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Xiong S, Liu Z, Zhang X, Huang S, Ding X, Zhou J, Yao J, Li W, Liu S, Zhao F. Resurgence of syphilis: focusing on emerging clinical strategies and preclinical models. J Transl Med 2023; 21:917. [PMID: 38105236 PMCID: PMC10726518 DOI: 10.1186/s12967-023-04685-4] [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: 07/02/2023] [Accepted: 10/30/2023] [Indexed: 12/19/2023] Open
Abstract
Syphilis, a sexually transmitted disease (STD) caused by Treponema pallidum (T. pallidum), has had a worldwide resurgence in recent years and remains a public health threat. As such, there has been a great deal of research into clinical strategies for the disease, including diagnostic biomarkers and possible strategies for treatment and prevention. Although serological testing remains the predominant laboratory diagnostic method for syphilis, it is worth noting that investigations pertaining to the DNA of T. pallidum, non-coding RNAs (ncRNAs), chemokines, and metabolites in peripheral blood, cerebrospinal fluid, and other bodily fluids have the potential to offer novel perspectives on the diagnosis of syphilis. In addition, the global spread of antibiotic resistance, such as macrolides and tetracyclines, has posed significant challenges for the treatment of syphilis. Fortunately, there is still no evidence of penicillin resistance. Hence, penicillin is the recommended course of treatment for syphilis, whereas doxycycline, tetracycline, ceftriaxone, and amoxicillin are viable alternative options. In recent years, efforts to discover a vaccine for syphilis have been reignited with better knowledge of the repertoire of T. pallidum outer membrane proteins (OMPs), which are the most probable syphilis vaccine candidates. However, research on therapeutic interventions and vaccine development for human subjects is limited due to practical and ethical considerations. Thus, the preclinical model is ideal for conducting research, and it plays an important role in clinical transformation. Different preclinical models have recently emerged, such as in vitro culture and mouse models, which will lay a solid foundation for clinical treatment and prevention of syphilis. This review aims to provide a comprehensive summary of the most recent syphilis tactics, including detection, drug resistance treatments, vaccine development, and preclinical models in clinical practice.
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Affiliation(s)
- Shun Xiong
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, 421001, China
| | - Zhaoping Liu
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, 421001, China
| | - Xiaohong Zhang
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, 421001, China
| | - Shaobin Huang
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, 421001, China
| | - Xuan Ding
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, 421001, China
| | - Jie Zhou
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, 421001, China
| | - Jiangchen Yao
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, 421001, China
| | - Weiwei Li
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, 421001, China
| | - Shuangquan Liu
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, 421001, China.
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital, Institution of Microbiology and Infectious Diseases, Hengyang Medical College, University of South China, Hengyang, 421001, China.
| | - Feijun Zhao
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, 421001, China.
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital, Institution of Microbiology and Infectious Diseases, Hengyang Medical College, University of South China, Hengyang, 421001, China.
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Liu D, Chen R, He Y, Wang YJ, Lin LR, Liu LL, Yang TC, Tong ML. Longitudinal Variations in the tprK Gene of Treponema pallidum in an Amoy Strain-Infected Rabbit Model. Microbiol Spectr 2023; 11:e0106723. [PMID: 37347187 PMCID: PMC10433980 DOI: 10.1128/spectrum.01067-23] [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: 03/12/2023] [Accepted: 06/01/2023] [Indexed: 06/23/2023] Open
Abstract
Heterogeneous tprK sequences have been hypothesized to be an important factor for persistent infection of Treponema pallidum subsp. pallidum (T. pallidum) in humans. Previous research has only explored tprK diversity using a rabbit model infected with almost clonal isolates, which is inconsistent with the fact that infected human isolates contain multiple heterogeneous tprK sequences. Here, we used the T. pallidum Amoy strain with heterogeneous tprK sequences to establish a rabbit infection model and explore longitudinal variations in the tprK gene under normal infection, immunosuppression treatment, and benzathine penicillin G (BPG) treatment using next-generation sequencing. The diversity of the tprK gene was high in all three groups but was highest in the control group and lowest in the BPG group. Interestingly, the overall diversity of tprK in all three groups decreased during infection, exhibiting a "more to less" trend, indicating that survival selection may be an important factor affecting tprK variation in the later infection stage. BPG treatment appeared to reduce the diversity of tprK but increased the frequency of predominant sequence changes, which might facilitate the escape of T. pallidum from the host immune clearance. Furthermore, the original predominant V region sequence did not disappear with disease progression but retained a relatively high proportion within the population, suggesting a new direction for tprK-related vaccine research. This study provides insights into longitudinal variations within the highly heterogeneous tprK gene sequences of T. pallidum and will contribute to further exploration of the pathogenesis of syphilis. IMPORTANCE The tprK variations are an important factor in persistent T. pallidum infection. A nearly clonal isolate has been used previously to investigate the mechanism of tprK gene variations; however, clinical T. pallidum isolates in infected humans exhibit multiple heterogeneous tprK sequences. Here, we use next-generation sequencing to explore longitudinal variations in the tprK gene under normal infection and immunosuppression and benzathine penicillin G treatment in a rabbit model infected with the Amoy strain with heterogeneous tprK sequences. The overall diversity of tprK in all three groups was high and decreased during infection, exhibiting a "more to less" trend. Benzathine penicillin G treatment reduced the diversity of tprK but increased the frequency of predominant sequence changes. Moreover, the original predominant V region sequence did not disappear as the disease progressed but remained at a relatively high proportion within the population. The research results give us a new understanding about tprK variation.
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Affiliation(s)
- Dan Liu
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Rui Chen
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Yun He
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Yong-jing Wang
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Li-Rong Lin
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Li-Li Liu
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Tian-Ci Yang
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Man-Li Tong
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
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Li S, Li W, Jin Y, Wu B, Wu Y. Advancements in the development of nucleic acid vaccines for syphilis prevention and control. Hum Vaccin Immunother 2023; 19:2234790. [PMID: 37538024 PMCID: PMC10405752 DOI: 10.1080/21645515.2023.2234790] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 06/12/2023] [Accepted: 07/05/2023] [Indexed: 08/05/2023] Open
Abstract
Syphilis, a chronic systemic sexually transmitted disease, is caused by the bacterium Treponema pallidum (T. pallidum). Currently, syphilis remains a widespread infectious disease with significant disease burden in many countries. Despite the absence of identified penicillin-resistant strains, challenges in syphilis treatment persist due to penicillin allergies, supply issues, and the emergence of macrolide-resistant strains. Vaccines represent the most cost-effective strategy to prevent and control the syphilis epidemic. In light of the ongoing global coronavirus disease 2019 (COVID-19) pandemic, nucleic acid vaccines have gained prominence in the field of vaccine research and development, owing to their superior efficiency compared to traditional vaccines. This review summarizes the current state of the syphilis epidemic and the preliminary findings in T. pallidum nucleic acid vaccine research, discusses the challenges associated with the development of T. pallidum nucleic acid vaccines, and proposes strategies and measures for future T. pallidum vaccine development.
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Affiliation(s)
- Sijia Li
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Weiwei Li
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
- Department of Clinical Laboratory, The Second People’s Hospital of Foshan, Foshan, China
| | - Yinqi Jin
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Bin Wu
- First Affiliated Hospital, Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Yimou Wu
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
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Liu D, Liu LL, Zheng XQ, Chen R, Lin LR, Yang TC, Tong ML. Genetic Profiling of the Full-Length tprK Gene in Patients with Primary and Secondary Syphilis. Microbiol Spectr 2023; 11:e0493122. [PMID: 37036342 PMCID: PMC10269439 DOI: 10.1128/spectrum.04931-22] [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: 11/30/2022] [Accepted: 03/17/2023] [Indexed: 04/11/2023] Open
Abstract
TprK antigenic variation is acknowledged as an important strategy developed by Treponema pallidum to achieve immune evasion. Previous studies applied short-read sequencing to explore tprK gene sequence diversity in clinical samples; however, due to the limitations of short-read sequencing, it was difficult to determine the linkage between the seven V regions, and crucial information about full-length tprK variants was lost. Although two recent studies explored complete tprK gene profiles in natural human syphilis infection, there are still too few profiled full-length tprK variants among clinical T. pallidum isolates to fully understand the characteristics of TprK coding diversity. Here, Pacific Biosciences (PacBio) long-read sequencing was applied to examine the diversity of full-length tprK variants in 21 clinical T. pallidum isolates from 11 patients with primary syphilis and 10 patients with secondary syphilis. A total of 398 high-confidence full-length sequences, which presented remarkable sequence heterogeneity, were found. However, these full-length tprK variants exhibited limited variation in length and GC content, showing 24 length types and average GC content of 51.5 ± 0.42% and 51.6 ± 0.26% for primary and secondary syphilis samples, respectively. Additionally, the combined patterns of mutated V regions generating new tprK variants were obviously different in primary and secondary syphilis samples. The diversity of tprK gene sequences in primary syphilis samples may represent the underlying variability of the bacterium; conversely, the variability of the tprK gene in secondary syphilis samples may more accurately reflect how T. pallidum escapes host immune clearance. These data highlight the tprK gene as an important coding gene that shows conflicting genetic characteristics but underlies the persistence of spirochete infection. IMPORTANCE The resurgence of syphilis in both low- and high-income countries has attracted attention, and persistent infection by the pathogen has long been a research focus. The tprK gene, encoding the hypervariable outer membrane protein, is thought to be responsible for pathogen immune evasion and persistent infection. Here, PacBio long-read sequencing was applied to examine the diversity of full-length tprK variants in 21 clinical T. pallidum isolates from 11 patients with primary syphilis and 10 patients with secondary syphilis. The results showed that the sequences of the tprK gene were remarkably heterogeneous; however, the sequences presented limited variation in length and GC content. The investigation of the combined patterns of the V regions allowed us to gain insight into the features of the tprK gene generating new variants at different clinical stages. The findings of this study will be helpful for further exploration of the pathogenesis of syphilis.
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Affiliation(s)
- Dan Liu
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Li-Li Liu
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Xin-Qi Zheng
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Rui Chen
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Li-Rong Lin
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Tian-Ci Yang
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Man-Li Tong
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
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Tang Y, Zhou Y, He B, Cao T, Zhou X, Ning L, Chen E, Li Y, Xie X, Peng B, Hu Y, Liu S. Investigation of the immune escape mechanism of Treponema pallidum. Infection 2022; 51:305-321. [PMID: 36260281 DOI: 10.1007/s15010-022-01939-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 10/07/2022] [Indexed: 11/25/2022]
Abstract
BACKGROUND Syphilis is a chronic sexually transmitted disease caused by Treponema pallidum subspecies pallidum (T. pallidum), which is a public health problem that seriously affects human health worldwide. T. pallidum is characterized by early transmission and immune escape and is therefore termed an "invisible pathogen". METHODS This review systematically summarizes the host's innate and adaptive immune responses to T. pallidum infection as well as the escape mechanisms of T. pallidum. PURPOSE To lay the foundation for assessing the pathogenic mechanism and the systematic prevention and treatment of syphilis. CONCLUSION The immune escape mechanism of T. pallidum plays an important role in its survival. Exploring the occurrence and development of these mechanisms has laid the foundation for the development of syphilis vaccine.
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Affiliation(s)
- Yun Tang
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Yingjie Zhou
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Bisha He
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Ting Cao
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Xiangping Zhou
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Lichang Ning
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - En Chen
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Yumeng Li
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Xiaoping Xie
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Binfeng Peng
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Yibao Hu
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Shuangquan Liu
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China.
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Beiras CG, Marks M, Quintó L, Gavilán S, Kolmau R, Ubals M, Vall-Mayans M, Mitjà O. Yaws recurrence in children at continued risk of infection. PLoS Negl Trop Dis 2022; 16:e0010197. [PMID: 35312686 PMCID: PMC8970528 DOI: 10.1371/journal.pntd.0010197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 03/31/2022] [Accepted: 01/24/2022] [Indexed: 11/19/2022] Open
Abstract
Background
In yaws-endemic areas, children with Treponema pallidum subsp. pertenue infection may suffer recurrent episodes due to either reinfection or relapse. However, the possibility of infection with other cutaneous ulcer causative agents and difficulties in interpreting standard laboratory results challenges the estimation of yaws recurrence rates.
Methods
We estimated the rates of yaws recurrences in the Lihir Island (Papua New Guinea) using two approaches: passive surveillance based on a retrospective screening of electronic medical records of cutaneous ulcers diagnosed using serological testing between 2005 and 2016, and active surveillance conducted during a cross-sectional prevalence study which included PCR analyses of ulcers of all suspected cases of yaws. The risk of recurrent infection was assessed based on data from the passive surveillance analysis and using two Cox regression models (crude and multivariate), stratified by year of index episode. Data gathered from the active surveillance was used to characterize the recurrences and no hypothesis testing was performed.
Results
The electronic medical records included 6,125 patients (7,889 ulcer episodes) with documented serological results of cutaneous ulcers of which1,486 were diagnosed with yaws. Overall, 1,246/6,125 patients (20.3%) presented more than once with a cutaneous ulcer, and 103/1,486 (6.7%) patients had multiple episodes of yaws. The risk of yaws recurrence significantly increased with age and was higher in patients with ≥3 recurrent episodes. In the active surveillance, we identified 50 individuals with recurrent cutaneous ulcer that had PCR results available for both the index and recurrent episode. Of 12 individuals with T. pallidum in the index ulcer, 8 (66%) had T. pallidum in subsequent assessments, relapse related to macrolide-resistance was identified in two of these cases.
Conclusions
Our results confirm the need for active follow-up of yaws patients after treatment, particularly children and individuals with a history of recurrence.
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Affiliation(s)
- Camila G. Beiras
- STI and Skin NTDs Unit, Department of Infectious Diseases and Fight AIDS and Infectious Diseases Foundation, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
- * E-mail:
| | - Michael Marks
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Hospital for Tropical Diseases, University College London Hospitals, London, United Kingdom
| | - Llorenç Quintó
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
- Manhiça Health Research Institute (CISM), Manhiça, Mozambique
| | - Sergi Gavilán
- STI and Skin NTDs Unit, Department of Infectious Diseases and Fight AIDS and Infectious Diseases Foundation, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
| | - Reman Kolmau
- Lihir Medical Centre, International SOS, Londolovit, Papua New Guinea
| | - Maria Ubals
- STI and Skin NTDs Unit, Department of Infectious Diseases and Fight AIDS and Infectious Diseases Foundation, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
| | - Marti Vall-Mayans
- STI and Skin NTDs Unit, Department of Infectious Diseases and Fight AIDS and Infectious Diseases Foundation, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
| | - Oriol Mitjà
- STI and Skin NTDs Unit, Department of Infectious Diseases and Fight AIDS and Infectious Diseases Foundation, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
- Lihir Medical Centre, International SOS, Londolovit, Papua New Guinea
- School of Medicine and Health Sciences, University of Papua New Guinea, Port Moresby, Papua New Guinea
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Lian T, Zhang B, Giacani L, Kou C, Yang X, Zhang R, Wang Q. Full-length TprK of Treponema pallidum subsp. pallidum in lipid nanodiscs is a monomeric porin. Enzyme Microb Technol 2022; 153:109897. [PMID: 34670182 PMCID: PMC10929906 DOI: 10.1016/j.enzmictec.2021.109897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/27/2021] [Accepted: 08/23/2021] [Indexed: 11/22/2022]
Abstract
TprK is a key virulence factor of Treponema pallidum subsp. pallidum (T. pallidum) due to its ability to undergo intra-strain antigenic variation through gene conversion. This mechanism can generate millions of tprK gene and protein variants to allow immune evasion and pathogen persistence during infection. In silico structural modeling supports that TprK is an outer membrane β-barrel with porin function and with several surface-exposed loops, seven of which corresponding to the variable regions. No definitive structural of functional data, however, exist for this protein aside from its role in immune evasion. Studies to elucidate TprK biological function as a porin, are hindered by the evidence that TprK is not abundant on T. pallidum outer membrane, and by the fragility of T. pallidum envelope. To gain insight onto TprK structure and possible function as a porin, we used an Escherichia coli - based expression system that yielded highly pure full-length TprK without any intermediate denaturation step, and proceeded to reconstitute it in detergents and lipid nanodiscs. Visualization of TprK in nanodiscs using negative staining electron microscopy supported that TprK is a monomeric porin in an artificial lipid environment mimicking T. pallidum membrane. Our work provided evidence that TprK is a possible porin transporter of T. pallidum, a biological function compatible with its structural models. These results bring us closer to a comprehensive understanding of the function of this important virulence factor in syphilis pathogenesis and T. pallidum biology.
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Affiliation(s)
- Tingting Lian
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, China.
| | - Bing Zhang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 200120, China.
| | - Lorenzo Giacani
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, USA; Department of Global Health, University of Washington, Seattle, WA, USA.
| | - Caixia Kou
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, China.
| | - Xiuna Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 200120, China.
| | - Ruili Zhang
- Department of Dermatology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 210042, China.
| | - Qianqiu Wang
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, China.
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Tiecco G, Degli Antoni M, Storti S, Marchese V, Focà E, Torti C, Castelli F, Quiros-Roldan E. A 2021 Update on Syphilis: Taking Stock from Pathogenesis to Vaccines. Pathogens 2021; 10:pathogens10111364. [PMID: 34832520 PMCID: PMC8620723 DOI: 10.3390/pathogens10111364] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/14/2021] [Accepted: 10/19/2021] [Indexed: 12/22/2022] Open
Abstract
In 2021 the scientific community’s efforts have been focused on solving the back-breaking challenge of the COVID-19 pandemic, but sexually transmitted infections (STI) are still one of the most common global health problems. Syphilis is a systemic disease caused by the spirochaete Treponema pallidum (TP) and is one of the oldest known diseases. Its incidence has increased in the last few years and syphilis still remains a contemporary plague that continues to afflict millions of people worldwide. Despite research improvements, syphilis pathogenesis is not completely clear; clinical presentation is very heterogeneous and the diagnosis can sometimes be difficult. Furthermore, few therapeutic options are available, and a vaccine has not been found yet. In this review, we describe the most recent evidence concerning the clinical manifestation, diagnosis, treatment and vaccine prospectives for this disease.
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Affiliation(s)
- Giorgio Tiecco
- Unit of Infectious and Tropical Diseases, Department of Clinical and Experimental Sciences, ASST Spedali di Brescia, University of Brescia, 25123 Brescia, Italy; (G.T.); (M.D.A.); (S.S.); (V.M.); (E.F.); (F.C.)
| | - Melania Degli Antoni
- Unit of Infectious and Tropical Diseases, Department of Clinical and Experimental Sciences, ASST Spedali di Brescia, University of Brescia, 25123 Brescia, Italy; (G.T.); (M.D.A.); (S.S.); (V.M.); (E.F.); (F.C.)
| | - Samuele Storti
- Unit of Infectious and Tropical Diseases, Department of Clinical and Experimental Sciences, ASST Spedali di Brescia, University of Brescia, 25123 Brescia, Italy; (G.T.); (M.D.A.); (S.S.); (V.M.); (E.F.); (F.C.)
| | - Valentina Marchese
- Unit of Infectious and Tropical Diseases, Department of Clinical and Experimental Sciences, ASST Spedali di Brescia, University of Brescia, 25123 Brescia, Italy; (G.T.); (M.D.A.); (S.S.); (V.M.); (E.F.); (F.C.)
| | - Emanuele Focà
- Unit of Infectious and Tropical Diseases, Department of Clinical and Experimental Sciences, ASST Spedali di Brescia, University of Brescia, 25123 Brescia, Italy; (G.T.); (M.D.A.); (S.S.); (V.M.); (E.F.); (F.C.)
| | - Carlo Torti
- Infectious and Tropical Disease Unit, Department of Medical and Surgical Sciences, “Magna Graecia” University of Catanzaro, 88100 Catanzaro, Italy;
| | - Francesco Castelli
- Unit of Infectious and Tropical Diseases, Department of Clinical and Experimental Sciences, ASST Spedali di Brescia, University of Brescia, 25123 Brescia, Italy; (G.T.); (M.D.A.); (S.S.); (V.M.); (E.F.); (F.C.)
| | - Eugenia Quiros-Roldan
- Unit of Infectious and Tropical Diseases, Department of Clinical and Experimental Sciences, ASST Spedali di Brescia, University of Brescia, 25123 Brescia, Italy; (G.T.); (M.D.A.); (S.S.); (V.M.); (E.F.); (F.C.)
- Correspondence: ; Tel.: +39-(030)-399-5677
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9
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Lin MJ, Haynes AM, Addetia A, Lieberman NAP, Phung Q, Xie H, Nguyen TV, Molini BJ, Lukehart SA, Giacani L, Greninger AL. Longitudinal TprK profiling of in vivo and in vitro-propagated Treponema pallidum subsp. pallidum reveals accumulation of antigenic variants in absence of immune pressure. PLoS Negl Trop Dis 2021; 15:e0009753. [PMID: 34492041 PMCID: PMC8480903 DOI: 10.1371/journal.pntd.0009753] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 09/29/2021] [Accepted: 08/23/2021] [Indexed: 11/25/2022] Open
Abstract
Immune evasion by Treponema pallidum subspecies pallidum (T. pallidum) has been attributed to antigenic variation of its putative outer-membrane protein TprK. In TprK, amino acid diversity is confined to seven variable (V) regions, and generation of sequence diversity within the V regions occurs via a non-reciprocal segmental gene conversion mechanism where donor cassettes recombine into the tprK expression site. Although previous studies have shown the significant role of immune selection in driving accumulation of TprK variants, the contribution of baseline gene conversion activity to variant diversity is less clear. Here, combining longitudinal tprK deep sequencing of near clonal Chicago C from immunocompetent and immunosuppressed rabbits along with the newly developed in vitro cultivation system for T. pallidum, we directly characterized TprK alleles in the presence and absence of immune selection. Our data confirm significantly greater sequence diversity over time within the V6 region during syphilis infection in immunocompetent rabbits compared to immunosuppressed rabbits, consistent with previous studies on the role of TprK in evasion of the host immune response. Compared to strains grown in immunocompetent rabbits, strains passaged in vitro displayed low level changes in allele frequencies of TprK variable region sequences similar to that of strains passaged in immunosuppressed rabbits. Notably, we found significantly increased rates of V6 allele generation relative to other variable regions in in vitro cultivated T, pallidum strains, illustrating that the diversity within these hypervariable regions occurs in the complete absence of immune selection. Together, our results demonstrate antigenic variation in T. pallidum can be studied in vitro and occurs even in the complete absence of immune pressure, allowing the T. pallidum population to continuously evade the immune system of the infected host.
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Affiliation(s)
- Michelle J. Lin
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Austin M. Haynes
- Pathobiology Graduate Program, University of Washington, Seattle, Washington, United States of America
| | - Amin Addetia
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington, United States of America
| | - Nicole A. P. Lieberman
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Quynh Phung
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Hong Xie
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Tien V. Nguyen
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Barbara J. Molini
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America
| | - Sheila A. Lukehart
- 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
| | - Lorenzo Giacani
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America
| | - Alexander L. Greninger
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- * E-mail:
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10
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Lu S, Zheng K, Wang J, Xu M, Xie Y, Yuan S, Wang C, Wu Y. Characterization of Treponema pallidum Dissemination in C57BL/6 Mice. Front Immunol 2021; 11:577129. [PMID: 33488577 PMCID: PMC7819853 DOI: 10.3389/fimmu.2020.577129] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 11/20/2020] [Indexed: 11/13/2022] Open
Abstract
The spirochetal pathogen Treponema pallidum causes 5 million new cases of venereal syphilis worldwide each year. One major obstacle to syphilis prevention and treatment is the lack of suitable experimental animal models to study its pathogenesis. Accordingly, in this study, we further evaluated the responses of mice to Treponema pallidum. Quantitative polymerase chain reaction showed that Treponema pallidum could colonize the heart, liver, spleen, kidneys, and testicles of C57BL/6 mice, and the organism may be able to rapidly penetrate the blood-brain barrier in mice by 24 h after infection. In subsequent rabbit infectivity tests, we observed evident signs of the microorganism in the mouse lymph node suspension. After infection, bacterial loads were higher in the tissues than in the blood of C57BL/6 mice. Moreover, a significant Th1 immune response was recorded by cytokine assays. Flow cytometric analysis suggested an obvious increase in the proportion of CD3+ T and CD4+ T cells in the spleen cells in the infected mice. Thus, improving our understanding of the response of C57BL/6 mice for Treponema pallidum will help to comprehensive elucidate the pathogenic mechanisms of this bacterium and lay the foundation for the development of a new research model of Treponema pallidum.
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Affiliation(s)
- Simin Lu
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Kang Zheng
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Jianye Wang
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Man Xu
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Yafeng Xie
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
- Clinical Laboratory, The Second Affiliated Hospital of University of South China, Hengyang, China
| | - Shuai Yuan
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Chuan Wang
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Yimou Wu
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
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11
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Abstract
Syphilis continues to be a significant public health issue in both low- and high-income countries, including the United States where the rate of syphilis infection has increased over the past 5 years. Treponema pallidum subsp. pallidum, the causative agent of syphilis, carries the outer membrane protein TprK that undergoes segmental gene conversion to constantly create new sequences. We performed full-length deep sequencing of TprK to examine TprK diversity in clinical T. pallidum subsp. pallidum strains. We then combined our results with data from all samples for which TprK deep sequencing results were available. We found almost no overlap in TprK sequences between different patients. Moreover, our data allowed us to estimate the total number of TprK variants that T. pallidum subsp. pallidum can potentially generate. Our results support how the T. pallidum subsp. pallidum TprK antigenic variation system is an equal adversary of the human immune system leading to pathogen persistence in the host. Immune evasion and disease progression of Treponema pallidum subsp. pallidum are associated with sequence diversity in the hypervariable outer membrane protein TprK. Previous attempts to study variation within TprK have sequenced at depths insufficient to fully appreciate the hypervariable nature of the protein, failed to establish linkage between the protein’s seven variable regions, or were conducted on isolates passed through rabbits. As a consequence, a complete profile of tprK during infection in the human host is still lacking. Furthermore, prior studies examining how T. pallidum subsp. pallidum uses its repertoire of genomic donor sites to generate diversity within the variable regions of the tprK have yielded a partial understanding of this process due to the limited number of tprK alleles examined. In this study, we used short- and long-read deep sequencing to directly characterize full-length tprK alleles from T. pallidum subsp. pallidum collected from early lesions of patients attending two sexually transmitted infection clinics in Italy. We demonstrate that strains collected from cases of secondary syphilis contain significantly more unique variable region sequences and full-length TprK sequences than those from cases of primary syphilis. Our data, combined with recent data available on Chinese T. pallidum subsp. pallidum specimens, show the near-complete absence of overlap in TprK sequences among the 41 specimens profiled to date. We further estimate that the potential antigenic variability carried by TprK rivals that of current estimates of the human adaptive immune system. These data underscore the immunoevasive ability of TprK that allows T. pallidum subsp. pallidum to establish lifelong infection.
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12
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Addetia A, Tantalo LC, Lin MJ, Xie H, Huang ML, Marra CM, Greninger AL. Comparative genomics and full-length Tprk profiling of Treponema pallidum subsp. pallidum reinfection. PLoS Negl Trop Dis 2020; 14:e0007921. [PMID: 32251462 PMCID: PMC7162541 DOI: 10.1371/journal.pntd.0007921] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 04/16/2020] [Accepted: 02/08/2020] [Indexed: 12/25/2022] Open
Abstract
Developing a vaccine against Treponema pallidum subspecies pallidum, the causative agent of syphilis, remains a public health priority. Syphilis vaccine design efforts have been complicated by lack of an in vitro T. pallidum culture system, prolific antigenic variation in outer membrane protein TprK, and lack of functional annotation for nearly half of the genes. Understanding the genetic basis of T. pallidum reinfection can provide insights into variation among strains that escape cross-protective immunity. Here, we present comparative genomic sequencing and deep, full-length tprK profiling of two T. pallidum isolates from blood from the same patient that were collected six years apart. Notably, this patient was diagnosed with syphilis four times, with two of these episodes meeting the definition of neurosyphilis, during this interval. Outside of the highly variable tprK gene, we identified 14 coding changes in 13 genes. Nine of these genes putatively localized to the periplasmic or outer membrane spaces, consistent with a potential role in serological immunoevasion. Using a newly developed full-length tprK deep sequencing protocol, we profiled the diversity of this gene that far outpaces the rest of the genome. Intriguingly, we found that the reinfecting isolate demonstrated less diversity across each tprK variable region compared to the isolate from the first infection. Notably, the two isolates did not share any full-length TprK sequences. Our results are consistent with an immunodominant-evasion model in which the diversity of TprK explains the ability of T. pallidum to successfully reinfect individuals, even when they have been infected with the organism multiple times.
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Affiliation(s)
- Amin Addetia
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Lauren C. Tantalo
- Department of Neurology, University of Washington, Seattle, Washington, United States of America
| | - Michelle J. Lin
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Hong Xie
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Meei-Li Huang
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Christina M. Marra
- Department of Neurology, University of Washington, Seattle, Washington, United States of America
| | - Alexander L. Greninger
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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13
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Mikalová L, Janečková K, Nováková M, Strouhal M, Čejková D, Harper KN, Šmajs D. Whole genome sequence of the Treponema pallidum subsp. endemicum strain Iraq B: A subpopulation of bejel treponemes contains full-length tprF and tprG genes similar to those present in T. p. subsp. pertenue strains. PLoS One 2020; 15:e0230926. [PMID: 32236138 PMCID: PMC7112178 DOI: 10.1371/journal.pone.0230926] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 03/11/2020] [Indexed: 11/25/2022] Open
Abstract
Treponema pallidum subsp. endemicum (TEN) is the causative agent of endemic syphilis (bejel). Until now, only a single TEN strain, Bosnia A, has been completely sequenced. The only other laboratory TEN strain available, Iraq B, was isolated in Iraq in 1951 by researchers from the US Centers for Disease Control and Prevention. In this study, the complete genome of the Iraq B strain was amplified as overlapping PCR products and sequenced using the pooled segment genome sequencing method and Illumina sequencing. Total average genome sequencing coverage reached 3469×, with a total genome size of 1,137,653 bp. Compared to the genome sequence of Bosnia A, a set of 37 single nucleotide differences, 4 indels, 2 differences in the number of tandem repetitions, and 18 differences in the length of homopolymeric regions were found in the Iraq B genome. Moreover, the tprF and tprG genes that were previously found deleted in the genome of the TEN Bosnia A strain (spanning 2.3 kb in length) were present in a subpopulation of TEN Iraq B and Bosnia A microbes, and their sequence was highly similar to those found in T. p. subsp. pertenue strains, which cause the disease yaws. The genome sequence of TEN Iraq B revealed close genetic relatedness between both available bejel-causing laboratory strains (i.e., Iraq B and Bosnia A) and also genetic variability within the bejel treponemes comparable to that found within yaws- or syphilis-causing strains. In addition, genetic relatedness to TPE strains was demonstrated by the sequence of the tprF and tprG genes found in subpopulations of both TEN Iraq B and Bosnia A. The loss of the tprF and tprG genes in most TEN microbes suggest that TEN genomes have been evolving via the loss of genomic regions, a phenomenon previously found among the treponemes causing both syphilis and rabbit syphilis.
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Affiliation(s)
- Lenka Mikalová
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Klára Janečková
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Markéta Nováková
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Michal Strouhal
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Darina Čejková
- Department of Immunology, Veterinary Research Institute, Brno, Czech Republic
| | - Kristin N. Harper
- Department of Population Biology, Ecology, and Evolution, Emory University, Atlanta, Georgia, United States of America
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
- * E-mail:
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14
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Jaiswal AK, Tiwari S, Jamal SB, de Castro Oliveira L, Alves LG, Azevedo V, Ghosh P, Oliveira CJF, Soares SC. The pan-genome of Treponema pallidum reveals differences in genome plasticity between subspecies related to venereal and non-venereal syphilis. BMC Genomics 2020; 21:33. [PMID: 31924165 PMCID: PMC6953169 DOI: 10.1186/s12864-019-6430-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 12/24/2019] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Spirochetal organisms of the Treponema genus are responsible for causing Treponematoses. Pathogenic treponemes is a Gram-negative, motile, spirochete pathogen that causes syphilis in human. Treponema pallidum subsp. endemicum (TEN) causes endemic syphilis (bejel); T. pallidum subsp. pallidum (TPA) causes venereal syphilis; T. pallidum subsp. pertenue (TPE) causes yaws; and T. pallidum subsp. Ccarateum causes pinta. Out of these four high morbidity diseases, venereal syphilis is mediated by sexual contact; the other three diseases are transmitted by close personal contact. The global distribution of syphilis is alarming and there is an increasing need of proper treatment and preventive measures. Unfortunately, effective measures are limited. RESULTS Here, the genome sequences of 53 T. pallidum strains isolated from different parts of the world and a diverse range of hosts were comparatively analysed using pan-genomic strategy. Phylogenomic, pan-genomic, core genomic and singleton analysis disclosed the close connection among all strains of the pathogen T. pallidum, its clonal behaviour and showed increases in the sizes of the pan-genome. Based on the genome plasticity analysis of the subsets containing the subspecies T pallidum subsp. pallidum, T. pallidum subsp. endemicum and T. pallidum subsp. pertenue, we found differences in the presence/absence of pathogenicity islands (PAIs) and genomic islands (GIs) on subsp.-based study. CONCLUSIONS In summary, we identified four pathogenicity islands (PAIs), eight genomic islands (GIs) in subsp. pallidum, whereas subsp. endemicum has three PAIs and seven GIs and subsp. pertenue harbours three PAIs and eight GIs. Concerning the presence of genes in PAIs and GIs, we found some genes related to lipid and amino acid biosynthesis that were only present in the subsp. of T. pallidum, compared to T. pallidum subsp. endemicum and T. pallidum subsp. pertenue.
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Affiliation(s)
- Arun Kumar Jaiswal
- PG Program in Bioinformatics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.,Department of Immunology, Microbiology and Parasitology, Institute of Biological Sciences and Natural Sciences, Federal University of Triângulo Mineiro (UFTM), Uberaba, MG, Brazil
| | - Sandeep Tiwari
- PG Program in Bioinformatics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
| | - Syed Babar Jamal
- Department of Biological Sciences, National University of Medical Sciences, Abid Majeed Road, Rawalpindi, Punjab, 46000, Pakistan
| | - Letícia de Castro Oliveira
- PG Program in Bioinformatics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.,Department of Immunology, Microbiology and Parasitology, Institute of Biological Sciences and Natural Sciences, Federal University of Triângulo Mineiro (UFTM), Uberaba, MG, Brazil
| | - Leandro Gomes Alves
- Department of Immunology, Microbiology and Parasitology, Institute of Biological Sciences and Natural Sciences, Federal University of Triângulo Mineiro (UFTM), Uberaba, MG, Brazil
| | - Vasco Azevedo
- PG Program in Bioinformatics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Preetam Ghosh
- Department of Computer Science, Virginia Commonwealth University, Richmond, VA-23284, USA
| | - Carlo Jose Freira Oliveira
- Department of Immunology, Microbiology and Parasitology, Institute of Biological Sciences and Natural Sciences, Federal University of Triângulo Mineiro (UFTM), Uberaba, MG, Brazil
| | - Siomar C Soares
- Department of Immunology, Microbiology and Parasitology, Institute of Biological Sciences and Natural Sciences, Federal University of Triângulo Mineiro (UFTM), Uberaba, MG, Brazil.
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