Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Sex Transm Dis ; 49(11): 786-789, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-35404912

RESUMO

ABSTRACT: Between 2001 and 2020, 54 LGV cases were diagnosed in a sexually transmitted disease clinic in Lisbon, most in men who have sex with men (87%), HIV negative (63%), from the anorectal mucosa (72.2%). Cases among heterosexuals were also identified (13%). Surveillance programs irrespective of sexual orientation and HIV status are needed to avoid the morbidity associated with LGV.


Assuntos
Infecções por HIV , Linfogranuloma Venéreo , Minorias Sexuais e de Gênero , Chlamydia trachomatis , Feminino , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Homossexualidade Masculina , Humanos , Linfogranuloma Venéreo/complicações , Linfogranuloma Venéreo/diagnóstico , Linfogranuloma Venéreo/epidemiologia , Masculino
2.
Cell Mol Biol (Noisy-le-grand) ; 68(7): 1-8, 2022 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-36495527

RESUMO

A comparative overview of the global gene expression levels of S. agalactiae reference strain NEM316 at the exponential growth phase was done through RNA-sequencing. The expression levels of 47 genes potentially linked to virulence evidenced that: i) the major nuclease, GBS_RS03720/gbs0661, presented higher mean expression values than the remainder of DNase genes; ii) the genetic pilus island PI-2a genes presented higher mean expression values than PI-1 coding genes; and, iii) three virulence-associated genes ranked among the top-100 most expressed genes (GBS_RS07760, GBS_RS09445 and GBS_RS03485). Among this top-100, genes encoding proteins involved in "Translation, ribosomal structure and biogenesis" represented 46%. Curiously, genes with no assigned function were grouped in the category of highly expressed genes. As very little is known about the molecular mechanisms behind the release of DNases, preliminary assays were developed to understand whether direct DNA exposure would affect gene expression at the exponential growth phase. No differentially expressed genes were detected, indicating that follow-up studies are needed to disclose the complex molecular pathways (and stimuli) triggering the release of DNases. In general, our insights on the global expression levels of NEM316 at exponential growth phase with and without DNA exposure should open novel research lines to decipher S. agalactiae puzzling adaptation and virulence mechanisms, such as DNase production.


Assuntos
Infecções Estreptocócicas , Streptococcus agalactiae , Humanos , Streptococcus agalactiae/genética , Streptococcus agalactiae/metabolismo , Fímbrias Bacterianas/genética , Fímbrias Bacterianas/metabolismo , Virulência/genética , Perfilação da Expressão Gênica , Infecções Estreptocócicas/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
3.
Euro Surveill ; 27(22)2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35656830

RESUMO

Up to 27 May 2022, Portugal has detected 96 confirmed cases of monkeypox. We describe 27 confirmed cases (median age: 33 years (range: 22-51); all males), with an earliest symptom onset date of 29 April. Almost all cases (n = 25) live in the Lisbon and Tagus Valley health region. Most cases were neither part of identified transmission chains, nor linked to travel or had contact with symptomatic persons or with animals, suggesting the possible previously undetected spread of monkeypox.


Assuntos
Monkeypox virus , Mpox , Surtos de Doenças , Humanos , Masculino , Mpox/diagnóstico , Mpox/epidemiologia , Monkeypox virus/genética , Portugal/epidemiologia , Viagem
5.
Sex Transm Dis ; 47(11): e54-e56, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32530860

RESUMO

We report a multidrug-resistant Neisseria gonorrhoeae exhibiting resistance to ceftriaxone and cefixime, isolated in Portugal in 2019. Whole-genome sequencing was performed for typing and identification of genetic determinants of antimicrobial resistance. Because of its antimicrobial susceptibility profile, awareness should be raised for the circulation of this strain.


Assuntos
Antibacterianos/farmacologia , Cefixima/farmacologia , Ceftriaxona/farmacologia , Gonorreia/tratamento farmacológico , Neisseria gonorrhoeae/efeitos dos fármacos , Adulto , Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana Múltipla , Gonorreia/diagnóstico , Humanos , Masculino , Testes de Sensibilidade Microbiana , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/isolamento & purificação , Portugal
6.
Eur J Clin Microbiol Infect Dis ; 39(9): 1761-1770, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32494956

RESUMO

Neisseria gonorrhoeae antimicrobial resistance (AMR) and gonorrhea disease burden remain major public health concerns worldwide. To contribute to the supranational demands to monitor and manage the spread of antimicrobial-resistant N. gonorrhoeae, the Portuguese NIH promoted the creation of the National Laboratory Network for Neisseria gonorrhoeae Collection (PTGonoNet). The present study reports the N. gonorrhoeae major AMR trends observed from 2003 up to 2018. All isolates described in the present study constitute the opportunistic ongoing N. gonorrhoeae isolate collection supported by the National Reference Laboratory for Sexually Transmitted Infections of the Portuguese NIH, enrolling strains isolated in 35 different public and private laboratories. Minimum inhibitory concentrations were determined using E-tests for azithromycin, benzylpenicillin, cefixime, ceftriaxone, ciprofloxacin, gentamicin, spectinomycin and tetracycline. Molecular typing was determined using NG-MAST. AMR data of 2596 country-spread isolates show that 87.67% of all N. gonorrhoeae isolates presented decreased susceptibility to at least one antimicrobial. A continuous decreased susceptibility and resistance to penicillin, tetracycline and ciprofloxacin can be observed along the years. However, no decreased susceptibility to cephalosporins was observed until 2018, while for azithromycin, this was always low. The most common observed NG-MAST genogroups were G1407, G7445, G225, G2, and G1034. This study evidences the advantages of a nationwide collection of isolates and of centralized AMR testing to respond to supranational (EURO-GASP) requirements while providing unprecedented data on AMR in the context of 15 years of surveillance.


Assuntos
Antibacterianos/farmacologia , Gonorreia/epidemiologia , Neisseria gonorrhoeae/isolamento & purificação , Adolescente , Adulto , Criança , Demografia , Farmacorresistência Bacteriana , Feminino , Gonorreia/tratamento farmacológico , Gonorreia/microbiologia , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Epidemiologia Molecular , Neisseria gonorrhoeae/efeitos dos fármacos , Neisseria gonorrhoeae/genética , Portugal/epidemiologia , Manejo de Espécimes , Adulto Jovem
7.
BMC Infect Dis ; 19(1): 281, 2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30909883

RESUMO

BACKGROUND: Confidence in any diagnostic and antimicrobial susceptibility testing data is provided by appropriate and regular quality assurance (QA) procedures. In Europe, the European Gonococcal Antimicrobial Susceptibility Programme (Euro-GASP) has been monitoring the antimicrobial susceptibility in Neisseria gonorrhoeae since 2004. Euro-GASP includes an external quality assessment (EQA) scheme as an essential component for a quality-assured laboratory-based surveillance programme. Participation in the EQA scheme enables any problems with the performed antimicrobial susceptibility testing to be identified and addressed, feeds into the curricula of laboratory training organised by the Euro-GASP network, and assesses the capacity of individual laboratories to detect emerging new, rare and increasing antimicrobial resistance phenotypes. Participant performance in the Euro-GASP EQA scheme over a 10 year period (2007 to 2016, no EQA in 2013) was evaluated. METHODS: Antimicrobial susceptibility category and MIC results from the first 5 years (2007-2011) of the Euro-GASP EQA were compared with the latter 5 years (2012-2016). These time periods were selected to assess the impact of the 2012 European Union case definitions for the reporting of antimicrobial susceptibility. RESULTS: Antimicrobial susceptibility category agreement in each year was ≥91%. Discrepancies in susceptibility categories were generally because the MICs for EQA panel isolates were on or very close to the susceptibility or resistance breakpoints. A high proportion of isolates tested over the 10 years were within one (≥90%) or two (≥97%) MIC log2 dilutions of the modal MIC, respectively. The most common method used was Etest on GC agar base. There was a shift to using breakpoints published by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) in the latter 5 years, however overall impact on the validity of results was limited, as the percentage categorical agreement and MIC concordance changed very little between the two five-year periods. CONCLUSIONS: The high level of comparability of results in this EQA scheme indicates that high quality data are produced by the Euro-GASP participants and gives confidence in susceptibility and resistance data generated by laboratories performing decentralised testing.


Assuntos
Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana/normas , Neisseria gonorrhoeae/efeitos dos fármacos , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão/normas , Farmacorresistência Bacteriana , Europa (Continente) , Laboratórios , Controle de Qualidade , Reprodutibilidade dos Testes
11.
Microb Pathog ; 104: 296-302, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28161356

RESUMO

Syphilis is the sexually transmitted disease caused by Treponema pallidum, a pathogen highly adapted to the human host. As a multistage disease, syphilis presents distinct clinical manifestations that pose different implications for diagnosis. Nevertheless, the inherent factors leading to diverse disease progressions are still unknown. We aimed to assess the association between treponemal loads and dissimilar disease outcomes, to better understand syphilis. We retrospectively analyzed 309 DNA samples distinct anatomic sites associated with particular syphilis manifestations. All samples had previously tested positive by a PCR-based diagnostic kit. An absolute quantitative real-time PCR procedure was used to precisely quantify the number of treponemal and human cells to determine T. pallidum loads in each sample. In general, lesion exudates presented the highest T. pallidum loads in contrast with blood-derived samples. Within the latter, a higher dispersion of T. pallidum quantities was observed for secondary syphilis. T. pallidum was detected in substantial amounts in 37 samples of seronegative individuals and in 13 cases considered as syphilis-treated. No association was found between treponemal loads and serological results or HIV status. This study suggests a scenario where syphilis may be characterized by: i) heterogeneous and high treponemal loads in primary syphilis, regardless of the anatomic site, reflecting dissimilar duration of chancres development and resolution; ii) high dispersion of bacterial concentrations in secondary syphilis, potentially suggesting replication capability of T. pallidum while in the bloodstream; and iii) bacterial evasiveness, either to the host immune system or antibiotic treatment, while remaining hidden in privileged niches. This work highlights the importance of using molecular approaches to study uncultivable human pathogens, such as T. pallidum, in the infection process.


Assuntos
Carga Bacteriana , Sífilis/microbiologia , Sífilis/patologia , Treponema pallidum/isolamento & purificação , Estudos Transversais , Feminino , Humanos , Masculino , Portugal , Reação em Cadeia da Polimerase em Tempo Real , Estudos Retrospectivos , Testes Sorológicos , Treponema pallidum/genética
12.
J Antimicrob Chemother ; 71(11): 3109-3116, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27432597

RESUMO

OBJECTIVES: To elucidate the genome-based epidemiology and phylogenomics of azithromycin-resistant (MIC >2 mg/L) Neisseria gonorrhoeae strains collected in 2009-14 in Europe and clarify the azithromycin resistance mechanisms. METHODS: Seventy-five azithromycin-resistant (MIC 4 to >256 mg/L) N. gonorrhoeae isolates collected in 17 European countries during 2009-14 were examined using antimicrobial susceptibility testing and WGS. RESULTS: Thirty-six N. gonorrhoeae multi-antigen sequence typing STs and five phylogenomic clades, including 4-22 isolates from several countries per clade, were identified. The azithromycin target mutation A2059G (Escherichia coli numbering) was found in all four alleles of the 23S rRNA gene in all isolates with high-level azithromycin resistance (n = 4; MIC ≥256 mg/L). The C2611T mutation was identified in two to four alleles of the 23S rRNA gene in the remaining 71 isolates. Mutations in mtrR and its promoter were identified in 43 isolates, comprising isolates within the whole azithromycin MIC range. No mutations associated with azithromycin resistance were found in the rplD gene or the rplV gene and none of the macrolide resistance-associated genes [mef(A/E), ere(A), ere(B), erm(A), erm(B), erm(C) and erm(F)] were identified in any isolate. CONCLUSIONS: Clonal spread of relatively few N. gonorrhoeae strains accounts for the majority of the azithromycin resistance (MIC >2 mg/L) in Europe. The four isolates with high-level resistance to azithromycin (MIC ≥256 mg/L) were widely separated in the phylogenomic tree and did not belong to any of the main clades. The main azithromycin resistance mechanisms were the A2059G mutation (high-level resistance) and the C2611T mutation (low- and moderate-level resistance) in the 23S rRNA gene.


Assuntos
Antibacterianos/farmacologia , Azitromicina/farmacologia , Farmacorresistência Bacteriana , Genótipo , Gonorreia/microbiologia , Neisseria gonorrhoeae/efeitos dos fármacos , Neisseria gonorrhoeae/genética , Adolescente , Adulto , Idoso , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Europa (Continente)/epidemiologia , Feminino , Genes Bacterianos , Genoma Bacteriano , Gonorreia/epidemiologia , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Epidemiologia Molecular , Neisseria gonorrhoeae/classificação , Neisseria gonorrhoeae/isolamento & purificação , Filogenia , RNA Ribossômico 23S/genética , Análise de Sequência de DNA , Adulto Jovem
13.
BMC Microbiol ; 14: 40, 2014 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-24533538

RESUMO

BACKGROUND: Chlamydia trachomatis is an obligate intracellular human pathogen causing ocular and urogenital infections that are a significant clinical and public health concern. This bacterium uses a type III secretion (T3S) system to manipulate host cells, through the delivery of effector proteins into their cytosol, membranes, and nucleus. In this work, we aimed to find previously unidentified C. trachomatis T3S substrates. RESULTS: We first analyzed the genome of C. trachomatis L2/434 strain for genes encoding mostly uncharacterized proteins that did not appear to possess a signal of the general secretory pathway and which had not been previously experimentally shown to be T3S substrates. We selected several genes with these characteristics and analyzed T3S of the encoding proteins using Yersinia enterocolitica as a heterologous system. We identified 23 C. trachomatis proteins whose first 20 amino acids were sufficient to drive T3S of the mature form of ß-lactamase TEM-1 by Y. enterocolitica. We found that 10 of these 23 proteins were also type III secreted in their full-length versions by Y. enterocolitica, providing additional support that they are T3S substrates. Seven of these 10 likely T3S substrates of C. trachomatis were delivered by Y. enterocolitica into host cells, further suggesting that they could be effectors. Finally, real-time quantitative PCR analysis of expression of genes encoding the 10 likely T3S substrates of C. trachomatis showed that 9 of them were clearly expressed during infection of host cells. CONCLUSIONS: Using Y. enterocolitica as a heterologous system, we identified 10 likely T3S substrates of C. trachomatis (CT053, CT105, CT142, CT143, CT144, CT161, CT338, CT429, CT656, and CT849) and could detect translocation into host cells of CT053, CT105, CT142, CT143, CT161, CT338, and CT429. Therefore, we revealed several C. trachomatis proteins that could be effectors subverting host cell processes.


Assuntos
Sistemas de Secreção Bacterianos , Chlamydia trachomatis/genética , Chlamydia trachomatis/metabolismo , Fatores de Virulência/metabolismo , Clonagem Molecular , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Expressão Gênica , Células HeLa , Humanos , Transporte Proteico , Yersinia enterocolitica/genética , Yersinia enterocolitica/metabolismo
14.
Int J STD AIDS ; 35(5): 379-388, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38166231

RESUMO

BACKGROUND: Men who have sex with men (MSM) are at risk for sexually transmitted infections (STIs), but more data on extragenital carriage are needed. AIM: We assessed the genital and extragenital prevalence of bacterial and other STIs in MSM in a Lisbon sexual health clinic. METHODS: We screened oral, anal, and urine samples of MSM visiting the GAT-CheckpointLX clinic June 2017-December 2021 for Chlamydia trachomatis (including lymphogranuloma venereum, LGV), Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis, Mycoplasma hominis, Ureaplasma urealyticum, and U. parvum. Ano-oro-genital lesions were tested for LGV, Treponema pallidum, and Herpes Simplex Virus. Blood was tested for HIV and T. pallidum antibodies. RESULTS: N. gonorrhoeae was found in 16.6% of the MSM followed by C. trachomatis (13.2%), M. genitalium (10.3%) and T. vaginalis (0.2%). The most frequent occurrence was anorectal (C. trachomatis, M. genitalium) and oral (N. gonorrhoeae). We found high carriage of U. urealyticum (36.1%) and M. hominis (22.1%). LGV was detected in 21.8% of chlamydia-positive anorectal swabs. Syphilis was detected in 22.6% of tested MSM, while 13.8% had HIV. Gonorrhoea and chlamydia were significantly more prevalent in MSM with concomitant HIV or syphilis. CONCLUSION: The substantial extragenital prevalence of bacterial STIs in MSM, and HIV and syphilis coinfections, suggest screening has value in identifying hidden carriage and in contributing for providing better care.


Assuntos
Doenças do Ânus , Infecções por Chlamydia , Gonorreia , Infecções por HIV , Linfogranuloma Venéreo , Infecções por Mycoplasma , Mycoplasma genitalium , Minorias Sexuais e de Gênero , Infecções Sexualmente Transmissíveis , Sífilis , Masculino , Humanos , Chlamydia trachomatis , Neisseria gonorrhoeae , Homossexualidade Masculina , Infecções por Mycoplasma/diagnóstico , Infecções Sexualmente Transmissíveis/epidemiologia , Gonorreia/diagnóstico , Infecções por HIV/epidemiologia , Infecções por Chlamydia/diagnóstico , Prevalência
15.
J Pers Med ; 13(7)2023 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-37511783

RESUMO

Sexually transmitted infections (STIs) constitute one of the leading causes of disease burden worldwide, leading to considerable morbidity, mortality, health expenditures, and stigma. Of note are the most common bacterial STIs, chlamydial and gonococcal infections, whose etiological agents are Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG), respectively. Despite being usually asymptomatic, in some cases these infections can be associated with long-term severe complications, such as pelvic inflammatory disease, chronic pelvic pain, infertility, ectopic pregnancy, and increased risk of other STIs acquisition. As the symptoms, when present, are usually similar in both infections, and in most of the cases these infections co-occur, the dual-test strategy, searching for both pathogens, should be preferred. In line with this, herein we focus on the main aspects of CT and NG infections, the clinical symptoms as well as the appropriate state-of-the-art diagnostic tests and treatment. Cost-effective strategies for controlling CT and NG infections worldwide are addressed. The treatment for both infections is based on antibiotics. However, the continuing global rise in the incidence of these infections, concomitantly with the increased risk of antibiotics resistance, leads to difficulties in their control, particularly in the case of NG infections. We also discuss the potential mechanism of tumorigenesis related to CT infections. The molecular bases of CT and NG infections are addressed, as they should provide clues for control or eradication, through the development of new drugs and/or effective vaccines against these pathogens.

16.
Front Physiol ; 14: 1212031, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37492638

RESUMO

Introduction: Medical education should promote the development of skills and abilities that can be applied to real-world work performance. The aim of this study is to evaluate technical and methodological knowledge, as well as physician-patient communication skills, as one of the most important transversal competencies that a good physician should acquire; all this in a reliable, accurate and objective way. Methods: We present a rubric specifically designed and implemented for the evaluation of specific and transversal competencies in the physiology practical sessions, during the second year of the medical degree. The assessment consists in two evaluation tests: 1) a theoretical test that consists of multiple-choice questions. Students must demonstrate that they have acquired adequate theoretical knowledge (specific competency "to know"); 2) a practical test, in which students are evaluated by the rubric through the simulation of a medical consultation. Thus, demonstrating their ability to execute/apply what they have learned in class (specific competency "to know how to do"). They are also evaluated on the transversal competencies that we call "communication with the patient" (transversal competency "to know how to be there") and "dealing with the patient" (transversal competency "to know how to be"). Results: We evaluated whether there were differences in the grades obtained by students when the transversal competencies were not assessed (academic years 2017-2018 and 2018-2019; n = 289), and when the transversal competencies were assessed by applying the rubric in the academic years 2019-2020, 2021-2022, and 2022-2023 (n = 526). Furthermore, we present a student perception that supports the use of clinical simulation and our rubric as a good method within the competency learning process. Discussion: The acquisition of these competencies, starting from the first courses of undergraduate education, helps to raise the students' awareness in the development of a more humanized medicine, allowing a better response to the patients' needs. Our rubric, which clearly indicate the performance criteria, have become an excellent method to carry out the assessment of competencies, both for students and teachers, since they allow to obtain clear evidence of the level of acquisition and application of knowledge.

17.
Artigo em Inglês | MEDLINE | ID: mdl-37835073

RESUMO

Mpox is a viral disease caused by the monkeypox virus, which marked the year of 2022 with a global outbreak. While previously considered to be a zoonosis of almost exclusive animal-to-human transmission, the current outbreak has been attributed to human-to-human transmission, particularly sexual transmission. As a new sexually transmissible disease, we studied the epidemiological and clinical features, as well as the concomitant occurrence of other sexually transmissible diseases, treatment approach, and outcome of our 291 patients, in the current outbreak. We found a total of 169 concomitant sexually transmissible infections of bacterial and viral origins, corresponding to 107 patients. Neisseria gonorrhoeae was the most common agent, particularly in the anal location. With this work, we emphasize the need for a thorough epidemiological and medical history, as well as a concomitant complete laboratorial screening for other STIs in patients with confirmed or suspected mpox.


Assuntos
Mpox , Animais , Humanos , Zoonoses , Instituições de Assistência Ambulatorial , Surtos de Doenças , Demografia
18.
Nat Med ; 29(10): 2509-2517, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37696933

RESUMO

Pathogen genome sequencing during epidemics enhances our ability to identify and understand suspected clusters and investigate their relationships. Here, we combine genomic and epidemiological data of the 2022 mpox outbreak to better understand early viral spread, diversification and transmission dynamics. By sequencing 52% of the confirmed cases in Portugal, we identified the mpox virus sublineages with the highest impact on case numbers and fitted them into a global context, finding evidence that several international sublineages probably emerged or spread early in Portugal. We estimated a 62% infection reporting rate and that 1.3% of the population of men who have sex with men in Portugal were infected. We infer the critical role played by sexual networks and superspreader gatherings, such as sauna attendance, in the dissemination of mpox virus. Overall, our findings highlight genomic epidemiology as a tool for the real-time monitoring and control of mpox epidemics, and can guide future vaccine policy in a highly susceptible population.


Assuntos
Mpox , Minorias Sexuais e de Gênero , Masculino , Humanos , Portugal/epidemiologia , Homossexualidade Masculina , Surtos de Doenças , Análise por Conglomerados
19.
J Bacteriol ; 194(23): 6574-85, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23042990

RESUMO

Chlamydia trachomatis is a human bacterial pathogen that multiplies only within an intracellular membrane-bound vacuole, the inclusion. C. trachomatis includes ocular and urogenital strains, usually causing infections restricted to epithelial cells of the conjunctiva and genital mucosa, respectively, and lymphogranuloma venereum (LGV) strains, which can infect macrophages and spread into lymph nodes. However, C. trachomatis genomes display >98% identity at the DNA level. In this work, we studied whether C. trachomatis Inc proteins, which have a bilobed hydrophobic domain that may mediate their insertion in the inclusion membrane, could be a factor determining these different types of infection and tropisms. Analyses of polymorphisms and phylogeny of 48 Inc proteins from 51 strains encompassing the three disease groups showed significant amino acid differences that were mainly due to variations between Inc proteins from LGV and ocular or urogenital isolates. Studies of the evolutionary dynamics of inc genes suggested that 10 of them are likely under positive selection and indicated that most nonsilent mutations are LGV specific. Additionally, real-time quantitative PCR analyses in prototype and clinical strains covering the three disease groups identified three inc genes with LGV-specific expression. We determined the transcriptional start sites of these genes and found LGV-specific nucleotides within their promoters. Thus, subtle variations in the amino acids of a subset of Inc proteins and in the expression of inc genes may contribute to the unique tropism and invasiveness of C. trachomatis LGV strains.


Assuntos
Chlamydia trachomatis/genética , Chlamydia trachomatis/patogenicidade , Linfogranuloma Venéreo/microbiologia , Polimorfismo Genético , Fatores de Virulência/genética , Chlamydia trachomatis/isolamento & purificação , DNA Bacteriano/química , DNA Bacteriano/genética , Evolução Molecular , Humanos , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Sítio de Iniciação de Transcrição , Transcrição Gênica , Tropismo
20.
Front Cell Infect Microbiol ; 12: 902210, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35903198

RESUMO

Chlamydia trachomatis is an obligate intracellular bacterium causing ocular and urogenital infections in humans that are a significant burden worldwide. The completion of its characteristic infectious cycle relies on the manipulation of several host cell processes by numerous chlamydial type III secretion effector proteins. We previously identified the C. trachomatis CteG effector and showed it localizes at the host cell plasma membrane at late stages of infection. Here, we showed that, from 48 h post-infection, mammalian cells infected by wild-type C. trachomatis contained more infectious chlamydiae in the culture supernatant than cells infected by a CteG-deficient strain. This phenotype was CteG-dependent as it could be complemented in cells infected by the CteG-deficient strain carrying a plasmid encoding CteG. Furthermore, we detected a CteG-dependent defect on host cell cytotoxicity, indicating that CteG mediates chlamydial lytic exit. Previous studies showed that Pgp4, a global regulator of transcription encoded in the C. trachomatis virulence plasmid, also mediates chlamydial lytic exit. However, by using C. trachomatis strains encoding or lacking Pgp4, we showed that production and localization of CteG are not regulated by Pgp4. A C. trachomatis strain lacking both CteG and Pgp4 was as defective in promoting host cell cytotoxicity as mutant strains lacking only CteG or Pgp4. Furthermore, CteG overproduction in a plasmid suppressed the host cell cytotoxic defect of CteG- and Pgp4-deficient chlamydiae. Overall, we revealed the first chlamydial type III secretion effector involved in host cell lytic exit. Our data indicates that CteG and Pgp4 participate in a single cascade of events, but involving multiple layers of regulation, leading to lysis of host cells and release of the infectious chlamydiae.


Assuntos
Infecções por Chlamydia , Chlamydia trachomatis , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Infecções por Chlamydia/microbiologia , Células HeLa , Humanos , Mamíferos/genética , Plasmídeos/genética
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa