Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
1.
Front Immunol ; 14: 1277745, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38146374

RESUMO

Introduction: Pulmonary granuloma diseases caused by Mycobacterium abscessus (M. abscessus) have increased in past decades, and drug-resistance in this pathogen is a growing public health concern. Therefore, an animal model of chronic granuloma disease is urgently needed. Methods: In this study, M. abscessus embedded within agar beads (agar-AB) was used to develop such a model in C57BL/6JNarl mice. Results: Chronic infection was sustained for at least 3 months after agar-AB infection, visible granulomas spread in the lungs, and giant cells and foamy cells appeared in the granulomas. More importantly, pulmonary fibrosis progressed for 3 months, and collagen fibers were detected by Masson trichrome staining. Further, inducible nitric oxide synthase (iNOS) was highly expressed within the alveolar space, and the fibrosis-mediator transforming growth factor beta (TGF-ß) began to be expressed at 1 month. Hypoxia-inducible factor (HIF-1α) expression also increased, which aided in normalizing oxygen partial pressure. Discussion: Although the transient fibrosis persisted for only 3 months, and the pulmonary structure resolved when the pathogen was cleard, this pulmonary fibrosis model for M. abscessus infection will provide a novel test platform for development of new drugs, regimens, and therapies.


Assuntos
Mycobacterium abscessus , Fibrose Pulmonar , Animais , Camundongos , Mycobacterium abscessus/metabolismo , Ágar/metabolismo , Camundongos Endogâmicos C57BL , Fibrose , Granuloma/patologia
2.
PLoS Pathog ; 19(4): e1010893, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37014917

RESUMO

In settings with high tuberculosis (TB) endemicity, distinct genotypes of the Mycobacterium tuberculosis complex (MTBC) often differ in prevalence. However, the factors leading to these differences remain poorly understood. Here we studied the MTBC population in Dar es Salaam, Tanzania over a six-year period, using 1,082 unique patient-derived MTBC whole-genome sequences (WGS) and associated clinical data. We show that the TB epidemic in Dar es Salaam is dominated by multiple MTBC genotypes introduced to Tanzania from different parts of the world during the last 300 years. The most common MTBC genotypes deriving from these introductions exhibited differences in transmission rates and in the duration of the infectious period, but little differences in overall fitness, as measured by the effective reproductive number. Moreover, measures of disease severity and bacterial load indicated no differences in virulence between these genotypes during active TB. Instead, the combination of an early introduction and a high transmission rate accounted for the high prevalence of L3.1.1, the most dominant MTBC genotype in this setting. Yet, a longer co-existence with the host population did not always result in a higher transmission rate, suggesting that distinct life-history traits have evolved in the different MTBC genotypes. Taken together, our results point to bacterial factors as important determinants of the TB epidemic in Dar es Salaam.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Humanos , Mycobacterium tuberculosis/genética , Tanzânia/epidemiologia , Tuberculose/epidemiologia , Genótipo , Virulência
4.
NPJ Vaccines ; 7(1): 60, 2022 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-35662254

RESUMO

A major challenge in the use of DNA vaccines is efficient DNA delivery in vivo. Establishing a safe and efficient electric transfer method is the key to developing rapid DNA vaccines against emerging infectious diseases. To overcome the complexity of designing new electric transfer machines for DNA delivery, a clinically approved electric transfer machine could be considered as an alternative. Here, we report an electroacupuncture machine-based method for DNA vaccine delivery after intramuscular injection of the COVID-19 DNA vaccine. The S gene of SARS-CoV-2 in the pVAX1 plasmid (pSARS2-S) was used as an antigen in this study. We optimized the clinically used electroacupuncture machine settings for efficient induction of the neutralizing antibody titer after intramuscular injection of pSARS2-S in mice. We found that pSARS2-S immunization at 40 Vpp for 3-5 s could induce high neutralizing antibody titers and Th1-biased immune responses. IFN-γ/TNF-α-secreting CD4+ and CD8+ T cells were also observed in the DNA vaccination group but not in the recombinant protein vaccination group. T-cell epitope mapping shows that the major reactive epitopes were located in the N-terminal domain (a.a. 261-285) and receptor-binding domain (a.a. 352-363). Importantly, pSARS2-S immunization in hamsters could induce protective immunity against SARS-CoV-2 challenge in vivo. In the preclinical toxicology study, blood biochemistry, hematology, and DNA persistence analysis reveal that the DNA delivery method is safe. Furthermore, the raised antisera could also cross-neutralize different variants of concern. These findings suggest that DNA vaccination using an electroacupuncture machine is feasible for use in humans in the future.

5.
Front Immunol ; 13: 872047, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35585971

RESUMO

An effective COVID-19 vaccine against broad SARS-CoV-2 variants is still an unmet need. In the study, the vesicular stomatitis virus (VSV)-based vector was used to express the SARS-CoV-2 Spike protein to identify better vaccine designs. The replication-competent of the recombinant VSV-spike virus with C-terminal 19 amino acid truncation (SΔ19 Rep) was generated. A single dose of SΔ19 Rep intranasal vaccination is sufficient to induce protective immunity against SARS-CoV-2 infection in hamsters. All the clones isolated from the SΔ19 Rep virus contained R682G mutation located at the Furin cleavage site. An additional S813Y mutation close to the TMPRSS2 cleavage site was identified in some clones. The enzymatic processing of S protein was blocked by these mutations. The vaccination of the R682G-S813Y virus produced a high antibody response against S protein and a robust S protein-specific CD8+ T cell response. The vaccinated animals were protected from the lethal SARS-CoV-2 (delta variant) challenge. The S antigen with resistance to enzymatic processes by Furin and TMPRSS2 will provide better immunogenicity for vaccine design.


Assuntos
COVID-19 , Furina , SARS-CoV-2 , Serina Endopeptidases , Animais , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/virologia , Vacinas contra COVID-19 , Furina/genética , Furina/metabolismo , Humanos , Imunidade Celular , SARS-CoV-2/imunologia , Serina Endopeptidases/genética , Serina Endopeptidases/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia
6.
Vaccine ; 40(4): 574-586, 2022 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-34952759

RESUMO

A series of recombinant human type 5 adenoviruses that express the full-length or membrane-truncated spike protein (S) of SARS-CoV-2 (AdCoV2-S or AdCoV2-SdTM, respectively) was tested the efficacy against SARS-CoV-2 via intranasal (i.n.) or subcutaneous (s.c.) immunization in a rodent model. Mucosal delivery of adenovirus (Ad) vaccines could induce anti-SARS-CoV-2 IgG and IgA in the serum and in the mucosal, respectively as indicated by vaginal wash (vw) and bronchoalveolar lavage fluid (BALF). Serum anti-SARS-CoV-2 IgG but not IgA in the vw and BALF was induced by AdCoV2-S s.c.. Administration of AdCoV2-S i.n. was able to induce higher anti-SARS-CoV-2 binding and neutralizing antibody levels than s.c. injection. AdCoV2-SdTM i.n. induced a lower antibody responses than AdCoV2-S i.n.. Induced anti-S antibody responses by AdCoV2-S via i.n. or s.c. were not influenced by the pre-existing serum anti-Ad antibody. Novelty, S-specific IgG1 which represented Th2-mediated humoral response was dominantly induced in Ad i.n.-immunized serum in contrast to more IgG2a which represented Th1-mediated cellular response found in Ad s.c.-immunized serum. The activation of S-specific IFN-É£ and IL-4 in splenic Th1 and Th2 cells, respectively, was observed in the AdCoV2-S i.n. and s.c. groups, indicating the Th1 and Th2 immunity were activated. AdCoV2-S and AdCoV2-SdTM significantly prevented body weight loss and reduced pulmonary viral loads in hamsters. A reduction in inflammation in the lungs was observed in AdCoV-S via i.n. or s.c.-immunized hamsters following a SARS-CoV-2 challenge. It correlated to Th1 cytokine but no inflammatory cytokines secretions found in AdCoV-S i.n. -immunized BALF. These results indicate that intranasal delivery of AdCoV2-S vaccines is safe and potent at preventing SARS-CoV-2 infections.


Assuntos
Vacinas contra Adenovirus , COVID-19 , Animais , Anticorpos Antivirais , Vacinas contra COVID-19 , Cricetinae , Feminino , Humanos , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/genética
7.
Front Pharmacol ; 12: 746496, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34899300

RESUMO

Tuberculosis (TB) is a leading cause of death from a single infectious agent, Mycobacterium tuberculosis (Mtb). Although progress has been made in TB control, still about 10 million people worldwide develop TB annually and 1.5 million die of the disease. The rapid emergence of aggressive, drug-resistant strains and latent infections have caused TB to remain a global health challenge. TB treatments are lengthy and their side effects lead to poor patient compliance, which in turn has contributed to the drug resistance and exacerbated the TB epidemic. The relatively low output of newly approved antibiotics has spurred research interest toward alternative antibacterial molecules such as silver nanoparticles (AgNPs). In the present study, we use the natural biopolymer alginate to serve as a stabilizer and/or reductant to green synthesize AgNPs, which improves their biocompatibility and avoids the use of toxic chemicals. The average size of the alginate-capped AgNPs (ALG-AgNPs) was characterized as nanoscale, and the particles were round in shape. Drug susceptibility tests showed that these ALG-AgNPs are effective against both drug-resistant Mtb strains and dormant Mtb. A bacterial cell-wall permeability assay showed that the anti-mycobacterial action of ALG-AgNPs is mediated through an increase in cell-wall permeability. Notably, the anti-mycobacterial potential of ALG-AgNPs was effective in both zebrafish and mouse TB animal models in vivo. These results suggest that ALG-AgNPs could provide a new therapeutic option to overcome the difficulties of current TB treatments.

8.
J Inflamm Res ; 14: 3781-3795, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34408462

RESUMO

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus which caused a global respiratory disease pandemic beginning in December 2019. Understanding the pathogenesis of infection and the immune responses in a SARS-CoV-2-infected animal model is urgently needed for vaccine development. METHODS: Syrian hamsters (Mesocricetus auratus) were intranasally inoculated with 105, 5×105, and 106 TCID50 of SARS-CoV-2 per animal and studied for up to 14 days. Body weight, viral load and real-time PCR amplification of the SARS-CoV-2 N gene were measured. On days 3, 6 and 9, lung, blood, liver, pancreas, heart, kidney, and bone marrow were harvested and processed for pathology, viral load, and cytokine expression. RESULTS: Body weight loss, increased viral load, immune cell infiltration, upregulated cytokine expression, viral RNA, SARS-CoV-2 nucleoprotein, and mucus were detected in the lungs, particularly on day 3 post-infection. Extremely high expression of the pro-inflammatory cytokines MIP-1 and RANTES was detected in lung tissue, as was high expression of IL-1ß, IL-6, IL-12, and PD-L1. The glutamic oxalacetic transaminase/glutamic pyruvic transaminase (GOT/GPT) ratio in blood was significantly increased at 6 days post-infection, and plasma amylase and lipase levels were also elevated in infected hamsters. CONCLUSION: Our results provide new information on immunological cytokines and biological parameters related to the pathogenesis and immune response profile in the Syrian hamster model of SARS-CoV-2 infection.

9.
PLoS Negl Trop Dis ; 15(5): e0009374, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34043618

RESUMO

The development of efficient vaccines against COVID-19 is an emergent need for global public health. The spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a major target for the COVID-19 vaccine. To quickly respond to the outbreak of the SARS-CoV-2 pandemic, a nucleic acid-based vaccine is a novel option, beyond the traditional inactivated virus vaccine or recombinant protein vaccine. Here, we report a DNA vaccine containing the spike gene for delivery via electroporation. The spike genes of SARS-CoV and SARS-CoV-2 were codon optimized for mammalian cell expression and then cloned into mammalian cell expression vectors, called pSARS-S and pSARS2-S, respectively. Spike protein expression was confirmed by immunoblotting after transient expression in HEK293T cells. After immunization, sera were collected for antigen-specific antibody and neutralizing antibody titer analyses. We found that both pSARS-S and pSARS2-S immunization induced similar levels of antibodies against S2 of SARS-CoV-2. In contrast, only pSARS2-S immunization induced antibodies against the receptor-binding domain of SARS-CoV-2. We further found that pSARS2-S immunization, but not pSARS-S immunization, could induce very high titers of neutralizing antibodies against SARS-CoV-2. We further analyzed SARS-CoV-2 S protein-specific T cell responses and found that the immune responses were biased toward Th1. Importantly, pSARS2-S immunization in hamsters could induce protective immunity against SARS-CoV-2 challenge in vivo. These data suggest that DNA vaccination could be a promising approach for protecting against COVID-19.


Assuntos
COVID-19/prevenção & controle , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas de DNA/normas , Animais , Chlorocebus aethiops , Cricetinae , Eletroporação , Células HEK293 , Humanos , Mesocricetus , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Plasmídeos , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética , Vacinas de DNA/imunologia , Células Vero
11.
F1000Res ; 10: 60, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33732436

RESUMO

Background: Lineage 1 (L1) and 3 (L3) are two lineages of the Mycobacterium tuberculosis complex (MTBC) causing tuberculosis (TB) in humans. L1 and L3 are prevalent around the rim of the Indian Ocean, the region that accounts for most of the world's new TB cases. Despite their relevance for this region, L1 and L3 remain understudied. Methods: We analyzed 2,938 L1 and 2,030 L3 whole genome sequences originating from 69 countries. We reconstructed the evolutionary history of these two lineages and identified genes under positive selection. Results: We found a strongly asymmetric pattern of migration from South Asia toward neighboring regions, highlighting the historical role of South Asia in the dispersion of L1 and L3. Moreover, we found that several genes were under positive selection, including genes involved in virulence and resistance to antibiotics. For L1 we identified signatures of local adaptation at the esxH locus, a gene coding for a secreted effector that targets the human endosomal sorting complex, and is included in several vaccine candidates. Conclusions: Our study highlights the importance of genetic diversity in the MTBC, and sheds new light on two of the most important MTBC lineages affecting humans.


Assuntos
Mycobacterium tuberculosis , Genótipo , Humanos , Oceano Índico , Mycobacterium tuberculosis/genética
12.
Front Immunol ; 11: 1298, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32655570

RESUMO

Pulmonary tuberculosis (TB) is a difficult-to-eliminate disease. Although the Bacille Calmette-Guérin (BCG) vaccine against Mycobacterium tuberculosis (MTB) has been available for decades, its efficacy is variable and has lessened over time. Furthermore, the BCG vaccine no longer protects against newly emerged Beijing strains which are responsible for many current infections in adults. Development of a novel vaccine is urgently needed. In this study, we first tested the efficacy of our recombinant BCG vaccines rBCG1 and rBCG2, compared to parental BCG, against MTB strain H37Ra in mice. Both the bacterial load and the level of lymphocyte infiltration decreased dramatically in the three groups treated with vaccine, especially rBCG1 and rBCG2. Furthermore, the Th1 and Th17 responses increased and macrophage numbers rose in the vaccination groups. Th1-mediated production of cytokines TNF-α, IFN-γ, and MCP-1 as well as M1-polarized cells all increased in lung tissue of the rBCG1 and rBCG2 groups. Clodronate-induced depletion of macrophages reduced the level of protection. Based on these results, we conclude that rBCG vaccines induce a significant increase in the number of M1 macrophages, which augments their potential as TB vaccine candidates.


Assuntos
Vacina BCG/imunologia , Ativação de Macrófagos/efeitos dos fármacos , Ativação de Macrófagos/imunologia , Macrófagos/imunologia , Tuberculose Pulmonar/imunologia , Animais , Macrófagos/efeitos dos fármacos , Camundongos , Mycobacterium tuberculosis/imunologia , Tuberculose Pulmonar/prevenção & controle , Vacinas Sintéticas/imunologia
13.
BMJ Open ; 9(10): e029948, 2019 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-31662365

RESUMO

OBJECTIVE: To investigate the association between diabetes and latent tuberculosis infections (LTBI) in high TB incidence areas. DESIGN: Community-based comparison study. SETTING: Outpatient diabetes clinics at 4 hospitals and 13 health centres in urban and rural townships. A community-based screening programme was used to recruit non-diabetic participants. PARTICIPANTS: A total of 2948 patients with diabetes aged older than 40 years were recruited, and 453 non-diabetic participants from the community were enrolled. PRIMARY AND SECONDARY OUTCOME MEASURES: The interferon-gamma release assay (IGRA) and the tuberculin skin test were used to detect LTBI. The IGRA result was used as a surrogate of LTBI in logistic regression analysis. RESULTS: Diabetes was significantly associated with LTBI (adjusted OR (aOR)=1.59; 95% CI 1.11 to 2.28) and age correlated positively with LTBI. Many subjects with diabetes also had additional risk factors (current smokers (aOR=1.28; 95% CI 0.95 to 1.71), comorbid chronic kidney disease (aOR=1.26; 95% CI 1.03 to 1.55) and history of TB (aOR=2.08; 95% CI 1.19 to 3.63)). The presence of BCG scar was protective (aOR=0.66; 95% CI 0.51 to 0.85). Duration of diabetes and poor glycaemic control were unrelated to the risk of LTBI. CONCLUSION: There was a moderately increased risk of LTBI in patients with diabetes from this high TB incidence area. This finding suggests LTBI screening for the diabetics be combined with other risk factors and comorbidities of TB to better identify high-risk groups and improve the efficacy of targeted screening for LTBI.


Assuntos
Diabetes Mellitus/epidemiologia , Tuberculose Latente/epidemiologia , Adulto , Idoso , Vacina BCG/uso terapêutico , Estudos de Casos e Controles , Diabetes Mellitus/metabolismo , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Incidência , Testes de Liberação de Interferon-gama , Tuberculose Latente/diagnóstico , Masculino , Pessoa de Meia-Idade , Razão de Chances , Insuficiência Renal Crônica/epidemiologia , Fatores de Risco , Fumar/epidemiologia , Taiwan/epidemiologia , Teste Tuberculínico , Tuberculose/prevenção & controle
14.
Anal Chim Acta ; 1007: 1-9, 2018 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-29405982

RESUMO

Tuberculosis (TB) remains one of the major infectious diseases worldwide. The pathogenic bacterium, Mycobacterium tuberculosis (M.tb), continuously evolves strains carrying drug-resistance genes, thus posing a growing challenge to TB prevention and treatment. We report a diagnostic system that uses a molecular beacon probe and an assistant strand as the core to simultaneously interact with an M.tb-specific fragment (in IS6110) and a single nucleotide substitution (SNS)-encoded segment (in rpoB) associated with drug resistance. A single fluorescent output in three-tiered levels was produced for combinatorial interpretations based on formation of a four-way DNA junction (4WJ). The SNS caused the 4WJ to partially dissociate, thus resulting in medium-level fluorescence. By contrast, high- and low-level fluorescence, represented the complete complementary complex and absence of either targeted fragments, respectively. Manipulating the length of the analyte-binding arm realized the medium output. The thermodynamics and kinetics of 4WJ construction were investigated to maximize the tiered-output performance. Biocatalytic amplification driven by the Klenow Fragment and Nt.AlwI was incorporated into the method to enhance the signal 64-fold and ensure long-term stability of the three-tiered output. The detection accuracy of the sensing system was verified using unpurified amplicons with templates of extracted DNA and boiled bacterial solutions. The tiered-output mechanism was usable at bacterial loads ranging from 4 × 100 to 4 × 103 CFU per reaction. The interference caused by nontuberculous mycobacteria was minimal. The results demonstrated the integrity of the sensing method as an alternative strategy for rapid screening of M.tb and detecting rifampin-resistance.


Assuntos
Farmacorresistência Bacteriana/genética , Mutação , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/patogenicidade , Polimorfismo de Nucleotídeo Único/genética , Tuberculose/diagnóstico , Tuberculose/microbiologia , Cinética , Termodinâmica
15.
Sci Rep ; 7(1): 5394, 2017 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-28710410

RESUMO

In total, 303 randomly selected clinical Mycobacterium tuberculosis (MTB) isolates from 303 patients (collected January to December 2012) in central Taiwan were examined. The major lineages found were Beijing (N = 114, 37.62%), Haarlem (N = 76, 25.08%) and East African-Indian (EAI) (N = 42, 13.86%). Notably, younger persons (≤30 years old) were 6.58 times more likely to be infected with a Beijing genotype compared to older persons (>70 years) (p < 0.05). Combining molecular typing methods and geographical information system (GIS) analysis, we uncovered a twofold higher incidence of Beijing strains in a hotspot area (33%) compared to non-hotspot areas (17%). By 24 MIRU-VNTR typing, persons in clustered groups were 1.96 times more likely to be infected with a Beijing strain compared with non-clustered persons, suggesting recent spread and emergence of MTB. Finally, we observed a trend in which TB incidence increased as the density/concentration of analyzed environmental factors increased, suggesting that environmental factors are associated with TB transmission; however, only population density was found to be significantly associated with increased risk of TB (p < 0.05). Molecular typing methods combined with spatial analysis suggest possible TB transmission. Early intervention to interrupt transmission may be most effective if targeted to hot zones of TB.


Assuntos
Repetições Minissatélites , Mycobacterium tuberculosis/genética , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/transmissão , Adulto , Fatores Etários , Idoso , Técnicas de Tipagem Bacteriana , Monitoramento Ambiental , Feminino , Sistemas de Informação Geográfica , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/isolamento & purificação , Densidade Demográfica , Estudos Retrospectivos , Fatores de Risco , Taiwan/epidemiologia , Tuberculose Pulmonar/microbiologia
16.
Sci Rep ; 7(1): 1425, 2017 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-28469152

RESUMO

Tuberculosis (TB) is a severe infectious disease worldwide. Genetic variation of the causative agent, Mycobacterium tuberculosis (MTB), determines the outcomes of infection and anti-TB treatment. Until recently, there has been no effective and convenient way for classifying clinical isolates based on the DNA sequences of the divergent lineages of MTB infecting human populations. Here, we identified single nucleotide polymorphisms (SNPs) of six representative strains from Taiwan by whole-genome sequencing and comparing the results to the sequence of the H37Rv reference strain. One hundred and ten SNPs, each unique to one of the six strains, were used to genotype 150 additional isolates by applying DNA mass spectrometry. Lineage-specific SNPs were identified that could distinguish the major lineages of the clinical isolates. A subset including 32 SNPs was found to be sufficient to type four major groups of MTB isolates in Taiwan (ancient Beijing, modern Beijing, East African-Indian, and Latin-American Mediterranean). However, there was high genetic homozygosity within the Euro-American lineage, which included spoligotype-classified Haarlem and T strains. By whole-genome sequencing of 12 representative Euro-American isolates, we identified multiple subtype-specific SNPs which allowed us to distinguish two major branches within the Euro-American lineage.


Assuntos
Genótipo , Mycobacterium tuberculosis/genética , Polimorfismo de Nucleotídeo Único , Variação Genética , Humanos , Desequilíbrio de Ligação , Mycobacterium tuberculosis/isolamento & purificação , Sequenciamento Completo do Genoma
17.
J Microbiol Immunol Infect ; 50(6): 886-892, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26922173

RESUMO

BACKGROUND: The Beijing lineage of Mycobacterium tuberculosis (MTB) is the most predominant MTB strain in Asian countries and is spreading worldwide, however, the East African-Indian (EAI) lineage is also particularly prevalent in many tropical Asian countries. The evolutionary relationships among MTB EAI isolates from Taiwan and those of tropical Asian countries remain unknown. METHODS: The EAI strains collected from patients in Taiwan were analyzed using spacer oligonucleotide typing and mycobacterial interspersed repetitive unit-variable number of tandem repeats (MIRU-VNTR) typing, and compared with published profiles from Cambodia and Singapore to investigate potential epidemiological linkages. RESULTS: Among the three countries, the EAI lineage was most prevalent in Cambodia (60%; Singapore, 25.62%; and Taiwan, 21.85%), having also the highest rates of multidrug resistance and lowest rates of clustering of MTB isolates. We describe a convenient method using seven selected MIRU-VNTR loci for first-line typing to discriminate Beijing and EAI lineages. A potential epidemiological linkage in these tropical Asian countries is also discussed based on a minimum-spanning tree constructed using 24 MIRU-VNTR loci of MTB EAI strains. CONCLUSION: This study identified evolutionary relationships among MTB EAI isolates from Taiwan and those of two other tropical Asian countries, Cambodia and Singapore.


Assuntos
Mycobacterium tuberculosis , Tuberculose Pulmonar/epidemiologia , Povo Asiático , Camboja/epidemiologia , DNA Bacteriano/genética , DNA Intergênico/genética , Marcadores Genéticos/genética , Variação Genética/genética , Humanos , Sequências Repetitivas Dispersas/genética , Testes de Sensibilidade Microbiana , Tipagem Molecular , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Singapura/epidemiologia , Taiwan/epidemiologia , Tuberculose Pulmonar/microbiologia
18.
J Microbiol Immunol Infect ; 50(1): 90-96, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25732698

RESUMO

BACKGROUND: The tuberculosis (TB) pandemic remains a leading cause of human morbidity and mortality, despite widespread use of the only licensed anti-TB vaccine, bacille Calmette-Guerin (BCG). The protective efficacy of BCG in preventing pulmonary TB is highly variable; therefore, an effective new vaccine is urgently required. METHODS: In the present study, we assessed the ability of novel recombinant BCG vaccine (rBCG) against Mycobacterium tuberculosis by using modern immunological methods. RESULTS: Enzyme-linked immunospot assays demonstrated that the rBCG vaccine, which coexpresses two mycobacterial antigens (Ag85B and CFP10) and human interleukin (IL)-12 (rBCG2) elicits greater interferon-γ (IFN-γ) release in the mouse lung and spleen, compared to the parental BCG. In addition, rBCG2 triggers a Th1-polarized response. Our results also showed that rBCG2 vaccination significantly limits M. tuberculosis H37Rv multiplication in macrophages. The rBCG2 vaccine surprisingly induces significantly higher tumor necrosis factor-α (TNF-α) production by peripheral blood mononuclear cells that were exposed to a nonmycobacterial stimulus, compared to the parental BCG. CONCLUSION: In this study, we demonstrated that the novel rBCG2 vaccine may be a promising candidate vaccine against M. tuberculosis infection.


Assuntos
Aciltransferases/imunologia , Adjuvantes Imunológicos/administração & dosagem , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Interleucina-12/administração & dosagem , Mycobacterium bovis/imunologia , Vacinas contra a Tuberculose/imunologia , Tuberculose/prevenção & controle , Aciltransferases/administração & dosagem , Aciltransferases/genética , Adjuvantes Imunológicos/genética , Animais , Antígenos de Bactérias/administração & dosagem , Antígenos de Bactérias/genética , Proteínas de Bactérias/administração & dosagem , Proteínas de Bactérias/genética , ELISPOT , Feminino , Humanos , Interferon gama/metabolismo , Interleucina-12/genética , Leucócitos Mononucleares/imunologia , Pulmão/imunologia , Macrófagos/imunologia , Macrófagos/microbiologia , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Mycobacterium bovis/genética , Mycobacterium tuberculosis/crescimento & desenvolvimento , Mycobacterium tuberculosis/imunologia , Baço/imunologia , Células Th1/imunologia , Vacinas contra a Tuberculose/administração & dosagem , Vacinas contra a Tuberculose/genética , Fator de Necrose Tumoral alfa/metabolismo , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia
19.
Evol Bioinform Online ; 12: 213-221, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27721649

RESUMO

To better understand the transmission and evolution of Mycobacterium tuberculosis (MTB) in Taiwan, six different MTB isolates (representatives of the Beijing ancient sublineage, Beijing modern sublineage, Haarlem, East-African Indian, T1, and Latin-American Mediterranean (LAM)) were characterized and their genomes were sequenced. Discriminating among large sequence polymorphisms (LSPs) that occur once versus those that occur repeatedly in a genomic region may help to elucidate the biological roles of LSPs and to identify the useful phylogenetic relationships. In contrast to our previous LSP-based phylogeny, the sequencing data allowed us to determine actual genetic distances and to define precisely the phylogenetic relationships between the main lineages of the MTB complex. Comparative genomics analyses revealed more nonsynonymous substitutions than synonymous changes in the coding sequences. Furthermore, MTB isolate M7, a LAM-3 clinical strain isolated from a patient of Taiwanese aboriginal origin, is closely related to F11 (LAM), an epidemic tuberculosis strain isolated in the Western Cape of South Africa. The PE/PPE protein family showed a higher dn/ds ratio compared to that for all protein-coding genes. Finally, we found Haarlem-3 and LAM-3 isolates to be circulating in the aboriginal community in Taiwan, suggesting that they may have originated with post-Columbus Europeans. Taken together, our results revealed an interesting association with historical migrations of different ethnic populations, thus providing a good model to explore the global evolution and spread of MTB.

20.
Genome Announc ; 3(6)2015 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-26659689

RESUMO

Mycobacterium tuberculosis strain W06, analyzed by molecular methods, was classified as a modern Beijing M. tuberculosis strain, the most predominant strain in Taiwan. To our knowledge, this is the first draft genome announcement of a Beijing M. tuberculosis strain in Taiwan.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...