Skip to main content

Complete genome sequence of Treponema pallidum strain DAL-1


Treponema pallidum strain DAL-1 is a human uncultivable pathogen causing the sexually transmitted disease syphilis. Strain DAL-1 was isolated from the amniotic fluid of a pregnant woman in the secondary stage of syphilis. Here we describe the 1,139,971 bp long genome of T. pallidum strain DAL-1 which was sequenced using two independent sequencing methods (454 pyrosequencing and Illumina). In rabbits, strain DAL-1 replicated better than the T. pallidum strain Nichols. The comparison of the complete DAL-1 genome sequence with the Nichols sequence revealed a list of genetic differences that are potentially responsible for the increased rabbit virulence of the DAL-1 strain.


Treponema pallidum is an uncultivable human pathogen causing the sexually transmitted disease, syphilis. Until now, three syphilis causing strains of T. pallidum have been completely sequenced including strain Nichols [1], SS14 [2], and Chicago [3]. In addition, a number of related treponemes causing yaws including strains Samoa D, CDC-2, Gauthier [4] and T. paraluiscuniculi strain Cuniculi A [5] have been sequenced. The data indicates that pathogenic treponemes are extremely closely related and small genetic changes can result in profound changes in pathogenesis and host range [6]. The accumulation of genomic data provides new insights into the pathogenesis of treponemal diseases and into the evolution of pathogenic treponemes and brings new opportunities for molecular diagnostics of syphilis [6]. T. pallidum strain DAL-1 was isolated using intratesticular injection of rabbits with amniotic fluid taken from a 21-year-old African American woman (at 35 weeks of gestation) in the secondary stage of syphilis [7]. In rabbits, the DAL-1 strain replicated better than the Nichols strain [1,7]. Therefore, the genome sequencing of the DAL-1 strain and its comparison with the Nichols sequence should reveal a list of genetic differences that are potentially responsible for increased rabbit virulence of the DAL-1 strain.

Classification and features

Treponema pallidum, previously known as Spirochaeta pallida [8], is an etiologic agent of syphilis. Based on DNA hybridization studies [9], Treponema pallidum and yaws [10] causing Treponema pertenue were found to be genetically indistinguishable. The rabbit pathogen, Treponema paraluiscuniculi, is not pathogenic to humans and the sequence identity is greater than 98% on a genome wide scale [5]. The genus Treponema belongs to the family Spirochaetaceae (see Table 1). Genetic relatedness of T. pallidum strain DAL-1 to other treponemes and spirochetes is shown in Figure 1.

Figure 1.
figure 1

Phylogenetic tree based on 16S rRNA of T. pallidum DAL-1 and some strains of Treponema species. The bar scale represents the number of nucleotide substitutions per 1 nt site. The tree was generated using tree-builder, which is available from the Ribosomal Database project [28], using the Weighbor (weighted neighbor-joining) algorithm [29] and the Jukes-Cantor distance correction [30]. A Spirochaeta zuelzerae type strain was used as the out-group.

Table 1. Classification and the general features of T. pallidum DAL-1 according to the MIGS recommendations [11]

T. pallidum is a Gram-negative, spiral shaped bacterium 6 to 15 µm in length and 0.2 µm in diameter. T. pallidum is an anaerobic non spore-forming motile bacterium that moves by rotating around its longitudinal axis. This movement is powered by endoflagella located in the periplasmic space. The cell wall is composed of a cytoplasmic membrane, a thin peptidoglycan layer, a periplasmic space with endoflagella, and an outer membrane [31].

T. pallidum is an obligate human parasite, which does not survive outside its mammalian host and cannot be cultivated continuously under in vitro conditions. Optimal conditions for time-limited cultivation in tissue culture consisted of temperature between 33 °C and 35 °C, atmospheric oxygen concentration in the 1.5 to 5% range, 20% fetal bovine serum in the culture medium and the testes extract [21]. Cultivation in tissue cultures resulted in approximately 100-fold multiplication [32,33]. Stable propagation of T. pallidum strains can only be achieved in mammalian hosts, usually rabbits.

T. pallidum is sensitive to high temperatures [21,34], and is catalase- and oxidase-negative. As a consequence of its small genome, T. pallidum has limited metabolic capacity in general [13]. Most essential macromolecules are taken up from the host by a number of transport proteins with broad substrate specificity. In total, 113 genes of T. pallidum encode proteins involved in transport, which compensate for the absence of genes encoding components of the tricarboxylic acid cycle, oxidative phosphorylation, components for de novo synthesis of amino acids, fatty acids, enzyme cofactors and nucleotides [1].

Susceptibility of T. pallidum to antimicrobial agents has been tested in tissue culture models followed by testing of treponemal viability using intradermal inoculation of rabbits [35]. No skin lesions were detected following injections of penicillin G: 0.0025 µg/ml; tetracycline: 0.5 µg/ml; erythromycin: 0.005 µg/ml; and spectinomycin: 0.5 µg/ml, indicating that no viable bacteria were present following antibiotic treatment. Unlike penicillin, macrolide regimens have a risk of treatment failure due to chromosomally encoded resistance in T. pallidum [36,37].

Genome sequencing information

Genome project history

This organism was selected for sequencing on the basis of its increased virulence in rabbits compared to the Nichols strain [1]. The genome project is deposited in the Genomes On Line Database [38] and the complete genome sequence is available at the GenBank (CP003115). The details of the project are summarized in Table 2.

Table 2. Project information

Growth conditions and DNA isolation

Strain DAL-1 was grown in rabbit testis, treponemes were extracted and purified from testicular tissue using Hypaque gradient centrifugation [1,39]. Chromosomal DNA was prepared as described previously [1].

Genome sequencing and assembly

The genome of strain DAL-1 was sequenced using a combination of Illumina and 454 sequencing platforms (GS20). Pyrosequencing reads (506,607 raw reads of total read length 51,283,327 bp) showing sequence similarity to the Nichols genome sequence [1] were assembled using the Newbler assembler version into 235 contigs (45× genome coverage). Newbler contigs were assembled according to the reference Nichols genome [6] using Lasergene software (DNASTAR, Madison, WI, USA), this assembly reduced the number of contigs to 52 separated by 52 gaps (total length of 19,545 bp). Gaps between contigs were closed using Sanger sequencing. Altogether, 43 individual PCR products were sequenced including 5 XL-PCR products. The PCR products were sequenced using amplification and, when required, internal primers. In addition, 4 libraries of XL-PCR products were prepared and sequenced. The resulting complete genome sequence of strain DAL-1 was considered to be a draft sequence. Additional Illumina sequencing was applied to improve genome sequencing accuracy and the complete DAL-1 genome sequence was compiled from these data. A total of 2,881,557 raw Illumina reads (total length of 103,736,052 bp) were assembled, using the Velvet 0.6.05 assembler [40], into 303 contigs (with 91× average coverage). Out of these 303 contigs, 295 showed sequence similarities to the T. pallidum Nichols genome leaving 46,148 bp of T. pallidum DAL-1 unsequenced using the Illumina method. Each DAL-1 region not sequenced by Illumina and containing differences from the Nichols genome was resequenced using the Sanger method. In addition, all other discrepancies between the complete DAL-1 genome sequence and the Nichols genome sequence were resolved using Sanger sequencing of both DAL-1 and Nichols strains. Altogether, 15 errors were identified in the 1,093 kb Illumina resequenced region, indicating that the complete DAL-1 genome sequence contained 1 error per 73 kbp. Therefore, the final, corrected, strain DAL-1 genome sequence has an error rate less than 10-5.

Genome annotation

Strain DAL-1 genome was annotated with gene coordinates taken from the Nichols [1], SS14 [2] and Samoa D [4] genomes. These coordinates were adapted and recalculated. Genes identified in the DAL-1 genome were denoted with the prefix TPADAL followed by four numbers to indicate the gene number. Newly predicted genes were identified using the GeneMark and Glimmer programs. In most cases, the original locus tag values of annotated genes were preserved in the DAL-1 orthologs. Newly predicted genes in the DAL-1 genome were named according to the preceding gene with a letter suffix (e.g. TPADAL_0950a).

Genome properties

The genome consists of a single circular DNA chromosome, 1,139,971 bp in length. The G+C content is 52.8% (Figure 2, Table 3). Out of the 1,122 predicted genes, 1,068 genes were protein-coding. A set of 54 genes coded for RNA and 9 were identified as pseudogenes. The majority of the protein-coding genes (61.6% of all genes) were assigned a putative function while 33.6% of all genes code for proteins with unknown function. The distribution of genes into COGs functional categories is presented in Figure 2 and Table 4.

Figure 2.
figure 2

Graphical circular map of the T. pallidum strain DAL-1 genome. From the outside to the center: Genes on forward strand (color by COG categories), Genes on reverse strand (color by COG categories), RNA genes (tRNAs green, rRNAs red, other RNAs black), GC content, GC skew. The map was generated with help of DOE Joint Genome Institute [41].

Table 3. Genome Statistics
Table 4. Number of genes associated with general COG functional categories

Insights into the genome

Sequence changes differentiating the DAL-1 and Nichols genomes were identified mainly in the TPADAL_0136 gene (encoding fibronectin binding protein [42]) and comprised 94 nt changes. In addition, a repeat containing gene, TPADAL_0470 was found to contain 288 nts insertion composed of twelve, 24-bp repetitions. tpr genes including tprF (TP0316), tprG (TP0317) and tprK (TP0897) contained 2, 1 and 4 nt changes, respectively. However, the tprK gene was found variable within the DAL-1 strain and therefore the reported 4 nt changes do not refer to the variable tprK region [43]. Tpr proteins are known virulence factors in treponemes [4348] and the changes in the primary sequence of the protein may be of importance in increased DAL-1 rabbit virulence. In addition to the changes in the above mentioned genes, additional 31 nt changes were found throughout the genome (6 single nucleotide deletions, 3 single nucleotide insertions, 16 single nucleotide substitutions, one 2-nt deletion and one 4-nt deletion). All the indels (with exception of the 4-nt deletion) were found to be located in the G or C homopolymers. Indels resulted in truncation or elongation of several proteins including TPADAL_0012 (hypothetical protein, finally not annotated), TPADAL_0040 (probable methyl-accepting chemotaxis protein), TPADAL_0067 (conserved hypothetical protein), TPADAL_0127a (hypothetical protein), TPADAL_0134a (hypothetical protein), TPADAL_470 (conserved hypothetical protein), TPADAL_0479 (hypothetical protein), and TPADAL_0609 (AsnS, asparagine-tRNA ligase). In addition, TPADAL_0859-860 was identified as a fused protein (TPADAL_0859). Two of the indels in the G or C homopolymers were found in the intergenic regions (IGR TPADAL_0225-226, IGR TPADAL_0316-317). Since G homopolymers, of variable length, affected gene expression rates of tpr genes [49], these differences may change the gene expression pattern in the DAL-1 genome. Out of the 16 single nucleotide substitutions, 3 were located in intergenic regions (IGR TPADAL_0126c-0126d, IGR TPADAL_0582-584, IGR TPADAL_0698-700) and three resulted in synonymous mutations (TPADAL_0228, 0742, 0939). The remaining 10 substitutions resulted in 9 nonsynonymous changes in TPADAL_0051 (prfA, peptide chain release factor RF1), TPADAL_0065 (probable SAM dependent up methyltransferase), TPADAL_0279 (bifunctional cytidylate kinase/ribosomal protein S1), TPADAL_0433 (arp, a repeat containing gene), TPADAL_0674 (encoding conserved hypothetical protein), TPADAL_0720 (fliY, bifunctional chemotaxis protein CheC/flagellar motor switch protein FliY), and TPADAL_0854 (encoding conserved hypothetical protein). All of the above listed genes and all the changes in the intergenic regions (potentially affecting gene expression rates) should be considered as potential reason for the observed increased virulence in rabbits.


  1. Fraser CM, Norris SJ, Weinstock CM, White O, Sutton GG, Dodson R, Gwinn M, Hickey EK, Clayton R, Ketchum KA, et al. Complete genome sequence of Treponema pallidum, the syphilis spirochete. Science 1998; 281:375–388. PubMed

    Article  CAS  PubMed  Google Scholar 

  2. Matějková P, Strouhal M, Smajs D, Norris SJ, Palzkill T, Petrosino JF, Sodergren E, Norton JE, Singh J, Richmond TA, et al. Complete genome sequence of Treponema pallidum ssp pallidum strain SS14 determined with oligonucleotide arrays. BMC Microbiol 2008; 8:76. PubMed

    Article  PubMed Central  PubMed  Google Scholar 

  3. Giacani L, Jeffrey BM, Molini BJ, Le HT, Lukehart SA, Centurion-Lara A, Rockey DD. Complete genome sequence and annotation of the Treponema pallidum subsp. pallidum Chicago strain. J Bacteriol 2010; 192:2645–2646. PubMed

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  4. Čejková D, Zobaníková M, Chen L, Pospíšilová P, Strouhal M, Qin X, Mikalová L, Norris SJ, Muzny DM, Gibbs RA, et al. 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 Negl Trop Dis 2012; 6:e1471. PubMed

    Article  PubMed Central  PubMed  Google Scholar 

  5. Šmajs D, Zobaníková M, Strouhal M, Čejková D, Dugan-Rocha S, Pospísilová P, Norris SJ, Albert T, Qin X, Hallsworth-Pepin K, et al. Complete genome sequence of Treponema paraluiscuniculi, strain Cuniculi A: The loss of infectivity to humans is associated with genome decay. PLoS ONE 2011; 6:e20415. PubMed

    Article  PubMed Central  PubMed  Google Scholar 

  6. Smajs D, Norris SJ, Weinstock GM. Genetic diversity in Treponema pallidum: Implications for pathogenesis, evolution and molecular diagnostics of syphilis and yaws. Infect Genet Evol 2012; 12:191–202. PubMed

    Article  PubMed Central  PubMed  Google Scholar 

  7. Wendel GD, Sanchez PJ, Peters MT, Harstad TW, Potter LL, Norgard MV. Identification of Treponema pallidum in amniotic fluid and fetal blood from pregnancies complicated by congenital syphilis. Obstet Gynecol 1991; 78:890–895. PubMed

    PubMed  Google Scholar 

  8. Schaudin FR, Hoffmann E. Vorläufiger Bericht über das Vorkommen von Spirochäten in syphilitischen Krandkheitprodukten und bei Papillomen. Arb K Gesund 1905; 22:527–534.

    Google Scholar 

  9. Miao RM, Fieldsteel AH. Genetic relationship between Treponema pallidum and Treponema pertenue, two noncultivable human pathogens. J Bacteriol 1980; 141:427–429. PubMed

    PubMed Central  CAS  PubMed  Google Scholar 

  10. Castellani A. Further observations on parangi (Yaws). BMJ 1905; 2:1330–1331. PubMed

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  11. Field D, Garrity G, Gray T, Morrison N, Selengut J, Sterk P, Tatusova T, Thomson N, Allen MJ, Angiuoli SV, et al. The minimum information about a genome sequence (MIGS) specification. Nat Biotechnol 2008; 26:541–547. PubMed

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  12. Woese CR, Kandler O, Wheelis ML. Towards a Natural System of Organisms: Proposal for the Domains Archaea, Bacteria, and Eucarya. Proc Natl Acad Sci USA 1990; 87:4576–4579. PubMed

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  13. Garrity GM, Holt JG. The Road Map to the Manual. In: Garrity GM, Boone DR, Castenholz RW (eds), Bergey’s Manual of Systematic Bacteriology, Second Edition, Volume 1, Springer, New York, 2001, p. 119–169.

    Chapter  Google Scholar 

  14. Ludwig W, Euzeby J, Whitman WG. Draft taxonomic outline of the Bacteroidetes, Planctomycetes, Chlamydiae, Spirochaetes, Fibrobacteres, Fusobacteria, Acidobacteria, Verrucomicrobia, Dictyoglomi, and Gemmatimonadetes. Taxonomic Outline 2008.

  15. Judicial Commission of the International Committee on Systematics of Prokaryotes. The nomenclatural types of the orders Acholeplasmatales, Halanaerobiales, Halobacteriales, Methanobacteriales, Methanococcales, Methanomicrobiales, Planctomycetales, Prochlorales, Sulfolobales, Thermococcales, Thermoproteales and Verrucomicrobiales are the genera Acholeplasma, Halanaerobium, Halobacterium, Methanobacterium, Methanococcus, Methanomicrobium, Planctomyces, Prochloron, Sulfolobus, Thermococcus, Thermoproteus and Verrucomicrobium, respectively. Opinion 79. Int J Syst Evol Microbiol 2005; 55:517–518. PubMed

    Article  Google Scholar 

  16. Buchanan RE. Studies in the Nomenclature and Classification of the Bacteria: II. The Primary Subdivisions of the Schizomycetes. J Bacteriol 1917; 2:155–164. PubMed

    PubMed Central  CAS  PubMed  Google Scholar 

  17. Skerman VBD, McGowan V, Sneath PHA. Approved Lists of Bacterial Names. Int J Syst Bacteriol 1980; 30:225–420.

    Article  Google Scholar 

  18. Swellengrebel NH. Sur la cytologie comparée des spirochètes et des spirilles. Ann Inst Pasteur (Paris) 1907; 21:562–586.

    Google Scholar 

  19. Schaudinn F. Zur Kenntnis der Spirochaete pallida. Dtsch Med Wochenschr 1905; 31:1728.

    Article  Google Scholar 

  20. Smibert RM. Genus III. Treponema Schaudinn 1905, 1728. In: Buchanan RE, Gibbons NE (eds), Bergey’s Manual of Determinative Bacteriology, Eighth Edition, The Williams and Wilkins Co., Baltimore, 1974, p. 175–184.

    Google Scholar 

  21. Fieldsteel AH, Cox DL, Moeckli RA. Further studies on replication of virulent Treponema pallidum in tissue cultures of SFLEP cells. Infect Immun 1982; 35:449–455. PubMed

    PubMed Central  CAS  PubMed  Google Scholar 

  22. Baseman JB, Nichols JC, Hayes NS. Virulent Treponema pallidum — aerobe or anaerobe. Infect Immun 1976; 13:704–711. PubMed

    PubMed Central  CAS  PubMed  Google Scholar 

  23. Nichols JC, Baseman JB. Carbon sources utilized by virulent Treponema pallidum. Infect Immun 1975; 12:1044–1050. PubMed

    PubMed Central  CAS  PubMed  Google Scholar 

  24. Schiller NL, Cox CD. Catabolism of glucose and fatty acids by virulent Treponema pallidum. Infect Immun 1977; 16:60–68. PubMed

    PubMed Central  CAS  PubMed  Google Scholar 

  25. Turner TB, Hollander DH. Biology of the treponematoses based on studies carried out at the International Treponematosis Laboratory Center of the Johns Hopkins University under the auspices of the World Health Organization. Monogr Ser World Health Organ 1957; 35:3–266. PubMed

    PubMed  Google Scholar 

  26. BAuA. Classification of Bacteria and Archaea in risk groups. TRBA 466 p. 349.

  27. Ashburner M, Ball CA, Blake JA, Botstein D, Butler H, Cherry JM, Davis AP, Dolinski K, Dwight SS, Eppig JT et al. Gene ontology: tool for the unification of biology. Nat Genet 2000; 25(1):25–29. pmid: 10802651

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  28. Project RD.

  29. Bruno WJ, Socci ND, Halpern AL. Weighted neighbor joining: a likelihood-based approach to distance-based phylogeny reconstruction. Mol Biol Evol 2000; 17:189–197. PubMed

    Article  CAS  PubMed  Google Scholar 

  30. Som A. Theoretical foundation to estimate the relative efficiencies of the Jukes-Cantor+gamma model and the Jukes-Cantor model in obtaining the correct phylogenetic tree. Gene 2006; 385:103–110. PubMed

    Article  CAS  PubMed  Google Scholar 

  31. Jepsen OB, Hougen KH, Birch-Andersen A. Electron microscopy of Treponema pallidum Nichols. Acta Pathol Microbiol Scand 1968; 74:241–258. PubMed

    Article  CAS  PubMed  Google Scholar 

  32. Fieldsteel AH, Cox DL, Moeckli RA. Cultivation of virulent Treponema pallidum in tissue culture. Infect Immun 1981; 32:908–915. PubMed

    PubMed Central  CAS  PubMed  Google Scholar 

  33. Norris SJ. Invitro cultivation of Treponema pallidum — independent confirmation. Infect Immun 1982; 36:437–439. PubMed

    PubMed Central  CAS  PubMed  Google Scholar 

  34. Wagner-Jauregg J. Über die Einwirkung der Malaria auf die progressive Paralyse. Psychiatr Neurol Wochenschr 1918; 20:132–134.

    Google Scholar 

  35. Norris SJ, Edmondson DG. Invitro culture system to determine MICS and MBSC of antimicrobial agents against Treponema pallidum subsp. pallidum (Nichols strain). AAC 1988; 32:68–74.

    Article  CAS  Google Scholar 

  36. Stamm LV, Bergen HL. A point mutation associated with bacterial macrolide resistance is present in both 23S rRNA genes of an erythromycin-resistant Treponema pallidum clinical isolate. AAC 2000; 44(3):806–807. pmcid: 89774

    Article  CAS  Google Scholar 

  37. Matějková P, Flasarová M, Zakoucká H, Borek M, Křemenová S, Arenberger P, Woznicová V, Weinstock GM, Šmajs D. Macrolide treatment failure in a case of secondary syphilis: a novel A2059G mutation in the 23S rRNA gene of Treponema pallidum subsp pallidum. J Med Microbiol 2009; 58:832–836. PubMed

    Article  PubMed  Google Scholar 

  38. Liolios K, Chen IM, Mavromatis K, Tavernarakis N, Hugenholtz P, Markowitz VM, Kyrpides NC. The Genomes On Line Database (GOLD) in 2009: status of genomic and metagenomic projects and their associated metadata. Nucleic Acids Res 2010; 38(Database issue):D346–D354. PubMed

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  39. Baseman JB, Nichols JC, Rumpp JW, Hayes NS. Purification of Treponema pallidum from infected rabbit tissue — resolution into two treponemal populations. Infect Immun 1974; 10:1062–1067. PubMed

    PubMed Central  CAS  PubMed  Google Scholar 

  40. Zerbino DR, Birney E. Velvet: Algorithms for de novo short read assembly using de Bruijn graphs. Genome Res 2008; 18:821–829. PubMed

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  41. DOE Joint Genome Institute.

  42. Brinkman MB, McGill MA, Pettersson J, Rogers A, Matejkova P, Smajs D, Weinstock GM, Norris SJ, Palzkill T. A novel Treponema pallidum antigen, TP0136, is an outer membrane protein that binds human fibronectin. Infect Immun 2008; 76:1848–1857. PubMed

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  43. LaFond RE, Centurion-Lara A, Godornes C, Van Voorhis WC, Lukehart SA. TprK sequence diversity accumulates during infection of rabbits with Treponema pallidum subsp. pallidum Nichols strain. Infect Immun 2006; 74:1896–1906. PubMed

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  44. Centurion-Lara A, Godornes C, Castro C, Van Voorhis WC, Lukehart SA. The tprK gene is heterogeneous among Treponema pallidum strains and has multiple alleles. Infect Immun 2000; 68:824–831. PubMed

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  45. Centurion-Lara A, Sun ES, Barrett LK, Castro C, Lukehart SA, Van Voorhis WC. Multiple alleles of Treponema pallidum repeat gene D in Treponema pallidum isolates. J Bacteriol 2000; 182:2332–2335. PubMed

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  46. LaFond RE, Centurion-Lara A, Godornes C, Rompalo AM, Van Voorhis WC, Lukehart SA. Sequence diversity of Treponema pallidum subsp. pallidum tprK in human syphilis lesions and rabbit-propagated isolates. J Bacteriol 2003; 185:6262–6268. PubMed

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  47. Leader BT, Hevner K, Molini BJ, Barrett LK, Van Voorhis WC, Lukehart SA. Antibody responses elicited against the Treponema pallidum repeat proteins differ during infection with different isolates of Treponema pallidum subsp. pallidum. Infect Immun 2003; 71:6054–6057. PubMed

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  48. Palmer GH, Bankhead T, Lukehart SA. ‘Nothing is permanent but change’ — antigenic variation in persistent bacterial pathogens. Cell Microbiol 2009; 11:1697–1705. PubMed

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  49. Giacani L, Molini B, Godornes C, Barrett L, Van Voorhis W, Centurion-Lara A, Lukehart SA. Quantitative analysis of tpr gene expression in Treponema pallidum isolates: Differences among isolates and correlation with T-cell responsiveness in experimental syphilis. Infect Immun 2007; 75:104–112. PubMed

    Article  PubMed Central  CAS  PubMed  Google Scholar 

Download references


The authors thank Dr. David Cox for providing the DAL-1 strain and Dr. Nikos C. Kyrpides (DOE Joint Genome Institute) for COG calculations. This work was supported by grants from the U.S. Public Health Service to G.M.W. (R01 DE12488 and R01 DE13759), and by the grants of the Grant Agency of the Czech Republic (310/07/0321), and the Ministry of Education of the Czech Republic (VZ MSM0021622415) to D.S.

Author information

Authors and Affiliations


Corresponding author

Correspondence to David Šmajs.

Rights and permissions

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.

Reprints and permissions

About this article

Cite this article

Zobaníková, M., Mikolka, P., Čejková, D. et al. Complete genome sequence of Treponema pallidum strain DAL-1. Stand in Genomic Sci 7, 12–21 (2012).

Download citation

  • Published:

  • Issue Date:

  • DOI: