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1.
Infect Immun ; 83(6): 2275-89, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25802057

RESUMO

An effective mechanism for introduction of phenotypic diversity within a bacterial population exploits changes in the length of repetitive DNA elements located within gene promoters. This phenomenon, known as phase variation, causes rapid activation or silencing of gene expression and fosters bacterial adaptation to new or changing environments. Phase variation often occurs in surface-exposed proteins, and in Treponema pallidum subsp. pallidum, the syphilis agent, it was reported to affect transcription of three putative outer membrane protein (OMP)-encoding genes. When the T. pallidum subsp. pallidum Nichols strain genome was initially annotated, the TP0126 open reading frame was predicted to include a poly(G) tract and did not appear to have a predicted signal sequence that might suggest the possibility of its being an OMP. Here we show that the initial annotation was incorrect, that this poly(G) is instead located within the TP0126 promoter, and that it varies in length in vivo during experimental syphilis. Additionally, we show that TP0126 transcription is affected by changes in the poly(G) length consistent with regulation by phase variation. In silico analysis of the TP0126 open reading frame based on the experimentally identified transcriptional start site shortens this hypothetical protein by 69 amino acids, reveals a predicted cleavable signal peptide, and suggests structural homology with the OmpW family of porins. Circular dichroism of recombinant TP0126 supports structural homology to OmpW. Together with the evidence that TP0126 is fully conserved among T. pallidum subspecies and strains, these data suggest an important role for TP0126 in T. pallidum biology and syphilis pathogenesis.


Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Regulação Bacteriana da Expressão Gênica/fisiologia , Guanosina/química , Transcrição Gênica , Treponema pallidum/metabolismo , Animais , Proteínas da Membrana Bacteriana Externa/química , Proteínas da Membrana Bacteriana Externa/genética , Sequência de Bases , Humanos , Imunidade Humoral , Modelos Moleculares , Conformação Proteica , Coelhos , Proteínas Recombinantes/metabolismo , Sífilis/microbiologia , Sítio de Iniciação de Transcrição
2.
Int J Infect Dis ; 143: 107041, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38583824

RESUMO

OBJECTIVES: The objective of this study was to explore the factors and outcomes associated with gestational syphilis in Peru. METHODS: Women from the miscarriage, vaginal delivery, and C-section wards from a large maternity hospital in Lima with or without syphilis diagnosis were enrolled and their pregnancy outcomes compared. Maternal syphilis status using maternal blood and child serostatus using cord blood were determined by rapid plasma reagin (RPR) and rapid syphilis tests. The newborns' clinical records were used to determine congenital syphilis. RESULTS: A total of 340 women were enrolled, 197 were positive and 143 were negative for RPR/rapid syphilis tests. Antibody titers in sera from cord and maternal blood were comparable with RPR titers and were highly correlated (rho = 0.82, P <0.001). Young age (P = 0.009) and lower birth weight (P = 0.029) were associated with gestational syphilis. Of the women with gestational syphilis, 76% had received proper treatment. Mothers of all newborns with congenital syphilis also received appropriate treatment. Treatment of their sexual partners was not documented. CONCLUSIONS: Syphilis during pregnancy remains a major cause of the fetal loss and devastating effects of congenital syphilis in newborns.


Assuntos
Complicações Infecciosas na Gravidez , Sífilis Congênita , Sífilis , Humanos , Feminino , Gravidez , Peru/epidemiologia , Sífilis Congênita/epidemiologia , Sífilis Congênita/diagnóstico , Adulto , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/microbiologia , Estudos Prospectivos , Recém-Nascido , Sífilis/epidemiologia , Sífilis/diagnóstico , Adulto Jovem , Resultado da Gravidez/epidemiologia , Transmissão Vertical de Doenças Infecciosas , Sorodiagnóstico da Sífilis , Adolescente , Sangue Fetal
3.
J Bacteriol ; 195(4): 896-907, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23243302

RESUMO

Bacteria often respond to harmful environmental stimuli with the induction of extracytoplasmic function (ECF) sigma (σ) factors that in turn direct RNA polymerase to transcribe specific groups of response genes (or regulons) to minimize cellular damage and favor adaptation to the changed extracellular milieu. In Treponema pallidum subsp. pallidum, the agent of syphilis, the TP0092 gene is predicted to code for the pathogen's only annotated ECF σ factor, homologous to RpoE, known in Escherichia coli to control a key transduction pathway for maintenance of envelope homeostasis in response to external stress and cell growth. Here we have shown that TP0092 is highly transcribed during experimental syphilis. Furthermore, TP0092 transcription levels significantly increase as infection progresses toward immune clearance of the pathogen, suggesting a role for TP0092 in helping T. pallidum respond to harmful stimuli in the host environment. To investigate this hypothesis, we determined the TP0092 regulon at two different time points during infection using chromatin immunoprecipitation followed by high-throughput sequencing. A total of 22 chromosomal regions, all containing putative TP0092-binding sites and corresponding to as many T. pallidum genes, were identified. Noteworthy among them are the genes encoding desulfoferrodoxin and thioredoxin, involved in detoxification of reactive oxygen species (ROS). Because T. pallidum does not possess other enzymes for ROS detoxification, such as superoxide dismutase, catalase, or glutathione peroxidase, our results suggest that the TP0092 regulon is important in protecting the syphilis spirochete from damage caused by ROS produced at the site of infection during the inflammatory response.


Assuntos
Regulação Bacteriana da Expressão Gênica/fisiologia , Regulon/fisiologia , Fator sigma/genética , Sífilis/microbiologia , Sífilis/patologia , Treponema pallidum/fisiologia , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Membrana Celular , Imunoprecipitação da Cromatina , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , Humanos , RNA Bacteriano/genética , RNA Bacteriano/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Coelhos , Reação em Cadeia da Polimerase em Tempo Real , Fator sigma/metabolismo
4.
J Bacteriol ; 194(16): 4208-25, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22661689

RESUMO

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


Assuntos
Variação Antigênica , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Porinas/genética , Porinas/imunologia , Treponema/genética , Treponema/imunologia , Sequência Conservada , DNA Bacteriano/química , DNA Bacteriano/genética , Genoma Bacteriano , Dados de Sequência Molecular , Mutagênese Insercional , Polimorfismo Genético , Análise de Sequência de DNA , Deleção de Sequência , Homologia de Sequência , Sintenia , Treponema/classificação
5.
J Immunol ; 184(7): 3822-9, 2010 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-20190145

RESUMO

Pathogens that cause chronic infections often employ antigenic variation to evade the immune response and persist in the host. In Treponema pallidum (T. pallidum), the causative agent of syphilis, the TprK Ag undergoes variation of seven V regions (V1-V7) by nonreciprocal recombination of silent donor cassettes with the tprK expression site. These V regions are the targets of the host humoral immune response during experimental infection. The present study addresses the causal role of the acquired immune response in the selection of TprK variants in two ways: 1) by investigating TprK variants arising in immunocompetent versus immunosuppressed hosts; and 2) by investigating the effect of prior specific immunization on selection of TprK variants during infection. V region diversity, particularly in V6, accumulates more rapidly in immunocompetent rabbits than in pharmacologically immunosuppressed rabbits (treated with weekly injections of methylprednisolone acetate). In a complementary experiment, rabbits preimmunized with V6 region synthetic peptides had more rapid accumulation of V6 variant treponemes than control rabbits. These studies demonstrate that the host immune response selects against specific TprK epitopes expressed on T. pallidum, resulting in immune selection of new TprK variants during infection, confirming a role for antigenic variation in syphilis.


Assuntos
Variação Antigênica/genética , Proteínas de Bactérias/genética , Porinas/genética , Sífilis/genética , Sequência de Aminoácidos , Animais , Anticorpos Antibacterianos/imunologia , Variação Antigênica/imunologia , Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Sequência de Bases , Modelos Animais de Doenças , Dados de Sequência Molecular , Porinas/imunologia , RNA Mensageiro/análise , Coelhos , Recombinação Genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sífilis/imunologia , Treponema pallidum/genética , Treponema pallidum/imunologia
6.
J Infect Dis ; 202(9): 1380-8, 2010 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-20868271

RESUMO

BACKGROUND: Strain typing is a tool for determining the diversity and epidemiology of infections. METHODS: Treponema pallidum DNA was isolated from 158 patients with syphilis from the United States, China, Ireland, and Madagascar and from 15 T. pallidum isolates. Six typing targets were assessed: (1) the number of 60­bp repeats in the acidic repeat protein gene, (2) restriction fragment length polymorphism (RFLP) analysis of T. pallidum repeat (tpr) subfamily II genes, (3) RFLP analysis of the tprC gene, (4) determination of tprD allele in the tprD gene locus, (5) the presence of a 51­bp insertion between tp0126 and tp0127, and (6) sequence analysis of an 84­bp region of tp0548. The combination of targets 1 and 2 comprises the Centers for Disease Control and Prevention (CDC) T. pallidum subtyping method. RESULTS: Adding sequence analysis of tp0548 to the CDC method yielded the most discriminating typing system. Twenty­five strain types were identified and designated as "CDC subtype/tp0548 sequence type." Type 14d/f was found in samples from 5 of 6 locations. In Seattle, Washington, strain types changed from 1999 through 2008 (P < .001). Twenty­one (50%) of 42 patients infected with type 14d/f had neurosyphilis compared with 10 (24%) of 41 patients infected with any of the other types combined (P = .02). CONCLUSION: We describe an enhanced T. pallidum strain typing system that shows biological and clinical relevance.


Assuntos
Técnicas de Tipagem Bacteriana , Impressões Digitais de DNA , Polimorfismo Genético , Sífilis/microbiologia , Treponema pallidum/classificação , Treponema pallidum/isolamento & purificação , Proteínas de Bactérias/genética , China , DNA Bacteriano/genética , Feminino , Humanos , Irlanda , Madagáscar , Masculino , Epidemiologia Molecular/métodos , Análise de Sequência de DNA , Estados Unidos
7.
J Bacteriol ; 192(10): 2645-6, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20348263

RESUMO

In syphilis research, the Nichols strain of Treponema pallidum, isolated in 1912, has been the most widely studied. Recently, important differences among T. pallidum strains emerged; therefore, we sequenced and annotated the Chicago strain genome to facilitate and encourage the use of this strain in studying the pathogenesis of syphilis.


Assuntos
Genoma Bacteriano/genética , Treponema pallidum/genética , Dados de Sequência Molecular
8.
Mol Microbiol ; 72(5): 1087-99, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19432808

RESUMO

Transcriptional regulation in Treponema pallidum ssp. pallidum is poorly understood, primarily because this organism cannot be cultivated in vitro or genetically manipulated. We have recently shown a phase variation mechanism controlling transcription initiation of Subfamily II tpr (T. pallidumrepeat) genes (tprE, tprG and tprJ), a group of virulence factor candidates. Furthermore, the same study suggested that additional mechanisms might influence the level of transcription of these tprs. The T. pallidum genome sequence has revealed a few open reading frames with similarity to known bacterial transcription factors, including four catabolite activator protein homologues. In this work, sequences matching the Escherichia coli cAMP receptor protein (CRP) binding motif were identified in silico upstream of tprE, tprG and tprJ. Using elecrophoretic mobility shift assay and DNaseI footprinting assay, recombinant TP0262, a T. pallidum CRP homologue, was shown to bind specifically to amplicons obtained from the tpr promoters containing putative CRP binding motifs. Using a heterologous reporter system, binding of TP0262 to these promoters was shown to either increase (tprE and tprJ) or decrease (tprG) tpr promoter activity. This is the first characterization of a T. pallidum transcriptional modulator that influences tpr promoter activity.


Assuntos
Proteínas de Bactérias/genética , Proteína Receptora de AMP Cíclico/genética , Regiões Promotoras Genéticas , Treponema pallidum/genética , Proteínas de Bactérias/metabolismo , Sequência de Bases , Clonagem Molecular , Proteína Receptora de AMP Cíclico/metabolismo , Pegada de DNA , DNA Bacteriano/genética , Ensaio de Desvio de Mobilidade Eletroforética , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Dados de Sequência Molecular , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transcrição Gênica , Treponema pallidum/metabolismo
9.
Vaccine ; 37(13): 1807-1818, 2019 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-30797635

RESUMO

BACKGROUND: Syphilis is resurgent in many developed countries and still prevalent in developing nations. Current and future control campaigns would benefit from the development of a vaccine, but although promising vaccine candidates were identified among the putative surface-exposed integral outer membrane proteins of the syphilis spirochete, immunization experiments in the rabbit model using recombinant antigens have failed to fully protect animals upon infectious challenge. We speculated that such recombinant immunogens, purified under denaturing conditions from Escherichia coli prior to immunization might not necessarily harbor their original structure, and hypothesized that enhanced protection would result from performing similar immunization/challenge experiments with native antigens. METHODS: To test our hypothesis, we engineered non-infectious Borrelia burgdorferi strains to express the tp0897 (tprK) and tp0435 genes of Treponema pallidum subsp. pallidum and immunized two groups of rabbits by injecting recombinant strains intramuscularly with no adjuvant. TprK is a putative integral outer membrane protein of the syphilis agent, while tp0435 encodes the highly immunogenic T. pallidum 17-kDa lipoprotein, a periplasmic antigen that was also shown on the pathogen surface. Following development of a specific host immune response to these antigens as the result of immunization, animals were challenged by intradermal inoculation of T. pallidum. Cutaneous lesion development was monitored and treponemal burden within lesions were assessed by dark-field microscopy and RT-qPCR, in comparison to control rabbits. RESULTS: Partial protection was observed in rabbits immunized with B. burgdorferi expressing TprK while immunity to Tp0435 was not protective. Analysis of the humoral response to TprK antigen suggested reactivity to conformational epitopes. CONCLUSIONS: Immunization with native antigens might not be sufficient to obtain complete protection to infection. Nonetheless we showed that non-infectious B. burgdorferi can be an effective carrier to deliver and elicit a specific host response to T. pallidum antigens to assess the efficacy of syphilis vaccine candidates.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Borrelia burgdorferi/genética , Expressão Gênica , Porinas/imunologia , Sífilis/prevenção & controle , Treponema pallidum/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Vacinas Bacterianas/genética , Ensaio de Imunoadsorção Enzimática , Epitopos/química , Epitopos/imunologia , Imunofluorescência , Imunidade Celular , Imunização , Espectrometria de Massas , Camundongos , Peptídeos/síntese química , Peptídeos/imunologia , Porinas/química , Porinas/genética , Coelhos , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Sífilis/imunologia , Sífilis/patologia , Treponema pallidum/genética
10.
BMC Med Educ ; 8: 1, 2008 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-18194533

RESUMO

BACKGROUND: New technologies that emerge at the interface of computational and biomedical science could drive new advances in global health, therefore more training in technology is needed among health care workers. To assess the potential for informatics training using an approach designed to foster interaction at this interface, the University of Washington and the Universidad Peruana Cayetano Heredia developed and assessed a one-week course that included a new Bioinformatics (BIO) track along with an established Medical/Public Health Informatics track (MI) for participants in Peru. METHODS: We assessed the background of the participants, and measured the knowledge gained by track-specific (MI or BIO) 30-minute pre- and post-tests. Participants' attitudes were evaluated both by daily evaluations and by an end-course evaluation. RESULTS: Forty-three participants enrolled in the course - 20 in the MI track and 23 in the BIO track. Of 20 questions, the mean % score for the MI track increased from 49.7 pre-test (standard deviation or SD = 17.0) to 59.7 (SD = 15.2) for the post-test (P = 0.002, n = 18). The BIO track mean score increased from 33.6 pre-test to 51.2 post-test (P < 0.001, n = 21). Most comments (76%) about any aspect of the course were positive. The main perceived strength of the course was the quality of the speakers, and the main perceived weakness was the short duration of the course. Overall, the course acceptability was very good to excellent with a rating of 4.1 (scale 1-5), and the usefulness of the course was rated as very good. Most participants (62.9%) expressed a positive opinion about having had the BIO and MI tracks come together for some of the lectures. CONCLUSION: Pre- and post-test results and the positive evaluations by the participants indicate that this first joint Bioinformatics and Medical/Public Health Informatics (MI and BIO) course was a success.


Assuntos
Biologia Computacional/educação , Currículo , Conhecimentos, Atitudes e Prática em Saúde , Internacionalidade , Informática Médica/educação , Saúde Pública/educação , Adulto , Coleta de Dados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Educacionais , Peru , Fatores de Tempo , Estados Unidos
11.
PLoS One ; 13(8): e0202619, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30130365

RESUMO

Treponema pallidum subsp. pallidum (TPA) is the infectious agent of syphilis, a disease that infects more than 5 million people annually. Since TPA is an uncultivable bacterium, most of the information on TPA genetics comes from genome sequencing and molecular typing studies. This study presents the first complete TPA genome (without sequencing gaps) of clinical isolate (UZ1974), which was obtained directly from clinical material, without multiplication in rabbits. Whole genome sequencing was performed using a newly developed Anti-Treponemal Antibody Enrichment technique combined with previously reported Pooled Segment Genome Sequencing. We identified the UW074B genome, isolated from a sample previously propagated in rabbits, to be the closest relative of the UZ1974 genome and calculated the TPA mutation rate as 2.8 x 10(-10) per site per generation.


Assuntos
Genoma Bacteriano/genética , Sífilis/genética , Treponema pallidum/genética , Sequenciamento Completo do Genoma , Animais , Variação Genética , Humanos , Taxa de Mutação , Filogenia , Coelhos , Análise de Sequência de DNA , Sífilis/microbiologia , Treponema pallidum/patogenicidade
12.
FEMS Immunol Med Microbiol ; 51(2): 289-301, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17683506

RESUMO

In Treponema pallidum, homopolymeric guanosine repeats of varying length are present upstream of both Subfamily I (tprC, D, F and I) and II (tprE, G and J) tpr genes, a group of potential virulence factors, immediately upstream of the +1 nucleotide. To investigate the influence of these poly-G sequences on promoter activity, tprE, G, J, F and I promoter regions containing homopolymeric tracts with different numbers of Gs, the ribosomal binding site and start codon were cloned in frame with the green fluorescent protein reporter gene (GFP), and promoter activity was measured both as fluorescence emission from Escherichia coli cultures transformed with the different plasmid constructs and using quantitative RT-PCR. For tprJ, G and E-derived clones, fluorescence was significantly higher with constructs containing eight Gs or fewer, while plasmids containing the same promoters with none or more Gs gave modest or no signal above the background. In contrast, tprF/I-derived clones induced similar levels of fluorescence regardless of the number of Gs within the promoter. GFP mRNA quantification showed that all of the promoters induced measurable transcription of the GFP gene; however, only for Subfamily II promoters was message synthesis inversely correlated to the number of Gs in the construct.


Assuntos
Proteínas da Membrana Bacteriana Externa/biossíntese , Proteínas da Membrana Bacteriana Externa/genética , Regiões Promotoras Genéticas , Sequências Repetitivas de Ácido Nucleico/genética , Treponema pallidum/genética , Treponema pallidum/metabolismo , Fusão Gênica Artificial , Sequência de Bases , DNA Bacteriano/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Fluorescência , Genes Reporter , Proteínas de Fluorescência Verde/análise , Proteínas de Fluorescência Verde/genética , Dados de Sequência Molecular , RNA Bacteriano/biossíntese , RNA Mensageiro/biossíntese , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos
13.
Sci Rep ; 6: 25593, 2016 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-27161310

RESUMO

The ability of Treponema pallidum, the syphilis spirochete to colonize various tissues requires the presence of surface-exposed adhesins that have been difficult to identify due to the inability to culture and genetically manipulate T. pallidum. Using a Borrelia burgdorferi-based heterologous system and gain-in-function approach, we show for the first time that a highly immunogenic lipoprotein TP0435 can be differentially processed into multiple isoforms with one variant stochastically displayed on the spirochete surface. TP0435 was previously believed to be exclusively located in T. pallidum periplasm. Furthermore, non-adherent B. burgdorferi strain expressing TP0435 acquires the ability to bind to a variety of host cells including placental cells and exhibits slow opsonophagocytosis in vitro similar to poor ex vivo phagocytosis of T. pallidum by host macrophages reported previously. This phenomenon of production of both surface and periplasmic immunogenic lipoprotein isoforms has possible implications in immune evasion of the obligate pathogen T. pallidum during infection.


Assuntos
Proteínas de Bactérias/imunologia , Borrelia burgdorferi/imunologia , Proteínas de Transporte/imunologia , Lipoproteínas/imunologia , Proteínas de Membrana/imunologia , Periplasma/imunologia , Animais , Aderência Bacteriana/genética , Aderência Bacteriana/imunologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Borrelia burgdorferi/genética , Borrelia burgdorferi/metabolismo , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Células HEK293 , Humanos , Lipoproteínas/genética , Lipoproteínas/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos BALB C , Periplasma/metabolismo , Fagocitose/imunologia , Isoformas de Proteínas/genética , Isoformas de Proteínas/imunologia , Isoformas de Proteínas/metabolismo , Transgenes/genética , Transgenes/imunologia , Treponema pallidum/genética , Treponema pallidum/imunologia , Treponema pallidum/metabolismo
14.
Nat Microbiol ; 2: 16245, 2016 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-27918528

RESUMO

The abrupt onslaught of the syphilis pandemic that started in the late fifteenth century established this devastating infectious disease as one of the most feared in human history1. Surprisingly, despite the availability of effective antibiotic treatment since the mid-twentieth century, this bacterial infection, which is caused by Treponema pallidum subsp. pallidum (TPA), has been re-emerging globally in the last few decades with an estimated 10.6 million cases in 2008 (ref. 2). Although resistance to penicillin has not yet been identified, an increasing number of strains fail to respond to the second-line antibiotic azithromycin3. Little is known about the genetic patterns in current infections or the evolutionary origins of the disease due to the low quantities of treponemal DNA in clinical samples and difficulties in cultivating the pathogen4. Here, we used DNA capture and whole-genome sequencing to successfully interrogate genome-wide variation from syphilis patient specimens, combined with laboratory samples of TPA and two other subspecies. Phylogenetic comparisons based on the sequenced genomes indicate that the TPA strains examined share a common ancestor after the fifteenth century, within the early modern era. Moreover, most contemporary strains are azithromycin-resistant and are members of a globally dominant cluster, named here as SS14-Ω. The cluster diversified from a common ancestor in the mid-twentieth century subsequent to the discovery of antibiotics. Its recent phylogenetic divergence and global presence point to the emergence of a pandemic strain cluster.


Assuntos
Variação Genética , Genótipo , Pandemias , Sífilis/epidemiologia , Sífilis/microbiologia , Treponema pallidum/classificação , Treponema pallidum/genética , Antibacterianos/farmacologia , Azitromicina/farmacologia , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Farmacorresistência Bacteriana , Evolução Molecular , Genoma Bacteriano , Saúde Global , Humanos , Epidemiologia Molecular , Filogenia , Análise de Sequência de DNA , Treponema pallidum/isolamento & purificação
15.
Sex Health ; 12(2): 141-7, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25844928

RESUMO

Pathogens adapt and evolve in response to pressures exerted by host environments, leading to generation of genetically diverse variants. Treponema pallidum subspecies pallidum displays a substantial amount of interstrain diversity. These variants have been identified in various parts of the world, indicating transmission linkage between geographical regions. Genotyping is based on molecular characterisation of various loci in the syphilis treponeme genome, but still require further development and continued research, as new bacterial types are continually being detected. The goal for studying the molecular epidemiology of Treponema pallidum variants is the global monitoring of the transmission of genetically distinct organisms with different drug sensitivities and, potentially, different virulence proprieties.

16.
Microbes Infect ; 6(8): 725-37, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15207819

RESUMO

A 12-membered Treponema pallidum repeat (Tpr) protein family has been identified in T. pallidum subsp. pallidum, the causative agent of syphilis. The subfamily I Tpr proteins (C, D, F, and I) possess conserved sequence at the N- and C-termini and central regions that differentiate the members. These proteins may be important in the immune response during syphilis infection and in protective immunity. Strong antibody responses have been observed toward some of the subfamily I Tpr proteins during infection with different syphilis isolates. Some sequence variation has also been identified in one subfamily I Tpr member, TprD, among T. pallidum subsp. pallidum isolates. In this study, we examined sequences in the remaining subfamily I Tpr proteins among strains. Both TprF and TprI were conserved among T. pallidum subsp. pallidum isolates. While some heterogeneity was identified in TprC. We further examined the immune response and protective capacity of TprF protein in this paper. We demonstrate that the N-terminal conserved region of the subfamily I Tpr proteins elicits strong antibody and T-cell responses during infection, and immunization with this region attenuates syphilitic lesion development upon infectious challenge.


Assuntos
Variação Antigênica , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/imunologia , Sífilis Cutânea/imunologia , Treponema pallidum/genética , Treponema pallidum/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Antibacterianos/sangue , Contagem de Colônia Microbiana , Sequência Conservada , DNA Bacteriano/química , DNA Bacteriano/isolamento & purificação , Modelos Animais de Doenças , Genes Bacterianos , Imunização , Ativação Linfocitária , Dados de Sequência Molecular , Polimorfismo Genético , Coelhos , Alinhamento de Sequência , Análise de Sequência de DNA , Sífilis Cutânea/microbiologia , Sífilis Cutânea/patologia
17.
Genome Announc ; 2(2)2014 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-24744342

RESUMO

Using the rabbit model of syphilis, the Sea81-4 strain of Treponema pallidum subsp. pallidum has been found to be more likely than other strains to invade the central nervous system (CNS). To identify possible explanations for this important phenotype at the genomic level, we sequenced the Sea81-4 strain genome.

18.
PLoS Negl Trop Dis ; 8(11): e3261, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25375929

RESUMO

BACKGROUND: T. pallidum subsp. endemicum (TEN) is the causative agent of bejel (also known as endemic syphilis). Clinical symptoms of syphilis and bejel are overlapping and the epidemiological context is important for correct diagnosis of both diseases. In contrast to syphilis, caused by T. pallidum subsp. pallidum (TPA), TEN infections are usually spread by direct contact or contaminated utensils rather than by sexual contact. Bejel is most often seen in western Africa and in the Middle East. The strain Bosnia A was isolated in 1950 in Bosnia, southern Europe. METHODOLOGY/PRINCIPAL FINDINGS: The complete genome of the Bosnia A strain was amplified and sequenced using the pooled segment genome sequencing (PSGS) method and a combination of three next-generation sequencing techniques (SOLiD, Roche 454, and Illumina). Using this approach, a total combined average genome coverage of 513× was achieved. The size of the Bosnia A genome was found to be 1,137,653 bp, i.e. 1.6-2.8 kbp shorter than any previously published genomes of uncultivable pathogenic treponemes. Conserved gene synteny was found in the Bosnia A genome compared to other sequenced syphilis and yaws treponemes. The TEN Bosnia A genome was distinct but very similar to the genome of yaws-causing T. pallidum subsp. pertenue (TPE) strains. Interestingly, the TEN Bosnia A genome was found to contain several sequences, which so far, have been uniquely identified only in syphilis treponemes. CONCLUSIONS/SIGNIFICANCE: The genome of TEN Bosnia A contains several sequences thought to be unique to TPA strains; these sequences very likely represent remnants of recombination events during the evolution of TEN treponemes. This finding emphasizes a possible role of repeated horizontal gene transfer between treponemal subspecies in shaping the Bosnia A genome.


Assuntos
Genoma Bacteriano/genética , Sífilis/microbiologia , Treponema pallidum/genética , Bouba/microbiologia , Sequência de Bases , Bósnia e Herzegóvina , Análise por Conglomerados , Transferência Genética Horizontal , Humanos , Dados de Sequência Molecular , Alinhamento de Sequência , Análise de Sequência de DNA , Especificidade da Espécie , Sintenia , Treponema pallidum/classificação
19.
PLoS Negl Trop Dis ; 7(5): e2222, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23696912

RESUMO

BACKGROUND: The pathogenic non-cultivable treponemes include three subspecies of Treponema pallidum (pallidum, pertenue, endemicum), T. carateum, T. paraluiscuniculi, and the unclassified Fribourg-Blanc treponeme (Simian isolate). These treponemes are morphologically indistinguishable and antigenically and genetically highly similar, yet cross-immunity is variable or non-existent. Although all of these organisms cause chronic, multistage skin and systemic disease, they have historically been classified by mode of transmission, clinical presentations and host ranges. Whole genome studies underscore the high degree of sequence identity among species, subspecies and strains, pinpointing a limited number of genomic regions for variation. Many of these "hot spots" include members of the tpr gene family, composed of 12 paralogs encoding candidate virulence factors. We hypothesize that the distinct clinical presentations, host specificity, and variable cross-immunity might reside on virulence factors such as the tpr genes. METHODOLOGY/PRINCIPAL FINDINGS: Sequence analysis of 11 tpr loci (excluding tprK) from 12 strains demonstrated an impressive heterogeneity, including SNPs, indels, chimeric genes, truncated gene products and large deletions. Comparative analyses of sequences and 3D models of predicted proteins in Subfamily I highlight the striking co-localization of discrete variable regions with predicted surface-exposed loops. A hallmark of Subfamily II is the presence of chimeric genes in the tprG and J loci. Diversity in Subfamily III is limited to tprA and tprL. CONCLUSIONS/SIGNIFICANCE: An impressive sequence variability was found in tpr sequences among the Treponema isolates examined in this study, with most of the variation being consistent within subspecies or species, or between syphilis vs. non-syphilis strains. Variability was seen in the pallidum subspecies, which can be divided into 5 genogroups. These findings support a genetic basis for the classification of these organisms into their respective subspecies and species. Future functional studies will determine whether the identified genetic differences relate to cross-immunity, clinical differences, or host ranges.


Assuntos
Proteínas da Membrana Bacteriana Externa/genética , Variação Genética , Mutação , Treponema/classificação , Treponema/genética , Infecções por Treponema/microbiologia , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Filogenia , Conformação Proteica , Análise de Sequência de DNA , Homologia de Sequência , Treponema/isolamento & purificação
20.
PLoS Negl Trop Dis ; 6(6): e1698, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22720110

RESUMO

In the rabbit model of syphilis, infection phenotypes associated with the Nichols and Chicago strains of Treponema pallidum (T. pallidum), though similar, are not identical. Between these strains, significant differences are found in expression of, and antibody responses to some candidate virulence factors, suggesting the existence of functional genetic differences between isolates. The Chicago strain genome was therefore sequenced and compared to the Nichols genome, available since 1998. Initial comparative analysis suggested the presence of 44 single nucleotide polymorphisms (SNPs), 103 small (≤3 nucleotides) indels, and 1 large (1204 bp) insertion in the Chicago genome with respect to the Nichols genome. To confirm the above findings, Sanger sequencing was performed on most loci carrying differences using DNA from Chicago and the Nichols strain used in the original T. pallidum genome project. A majority of the previously identified differences were found to be due to errors in the published Nichols genome, while the accuracy of the Chicago genome was confirmed. However, 20 SNPs were confirmed between the two genomes, and 16 (80.0%) were found in coding regions, with all being of non-synonymous nature, strongly indicating action of positive selection. Sequencing of 16 genomic loci harboring SNPs in 12 additional T. pallidum strains, (SS14, Bal 3, Bal 7, Bal 9, Sea 81-3, Sea 81-8, Sea 86-1, Sea 87-1, Mexico A, UW231B, UW236B, and UW249C), was used to identify "Chicago-" or "Nichols -specific" differences. All but one of the 16 SNPs were "Nichols-specific", with Chicago having identical sequences at these positions to almost all of the additional strains examined. These mutations could reflect differential adaptation of the Nichols strain to the rabbit host or pathoadaptive mutations acquired during human infection. Our findings indicate that SNPs among T. pallidum strains emerge under positive selection and, therefore, are likely to be functional in nature.


Assuntos
Evolução Molecular , Seleção Genética , Sífilis/microbiologia , Treponema pallidum/classificação , Treponema pallidum/genética , Adaptação Biológica , Animais , Sequência de Bases , Biologia Computacional , DNA Bacteriano/genética , Modelos Animais de Doenças , Genoma Bacteriano , Humanos , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único , Coelhos , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico
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