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Seña AC, Matoga MM, Yang L, Lopez-Medina E, Aghakhanian F, Chen JS, Bettin EB, Caimano MJ, Chen W, Garcia-Luna JA, Hennelly CM, Jere E, Jiang Y, Juliano JJ, Pospíšilová P, Ramirez L, Šmajs D, Tucker JD, Vargas Cely F, Zheng H, Hoffman IF, Yang B, Moody MA, Hawley KL, Salazar JC, Radolf JD, Parr JB. Clinical and genomic diversity of Treponema pallidum subspecies pallidum to inform vaccine research: an international, molecular epidemiology study. THE LANCET. MICROBE 2024; 5:100871. [PMID: 39181152 PMCID: PMC11371664 DOI: 10.1016/s2666-5247(24)00087-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 02/19/2024] [Accepted: 03/25/2024] [Indexed: 08/27/2024]
Abstract
BACKGROUND The increase in syphilis rates worldwide necessitates development of a vaccine with global efficacy. We aimed to explore Treponema pallidum subspecies pallidum (TPA) molecular epidemiology essential for vaccine research by analysing clinical data and specimens from early syphilis patients using whole-genome sequencing (WGS) and publicly available WGS data. METHODS In this multicentre, cross-sectional, molecular epidemiology study, we enrolled patients with primary, secondary, or early latent syphilis from clinics in China, Colombia, Malawi, and the USA between Nov 28, 2019, and May 27, 2022. Participants aged 18 years or older with laboratory confirmation of syphilis by direct detection methods or serological testing, or both, were included. Patients were excluded from enrolment if they were unwilling or unable to give informed consent, did not understand the study purpose or nature of their participation, or received antibiotics active against syphilis in the past 30 days. TPA detection and WGS were conducted on lesion swabs, skin biopsies, skin scrapings, whole blood, or rabbit-passaged isolates. We compared our WGS data to publicly available genomes and analysed TPA populations to identify mutations associated with lineage and geography. FINDINGS We screened 2802 patients and enrolled 233 participants, of whom 77 (33%) had primary syphilis, 154 (66%) had secondary syphilis, and two (1%) had early latent syphilis. The median age of participants was 28 years (IQR 22-35); 154 (66%) participants were cisgender men, 77 (33%) were cisgender women, and two (1%) were transgender women. Of the cisgender men, 66 (43%) identified as gay, bisexual, or other sexuality. Among all participants, 56 (24%) had HIV co-infection. WGS data from 113 participants showed a predominance of SS14-lineage strains with geographical clustering. Phylogenomic analyses confirmed that Nichols-lineage strains were more genetically diverse than SS14-lineage strains and clustered into more distinct subclades. Differences in single nucleotide variants (SNVs) were evident by TPA lineage and geography. Mapping of highly differentiated SNVs to three-dimensional protein models showed population-specific substitutions, some in outer membrane proteins (OMPs) of interest. INTERPRETATION Our study substantiates the global diversity of TPA strains. Additional analyses to explore TPA OMP variability within strains is vital for vaccine development and understanding syphilis pathogenesis on a population level. FUNDING US National Institutes of Health National Institute for Allergy and Infectious Disease, the Bill & Melinda Gates Foundation, Connecticut Children's, and the Czech Republic National Institute of Virology and Bacteriology.
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Affiliation(s)
- Arlene C Seña
- Department of Medicine, Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | | | - Ligang Yang
- Dermatology Hospital, Southern Medical University, Guangdong Provincial Center for Skin Diseases and STD Control, Guangzhou, China
| | - Eduardo Lopez-Medina
- Centro Internacional de Entrenamiento e Investigaciones Medicas, Campus de la Universidad Icesi, Cali, Colombia; Department of Pediatrics, Universidad del Valle, Cali, Colombia
| | - Farhang Aghakhanian
- Institute for Global Health and Infectious Diseases, Infectious Diseases Epidemiology and Ecology Laboratory, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jane S Chen
- Department of Health Behavior, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | | | - Melissa J Caimano
- Department of Medicine, UConn Health, Farmington, CT, USA; Department of Pediatrics, UConn Health, Farmington, CT, USA; Connecticut Children's, Hartford, CT, USA
| | - Wentao Chen
- Dermatology Hospital, Southern Medical University, Guangdong Provincial Center for Skin Diseases and STD Control, Guangzhou, China; BSL-3 Laboratory, Guangdong Provincial Key Laboratory of Tropical Disease Research School of Public Health, Southern Medical University, Guangzhou, China
| | - Jonny A Garcia-Luna
- Centro Internacional de Entrenamiento e Investigaciones Medicas, Campus de la Universidad Icesi, Cali, Colombia; Universidad Icesi, Cali, Colombia; Division of Dermatology, Department of Internal Medicine, School of Medicine, Universidad del Valle, Cali, Colombia
| | - Christopher M Hennelly
- Institute for Global Health and Infectious Diseases, Infectious Diseases Epidemiology and Ecology Laboratory, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Edward Jere
- UNC Project Malawi, Tidziwe Centre, Lilongwe, Malawi
| | - Yinbo Jiang
- Dermatology Hospital, Southern Medical University, Guangdong Provincial Center for Skin Diseases and STD Control, Guangzhou, China
| | - Jonathan J Juliano
- Department of Medicine, Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Institute for Global Health and Infectious Diseases, Infectious Diseases Epidemiology and Ecology Laboratory, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Petra Pospíšilová
- Department of Biology, Faculty of Medicine, Masaryk University Brno, Czech Republic
| | - Lady Ramirez
- Centro Internacional de Entrenamiento e Investigaciones Medicas, Campus de la Universidad Icesi, Cali, Colombia; Universidad Icesi, Cali, Colombia
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University Brno, Czech Republic
| | - Joseph D Tucker
- Department of Medicine, Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Fabio Vargas Cely
- Centro Internacional de Entrenamiento e Investigaciones Medicas, Campus de la Universidad Icesi, Cali, Colombia
| | - Heping Zheng
- Dermatology Hospital, Southern Medical University, Guangdong Provincial Center for Skin Diseases and STD Control, Guangzhou, China
| | - Irving F Hoffman
- Department of Medicine, Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Bin Yang
- Dermatology Hospital, Southern Medical University, Guangdong Provincial Center for Skin Diseases and STD Control, Guangzhou, China
| | - M Anthony Moody
- Department of Pediatrics, Division of Infectious Diseases, Duke University Medical Center, Durham, NC, USA; Department of Integrative Immunology, Duke University Medical Center, Durham, NC, USA; Duke Human Vaccine Institute, Durham, NC, USA
| | - Kelly L Hawley
- Department of Medicine, UConn Health, Farmington, CT, USA; Department of Pediatrics, UConn Health, Farmington, CT, USA; Department of Immunology, UConn Health, Farmington, CT, USA; Connecticut Children's, Hartford, CT, USA
| | - Juan C Salazar
- Department of Pediatrics, UConn Health, Farmington, CT, USA; Department of Immunology, UConn Health, Farmington, CT, USA; Connecticut Children's, Hartford, CT, USA
| | - Justin D Radolf
- Department of Medicine, UConn Health, Farmington, CT, USA; Department of Pediatrics, UConn Health, Farmington, CT, USA; Department of Immunology, UConn Health, Farmington, CT, USA; Connecticut Children's, Hartford, CT, USA
| | - Jonathan B Parr
- Department of Medicine, Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Institute for Global Health and Infectious Diseases, Infectious Diseases Epidemiology and Ecology Laboratory, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Scott C, Dias AP, De Buck J. Adherence and metal-ion acquisition gene expression increases during infection with Treponema phagedenis strains from bovine digital dermatitis. Infect Immun 2024; 92:e0011724. [PMID: 38940601 PMCID: PMC11320908 DOI: 10.1128/iai.00117-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 05/16/2024] [Indexed: 06/29/2024] Open
Abstract
Digital dermatitis (DD) is an ulcerative foot lesion on the heel bulbs of dairy cattle. DD is a polymicrobial disease with no precise etiology, although Treponema spirochetes are found disproportionally abundant in diseased tissue. Within Treponema, several different species are found in DD; however, the species Treponema phagedenis is uniformly found in copious quantities and deep within the skin layers of the active, ulcerative stages of disease. The pathogenic mechanisms these bacteria use to persist in the skin and the precise role they play in the pathology of DD are widely unknown. To explore the pathogenesis and virulence of Treponema phagedenis, newly isolated strains of this species were investigated in a subcutaneous murine abscess model. In the first trial, a dosage study was conducted to compare the pathogenicity of different strains across three different treponemes per inoculum (TPI) doses based on abscess volumes. In the second trial, the expression levels of 11 putative virulence genes were obtained to gain insight into their involvement in pathogenesis. During the RT-qPCR analysis, it was determined that genes encoding for two metal-ion import lipoproteins and two adherence genes were found highly upregulated during infection. Conversely, two genes involved in motility and chemotaxis were found to not be significantly upregulated or utilized during infection. These results were supported by gene expression data from natural M2 lesions of dairy cattle. This gene expression analysis could highlight the preference in strategy for T. phagedenis to persist and adhere in the host rather than engage in motility and disseminate.
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Affiliation(s)
- Colton Scott
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Angelica P. Dias
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jeroen De Buck
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
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Numata Y, Kikuchi Y, Sato T, Okamoto-Shibayama K, Ando Y, Miyai-Murai Y, Kokubu E, Ishihara K. Novel transcriptional regulator OxtR1 regulates potential ferrodoxin in response to oxygen stress in Treponema denticola. Anaerobe 2024; 87:102852. [PMID: 38614291 DOI: 10.1016/j.anaerobe.2024.102852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 02/26/2024] [Accepted: 04/08/2024] [Indexed: 04/15/2024]
Abstract
OBJECTIVE Treponema denticola has been strongly implicated in the pathogenesis of chronic periodontitis. Previously, we reported that the potential transcriptional regulator TDE_0259 (oxtR1) is upregulated in the bacteriocin ABC transporter gene-deficient mutant. OxtR1 may regulate genes to adapt to environmental conditions during colonization; however, the exact role of the gene in T. denticola has not been reported. Therefore, we investigated its function using an oxtR1-deficient mutant. METHODS The growth rates of the wild-type and oxtR1 mutant were monitored under anaerobic conditions; their antibacterial agent susceptibility and gene expression were assessed using a liquid dilution assay and DNA microarray, respectively. An electrophoretic mobility shift assay was performed to investigate the binding of OxtR1 to promoter regions. RESULTS The growth rate of the bacterium was accelerated by the inactivation of oxtR1, and the mutant exhibited an increased minimum inhibitory concentration against ofloxacin. We observed a relative increase in the expression of genes associated with potential ferrodoxin (TDE_0260), flavodoxin, ABC transporters, heat-shock proteins, DNA helicase, iron compounds, and lipoproteins in the mutant. OxtR1 expression increased upon oxygen exposure, and oxtR1 complementation suppressed the expression of potential ferrodoxin. Our findings also suggested that OxtR1 binds to a potential promoter region of the TDE_0259-260 operon. Moreover, the mutant showed a marginal yet significantly faster growth rate than the wild-type strain under H2O2 exposure. CONCLUSION The oxygen-sensing regulator OxtR1 plays a role in regulating the expression of a potential ferrodoxin, which may contribute to the response of T. denticola to oxygen-induced stress.
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Affiliation(s)
- Yumi Numata
- Department of Crown and Bridge Prosthodontics, Tokyo Dental College, 2-9-18 Kanda-Misakicho, Chiyoda-ku, Tokyo 101-0061, Japan
| | - Yuichiro Kikuchi
- Department of Microbiology, Tokyo Dental College, 2-1-14 Kanda-Misakicho, Chiyoda-ku, Tokyo 101-0061, Japan; Oral Health Science Center, Tokyo Dental College, 2-9-18 Kanda-Misakicho Chiyoda-ku, Tokyo 101-0061, Japan
| | - Toru Sato
- Department of Crown and Bridge Prosthodontics, Tokyo Dental College, 2-9-18 Kanda-Misakicho, Chiyoda-ku, Tokyo 101-0061, Japan
| | - Kazuko Okamoto-Shibayama
- Department of Microbiology, Tokyo Dental College, 2-1-14 Kanda-Misakicho, Chiyoda-ku, Tokyo 101-0061, Japan; Oral Health Science Center, Tokyo Dental College, 2-9-18 Kanda-Misakicho Chiyoda-ku, Tokyo 101-0061, Japan
| | - Yutaro Ando
- Department of Microbiology, Tokyo Dental College, 2-1-14 Kanda-Misakicho, Chiyoda-ku, Tokyo 101-0061, Japan; Oral Health Science Center, Tokyo Dental College, 2-9-18 Kanda-Misakicho Chiyoda-ku, Tokyo 101-0061, Japan
| | - Yuri Miyai-Murai
- Department of Crown and Bridge Prosthodontics, Tokyo Dental College, 2-9-18 Kanda-Misakicho, Chiyoda-ku, Tokyo 101-0061, Japan
| | - Eitoyo Kokubu
- Department of Microbiology, Tokyo Dental College, 2-1-14 Kanda-Misakicho, Chiyoda-ku, Tokyo 101-0061, Japan; Oral Health Science Center, Tokyo Dental College, 2-9-18 Kanda-Misakicho Chiyoda-ku, Tokyo 101-0061, Japan
| | - Kazuyuki Ishihara
- Department of Microbiology, Tokyo Dental College, 2-1-14 Kanda-Misakicho, Chiyoda-ku, Tokyo 101-0061, Japan; Oral Health Science Center, Tokyo Dental College, 2-9-18 Kanda-Misakicho Chiyoda-ku, Tokyo 101-0061, Japan.
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Seña AC, Matoga MM, Yang L, Lopez-Medina E, Aghakanian F, Chen JS, Bettin EB, Caimano MJ, Chen W, Garcia-Luna JA, Hennelly CM, Jiang Y, Juliano JJ, Pospíšilová P, Ramirez L, Šmajs D, Tucker JD, Cely FV, Zheng H, Hoffman IF, Yang B, Moody MA, Hawley KL, Salazar JC, Radolf JD, Parr JB. Clinical and genomic diversity of Treponema pallidum subsp. pallidum: A global, multi-center study of early syphilis to inform vaccine research. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.07.19.23291250. [PMID: 37546832 PMCID: PMC10402240 DOI: 10.1101/2023.07.19.23291250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Background The continuing increase in syphilis rates worldwide necessitates development of a vaccine with global efficacy. We conducted a multi-center, observational study to explore Treponema pallidum subsp. pallidum ( TPA ) molecular epidemiology essential for vaccine research by analyzing clinical data and specimens from early syphilis patients using whole-genome sequencing (WGS) and publicly available WGS data. Methods We enrolled patients with primary (PS), secondary (SS) or early latent (ELS) syphilis from clinics in China, Colombia, Malawi and the United States between November 2019 - May 2022. Inclusion criteria included age ≥18 years, and syphilis confirmation by direct detection methods and/or serological testing. TPA detection and WGS were conducted on lesion swabs, skin biopsies/scrapings, whole blood, and/or rabbit-passaged isolates. We compared our WGS data to publicly available genomes, and analysed TPA populations to identify mutations associated with lineage and geography. Findings We screened 2,820 patients and enrolled 233 participants - 77 (33%) with PS, 154 (66%) with SS, and two (1%) with ELS. Median age of participants was 28; 66% were cis -gender male, of which 43% reported identifying as "gay", "bisexual", or "other sexuality". Among all participants, 56 (24%) had HIV co-infection. WGS data from 113 participants demonstrated a predominance of SS14-lineage strains with geographic clustering. Phylogenomic analysis confirmed that Nichols-lineage strains are more genetically diverse than SS14-lineage strains and cluster into more distinct subclades. Differences in single nucleotide variants (SNVs) were evident by TPA lineage and geography. Mapping of highly differentiated SNVs to three-dimensional protein models demonstrated population-specific substitutions, some in outer membrane proteins (OMPs) of interest. Interpretation Our study involving participants from four countries substantiates the global diversity of TPA strains. Additional analyses to explore TPA OMP variability within strains will be vital for vaccine development and improved understanding of syphilis pathogenesis on a population level. Funding National Institutes of Health, Bill and Melinda Gates Foundation.
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Phan A, Romeis E, Tantalo L, Giacani L. In Vitro Transformation and Selection of Treponema pallidum subsp. pallidum. Curr Protoc 2022; 2:e507. [PMID: 35976045 PMCID: PMC9389596 DOI: 10.1002/cpz1.507] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Although the isolation of Treponema pallidum subsp. pallidum (T. pallidum) from a syphilis patient dates to 1912, for the duration of the 20th century, this pathogen has remained an exceedingly difficult organism to study due to the lack of a system to support its viability in vitro. This limitation, in turn, has precluded the application of genetic engineering techniques via transformation and subsequent selection of T. pallidum transformants. A recently described method for in vitro cultivation of T. pallidum, however, has made it possible for us to experiment with transformation and selection methods. Here we describe the approach that we adopted to successfully transform T. pallidum with foreign DNA and select the resulting recombinant strain using kanamycin. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Transformation of T. pallidum Support Protocol 1: Quantification of T. pallidum in suspensions using dark-field microscopy Support Protocol 2: Counting cells using a hemacytometer Basic Protocol 2: Selection, initial passaging, and expansion of transformed cultures Basic Protocol 3: Isolation of a clonal strain through limiting dilution.
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Affiliation(s)
- Amber Phan
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Harborview Medical Center, 325 9 Ave., Seattle, WA, 98104, USA. Tel: (206)-897-5400 (AP, ER, LT), and (206)-897-5402 (LG)
| | - Emily Romeis
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Harborview Medical Center, 325 9 Ave., Seattle, WA, 98104, USA. Tel: (206)-897-5400 (AP, ER, LT), and (206)-897-5402 (LG)
| | - Lauren Tantalo
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Harborview Medical Center, 325 9 Ave., Seattle, WA, 98104, USA. Tel: (206)-897-5400 (AP, ER, LT), and (206)-897-5402 (LG)
| | - Lorenzo Giacani
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Harborview Medical Center, 325 9 Ave., Seattle, WA, 98104, USA. Tel: (206)-897-5400 (AP, ER, LT), and (206)-897-5402 (LG)
- Department of Global Health, University of Washington, Harborview Medical Center, 325 9 Ave., Seattle, WA, 98104, USA
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De Lay BD, Cameron TA, De Lay NR, Norris SJ, Edmondson DG. Comparison of transcriptional profiles of Treponema pallidum during experimental infection of rabbits and in vitro culture: Highly similar, yet different. PLoS Pathog 2021; 17:e1009949. [PMID: 34570834 PMCID: PMC8525777 DOI: 10.1371/journal.ppat.1009949] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 10/19/2021] [Accepted: 09/08/2021] [Indexed: 12/15/2022] Open
Abstract
Treponema pallidum ssp. pallidum, the causative agent of syphilis, can now be cultured continuously in vitro utilizing a tissue culture system, and the multiplication rates are similar to those obtained in experimental infection of rabbits. In this study, the RNA transcript profiles of the T. pallidum Nichols during in vitro culture and rabbit infection were compared to examine whether gene expression patterns differed in these two environments. To this end, RNA preparations were converted to cDNA and subjected to RNA-seq using high throughput Illumina sequencing; reverse transcriptase quantitative PCR was also performed on selected genes for validation of results. The transcript profiles in the in vivo and in vitro environments were remarkably similar, exhibiting a high degree of concordance overall. However, transcript levels of 94 genes (9%) out of the 1,063 predicted genes in the T. pallidum genome were significantly different during rabbit infection versus in vitro culture, varying by up to 8-fold in the two environments. Genes that exhibited significantly higher transcript levels during rabbit infection included those encoding multiple ribosomal proteins, several prominent membrane proteins, glycolysis-associated enzymes, replication initiator DnaA, rubredoxin, thioredoxin, two putative regulatory proteins, and proteins associated with solute transport. In vitro cultured T. pallidum had higher transcript levels of DNA repair proteins, cofactor synthesis enzymes, and several hypothetical proteins. The overall concordance of the transcript profiles may indicate that these environments are highly similar in terms of their effects on T. pallidum physiology and growth, and may also reflect a relatively low level of transcriptional regulation in this reduced genome organism.
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Affiliation(s)
- Bridget D. De Lay
- Department of Pathology and Laboratory Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Todd A. Cameron
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Nicholas R. De Lay
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Steven J. Norris
- Department of Pathology and Laboratory Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Diane G. Edmondson
- Department of Pathology and Laboratory Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
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Romeis E, Tantalo L, Lieberman N, Phung Q, Greninger A, Giacani L. Genetic engineering of Treponema pallidum subsp. pallidum, the Syphilis Spirochete. PLoS Pathog 2021; 17:e1009612. [PMID: 34228757 PMCID: PMC8284648 DOI: 10.1371/journal.ppat.1009612] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 07/16/2021] [Accepted: 06/21/2021] [Indexed: 12/28/2022] Open
Abstract
Despite more than a century of research, genetic manipulation of Treponema pallidum subsp. pallidum (T. pallidum), the causative agent of syphilis, has not been successful. The lack of genetic engineering tools has severely limited understanding of the mechanisms behind T. pallidum success as a pathogen. A recently described method for in vitro cultivation of T. pallidum, however, has made it possible to experiment with transformation and selection protocols in this pathogen. Here, we describe an approach that successfully replaced the tprA (tp0009) pseudogene in the SS14 T. pallidum strain with a kanamycin resistance (kanR) cassette. A suicide vector was constructed using the pUC57 plasmid backbone. In the vector, the kanR gene was cloned downstream of the tp0574 gene promoter. The tp0574prom-kanR cassette was then placed between two 1-kbp homology arms identical to the sequences upstream and downstream of the tprA pseudogene. To induce homologous recombination and integration of the kanR cassette into the T. pallidum chromosome, in vitro-cultured SS14 strain spirochetes were exposed to the engineered vector in a CaCl2-based transformation buffer and let recover for 24 hours before adding kanamycin-containing selective media. Integration of the kanR cassette was demonstrated by qualitative PCR, droplet digital PCR (ddPCR), and whole-genome sequencing (WGS) of transformed treponemes propagated in vitro and/or in vivo. ddPCR analysis of RNA and mass spectrometry confirmed expression of the kanR message and protein in treponemes propagated in vitro. Moreover, tprA knockout (tprAko-SS14) treponemes grew in kanamycin concentrations that were 64 times higher than the MIC for the wild-type SS14 (wt-SS14) strain and in infected rabbits treated with kanamycin. We demonstrated that genetic manipulation of T. pallidum is attainable. This discovery will allow the application of functional genetics techniques to study syphilis pathogenesis and improve syphilis vaccine development. Syphilis is still an endemic disease in many low- and middle-income countries, and it has been resurgent in high-income nations for almost two decades. In endemic areas, syphilis causes significant morbidity and mortality, particularly when its causative agent, the spirochete Treponema pallidum subsp. pallidum (T. pallidum) is transmitted to the fetus during pregnancy. A better understanding of T. pallidum biology and syphilis pathogenesis would help devise better control strategies for this infection. One of the limitations associated with working with T. pallidum was our inability to genetically alter this pathogen to evaluate the function of genes encoding virulence factors or create attenuated strains that could be informative for vaccine development when studied using the rabbit model of the disease. Here, we report a transformation protocol that allowed us to replace a specific region of the T. pallidum genome containing a pseudogene (i.e., a non-functional gene) with a stably integrated kanamycin resistance gene. To our knowledge, this is the first-ever report of a method to achieve a genetically modified T. pallidum strain.
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Affiliation(s)
- Emily Romeis
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America
| | - Lauren Tantalo
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America
| | - Nicole Lieberman
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Quynh Phung
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Alex Greninger
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Lorenzo Giacani
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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Goetting-Minesky MP, Godovikova V, Fenno JC. Approaches to Understanding Mechanisms of Dentilisin Protease Complex Expression in Treponema denticola. Front Cell Infect Microbiol 2021; 11:668287. [PMID: 34084756 PMCID: PMC8167434 DOI: 10.3389/fcimb.2021.668287] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 05/04/2021] [Indexed: 11/25/2022] Open
Abstract
The oral spirochete Treponema denticola is a keystone periodontal pathogen that, in association with members of a complex polymicrobial oral biofilm, contributes to tissue damage and alveolar bone loss in periodontal disease. Virulence-associated behaviors attributed to T. denticola include disruption of the host cell extracellular matrix, tissue penetration and disruption of host cell membranes accompanied by dysregulation of host immunoregulatory factors. T. denticola dentilisin is associated with several of these behaviors. Dentilisin is an outer membrane-associated complex of acylated subtilisin-family PrtP protease and two other lipoproteins, PrcB and PrcA, that are unique to oral spirochetes. Dentilisin is encoded in a single operon consisting of prcB-prcA-prtP. We employ multiple approaches to study mechanisms of dentilisin assembly and PrtP protease activity. To determine the role of each protein in the protease complex, we have made targeted mutations throughout the protease locus, including polar and nonpolar mutations in each gene (prcB, prcA, prtP) and deletions of specific PrtP domains, including single base mutagenesis of key PrtP residues. These will facilitate distinguishing between host cell responses to dentilisin protease activity and its acyl groups. The boundaries of the divergent promoter region and the relationship between dentilisin and the adjacent iron transport operon are being resolved by incremental deletions in the sequence immediately 5’ to the protease locus. Comparison of the predicted three-dimensional structure of PrtP to that of other subtilisin-like proteases shows a unique PrtP C-terminal domain of approximately 250 residues. A survey of global gene expression in the presence or absence of protease gene expression reveals potential links between dentilisin and iron uptake and homeostasis in T. denticola. Understanding the mechanisms of dentilisin transport, assembly and activity of this unique protease complex may lead to more effective prophylactic or therapeutic treatments for periodontal disease.
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Affiliation(s)
- M Paula Goetting-Minesky
- Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI, United States
| | - Valentina Godovikova
- Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI, United States
| | - J Christopher Fenno
- Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI, United States
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Patel DT, O'Bier NS, Schuler EJA, Marconi RT. The Treponema denticola DgcA protein (TDE0125) is a functional diguanylate cyclase. Pathog Dis 2021; 79:6102550. [PMID: 33452878 DOI: 10.1093/femspd/ftab004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 01/13/2021] [Indexed: 11/12/2022] Open
Abstract
Periodontal disease (PD) is a progressive inflammatory condition characterized by degradation of the gingival epithelium, periodontal ligament, and alveolar bone ultimately resulting in tooth loss. Treponema denticola is a keystone periopathogen that contributes to immune dysregulation and direct tissue destruction. As periodontal disease develops, T. denticola must adapt to environmental, immunological and physiochemical changes in the subgingival crevice. Treponema denticola produces bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP), an important regulatory nucleotide. While T. denticola encodes several putative diguanylate cyclases (DGCs), none have been studied and hence the biological role of c-di-GMP in oral treponemes remains largely unexplored. Here, we demonstrate that the T. denticola open reading frame, TDE0125, encodes a functional DGC designated as DgcA (Diguanylate cyclase A). The dgcA gene is universal among T. denticola isolates, highly conserved and is a stand-alone GGEEF protein with a GAF domain. Recombinant DgcA converts GTP to c-di-GMP using either manganese or magnesium under aerobic and anaerobic reaction conditions. Size exclusion chromatography revealed that DgcA exists as a homodimer and in larger oligomers. Site-directed mutagenesis of residues that define the putative inhibitory site of DgcA suggest that c-di-GMP production is allosterically regulated. This report is the first to characterize a DGC of an oral treponeme.
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Affiliation(s)
- Dhara T Patel
- Department of Microbiology and Immunology, VCU Medical Center, 1112 East Clay Street, Room 101 McGuire Hall, PO Box 980678, Richmond, VA 23298-0678, USA
| | - Nathaniel S O'Bier
- Department of Microbiology and Immunology, VCU Medical Center, 1112 East Clay Street, Room 101 McGuire Hall, PO Box 980678, Richmond, VA 23298-0678, USA
| | - Edward J A Schuler
- Department of Microbiology and Immunology, VCU Medical Center, 1112 East Clay Street, Room 101 McGuire Hall, PO Box 980678, Richmond, VA 23298-0678, USA
| | - Richard T Marconi
- Department of Microbiology and Immunology, VCU Medical Center, 1112 East Clay Street, Room 101 McGuire Hall, PO Box 980678, Richmond, VA 23298-0678, USA
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Arai Y, Kikuchi Y, Okamoto-Shibayama K, Kokubu E, Shintani S, Ishihara K. Investigation of the potential regulator proteins associated with the expression of major surface protein and dentilisin in Treponema denticola. J Oral Microbiol 2020; 12:1829404. [PMID: 33149843 PMCID: PMC7586716 DOI: 10.1080/20002297.2020.1829404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
ObjectiveTreponema denticola is involved in ‘chronic’ periodontitis pathogenesis. The mechanism underlying the regulation of the expression of its virulence factors, such as major surface protein (Msp) and prolyl-phenylalanine specific protease (dentilisin) is yet to be clarified. We determined the gene expression profiles of Msp- and dentilisin-deficient mutants of T. denticola to identify the regulation network of gene expression concomitant with the inactivation of these virulence genes. Methods Gene expression profiles of T. denticola ATCC 35405 (wild type), dentilisin-deficient mutant K1, and msp-deficient mutant DMSP3 were determined using DNA microarray analysis and quantitative real-time reverse transcription PCR (qRT-PCR). Msp and dentilisin protein levels were determined by immunoblotting and proteolytic activity assays. Results In addition to several differentially expressed genes, dentilisin expression was reduced in DMSP3; msp expression was significantly reduced in K1 (p < 0.05), both at the gene and protein levels. To identify the regulatory system involved, the expression levels of the potential regulators whose expression showed changes in the mutants were evaluated using qRT-PCR. Transcriptional regulators TDE_0127 and TDE_0814 were upregulated in K1, and the potential repressor, TDE_0344, was elevated in DMSP3. Conclusions Dentilisin and Msp expression were interrelated, and gene expression regulators, such as TDE_0127, may be involved in their regulation.
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Affiliation(s)
- Yuki Arai
- Department of Pediatric Dentistry, Tokyo Dental College, Tokyo, Japan
| | | | | | - Eitoyo Kokubu
- Department of Microbiology, Tokyo Dental College, Tokyo, Japan
| | - Seikou Shintani
- Department of Pediatric Dentistry, Tokyo Dental College, Tokyo, Japan
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