days after completing his trip, and was admitted to our hospital on july 23. on admission he showed conjunctival suffusion and complained of myalgias. ... | 2005 | 15977569 |
| surfaceome of leptospira spp. | the identification of the subset of outer membrane proteins exposed on the surface of a bacterial cell (the surfaceome) is critical to understanding the interactions of bacteria with their environments and greatly narrows the search for protective antigens of extracellular pathogens. the surfaceome of leptospira was investigated by biotin labeling of viable leptospires, affinity capture of the biotinylated proteins, two-dimensional gel electrophoresis, and mass spectrometry (ms). the leptospiral ... | 2005 | 16040999 |
| expression and comparative analysis of genes encoding outer membrane proteins lipl21, lipl32 and ompl1 in epidemic leptospires. | leptospiral outer membrane proteins (omps) are highly conserved in different species, and play an essential role in the development of new immunoprotection and serodiagnosis strategies. the genes encoding lipl21, lipl32 and ompl1 were cloned from the complete genome sequence of leptospira interrogans serovar lai strain lai and expressed in vitro. sequence comparison analysis revealed that the three genes were highly conserved among distinct epidemic leptospires, including three major epidemic sp ... | 2005 | 16215631 |
| serological survey of pre-weaned new zealand fur seals (arctocephalus forsteri) for brucellosis and leptospirosis. | to conduct a longitudinal serological survey for evidence of brucella spp and leptospira spp infection of pre-weaned new zealand fur seals in a colony on the otago peninsula. | 2005 | 16317444 |
| a global research agenda for leptospirosis. | leptospirosis is a zoonotic spirochetal disease of global importance. this disease continues to have a major impact on people living in urban and rural areas of developing countries with inestimable morbidity and mortality. funding for research and control efforts is currently haphazard, not organized and not effective for public health efforts, primarily because there are no concerted, ongoing international efforts to assess the impact of leptospirosis on human health. major issues in the field ... | 2005 | 16333188 |
| immunoprotection of recombinant leptospiral immunoglobulin-like protein a against leptospira interrogans serovar pomona infection. | we previously reported the cloning and characterization of leptospiral immunoglobulin-like proteins liga and ligb of leptospira interrogans. liga and ligb are conserved at the amino-terminal region but are variable at the carboxyl-terminal region. here, we evaluate the potential of recombinant liga (rliga) as a vaccine candidate against infection by l. interrogans serovar pomona in a hamster model. rliga was truncated into conserved (rligacon) and variable (rligavar) regions and expressed in esc ... | 2006 | 16495547 |
| comparison of culture and a novel 5' taq nuclease assay for direct detection of campylobacter fetus subsp. venerealis in clinical specimens from cattle. | a campylobacter fetus subsp. venerealis-specific 5' taq nuclease pcr assay using a 3' minor groove binder-dna probe (taqman mgb) was developed based on a subspecies-specific fragment of unknown identity (s. hum, k. quinn, j. brunner, and s. l. on, aust. vet. j. 75:827-831, 1997). the assay specifically detected four c. fetus subsp. venerealis strains with no observed cross-reaction with c. fetus subsp. fetus-related campylobacter species or other bovine venereal microflora. the 5' taq nuclease a ... | 2006 | 16517880 |
| the epidemiology of leptospirosis and the emergence of leptospira borgpetersenii serovar arborea in queensland, australia, 1998-2004. | leptospirosis is one of the most commonly encountered zoonoses in both australia and the rest of the world. the incidence of leptospirosis in queensland over the 7-year study period (1998-2004) was 3.1/100000 population. enhanced surveillance questionnaires were used to collect patient data and facilitate an epidemiological investigation of leptospirosis in queensland. farming occupations comprised the majority of occupational exposure cases, however, recreational exposure accounted for 18% of t ... | 2006 | 16690001 |
| neospora caninum and leptospira serovar serostatus in dairy cattle in ontario. | no significant association existed between neospora caninum titer and serostatus to leptospira serovar hardjo, icterohaemorrhagiae, or pomona in cattle on 78 dairy herds in ontario. leptospira titer increased with parity. amongst herds not vaccinated against leptospira, the proportions of herds with > or = 1 animal seropositive to serovar hardjo, icterohaemorrhagiae, or pomona were 45%, 42%, and 58%, respectively. | 2006 | 16734373 |
| first record of leptospira borgpetersenii isolation in the amami islands, japan. | in 2003, a leptospira survey was performed on yoroshima island of the amami islands located in the southwestern part of japan. seven leptospira strains were isolated from the field rat rattus rattus, which were identified as l. borgpetersenii by flab sequencing, 16s rdna sequencing and gyrb sequencing, and serovar javanica was determined by a microscopic agglutination test. noti-long restriction fragment analysis indicated that these isolates were genetically indistinguishable from an isolate fr ... | 2006 | 16785714 |
| genome reduction in leptospira borgpetersenii reflects limited transmission potential. | leptospirosis is one of the most common zoonotic diseases in the world, resulting in high morbidity and mortality in humans and affecting global livestock production. most infections are caused by either leptospira borgpetersenii or leptospira interrogans, bacteria that vary in their distribution in nature and rely on different modes of transmission. we report the complete genomic sequences of two strains of l. borgpetersenii serovar hardjo that have distinct phenotypes and virulence. these two ... | 2006 | 16973745 |
| effects of temperature on gene expression patterns in leptospira interrogans serovar lai as assessed by whole-genome microarrays. | leptospirosis is an important zoonosis of worldwide distribution. humans become infected via exposure to pathogenic leptospira spp. from infected animals or contaminated water or soil. the availability of genome sequences for leptospira interrogans, serovars lai and copenhageni, has opened up opportunities to examine global transcription profiles using microarray technology. temperature is a key environmental factor known to affect leptospiral protein expression. leptospira spp. can grow in arti ... | 2006 | 16988264 |
| development of species-specific pcr primer sets for the detection of leptospira. | spirochetes of the genus leptospira infect animals and humans and are the causative agents for the emerging infectious disease leptospirosis. rapid and simple assays for the identification of individual leptospira species are currently not available. for identification of individual leptospira species, pcr primers that detect the ompl1 gene sequence for the majority of pathogenic leptospires were developed in this study. the primer pairs detect leptospira interrogans, leptospira borgpetersenii, ... | 2006 | 17020546 |
| species-specific identification of leptospiraceae by 16s rrna gene sequencing. | the genus leptospira is classified into 13 named species and 4 genomospecies based upon dna-dna reassociation studies. phenotypic tests are unable to distinguish between species of leptospira, and there is a need for a simplified molecular approach to the identification of leptospires. 16s rrna gene sequences are potentially useful for species identification of leptospira, but there are a large number of sequences of various lengths and quality in the public databases. 16s rrna gene sequences of ... | 2006 | 17021075 |
| identification of pathogenic leptospira species by conventional or real-time pcr and sequencing of the dna gyrase subunit b encoding gene. | leptospira is the causative genus of the disease, leptospirosis. species identification of pathogenic leptospira in the past was generally performed by either dna-dna hybridisation or 16s rrna gene sequencing. both methods have inherent disadvantages such as the need for radio-labelled isotopes or significant homology between species. a conventional and real-time pcr amplification and sequencing method was developed for an alternate gene target: dna gyrase subunit b (gyrb). phylogenetic comparis ... | 2006 | 17067399 |
| comparison of gene expression by co-cultured wc1+ gammadelta and cd4+ alphabeta t cells exhibiting a recall response to bacterial antigen. | immunization of cattle with a leptospira borgpetersenii serovar hardjo-bovis vaccine results in the development of a recall response by wc1(+) gammadelta t cells and cd4(+) alphabeta t cells characterized by proliferation and interferon-gamma production. it was hypothesized that these two t cell subpopulations had largely redundant effector functions, principally differing in their requirements for activation. to test this, gene expression in cells proliferating to antigen were compared utilizin ... | 2007 | 17081609 |
| application of multilocus variable-number tandem-repeat analysis for molecular typing of the agent of leptospirosis. | leptospirosis is a worldwide-distributed zoonosis, endemic in tropical areas. epidemiologic investigations of leptospirosis still rely on tedious serological identification tests. recently, molecular typing systems based on variable-number tandem-repeat (vntr) analysis have been described and have been used to identify leptospira interrogans strains. although l. interrogans is the most common leptospira species encountered in human infections around the world, other pathogenic species, such as l ... | 2006 | 17088367 |
| in silico and microarray-based genomic approaches to identifying potential vaccine candidates against leptospira interrogans. | currently available vaccines against leptospirosis are of low efficacy, have an unacceptable side-effect profile, do not induce long-term protection, and provide no cross-protection against the different serovars of pathogenic leptospira. the current major focus in leptospirosis research is to discover conserved protective antigens that may elicit longer-term protection against a broad range of leptospira. there is a need to screen vaccine candidate genes in the genome of leptospira interrogans. | 2006 | 17109759 |
| leptospirosis in wied's marmosets (callithrix kuhlii). | two adult wied's marmosets (callithrix kuhlii) presented with jaundice, anemia, and weight loss. death of one individual was attributed to renal tubular necrosis; liver and kidney were positive for leptospira antigen by immunohistochemical (ihc) staining. the second animal was negative for antigen by ihc staining, but serologically positive for leptospira borgpetersenii serovar ballum with an eightfold titer increase in paired samples, and was euthanized because of unresponsiveness to treatment. ... | 2006 | 17312798 |
| response of leptospira interrogans to physiologic osmolarity: relevance in signaling the environment-to-host transition. | transmission of pathogenic leptospira between mammalian hosts usually involves dissemination via soil or water contaminated by the urine of carrier animals. the ability of leptospira to adapt to the diverse conditions found inside and outside the host is reflected in its relatively large genome size and high percentage of signal transduction genes. an exception is leptospira borgpetersenii serovar hardjo, which is transmitted by direct contact and appears to have lost genes necessary for surviva ... | 2007 | 17371863 |
| 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 ... | 2007 | 17403048 |
| wc1+ gammadelta t cell memory population is induced by killed bacterial vaccine. | limited studies have addressed the ability of gammadelta t cells to become memory populations. we previously demonstrated that wc1.1(+) gammadelta t cells from ruminants vaccinated with killed leptospira borgpetersenii proliferate and produce ifn-gamma in recall responses. here we show that this response is dependent upon antigen-responsive cd4 t cells, at least across transwell membranes; this requirement cannot be replaced by il-2. the response was also dependent upon in vivo priming, since ga ... | 2007 | 17429840 |
| leptospirosis in urban wild boars, berlin, germany. | we found antibodies to leptospires in 25 (18%) of 141 wild boars from berlin (95% confidence interval 12-25). seropositivity was associated with chronic interstitial nephritis (odds ratio 10.5; p=0.01), and leptospires were detected in kidney tissues. wild boars represent a potential source for human leptospirosis in urban environments. | 2007 | 17553254 |
| expression and characterization of an iron-regulated hemin-binding protein, hbpa, from leptospira interrogans serovar lai. | in an earlier study, based on the ferric enterobactin receptor fepa of escherichia coli, we identified and modeled a tonb-dependent outer membrane receptor protein (lb191) from the genome of leptospira interrogans serovar lai. based on in silico analysis, we hypothesized that this protein was an iron-dependent hemin-binding protein. in this study, we provide experimental evidence to prove that this protein, termed hbpa (hemin-binding protein a), is indeed an iron-regulated hemin-binding protein. ... | 2007 | 17576761 |
| genetic diversity among major endemic strains of leptospira interrogans in china. | leptospirosis is a world-widely distributed zoonosis. humans become infected via exposure to pathogenic leptospira spp. from contaminated water or soil. the availability of genomic sequences of leptospira interrogans serovar lai and serovar copenhageni opened up opportunities to identify genetic diversity among different pathogenic strains of l. interrogans representing various kinds of serotypes (serogroups and serovars). | 2007 | 17603913 |
| increased prevalence of borrelia burgdorferi infections in bernese mountain dogs: a possible breed predisposition. | glomerulonephritis in dogs has been associated with b. burgdorferi infections. in bernese mountain dogs with glomerulonephritis antibodies against b. burgdorferi have been found in most dogs, raising the question if the breed is predisposed to infections with b. burgdorferi. the aim of this study was to determine the prevalence of antibodies against b. burgdorferi sensu lato in a well defined population of bernese mountain dogs and to compare this prevalence with data from dogs of other breeds. | 2007 | 17626630 |
| the terminal portion of leptospiral immunoglobulin-like protein liga confers protective immunity against lethal infection in the hamster model of leptospirosis. | subunit vaccines are a potential intervention strategy against leptospirosis, which is a major public health problem in developing countries and a veterinary disease in livestock and companion animals worldwide. leptospiral immunoglobulin-like (lig) proteins are a family of surface-exposed determinants that have ig-like repeat domains found in virulence factors such as intimin and invasin. we expressed fragments of the repeat domain regions of liga and ligb from leptospira interrogans serovar co ... | 2007 | 17629368 |
| the ompa-like protein loa22 is essential for leptospiral virulence. | pathogenic mechanisms of leptospira interrogans, the causal agent of leptospirosis, remain largely unknown. this is mainly due to the lack of tools for genetic manipulations of pathogenic species. in this study, we characterized a mutant obtained by insertion of the transposon himar1 into a gene encoding a putative lipoprotein, loa22, which has a predicted ompa domain based on sequence identity. the resulting mutant did not express loa22 and was attenuated in virulence in the guinea pig and hams ... | 2007 | 17630832 |
| evaluation of two antimicrobial therapies in the treatment of leptospira borgpetersenii serovar hardjo infection in experimentally infected cattle. | this study demonstrated the ability of the antimicrobials tulathromycin (draxxin) and ceftiofur crystalline free acid sterile suspension (excede) to clear the spirochete leptospira borgpetersenii serovar hardjo type hardjo-bovis (l. hardjo-bovis) from experimentally infected cattle. treatment with tulathromycin resulted in clearance of l. hardjo-bovis organisms from the urine and kidney tissue of all animals (9 of 9), and treatment with ceftiofur crystalline free acid resulted in clearance of th ... | 2007 | 17926305 |
| a motif-based search in bacterial genomes identifies the ortholog of the small rna yfr1 in all lineages of cyanobacteria. | non-coding rnas (ncrna) are regulators of gene expression in all domains of life. they control growth and differentiation, virulence, motility and various stress responses. the identification of ncrnas can be a tedious process due to the heterogeneous nature of this molecule class and the missing sequence similarity of orthologs, even among closely related species. the small ncrna yfr1 has previously been found in the prochlorococcus/synechococcus group of marine cyanobacteria. | 2007 | 17941988 |
| [expression in escherichia coli of the gspd(l) gene of the type ii secretion system in leptospira borgpetersenii serovariety hardjo]. | a fragment of 1.539 pb of the gene homologous to gspd of hardjobovis was clonated in the pet28a vector and it was transformed into e. coli c43 and rosetta strains. the sequence of gspd(l) showed 46 % of similitude with e. coli gspd secretin. the expression of recombinant gspd(l) was obtained in rosetta strain. | 2005 | 17966476 |
| a field study of the effects of a monovalent leptospira borgpetersenii serovar hardjo strain hardjobovis vaccine administered with oxytetracycline on reproductive performance in beef cattle. | to determine whether vaccination with a monovalent leptospira borgpetersenii serovar hardjo strain hardjobovis vaccine coupled with parenteral long-acting oxytetracycline treatment would improve the reproductive performance of beef cows. | 2007 | 18052809 |
| 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 |
| 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 |
| 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 |
| structure of the cytosolic part of the subunit b-dimer of escherichia coli f0f1-atp synthase. | the structure of the external stalk and its function in the catalytic mechanism of the f(0)f(1)-atp synthase remains one of the important questions in bioenergetics. the external stalk has been proposed to be either a rigid stator that binds f(1) or an elastic structural element that transmits energy from the small rotational steps of subunits c to the f(1) sector during catalysis. we employed proteomics, sequence-based structure prediction, molecular modeling, and electron spin resonance spectr ... | 2008 | 18326647 |
| 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 |
| 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 |
| 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 |
| 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 |
| insight into the coupling mechanism of the vitamin k-dependent carboxylase: mutation of histidine 160 disrupts glutamic acid carbanion formation and efficient coupling of vitamin k epoxidation to glutamic acid carboxylation. | vitamin k-dependent (vkd) proteins become activated by the vkd carboxylase, which converts glu's to carboxylated glu's (gla's) in their gla domains. the carboxylase uses vitamin k epoxidation to drive glu carboxylation, and the two half-reactions are coupled in 1:1 stoichiometry by an unknown mechanism. we now report the first identification of a residue, his160, required for coupling. a h160a mutant showed wild-type levels of epoxidation but substantially less carboxylation. monitoring proton a ... | 2008 | 18717596 |