Treponema paraluiscuniculi

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David Smajs - One of the best experts on this subject based on the ideXlab platform.

  • P1.010 Comparative Evolutionary Analyses of Nine Treponema Pallidum and Treponema paraluiscuniculi Strains
    Sexually Transmitted Infections, 2013
    Co-Authors: P Krecmerova, David Smajs
    Abstract:

    Background Pathogenic uncultivable treponemes include the agents of syphilis ( T. pallidum ssp. pallidum , TPA), yaws ( T. pallidum ssp. pertenue , TPE) and endemic syphilis ( T. pallidum ssp. endemicum , TEN). Treponema paraluiscuniculi (TPC) causes rabbit syphilis. Pathogenic treponemes are highly clonal bacteria showing minimal genetic variability in the genome sequence of individual strains. Methods Five TPA strains (Nichols, SS14, Chicago, Mexico A and DAL-1), three TPE strains (CDC-2, Samoa D and Gauthier) and a one TPC strain Cuniculi A were analysed in this study. All possible combinations of gene alignments were tested on type of selection by Z-test using modified Nei-Gojobori method based on Jukes-Cantor model. Complete deletion was used as a gap treatment and transition/transversion ratio was set to 0.85. Results were considered significant at 5% level. Results A total of 22 genes were found under positive selection in at least one comparison between Treponemal strains. Negative and neutral selection was found in at least one combination for 258 and 206 genes, respectively. While positive selection was identified in genes encoding putative virulence factors, proteins involved in cell structure and cell processes, negative selection was predominantly found in genes encoding components of general metabolism, transport and translation. Neutral selection was detected mainly in genes encoding hypothetical proteins and genes encoding proteins involved in general metabolism. Conclusions Positively selected genes are candidates for important Treponemal virulence factors while negatively selected and conserved genes are likely to encode essential genes. Genes under neutral evolution may indicate genome regions that could be lost during adaptation of pathogen to its host.

  • Is there a difference between hare syphilis and rabbit syphilis? Cross infection experiments between rabbits and hares.
    Veterinary Microbiology, 2013
    Co-Authors: Johannes T. Lumeij, Lenka Mikalová, David Smajs
    Abstract:

    Cross infection of rabbits and hares with Treponema paraluiscuniculi from rabbits and the related microorganism from hares, which was provisionally named "Treponema paraluisleporis", revealed that T. paraluiscuniculi affects rabbits clinically, but only causes seroconversion in hares without causing clinical disease, while "T. paraluisleporis" induces disease in both rabbits and hares. The 16S rRNA gene of "T. paraluisleporis" was sequenced (GenBank acc. no. JX899416) and compared to the sequence of T. paraluiscuniculi strain Cuniculi A. A phylogenetic tree based on the sequence alignment of 2002 bp taken from several Treponemal strains was constructed. Both "T. paraluisleporis" and T. paraluiscuniculi are clustered together indicating their common origin. The close phylogenetic relatedness of both representatives supports the conclusion that subspecies or ecovar status should be given to these strains rather than species status. A more appropriate species name might be Treponema paraluisleporidarum. The genitive refers to the nominative Leporidae (family of rabbits and hares). The naturally occurring strain in rabbits would than be T. paraluisleporidarum ecovar Cuniculus and the strain from hares T. paraluisleporidarum ecovar Lepus. Since the former seems to have fewer physiological hosts, ecovar Lepus may represent an evolutionary ancestor of ecovar Cuniculus.

  • structure of rrn operons in pathogenic non cultivable treponemes sequence but not genomic position of intergenic spacers correlates with classification of Treponema pallidum and Treponema paraluiscuniculi strains
    Journal of Medical Microbiology, 2013
    Co-Authors: George M Weinstock, Lenka Mikalová, Michal Strouhal, Petra Pospisilova, Marie Zobaníková, Darina Cejkova, David Smajs
    Abstract:

    This study examined the sequences of the two rRNA (rrn) operons of pathogenic non-cultivable treponemes, comprising 11 strains of T. pallidum ssp. pallidum (TPA), five strains of T. pallidum ssp. pertenue (TPE), two strains of T. pallidum ssp. endemicum (TEN), a simian Fribourg-Blanc strain and a rabbit T. paraluiscuniculi (TPc) strain. PCR was used to determine the type of 16S–23S ribosomal intergenic spacers in the rrn operons from 30 clinical samples belonging to five different genotypes. When compared with the TPA strains, TPc Cuniculi A strain had a 17 bp deletion, and the TPE, TEN and Fribourg-Blanc isolates had a deletion of 33 bp. Other than these deletions, only 17 heterogeneous sites were found within the entire region (excluding the 16S–23S intergenic spacer region encoding tRNA-Ile or tRNA-Ala). The pattern of nucleotide changes in the rrn operons corresponded to the classification of Treponemal strains, whilst two different rrn spacer patterns (Ile/Ala and Ala/Ile) appeared to be distributed randomly across species/subspecies classification, time and geographical source of the Treponemal strains. It is suggested that the random distribution of tRNA genes is caused by reciprocal translocation between repetitive sequences mediated by a recBCD-like system.

  • genetic diversity in Treponema pallidum implications for pathogenesis evolution and molecular diagnostics of syphilis and yaws
    Infection Genetics and Evolution, 2012
    Co-Authors: David Smajs, Steve J Norris, George M Weinstock
    Abstract:

    Pathogenic uncultivable treponemes, similar to syphilis-causing Treponema pallidum subspecies pallidum, include T. pallidum ssp. pertenue, T. pallidum ssp. endemicum and Treponema carateum, which cause yaws, bejel and pinta, respectively. Genetic analyses of these pathogens revealed striking similarity among these bacteria and also a high degree of similarity to the rabbit pathogen, Treponema paraluiscuniculi, a treponeme not infectious to humans. Genome comparisons between pallidum and non-pallidum treponemes revealed genes with potential involvement in human infectivity, whereas comparisons between pallidum and pertenue treponemes identified genes possibly involved in the high invasivity of syphilis treponemes. Genetic variability within syphilis strains is considered as the basis of syphilis molecular epidemiology with potential to detect more virulent strains, whereas genetic variability within a single strain is related to its ability to elude the immune system of the host. Genome analyses also shed light on Treponemal evolution and on chromosomal targets for molecular diagnostics of Treponemal infections.

  • Whole Genome Analyses of Treponemes: New Targets for Strain- and Subspecies-Specific Molecular Diagnostics
    Syphilis - Recognition Description and Diagnosis, 2011
    Co-Authors: David Smajs, Lenka Mikalová, Michal Strouhal, Petra Pospisilova, Steven J Norris, Marie Zobaníková, Darina Čejková, George M Weinstock
    Abstract:

    The genus Treponema comprises several human uncultivable pathogens including Treponema pallidum subspecies pallidum (TPA, the causative agent of the sexually transmitted syphilis), Treponema pallidum subspecies pertenue (TPE, causative agent of yaws), Treponema pallidum subspecies endemicum (TEN, causing endemic syphilis), and Treponema carateum causing pinta. Additionally, the rabbit pathogen Treponema paraluiscuniculi (TPC) is very similar to syphilis treponeme but is not pathogenic to humans. Other pathogenic treponemes (e.g. Treponema denticola and T. vincentii) differ from the others by having considerably larger genomes. Moreover, these treponemes can be cultivated under in vitro conditions. The infections caused by human uncultivable pathogenic treponemes can be classified according to their invasivity, from the most invasive bacterium causing venereal syphilis to Treponema carateum (pinta), which is a non- invasive spirochete causing local dermal lesions. Strains of non-venereal treponemes including Treponema pallidum subspecies pertenue and endemicum are considered moderately invasive.

George M Weinstock - One of the best experts on this subject based on the ideXlab platform.

  • structure of rrn operons in pathogenic non cultivable treponemes sequence but not genomic position of intergenic spacers correlates with classification of Treponema pallidum and Treponema paraluiscuniculi strains
    Journal of Medical Microbiology, 2013
    Co-Authors: George M Weinstock, Lenka Mikalová, Michal Strouhal, Petra Pospisilova, Marie Zobaníková, Darina Cejkova, David Smajs
    Abstract:

    This study examined the sequences of the two rRNA (rrn) operons of pathogenic non-cultivable treponemes, comprising 11 strains of T. pallidum ssp. pallidum (TPA), five strains of T. pallidum ssp. pertenue (TPE), two strains of T. pallidum ssp. endemicum (TEN), a simian Fribourg-Blanc strain and a rabbit T. paraluiscuniculi (TPc) strain. PCR was used to determine the type of 16S–23S ribosomal intergenic spacers in the rrn operons from 30 clinical samples belonging to five different genotypes. When compared with the TPA strains, TPc Cuniculi A strain had a 17 bp deletion, and the TPE, TEN and Fribourg-Blanc isolates had a deletion of 33 bp. Other than these deletions, only 17 heterogeneous sites were found within the entire region (excluding the 16S–23S intergenic spacer region encoding tRNA-Ile or tRNA-Ala). The pattern of nucleotide changes in the rrn operons corresponded to the classification of Treponemal strains, whilst two different rrn spacer patterns (Ile/Ala and Ala/Ile) appeared to be distributed randomly across species/subspecies classification, time and geographical source of the Treponemal strains. It is suggested that the random distribution of tRNA genes is caused by reciprocal translocation between repetitive sequences mediated by a recBCD-like system.

  • An unrooted tree constructed from whole genome sequence alignments of 10 complete genome nucleotide sequences.
    2013
    Co-Authors: Marie Zobaníková, Lenka Mikalová, Michal Strouhal, Petra Pospisilova, Lei Chen, Darina Čejková, Lenka Ambrožová, Lucinda L. Fulton, Erica Sodergren, George M Weinstock
    Abstract:

    An unrooted tree constructed from whole genome sequence alignments using the Maximum Parsimony method and MEGA software [34]. The bar scale corresponds to 1000 nt changes. Bootstrap values based on 1,000 replications are shown next to the branches. All positions containing deletions in at least one genome sequence were omitted from further analysis. The analysis comprised 10 complete genome nucleotide sequences including 5 strains of TPA (Treponema pallidum ssp. pallidum), 3 strains of TPE (Treponema pallidum ssp. pertenue), one TPc (Treponema paraluiscuniculi) strain and the FB strain. There were a total of 1,129,016 nucleotide positions aligned in the final dataset. Note the clustering of the FB genome with other TPE strains. The branch of TPc was shortened (//).

  • genetic diversity in Treponema pallidum implications for pathogenesis evolution and molecular diagnostics of syphilis and yaws
    Infection Genetics and Evolution, 2012
    Co-Authors: David Smajs, Steve J Norris, George M Weinstock
    Abstract:

    Pathogenic uncultivable treponemes, similar to syphilis-causing Treponema pallidum subspecies pallidum, include T. pallidum ssp. pertenue, T. pallidum ssp. endemicum and Treponema carateum, which cause yaws, bejel and pinta, respectively. Genetic analyses of these pathogens revealed striking similarity among these bacteria and also a high degree of similarity to the rabbit pathogen, Treponema paraluiscuniculi, a treponeme not infectious to humans. Genome comparisons between pallidum and non-pallidum treponemes revealed genes with potential involvement in human infectivity, whereas comparisons between pallidum and pertenue treponemes identified genes possibly involved in the high invasivity of syphilis treponemes. Genetic variability within syphilis strains is considered as the basis of syphilis molecular epidemiology with potential to detect more virulent strains, whereas genetic variability within a single strain is related to its ability to elude the immune system of the host. Genome analyses also shed light on Treponemal evolution and on chromosomal targets for molecular diagnostics of Treponemal infections.

  • G+C content variation in selected Treponema strains.
    2012
    Co-Authors: Helena Pětrošová, Lenka Mikalová, Michal Strouhal, Petra Pospisilova, Xiang Qin, Donna M. Muzny, Lei Chen, Marie Zobaníková, Darina Čejková, George M Weinstock
    Abstract:

    TPA Mexico A, TPA SS14, TPE Samoa D and Treponema paraluiscuniculi strain Cuniculi A were analyzed. Colored vertical lines represent 501 bp-long windows with G+C content above the 63% or below the 41% threshold. Black vertical lines represent genome locations of tpr genes. Stars denote 5 kb-long DNA regions with 40 or more nucleotide positions differentiating TPA and TPE strains [7]. Please note that there is no clear association of DNA regions with different G+C content and regions differentiating TPA and TPE strains [7] or locations of tpr genes.

  • Whole Genome Analyses of Treponemes: New Targets for Strain- and Subspecies-Specific Molecular Diagnostics
    Syphilis - Recognition Description and Diagnosis, 2011
    Co-Authors: David Smajs, Lenka Mikalová, Michal Strouhal, Petra Pospisilova, Steven J Norris, Marie Zobaníková, Darina Čejková, George M Weinstock
    Abstract:

    The genus Treponema comprises several human uncultivable pathogens including Treponema pallidum subspecies pallidum (TPA, the causative agent of the sexually transmitted syphilis), Treponema pallidum subspecies pertenue (TPE, causative agent of yaws), Treponema pallidum subspecies endemicum (TEN, causing endemic syphilis), and Treponema carateum causing pinta. Additionally, the rabbit pathogen Treponema paraluiscuniculi (TPC) is very similar to syphilis treponeme but is not pathogenic to humans. Other pathogenic treponemes (e.g. Treponema denticola and T. vincentii) differ from the others by having considerably larger genomes. Moreover, these treponemes can be cultivated under in vitro conditions. The infections caused by human uncultivable pathogenic treponemes can be classified according to their invasivity, from the most invasive bacterium causing venereal syphilis to Treponema carateum (pinta), which is a non- invasive spirochete causing local dermal lesions. Strains of non-venereal treponemes including Treponema pallidum subspecies pertenue and endemicum are considered moderately invasive.

Arturo Centurion-lara - One of the best experts on this subject based on the ideXlab platform.

  • Comparative Investigation of the Genomic Regions Involved in Antigenic Variation of the TprK Antigen among Treponemal Species, Subspecies, and Strains
    Journal of bacteriology, 2012
    Co-Authors: Lorenzo Giacani, Barbara J. Molini, Sheila A. Lukehart, Martin Benzler, Stephanie L. Brandt, Maritza Puray-chavez, Tara B. Reid, Charmie Godornes, Jörg S. Hartig, Arturo Centurion-lara
    Abstract:

    Although the three Treponema pallidum subspecies (T. pallidum subsp. pallidum, T. pallidum subsp. pertenue, and T. pallidum subsp. endemicum), Treponema paraluiscuniculi, and the unclassified Fribourg-Blanc treponeme cause clinically distinct diseases, these pathogens are genetically and antigenically highly related and are able to cause persistent infection. Recent evidence suggests that the putative surface-exposed variable antigen TprK plays an important role in both Treponemal immune evasion and persistence. tprK heterogeneity is generated by nonreciprocal gene conversion between the tprK expression site and donor sites. Although each of the above-mentioned species and subspecies has a functional tprK antigenic variation system, it is still unclear why the level of expression and the rate at which tprK diversifies during infection can differ significantly among isolates. To identify genomic differences that might affect the generation and expression of TprK variants among these pathogens, we performed comparative sequence analysis of the donor sites, as well as the tprK expression sites, among eight T. pallidum subsp. pallidum isolates (Nichols Gen, Nichols Sea, Chicago, Sea81-4, Dal-1, Street14, UW104, and UW126), three T. pallidum subsp. pertenue isolates (Gauthier, CDC2, and Samoa D), one T. pallidum subsp. endemicum isolate (Iraq B), the unclassified Fribourg-Blanc isolate, and the Cuniculi A strain of T. paraluiscuniculi. Synteny and sequence conservation, as well as deletions and insertions, were found in the regions harboring the donor sites. These data suggest that the tprK recombination system is harbored within dynamic genomic regions and that genomic differences might be an important key to explain discrepancies in generation and expression of tprK variants among these Treponema isolates.

  • Molecular Evolution of the tprC, D, I, K, G, and J Genes in the Pathogenic Genus Treponema
    Molecular biology and evolution, 2006
    Co-Authors: Rebecca R. Gray, Barbara J. Molini, Sheila A. Lukehart, Lorenzo Giacani, Charmie Godornes, Connie J. Mulligan, Eileen S. Sun, Andrew Kitchen, Arturo Centurion-lara
    Abstract:

    We investigated the evolution of 6 genes from the Treponema pallidum repeat (tpr) gene family, which encode potential virulence factors and are assumed to have evolved through gene duplication and gene conversion events. The 6 loci (tprC, D, G, J, I, and K) were sequenced and analyzed in several members of the genus Treponema, including the 3 subspecies of human T. pallidum (T. pallidum subsp. pallidum, pertenue, and endemicum), Treponema paraluiscuniculi (rabbit syphilis), and the unclassified Fribourg-Blanc (simian) isolate. Phylogenetic methods, recombination analysis, and measures of nucleotide diversity were used to investigate the evolutionary history of the tpr genes. Numerous instances of gene conversion were detected by all 3 methods including both homogenizing gene conversion that involved the entire length of the sequence as well as site-specific conversions that affected smaller regions. We determined the relative age and directionality of the gene conversion events whenever possible. Our data are also relevant to a discussion of the evolution of the treponemes themselves. Higher levels of variation exist between the human subspecies than within them, supporting the classification of the human treponemes into 3 subspecies. In contrast to published theories, the divergence and diversity of T. pallidum subsp. pertenue relative to the other subspecies does not support a much older origin of yaws at the emergence of modern human, nor is the level of divergence seen in T. pallidum subsp. pallidum consistent with a very recent (< 500 years) origin of this subspecies. In general, our results demonstrate that intragenomic recombination has played a significant role in the evolution of the studied tpr genes and emphasize that efforts to infer evolutionary history of the treponemes can be complicated if past recombination events are not recognized.

  • Tpr Homologs in Treponema paraluiscuniculi Cuniculi A Strain
    Infection and Immunity, 2004
    Co-Authors: Lorenzo Giacani, Karin Hevner, Barbara J. Molini, Sheila A. Lukehart, Wesley C Van Voorhis, Arturo Centurion-lara
    Abstract:

    Treponema paraluiscuniculi, the etiologic agent of rabbit venereal syphilis, is morphologically indistinguishable from Treponema pallidum subsp. pallidum (T. pallidum), the human syphilis treponeme, and induces similar immune responses and histopathologic changes in the infected host. Because of their high degree of relatedness, comparative studies are likely to identify genetic determinants that contribute to pathogenesis or virulence in human syphilis. The tpr (Treponema pallidum repeat) genes are believed to code for potential virulence factors. In this study, we identified 10 tpr homologs in Treponema paraluiscuniculi Cuniculi A strain and determined their sequence architecture. Half of this group of paralogous genes were predicted to be nonfunctional due to the presence of frameshifts and premature stop codons. Furthermore, the immune response against the T. paraluiscuniculi Tpr homologs in long-term-infected rabbits was studied by enzyme-linked immunosorbent assay and lymphocyte proliferation assay, showing that TprK is the only target of the antibody and T-cell responses during experimental infection and emphasizing the importance of this putative virulence factor in venereal Treponematosis.

  • The Flanking Region Sequences of the 15-kDa Lipoprotein Gene Differentiate Pathogenic Treponemes
    The Journal of infectious diseases, 1998
    Co-Authors: Arturo Centurion-lara, Jeanne M. Shaffer, Christa Castro, Raphael Castillo, Wesley C. Van Voorhis, Sheila A. Lukehart
    Abstract:

    The species Treponema pallidum includes three subspecies (pallidum, pertenue, and endemicum) that cause syphilis, yaws, and bejel, respectively. A closely related species, Treponema paraluiscuniculi, is the etiologic agent of venereal syphilis in rabbits but does not infect humans. Although these treponemes cause distinct diseases, no laboratory method for differentiation has been reported. Genetic signatures were defined in the 5' and 3' flanking regions of the 15-kDa lipoprotein gene (tpp15) that distinguish the human pathogens and T. paraluiscuniculi, as well as distinguishing T. pallidum subsp. pallidum from the causes of human nonvenereal Treponematoses. A single Eco47III restriction site in the 5' flanking region differentiates T. pallidum subsp. pallidum from the other subspecies and species, and an XcmI site in the 3' flanking region differentiates T. paraluiscuniculi from the human pathogens. Polymerase chain reaction methods and restriction polymorphism were used to analyze 27 strains of pathogenic Treponema species.

  • Conservation of the 15-kilodalton lipoprotein among Treponema pallidum subspecies and strains and other pathogenic treponemes : Genetic and antigenic analyses
    Infection and immunity, 1997
    Co-Authors: Arturo Centurion-lara, Jeanne M. Shaffer, Christa Castro, Thomas W. Arroll, R Castillo, W. C. Van Voorhis, Sheila A. Lukehart
    Abstract:

    The 15-kDa lipoprotein of Treponema pallidum is a major immunogen during natural syphilis infection in humans and experimental infection in other hosts. The humoral and cellular immune responses to this molecule appear late in infection as resistance to reinfection is developing. One therefore might hypothesize that this antigen is important for protective immunity. This possibility is explored by using both genetic and antigenic approaches. Limited or no cross-protection has been demonstrated between the T. pallidum subspecies and strains or between Treponema species. We therefore hypothesized that if the 15-kDa antigen was of major importance in protective immunity, it might be a likely site of antigenic diversity. To explore this possibility, the sequences of the open reading frames of the 15-kDa gene have been determined for Treponema pallidum subsp. pallidum (Nichols and Bal-3 strains), T. pallidum subsp. pertenue (Gauthier strain), T. pallidum subsp. endemicum (Bosnia strain), Treponema paraluiscuniculi (Cuniculi A, H, and K strains), and a little-characterized simian isolate of Treponema sp. (Fribourg-Blanc strain). No significant differences in DNA sequences of the genes for the coding region of the 15-kDa antigen were found among the different species and subspecies studied. In addition, all organisms showed expression of the 15-kDa antigen as determined by monoclonal antibody staining. The role of the 15-kDa antigen in protection against homologous infection with T. pallidum subsp. pallidum Nichols was examined in rabbits immunized with a purified recombinant 15-kDa fusion protein. No alteration in chancre development was observed in immunized, compared to unimmunized, rabbits, and the antisera induced by the immunization failed to enhance phagocytosis of T. pallidum subsp. pallidum by macrophages in vitro. These results do not support a major role for this antigen in protection against syphilis infection.

Michal Strouhal - One of the best experts on this subject based on the ideXlab platform.

  • Complete Genome Sequence of Treponema paraluiscuniculi, Strain Cuniculi A: The Loss of Infectivity to Humans Is Associated with Genome Decay
    2016
    Co-Authors: Michal Strouhal, Steven J Norris, Shannon Dugan-rocha, Tom Albert, Xiang Qin, Kym Hallsworth-pepin, Christian Buhay, Donna M. Muzny, Lei Chen, Richard A. Gibbs
    Abstract:

    Treponema paraluiscuniculi is the causative agent of rabbit venereal spirochetosis. It is not infectious to humans, although its genome structure is very closely related to other pathogenic Treponema species including Treponema pallidum subspecies pallidum, the etiological agent of syphilis. In this study, the genome sequence of Treponema paraluiscuniculi, strain Cuniculi A, was determined by a combination of several high-throughput sequencing strategies. Whereas the overall size (1,133,390 bp), arrangement, and gene content of the Cuniculi A genome closely resembled those of the T. pallidum genome, the T. paraluiscuniculi genome contained a markedly higher number of pseudogenes and gene fragments (51). In addition to pseudogenes, 33 divergent genes were also found in the T. paraluiscuniculi genome. A set of 32 (out of 84) affected genes encoded proteins of known or predicted function in the Nichols genome. These proteins included virulence factors, gene regulators and components of DNA repair and recombination. The majority (52 or 61.9%) of the Cuniculi A pseudogenes and divergent genes were of unknown function. Our results indicate that T. paraluiscuniculi has evolved from a T. pallidum-like ancestor and adapted to a specialized host-associated niche (rabbits) during loss of infectivity to humans. The genes that are inactivated or altered in T. paraluiscuniculi are candidates for virulence factors important in the infectivit

  • structure of rrn operons in pathogenic non cultivable treponemes sequence but not genomic position of intergenic spacers correlates with classification of Treponema pallidum and Treponema paraluiscuniculi strains
    Journal of Medical Microbiology, 2013
    Co-Authors: George M Weinstock, Lenka Mikalová, Michal Strouhal, Petra Pospisilova, Marie Zobaníková, Darina Cejkova, David Smajs
    Abstract:

    This study examined the sequences of the two rRNA (rrn) operons of pathogenic non-cultivable treponemes, comprising 11 strains of T. pallidum ssp. pallidum (TPA), five strains of T. pallidum ssp. pertenue (TPE), two strains of T. pallidum ssp. endemicum (TEN), a simian Fribourg-Blanc strain and a rabbit T. paraluiscuniculi (TPc) strain. PCR was used to determine the type of 16S–23S ribosomal intergenic spacers in the rrn operons from 30 clinical samples belonging to five different genotypes. When compared with the TPA strains, TPc Cuniculi A strain had a 17 bp deletion, and the TPE, TEN and Fribourg-Blanc isolates had a deletion of 33 bp. Other than these deletions, only 17 heterogeneous sites were found within the entire region (excluding the 16S–23S intergenic spacer region encoding tRNA-Ile or tRNA-Ala). The pattern of nucleotide changes in the rrn operons corresponded to the classification of Treponemal strains, whilst two different rrn spacer patterns (Ile/Ala and Ala/Ile) appeared to be distributed randomly across species/subspecies classification, time and geographical source of the Treponemal strains. It is suggested that the random distribution of tRNA genes is caused by reciprocal translocation between repetitive sequences mediated by a recBCD-like system.

  • An unrooted tree constructed from whole genome sequence alignments of 10 complete genome nucleotide sequences.
    2013
    Co-Authors: Marie Zobaníková, Lenka Mikalová, Michal Strouhal, Petra Pospisilova, Lei Chen, Darina Čejková, Lenka Ambrožová, Lucinda L. Fulton, Erica Sodergren, George M Weinstock
    Abstract:

    An unrooted tree constructed from whole genome sequence alignments using the Maximum Parsimony method and MEGA software [34]. The bar scale corresponds to 1000 nt changes. Bootstrap values based on 1,000 replications are shown next to the branches. All positions containing deletions in at least one genome sequence were omitted from further analysis. The analysis comprised 10 complete genome nucleotide sequences including 5 strains of TPA (Treponema pallidum ssp. pallidum), 3 strains of TPE (Treponema pallidum ssp. pertenue), one TPc (Treponema paraluiscuniculi) strain and the FB strain. There were a total of 1,129,016 nucleotide positions aligned in the final dataset. Note the clustering of the FB genome with other TPE strains. The branch of TPc was shortened (//).

  • G+C content variation in selected Treponema strains.
    2012
    Co-Authors: Helena Pětrošová, Lenka Mikalová, Michal Strouhal, Petra Pospisilova, Xiang Qin, Donna M. Muzny, Lei Chen, Marie Zobaníková, Darina Čejková, George M Weinstock
    Abstract:

    TPA Mexico A, TPA SS14, TPE Samoa D and Treponema paraluiscuniculi strain Cuniculi A were analyzed. Colored vertical lines represent 501 bp-long windows with G+C content above the 63% or below the 41% threshold. Black vertical lines represent genome locations of tpr genes. Stars denote 5 kb-long DNA regions with 40 or more nucleotide positions differentiating TPA and TPE strains [7]. Please note that there is no clear association of DNA regions with different G+C content and regions differentiating TPA and TPE strains [7] or locations of tpr genes.

  • TPE genes containing major sequence changes encoding proteins with predicted cell function.
    2012
    Co-Authors: Darina Čejková, Lenka Mikalová, Michal Strouhal, Petra Pospisilova, Steven J Norris, Xiang Qin, Donna M. Muzny, Lei Chen, Marie Zobaníková, Richard A. Gibbs
    Abstract:

    T. p. ssp. pertenue (TPE) genes encoding proteins with predicted cell function containing six or more amino acid changes and/or major sequence changes between all studied T. p. ssp. pertenue and all T. p. ssp. pallidum strains are shown.aD, deletion; fr. mut., frameshift mutation; I, insertion; MSC (major sequence changes) are defined in Table 1; rev. fr. mut., reverted frameshift mutation; S, substitution.bGene expression rate in Nichols strain grown in rabbits. The gene expression rates were taken from [58].cThe gene was shown to contain frameshift mutations or MSC in the genome of Treponema paraluiscuniculi Cuniculi A [33].dDetected recombination within the gene or previously identified recombination [56].eThe corresponding protein was identified as an antigen [54].fThe corresponding protein was identified as a lipoprotein [55].gThe selection test was calculated using the Kumar model [47] using MEGA4 [48] software.

Sheila A. Lukehart - One of the best experts on this subject based on the ideXlab platform.

  • Comparative Investigation of the Genomic Regions Involved in Antigenic Variation of the TprK Antigen among Treponemal Species, Subspecies, and Strains
    Journal of bacteriology, 2012
    Co-Authors: Lorenzo Giacani, Barbara J. Molini, Sheila A. Lukehart, Martin Benzler, Stephanie L. Brandt, Maritza Puray-chavez, Tara B. Reid, Charmie Godornes, Jörg S. Hartig, Arturo Centurion-lara
    Abstract:

    Although the three Treponema pallidum subspecies (T. pallidum subsp. pallidum, T. pallidum subsp. pertenue, and T. pallidum subsp. endemicum), Treponema paraluiscuniculi, and the unclassified Fribourg-Blanc treponeme cause clinically distinct diseases, these pathogens are genetically and antigenically highly related and are able to cause persistent infection. Recent evidence suggests that the putative surface-exposed variable antigen TprK plays an important role in both Treponemal immune evasion and persistence. tprK heterogeneity is generated by nonreciprocal gene conversion between the tprK expression site and donor sites. Although each of the above-mentioned species and subspecies has a functional tprK antigenic variation system, it is still unclear why the level of expression and the rate at which tprK diversifies during infection can differ significantly among isolates. To identify genomic differences that might affect the generation and expression of TprK variants among these pathogens, we performed comparative sequence analysis of the donor sites, as well as the tprK expression sites, among eight T. pallidum subsp. pallidum isolates (Nichols Gen, Nichols Sea, Chicago, Sea81-4, Dal-1, Street14, UW104, and UW126), three T. pallidum subsp. pertenue isolates (Gauthier, CDC2, and Samoa D), one T. pallidum subsp. endemicum isolate (Iraq B), the unclassified Fribourg-Blanc isolate, and the Cuniculi A strain of T. paraluiscuniculi. Synteny and sequence conservation, as well as deletions and insertions, were found in the regions harboring the donor sites. These data suggest that the tprK recombination system is harbored within dynamic genomic regions and that genomic differences might be an important key to explain discrepancies in generation and expression of tprK variants among these Treponema isolates.

  • Molecular Evolution of the tprC, D, I, K, G, and J Genes in the Pathogenic Genus Treponema
    Molecular biology and evolution, 2006
    Co-Authors: Rebecca R. Gray, Barbara J. Molini, Sheila A. Lukehart, Lorenzo Giacani, Charmie Godornes, Connie J. Mulligan, Eileen S. Sun, Andrew Kitchen, Arturo Centurion-lara
    Abstract:

    We investigated the evolution of 6 genes from the Treponema pallidum repeat (tpr) gene family, which encode potential virulence factors and are assumed to have evolved through gene duplication and gene conversion events. The 6 loci (tprC, D, G, J, I, and K) were sequenced and analyzed in several members of the genus Treponema, including the 3 subspecies of human T. pallidum (T. pallidum subsp. pallidum, pertenue, and endemicum), Treponema paraluiscuniculi (rabbit syphilis), and the unclassified Fribourg-Blanc (simian) isolate. Phylogenetic methods, recombination analysis, and measures of nucleotide diversity were used to investigate the evolutionary history of the tpr genes. Numerous instances of gene conversion were detected by all 3 methods including both homogenizing gene conversion that involved the entire length of the sequence as well as site-specific conversions that affected smaller regions. We determined the relative age and directionality of the gene conversion events whenever possible. Our data are also relevant to a discussion of the evolution of the treponemes themselves. Higher levels of variation exist between the human subspecies than within them, supporting the classification of the human treponemes into 3 subspecies. In contrast to published theories, the divergence and diversity of T. pallidum subsp. pertenue relative to the other subspecies does not support a much older origin of yaws at the emergence of modern human, nor is the level of divergence seen in T. pallidum subsp. pallidum consistent with a very recent (< 500 years) origin of this subspecies. In general, our results demonstrate that intragenomic recombination has played a significant role in the evolution of the studied tpr genes and emphasize that efforts to infer evolutionary history of the treponemes can be complicated if past recombination events are not recognized.

  • Tpr Homologs in Treponema paraluiscuniculi Cuniculi A Strain
    Infection and Immunity, 2004
    Co-Authors: Lorenzo Giacani, Karin Hevner, Barbara J. Molini, Sheila A. Lukehart, Wesley C Van Voorhis, Arturo Centurion-lara
    Abstract:

    Treponema paraluiscuniculi, the etiologic agent of rabbit venereal syphilis, is morphologically indistinguishable from Treponema pallidum subsp. pallidum (T. pallidum), the human syphilis treponeme, and induces similar immune responses and histopathologic changes in the infected host. Because of their high degree of relatedness, comparative studies are likely to identify genetic determinants that contribute to pathogenesis or virulence in human syphilis. The tpr (Treponema pallidum repeat) genes are believed to code for potential virulence factors. In this study, we identified 10 tpr homologs in Treponema paraluiscuniculi Cuniculi A strain and determined their sequence architecture. Half of this group of paralogous genes were predicted to be nonfunctional due to the presence of frameshifts and premature stop codons. Furthermore, the immune response against the T. paraluiscuniculi Tpr homologs in long-term-infected rabbits was studied by enzyme-linked immunosorbent assay and lymphocyte proliferation assay, showing that TprK is the only target of the antibody and T-cell responses during experimental infection and emphasizing the importance of this putative virulence factor in venereal Treponematosis.

  • The Flanking Region Sequences of the 15-kDa Lipoprotein Gene Differentiate Pathogenic Treponemes
    The Journal of infectious diseases, 1998
    Co-Authors: Arturo Centurion-lara, Jeanne M. Shaffer, Christa Castro, Raphael Castillo, Wesley C. Van Voorhis, Sheila A. Lukehart
    Abstract:

    The species Treponema pallidum includes three subspecies (pallidum, pertenue, and endemicum) that cause syphilis, yaws, and bejel, respectively. A closely related species, Treponema paraluiscuniculi, is the etiologic agent of venereal syphilis in rabbits but does not infect humans. Although these treponemes cause distinct diseases, no laboratory method for differentiation has been reported. Genetic signatures were defined in the 5' and 3' flanking regions of the 15-kDa lipoprotein gene (tpp15) that distinguish the human pathogens and T. paraluiscuniculi, as well as distinguishing T. pallidum subsp. pallidum from the causes of human nonvenereal Treponematoses. A single Eco47III restriction site in the 5' flanking region differentiates T. pallidum subsp. pallidum from the other subspecies and species, and an XcmI site in the 3' flanking region differentiates T. paraluiscuniculi from the human pathogens. Polymerase chain reaction methods and restriction polymorphism were used to analyze 27 strains of pathogenic Treponema species.

  • Conservation of the 15-kilodalton lipoprotein among Treponema pallidum subspecies and strains and other pathogenic treponemes : Genetic and antigenic analyses
    Infection and immunity, 1997
    Co-Authors: Arturo Centurion-lara, Jeanne M. Shaffer, Christa Castro, Thomas W. Arroll, R Castillo, W. C. Van Voorhis, Sheila A. Lukehart
    Abstract:

    The 15-kDa lipoprotein of Treponema pallidum is a major immunogen during natural syphilis infection in humans and experimental infection in other hosts. The humoral and cellular immune responses to this molecule appear late in infection as resistance to reinfection is developing. One therefore might hypothesize that this antigen is important for protective immunity. This possibility is explored by using both genetic and antigenic approaches. Limited or no cross-protection has been demonstrated between the T. pallidum subspecies and strains or between Treponema species. We therefore hypothesized that if the 15-kDa antigen was of major importance in protective immunity, it might be a likely site of antigenic diversity. To explore this possibility, the sequences of the open reading frames of the 15-kDa gene have been determined for Treponema pallidum subsp. pallidum (Nichols and Bal-3 strains), T. pallidum subsp. pertenue (Gauthier strain), T. pallidum subsp. endemicum (Bosnia strain), Treponema paraluiscuniculi (Cuniculi A, H, and K strains), and a little-characterized simian isolate of Treponema sp. (Fribourg-Blanc strain). No significant differences in DNA sequences of the genes for the coding region of the 15-kDa antigen were found among the different species and subspecies studied. In addition, all organisms showed expression of the 15-kDa antigen as determined by monoclonal antibody staining. The role of the 15-kDa antigen in protection against homologous infection with T. pallidum subsp. pallidum Nichols was examined in rabbits immunized with a purified recombinant 15-kDa fusion protein. No alteration in chancre development was observed in immunized, compared to unimmunized, rabbits, and the antisera induced by the immunization failed to enhance phagocytosis of T. pallidum subsp. pallidum by macrophages in vitro. These results do not support a major role for this antigen in protection against syphilis infection.

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