The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Michal Strouhal - One of the best experts on this subject based on the ideXlab platform.
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first report of hare Treponematosis seroprevalence of european brown hares lepus europaeus in the czech republic seroprevalence negatively correlates with altitude of sampling areas
BMC Veterinary Research, 2019Co-Authors: Marketa Novakova, David Najt, Marcela Kostkova, Eliska Vrbova, Annika Posautz, Michal Strouhal, Sascha Knauf, Lenka Mikalova, David SmajsAbstract:Background The aim of this study was to quantify the seroprevalence of hare Treponematosis in European brown hare (Lepus europaeus) populations in the Czech Republic and to test for an association between Treponematosis prevalence and the altitude of the areas in which hares were sampled. We tested 289 serum samples of brown hares collected between 2015 and 2017. The sampling areas included 12 districts (73 villages) distributed throughout the Czech Republic. Serum samples were tested for the presence of antibodies against the causative agent of hare Treponematosis (Treponema paraluisleporidarum ecovar Lepus, TPeL) using two serological tests for human syphilis that cross-react with TPeL: the Treponema pallidum hemagglutination assay (TPHA) and the fluorescent Treponemal antibody absorption (FTA-ABS) test. To account for the imperfect diagnostic sensitivity and specificity of each test, apparent prevalence estimates of TPeL were converted to true prevalence estimates using the Rogan Gladen estimator. The correlation between TPeL true seroprevalence and altitude of sampling areas was analyzed using Pearson’s correlation coefficient at three levels of spatial resolution: (1) four groups, each composed of two merged districts, with ≥20 samples collected, differing in their altitude median (206, 348, 495, and 522 m above sea level); (2) separately tested eight districts, where ≥20 samples were collected per district; and (3) 27 groups composed of villages of the same altitude level distributed across the whole dataset.
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Identification of positively selected genes in human pathogenic treponemes: Syphilis-, yaws-, and bejel-causing strains differ in sets of genes showing adaptive evolution
PLoS neglected tropical diseases, 2019Co-Authors: Denisa Maděránková, Michal Strouhal, Petra Pospíšilová, Lenka Mikalova, Šimon Vadják, Ivana Kuklová, Lenka Krbková, Pavlina Koscova, Ivo Provaznik, David SmajsAbstract:Background Pathogenic treponemes related to Treponema pallidum are both human (causing syphilis, yaws, bejel) and animal pathogens (infections of primates, venereal spirochetosis in rabbits). A set of 11 Treponemal genome sequences including those of five Treponema pallidum ssp. pallidum (TPA) strains (Nichols, DAL-1, Mexico A, SS14, Chicago), four T. p. ssp. pertenue (TPE) strains (CDC-2, Gauthier, Samoa D, Fribourg-Blanc), one T. p. ssp. endemicum (TEN) strain (Bosnia A) and one strain (Cuniculi A) of Treponema paraluisleporidarum ecovar Cuniculus (TPeC) were tested for the presence of positively selected genes. Methodology/Principal findings A total of 1068 orthologous genes annotated in all 11 genomes were tested for the presence of positively selected genes using both site and branch-site models with CODEML (PAML package). Subsequent analyses with sequences obtained from 62 Treponemal draft genomes were used for the identification of positively selected amino acid positions. Synthetic biotinylated peptides were designed to cover positively selected protein regions and these peptides were tested for reactivity with the patient's syphilis sera. Altogether, 22 positively selected genes were identified in the TP genomes and TPA sets of positively selected genes differed from TPE genes. While genetic variability among TPA strains was predominantly present in a number of genetic loci, genetic variability within TPE and TEN strains was distributed more equally along the chromosome. Several syphilitic sera were shown to react with some peptides derived from the protein sequences evolving under positive selection. Conclusions/Significance The syphilis-, yaws-, and bejel-causing strains differed relative to sets of positively selected genes. Most of the positively selected chromosomal loci were identified among the TPA treponemes. The local accumulation of genetic variability suggests that the diversification of TPA strains took place predominantly in a limited number of genomic regions compared to the more dispersed genetic diversity differentiating TPE and TEN strains. The identification of positively selected sites in tpr genes and genes encoding outer membrane proteins suggests their role during infection of human and animal hosts. The driving force for adaptive evolution at these loci thus appears to be the host immune response as supported by observed reactivity of syphilitic sera with some peptides derived from protein sequences showing adaptive evolution.
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sequencing of Treponema pallidum subsp pallidum from isolate uz1974 using anti Treponemal antibodies enrichment first complete whole genome sequence obtained directly from human clinical material
PLOS ONE, 2018Co-Authors: Linda Grillova, Christina M Marra, Arturo Centurionlara, Michal Strouhal, Lenka Mikalova, Radim Strnadel, Giancarlo Russo, Lucy Poveda, Lorenzo Giacani, Darina CejkovaAbstract:Treponema pallidum subsp. pallidum (TPA) is the infectious agent of syphilis, a disease that infects more than 5 million people annually. Since TPA is an uncultivable bacterium, most of the information on TPA genetics comes from genome sequencing and molecular typing studies. This study presents the first complete TPA genome (without sequencing gaps) of clinical isolate (UZ1974), which was obtained directly from clinical material, without multiplication in rabbits. Whole genome sequencing was performed using a newly developed Anti-Treponemal Antibody Enrichment technique combined with previously reported Pooled Segment Genome Sequencing. We identified the UW074B genome, isolated from a sample previously propagated in rabbits, to be the closest relative of the UZ1974 genome and calculated the TPA mutation rate as 2.8 x 10(-10) per site per generation.
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molecular typing of syphilis causing strains among human immunodeficiency virus positive patients in antwerp belgium
Sexually Transmitted Diseases, 2017Co-Authors: Lenka Mikalova, Michal Strouhal, Linda Grillova, Kara Osbak, Chris Kenyon, Tania Crucitti, David SmajsAbstract:Centers for Disease Control and Prevention and sequencing-based treponeme typing was used to analyze 72 blood samples, collected from human immunodeficiency virus and syphilis co-infected patients during 2014 to 2015 in Antwerp, Belgium. Twenty-nine (40.3%) isolates were polymerase chain reaction positive for Treponema pallidum, and all tested were macrolide-resistant. Four genotypes were identified by sequencing-based typing including two new genotypes, U4NR8 and SU9R8, whereas enhanced Centers for Disease Control and Prevention typing revealed 7 subtypes.
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african nonhuman primates are infected with the yaws bacterium Treponema pallidum subsp pertenue
bioRxiv, 2017Co-Authors: Sascha Knauf, Ja F Gogarte, Verena J Schuenema, Michal Strouhal, E K Atamuzi, Helene M De Nys, Ariane Due, Lenka Mikalova, Roy Armstrong, Idrissa S ChumaAbstract:Treponema pallidum subsp. pertenue (TPE) is the causative agent of yaws. The disease was subject to global eradication efforts in the mid 20th century but reemerged in West Africa, Southern Asia, and the Pacific region. Despite its importance for eradication, detailed data on possible nonhuman disease reservoirs are missing. A number of African nonhuman primates (NHPs) have been reported to show skin ulcerations suggestive of Treponemal infection in humans. Furthermore antibodies against Treponema pallidum (TP) have been repeatedly detected in wild NHP populations. While genetic studies confirmed that NHPs are infected with TP strains, subspecies identification was only possible once for a strain isolated in 1966, pinpointing the involvement of TPE. We therefore collected a number of recently isolated simian TP strains and determined eight whole genome sequences using hybridization capture or long-range PCR combined with next-generation sequencing. These new genomes were compared with those of known human TP isolates. Our results show that naturally occurring simian TP strains circulating in three African NHP species all cluster with human TPE strains and show the same genomic structure as human TPE strains. These data indicate that humans are not the exclusive host for the yaws bacterium and that a One Health approach is required to achieve sustainable eradication of human yaws.
Lenka Mikalova - One of the best experts on this subject based on the ideXlab platform.
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first report of hare Treponematosis seroprevalence of european brown hares lepus europaeus in the czech republic seroprevalence negatively correlates with altitude of sampling areas
BMC Veterinary Research, 2019Co-Authors: Marketa Novakova, David Najt, Marcela Kostkova, Eliska Vrbova, Annika Posautz, Michal Strouhal, Sascha Knauf, Lenka Mikalova, David SmajsAbstract:Background The aim of this study was to quantify the seroprevalence of hare Treponematosis in European brown hare (Lepus europaeus) populations in the Czech Republic and to test for an association between Treponematosis prevalence and the altitude of the areas in which hares were sampled. We tested 289 serum samples of brown hares collected between 2015 and 2017. The sampling areas included 12 districts (73 villages) distributed throughout the Czech Republic. Serum samples were tested for the presence of antibodies against the causative agent of hare Treponematosis (Treponema paraluisleporidarum ecovar Lepus, TPeL) using two serological tests for human syphilis that cross-react with TPeL: the Treponema pallidum hemagglutination assay (TPHA) and the fluorescent Treponemal antibody absorption (FTA-ABS) test. To account for the imperfect diagnostic sensitivity and specificity of each test, apparent prevalence estimates of TPeL were converted to true prevalence estimates using the Rogan Gladen estimator. The correlation between TPeL true seroprevalence and altitude of sampling areas was analyzed using Pearson’s correlation coefficient at three levels of spatial resolution: (1) four groups, each composed of two merged districts, with ≥20 samples collected, differing in their altitude median (206, 348, 495, and 522 m above sea level); (2) separately tested eight districts, where ≥20 samples were collected per district; and (3) 27 groups composed of villages of the same altitude level distributed across the whole dataset.
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Identification of positively selected genes in human pathogenic treponemes: Syphilis-, yaws-, and bejel-causing strains differ in sets of genes showing adaptive evolution
PLoS neglected tropical diseases, 2019Co-Authors: Denisa Maděránková, Michal Strouhal, Petra Pospíšilová, Lenka Mikalova, Šimon Vadják, Ivana Kuklová, Lenka Krbková, Pavlina Koscova, Ivo Provaznik, David SmajsAbstract:Background Pathogenic treponemes related to Treponema pallidum are both human (causing syphilis, yaws, bejel) and animal pathogens (infections of primates, venereal spirochetosis in rabbits). A set of 11 Treponemal genome sequences including those of five Treponema pallidum ssp. pallidum (TPA) strains (Nichols, DAL-1, Mexico A, SS14, Chicago), four T. p. ssp. pertenue (TPE) strains (CDC-2, Gauthier, Samoa D, Fribourg-Blanc), one T. p. ssp. endemicum (TEN) strain (Bosnia A) and one strain (Cuniculi A) of Treponema paraluisleporidarum ecovar Cuniculus (TPeC) were tested for the presence of positively selected genes. Methodology/Principal findings A total of 1068 orthologous genes annotated in all 11 genomes were tested for the presence of positively selected genes using both site and branch-site models with CODEML (PAML package). Subsequent analyses with sequences obtained from 62 Treponemal draft genomes were used for the identification of positively selected amino acid positions. Synthetic biotinylated peptides were designed to cover positively selected protein regions and these peptides were tested for reactivity with the patient's syphilis sera. Altogether, 22 positively selected genes were identified in the TP genomes and TPA sets of positively selected genes differed from TPE genes. While genetic variability among TPA strains was predominantly present in a number of genetic loci, genetic variability within TPE and TEN strains was distributed more equally along the chromosome. Several syphilitic sera were shown to react with some peptides derived from the protein sequences evolving under positive selection. Conclusions/Significance The syphilis-, yaws-, and bejel-causing strains differed relative to sets of positively selected genes. Most of the positively selected chromosomal loci were identified among the TPA treponemes. The local accumulation of genetic variability suggests that the diversification of TPA strains took place predominantly in a limited number of genomic regions compared to the more dispersed genetic diversity differentiating TPE and TEN strains. The identification of positively selected sites in tpr genes and genes encoding outer membrane proteins suggests their role during infection of human and animal hosts. The driving force for adaptive evolution at these loci thus appears to be the host immune response as supported by observed reactivity of syphilitic sera with some peptides derived from protein sequences showing adaptive evolution.
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sequencing of Treponema pallidum subsp pallidum from isolate uz1974 using anti Treponemal antibodies enrichment first complete whole genome sequence obtained directly from human clinical material
PLOS ONE, 2018Co-Authors: Linda Grillova, Christina M Marra, Arturo Centurionlara, Michal Strouhal, Lenka Mikalova, Radim Strnadel, Giancarlo Russo, Lucy Poveda, Lorenzo Giacani, Darina CejkovaAbstract:Treponema pallidum subsp. pallidum (TPA) is the infectious agent of syphilis, a disease that infects more than 5 million people annually. Since TPA is an uncultivable bacterium, most of the information on TPA genetics comes from genome sequencing and molecular typing studies. This study presents the first complete TPA genome (without sequencing gaps) of clinical isolate (UZ1974), which was obtained directly from clinical material, without multiplication in rabbits. Whole genome sequencing was performed using a newly developed Anti-Treponemal Antibody Enrichment technique combined with previously reported Pooled Segment Genome Sequencing. We identified the UW074B genome, isolated from a sample previously propagated in rabbits, to be the closest relative of the UZ1974 genome and calculated the TPA mutation rate as 2.8 x 10(-10) per site per generation.
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molecular typing of syphilis causing strains among human immunodeficiency virus positive patients in antwerp belgium
Sexually Transmitted Diseases, 2017Co-Authors: Lenka Mikalova, Michal Strouhal, Linda Grillova, Kara Osbak, Chris Kenyon, Tania Crucitti, David SmajsAbstract:Centers for Disease Control and Prevention and sequencing-based treponeme typing was used to analyze 72 blood samples, collected from human immunodeficiency virus and syphilis co-infected patients during 2014 to 2015 in Antwerp, Belgium. Twenty-nine (40.3%) isolates were polymerase chain reaction positive for Treponema pallidum, and all tested were macrolide-resistant. Four genotypes were identified by sequencing-based typing including two new genotypes, U4NR8 and SU9R8, whereas enhanced Centers for Disease Control and Prevention typing revealed 7 subtypes.
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african nonhuman primates are infected with the yaws bacterium Treponema pallidum subsp pertenue
bioRxiv, 2017Co-Authors: Sascha Knauf, Ja F Gogarte, Verena J Schuenema, Michal Strouhal, E K Atamuzi, Helene M De Nys, Ariane Due, Lenka Mikalova, Roy Armstrong, Idrissa S ChumaAbstract:Treponema pallidum subsp. pertenue (TPE) is the causative agent of yaws. The disease was subject to global eradication efforts in the mid 20th century but reemerged in West Africa, Southern Asia, and the Pacific region. Despite its importance for eradication, detailed data on possible nonhuman disease reservoirs are missing. A number of African nonhuman primates (NHPs) have been reported to show skin ulcerations suggestive of Treponemal infection in humans. Furthermore antibodies against Treponema pallidum (TP) have been repeatedly detected in wild NHP populations. While genetic studies confirmed that NHPs are infected with TP strains, subspecies identification was only possible once for a strain isolated in 1966, pinpointing the involvement of TPE. We therefore collected a number of recently isolated simian TP strains and determined eight whole genome sequences using hybridization capture or long-range PCR combined with next-generation sequencing. These new genomes were compared with those of known human TP isolates. Our results show that naturally occurring simian TP strains circulating in three African NHP species all cluster with human TPE strains and show the same genomic structure as human TPE strains. These data indicate that humans are not the exclusive host for the yaws bacterium and that a One Health approach is required to achieve sustainable eradication of human yaws.
Darina Cejkova - One of the best experts on this subject based on the ideXlab platform.
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sequencing of Treponema pallidum subsp pallidum from isolate uz1974 using anti Treponemal antibodies enrichment first complete whole genome sequence obtained directly from human clinical material
PLOS ONE, 2018Co-Authors: Linda Grillova, Christina M Marra, Arturo Centurionlara, Michal Strouhal, Lenka Mikalova, Radim Strnadel, Giancarlo Russo, Lucy Poveda, Lorenzo Giacani, Darina CejkovaAbstract:Treponema pallidum subsp. pallidum (TPA) is the infectious agent of syphilis, a disease that infects more than 5 million people annually. Since TPA is an uncultivable bacterium, most of the information on TPA genetics comes from genome sequencing and molecular typing studies. This study presents the first complete TPA genome (without sequencing gaps) of clinical isolate (UZ1974), which was obtained directly from clinical material, without multiplication in rabbits. Whole genome sequencing was performed using a newly developed Anti-Treponemal Antibody Enrichment technique combined with previously reported Pooled Segment Genome Sequencing. We identified the UW074B genome, isolated from a sample previously propagated in rabbits, to be the closest relative of the UZ1974 genome and calculated the TPA mutation rate as 2.8 x 10(-10) per site per generation.
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resequencing of Treponema pallidum ssp pallidum strains nichols and ss14 correction of sequencing errors resulted in increased separation of syphilis treponeme subclusters
PLOS ONE, 2013Co-Authors: Helena Pětrosova, Michal Strouhal, Marie Zobaníková, Petra Pospíšilová, Lenka Mikalova, Darina CejkovaAbstract:Article on the resequencing of Treponema pallidum ssp. pallidum strains nichols and SS14 and how the correction of sequencing errors resulted in increased separation of syphilis treponeme subclusters.
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whole genome sequence of Treponema pallidum ssp pallidum strain mexico a suggests recombination between yaws and syphilis strains
PLOS Neglected Tropical Diseases, 2012Co-Authors: Helena Pětrosova, Michal Strouhal, Marie Zobaníková, Petra Pospíšilová, Lenka Mikalova, Darina Cejkova, Lei CheAbstract:Treponema pallidum is a Gram-negative spirochete that causes diseases with distinct clinical manifestations and uses different transmission strategies. While syphilis (caused by subspecies pallidum) is a worldwide venereal and congenital disease, yaws (caused by subspecies pertenue) is a tropical disease transmitted by direct skin contact. Currently the genetic basis and evolution of these diseases remain unknown. In this study, we describe a high quality whole genome sequence of T. pallidum ssp. pallidum strain Mexico A, determined using the ?next generation? sequencing technique (Illumina). Although the genome of this strain contains no large rearrangements in comparison with other Treponemal genomes, we found two genes which combined sequences from both subspecies pallidum and pertenue. The observed mosaic character of these two genes is likely a result of inter-strain recombination between pallidum and pertenue during simultaneous infection of a single host.
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whole genome sequences of three Treponema pallidum ssp pertenue strains yaws and syphilis treponemes differ in less than 0 2 of the genome sequence
PLOS Neglected Tropical Diseases, 2012Co-Authors: Michal Strouhal, Marie Zobaníková, Petra Pospíšilová, Darina Cejkova, Lei CheAbstract:Spirochete Treponema pallidum ssp. pertenue (TPE) is the causative agent of yaws while strains of Treponema pallidum ssp. pallidum (TPA) cause syphilis. Both yaws and syphilis are distinguished on the basis of epidemiological characteristics and clinical symptoms. Neither treponeme can reproduce outside the host organism, which precludes the use of standard molecular biology techniques used to study cultivable pathogens. In this study, we determined high quality whole genome sequences of TPE strains and compared them to known genetic information for T. pallidum ssp. pallidum strains. The genome structure was identical in all three TPE strains and also between TPA and TPE strains. The TPE genome length ranged between 1,139,330 bp and 1,139,744 bp. The overall sequence identity between TPA and TPE genomes was 99.8%, indicating that the two pathogens are extremely closely related. A set of 34 TPE genes (3.5%) encoded proteins containing six or more amino acid replacements or other major sequence changes. These genes more often belonged to the group of genes with predicted virulence and unknown functions suggesting their involvement in infection differences between yaws and syphilis.
David Smajs - One of the best experts on this subject based on the ideXlab platform.
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first report of hare Treponematosis seroprevalence of european brown hares lepus europaeus in the czech republic seroprevalence negatively correlates with altitude of sampling areas
BMC Veterinary Research, 2019Co-Authors: Marketa Novakova, David Najt, Marcela Kostkova, Eliska Vrbova, Annika Posautz, Michal Strouhal, Sascha Knauf, Lenka Mikalova, David SmajsAbstract:Background The aim of this study was to quantify the seroprevalence of hare Treponematosis in European brown hare (Lepus europaeus) populations in the Czech Republic and to test for an association between Treponematosis prevalence and the altitude of the areas in which hares were sampled. We tested 289 serum samples of brown hares collected between 2015 and 2017. The sampling areas included 12 districts (73 villages) distributed throughout the Czech Republic. Serum samples were tested for the presence of antibodies against the causative agent of hare Treponematosis (Treponema paraluisleporidarum ecovar Lepus, TPeL) using two serological tests for human syphilis that cross-react with TPeL: the Treponema pallidum hemagglutination assay (TPHA) and the fluorescent Treponemal antibody absorption (FTA-ABS) test. To account for the imperfect diagnostic sensitivity and specificity of each test, apparent prevalence estimates of TPeL were converted to true prevalence estimates using the Rogan Gladen estimator. The correlation between TPeL true seroprevalence and altitude of sampling areas was analyzed using Pearson’s correlation coefficient at three levels of spatial resolution: (1) four groups, each composed of two merged districts, with ≥20 samples collected, differing in their altitude median (206, 348, 495, and 522 m above sea level); (2) separately tested eight districts, where ≥20 samples were collected per district; and (3) 27 groups composed of villages of the same altitude level distributed across the whole dataset.
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Identification of positively selected genes in human pathogenic treponemes: Syphilis-, yaws-, and bejel-causing strains differ in sets of genes showing adaptive evolution
PLoS neglected tropical diseases, 2019Co-Authors: Denisa Maděránková, Michal Strouhal, Petra Pospíšilová, Lenka Mikalova, Šimon Vadják, Ivana Kuklová, Lenka Krbková, Pavlina Koscova, Ivo Provaznik, David SmajsAbstract:Background Pathogenic treponemes related to Treponema pallidum are both human (causing syphilis, yaws, bejel) and animal pathogens (infections of primates, venereal spirochetosis in rabbits). A set of 11 Treponemal genome sequences including those of five Treponema pallidum ssp. pallidum (TPA) strains (Nichols, DAL-1, Mexico A, SS14, Chicago), four T. p. ssp. pertenue (TPE) strains (CDC-2, Gauthier, Samoa D, Fribourg-Blanc), one T. p. ssp. endemicum (TEN) strain (Bosnia A) and one strain (Cuniculi A) of Treponema paraluisleporidarum ecovar Cuniculus (TPeC) were tested for the presence of positively selected genes. Methodology/Principal findings A total of 1068 orthologous genes annotated in all 11 genomes were tested for the presence of positively selected genes using both site and branch-site models with CODEML (PAML package). Subsequent analyses with sequences obtained from 62 Treponemal draft genomes were used for the identification of positively selected amino acid positions. Synthetic biotinylated peptides were designed to cover positively selected protein regions and these peptides were tested for reactivity with the patient's syphilis sera. Altogether, 22 positively selected genes were identified in the TP genomes and TPA sets of positively selected genes differed from TPE genes. While genetic variability among TPA strains was predominantly present in a number of genetic loci, genetic variability within TPE and TEN strains was distributed more equally along the chromosome. Several syphilitic sera were shown to react with some peptides derived from the protein sequences evolving under positive selection. Conclusions/Significance The syphilis-, yaws-, and bejel-causing strains differed relative to sets of positively selected genes. Most of the positively selected chromosomal loci were identified among the TPA treponemes. The local accumulation of genetic variability suggests that the diversification of TPA strains took place predominantly in a limited number of genomic regions compared to the more dispersed genetic diversity differentiating TPE and TEN strains. The identification of positively selected sites in tpr genes and genes encoding outer membrane proteins suggests their role during infection of human and animal hosts. The driving force for adaptive evolution at these loci thus appears to be the host immune response as supported by observed reactivity of syphilitic sera with some peptides derived from protein sequences showing adaptive evolution.
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molecular typing of syphilis causing strains among human immunodeficiency virus positive patients in antwerp belgium
Sexually Transmitted Diseases, 2017Co-Authors: Lenka Mikalova, Michal Strouhal, Linda Grillova, Kara Osbak, Chris Kenyon, Tania Crucitti, David SmajsAbstract:Centers for Disease Control and Prevention and sequencing-based treponeme typing was used to analyze 72 blood samples, collected from human immunodeficiency virus and syphilis co-infected patients during 2014 to 2015 in Antwerp, Belgium. Twenty-nine (40.3%) isolates were polymerase chain reaction positive for Treponema pallidum, and all tested were macrolide-resistant. Four genotypes were identified by sequencing-based typing including two new genotypes, U4NR8 and SU9R8, whereas enhanced Centers for Disease Control and Prevention typing revealed 7 subtypes.
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molecular typing of Treponema pallidum isolates from buenos aires argentina frequent nichols like isolates and low levels of macrolide resistance
PLOS ONE, 2017Co-Authors: Lucia Gallo Vaule, Lenka Mikalova, Linda Grillova, Ricardo Casco, Marcelo Rodriguez Fermepi, Miguel A. Pando, David SmajsAbstract:A total of 54 clinical samples, including genital lesion swabs, whole blood and cerebrospinal fluid from patients diagnosed with syphilis were collected in 2006 and in 2013 in Buenos Aires, Argentina. Treponemal DNA was detected in 43 of the analyzed samples (79.6%) and further analyzed using Sequencing-based molecular typing (SBMT) and Enhanced CDC-typing (ECDCT). By SBMT, 10 different Treponema pallidum subsp. pallidum (TPA) genotypes were found, of which six were related to the TPA SS14 strain, and four to the TPA Nichols strain. The 23S rRNA gene was amplified in samples isolated from 42 patients, and in six of them (14.3%), either the A2058G (four patients, 9.5%) or the A2059G (two patients, 4.8%) mutations were found. In addition to Taiwan, Madagascar and Peru, Argentina is another country where the prevalence of Nichols-like isolates (26.8%) is greater than 10%.
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A Retrospective Study on Genetic Heterogeneity within Treponema Strains: Subpopulations Are Genetically Distinct in a Limited Number of Positions.
PLoS neglected tropical diseases, 2015Co-Authors: Darina Čejková, Michal Strouhal, George M Weinstock, Steven J Norris, David SmajsAbstract:BACKGROUND: Pathogenic uncultivable treponemes comprise human and animal pathogens including agents of syphilis, yaws, bejel, pinta, and venereal spirochetosis in rabbits and hares. A set of 10 Treponemal genome sequences including those of 4 Treponema pallidum ssp. pallidum (TPA) strains (Nichols, DAL-1, Mexico A, SS14), 4 T. p. ssp. pertenue (TPE) strains (CDC-2, Gauthier, Samoa D, Fribourg-Blanc), 1 T. p. ssp. endemicum (TEN) strain (Bosnia A) and one strain (Cuniculi A) of Treponema paraluisleporidarum ecovar Cuniculus (TPLC) were examined with respect to the presence of nucleotide intrastrain heterogeneous sites. METHODOLOGY/PRINCIPAL FINDINGS: The number of identified intrastrain heterogeneous sites in individual genomes ranged between 0 and 7. Altogether, 23 intrastrain heterogeneous sites (in 17 genes) were found in 5 out of 10 investigated Treponemal genomes including TPA strains Nichols (n = 5), DAL-1 (n = 4), and SS14 (n = 7), TPE strain Samoa D (n = 1), and TEN strain Bosnia A (n = 5). Although only one heterogeneous site was identified among 4 tested TPE strains, 16 such sites were identified among 4 TPA strains. Heterogeneous sites were mostly strain-specific and were identified in four tpr genes (tprC, GI, I, K), in genes involved in bacterial motility and chemotaxis (fliI, cheC-fliY), in genes involved in cell structure (murC), translation (prfA), general and DNA metabolism (putative SAM dependent methyltransferase, topA), and in seven hypothetical genes. CONCLUSIONS/SIGNIFICANCE: Heterogeneous sites likely represent both the selection of adaptive changes during infection of the host as well as an ongoing diversifying evolutionary process.
Lorenzo Giacani - One of the best experts on this subject based on the ideXlab platform.
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p165 evaluation of novel Treponema pallidum recombinant antigens for syphilis diagnosis
Sexually Transmitted Infections, 2021Co-Authors: Emily Romeis, Austin M Haynes, A Phan, Kelika A Konda, Silver K Vargas, Maria Eguiluz, Carlos F Caceres, Jeffrey D Klausner, Lorenzo GiacaniAbstract:Background Syphilis, caused by the spirochete Treponema pallidum subsp. pallidum (T. pallidum), continues to be a significant global health concern. The diagnosis of syphilis mainly relies on assessing clinical manifestations and performing serologic testing to detect Treponemal and non-Treponemal antibodies to discriminate between past and present infection and to evaluate response to treatment. Limitations, however, include that no test can discriminate among syphilis stages, and sensitivity is low during the very early stages of infection. New diagnostics could circumvent some of these deficiencies. Methods To this end, we developed a novel array of T. pallidum recombinant proteins to identify seroreactive proteins and compare their performance to that of antigens commonly used in Treponemal tests such as the 17 and 47 kDa lipoproteins (Tp0435 and Tp0574, respectively). Antigens were applied to the array, then reactivity was assessed via indirect enzyme-linked immunosorbent assay (ELISA). For this analysis, we used sera samples from 124 patients collected at various timepoints (0 months, 3 months, and 6 months). Samples from all three timepoints were available from 29 patients. Results The control antigens demonstrated the highest reactivity against the sera. Among the antigens tested so far Tp0954, a putative adhesin of the syphilis agent, exhibited seroreactivity similar to that of the controls. Conclusion Our data support Tp0954 as a possible candidate to improve the performance of currently available Treponemal tests.
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Topical treatment with gallium maltolate reduces Treponema pallidum subsp. pertenue burden in primary experimental lesions in a rabbit model of yaws.
Public Library of Science (PLoS), 2019Co-Authors: Lorenzo Giacani, Charmie Godornes, Lawrence R Bernstein, Austin M Haynes, Giulia Ciccarese, Francesco Drago, Aurora Parodi, Sefora Valdevit, Luca Anselmi, Carlo Francesco TomasiniAbstract:BACKGROUND:Gallium is a semi-metallic element known since the 1930s to have antimicrobial activity. This activity stems primarily from gallium's ability to mimic trivalent iron and disrupt specific Fe(III)-dependent pathways, particularly DNA synthesis (due to inhibition of ribonucleotide reductase). Because of its novel mechanism of action, gallium is currently being investigated as a new antibacterial agent, particularly in light of the increasing resistance of many pathogenic bacteria to existing antibiotics. Gallium maltolate (GaM) is being developed as an orally and topically administrable form of gallium. Yaws is a neglected tropical disease affecting mainly the skin and skeletal system of children in underprivileged settings. It is currently the object of a WHO-promoted eradication campaign using mass administration of the macrolide azithromycin, an antibiotic to which the yaws agent Treponema pallidum subsp. pertenue has slowly begun to develop genetic resistance. METHODS:Because yaws transmission is mainly due to direct skin contact with an infectious skin lesion, we evaluated the treponemicidal activity of GaM applied topically to skin lesions in a rabbit model of yaws. Treatment efficacy was evaluated by measuring lesion diameter, Treponemal burden in lesion aspirates as determined by dark field microscopy and amplification of Treponemal RNA, serology, and immunohistochemistry of biopsied tissue samples. RESULTS:Our results show that topical GaM was effective in reducing Treponemal burden in yaws experimental lesions, particularly when applied at the first sign of lesion appearance but, as expected, did not prevent pathogen dissemination. CONCLUSION:Early administration of GaM to yaws lesions could reduce the infectivity of the lesions and thus yaws transmission, potentially contributing to current and future yaws control campaigns
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sequencing of Treponema pallidum subsp pallidum from isolate uz1974 using anti Treponemal antibodies enrichment first complete whole genome sequence obtained directly from human clinical material
PLOS ONE, 2018Co-Authors: Linda Grillova, Christina M Marra, Arturo Centurionlara, Michal Strouhal, Lenka Mikalova, Radim Strnadel, Giancarlo Russo, Lucy Poveda, Lorenzo Giacani, Darina CejkovaAbstract:Treponema pallidum subsp. pallidum (TPA) is the infectious agent of syphilis, a disease that infects more than 5 million people annually. Since TPA is an uncultivable bacterium, most of the information on TPA genetics comes from genome sequencing and molecular typing studies. This study presents the first complete TPA genome (without sequencing gaps) of clinical isolate (UZ1974), which was obtained directly from clinical material, without multiplication in rabbits. Whole genome sequencing was performed using a newly developed Anti-Treponemal Antibody Enrichment technique combined with previously reported Pooled Segment Genome Sequencing. We identified the UW074B genome, isolated from a sample previously propagated in rabbits, to be the closest relative of the UZ1974 genome and calculated the TPA mutation rate as 2.8 x 10(-10) per site per generation.
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fine analysis of genetic diversity of the tpr gene family among Treponemal species subspecies and strains
PLOS Neglected Tropical Diseases, 2013Co-Authors: Arturo Centurionlara, Barbara J. Molini, Charmie Godornes, Lorenzo Giacani, Tara B. Reid, Sheila A. LukehartAbstract:Background The pathogenic non-cultivable treponemes include three subspecies of Treponema pallidum (pallidum, pertenue, endemicum), T. carateum, T. paraluiscuniculi, and the unclassified Fribourg-Blanc treponeme (Simian isolate). These treponemes are morphologically indistinguishable and antigenically and genetically highly similar, yet cross-immunity is variable or non-existent. Although all of these organisms cause chronic, multistage skin and systemic disease, they have historically been classified by mode of transmission, clinical presentations and host ranges. Whole genome studies underscore the high degree of sequence identity among species, subspecies and strains, pinpointing a limited number of genomic regions for variation. Many of these “hot spots” include members of the tpr gene family, composed of 12 paralogs encoding candidate virulence factors. We hypothesize that the distinct clinical presentations, host specificity, and variable cross-immunity might reside on virulence factors such as the tpr genes.
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Comparative Investigation of the Genomic Regions Involved in Antigenic Variation of the TprK Antigen among Treponemal Species, Subspecies, and Strains
Journal of bacteriology, 2012Co-Authors: Lorenzo Giacani, Barbara J. Molini, Sheila A. Lukehart, Charmie Godornes, Martin Benzler, Stephanie L. Brandt, Maritza Puray-chavez, Tara B. Reid, Jörg S. Hartig, Arturo Centurion-laraAbstract: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.
