Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Mem Inst Oswaldo Cruz ; 116: e200517, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33729319

RESUMO

Molecular-typing can help in unraveling epidemiological scenarios and improvement for disease control strategies. A literature review of Mycobacterium tuberculosis transmission in Brazil through genotyping on 56 studies published from 1996-2019 was performed. The clustering rate for mycobacterial interspersed repetitive units - variable tandem repeats (MIRU-VNTR) of 1,613 isolates were: 73%, 33% and 28% based on 12, 15 and 24-loci, respectively; while for RFLP-IS6110 were: 84% among prison population in Rio de Janeiro, 69% among multidrug-resistant isolates in Rio Grande do Sul, and 56.2% in general population in São Paulo. These findings could improve tuberculosis (TB) surveillance and set up a solid basis to build a database of Mycobacterium genomes.


Assuntos
Repetições Minissatélites/genética , Mycobacterium tuberculosis/genética , Polimorfismo de Fragmento de Restrição/genética , Técnicas de Tipagem Bacteriana , Brasil/epidemiologia , Genótipo , Humanos , Epidemiologia Molecular , Mycobacterium tuberculosis/isolamento & purificação , Sequenciamento Completo do Genoma
2.
Infect Genet Evol ; 73: 337-341, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31170529

RESUMO

Lineage 1 (L1) is one of seven Mycobacterium tuberculosis complex (MTBC) lineages. The objective of this study was to improve the complex taxonomy of L1 using phylogenetic SNPs, and to look for the origin of the main L1 sublineage prevalent in Para, Brazil. We developed a high-throughput SNPs-typing assay based on 12-L1-specific SNPs. This assay allowed us to experimentally retrieve SNP patterns on nine of these twelve SNPs in 277 isolates previously tentatively assigned to L1 spoligotyping-based sublineages. Three collections were used: Pará-Brazil (71); RIVM, the Netherlands (102), Madagascar (104). One-hundred more results were generated in Silico using the PolyTB database. Based on the final SNPs combination, the samples were classified into 11 clusters (C1-C11). Most isolates within a SNP-based cluster shared a mutual spoligotyping-defined lineage. However, L1/EAI1-SOM (SIT48) and L1/EAI6-BGD1 (SIT591) showed a poor correlation with SNP data and are not monophyletic. L1/EAI8-MDG and L1/EAI3-IND belonged to C5; this result suggests that they share a common ancestor. L1.1.3/SIT129, a spoligotype pattern found in SNPs-cluster C6, was found to be shared between Pará/Brazil and Malawi. SIT129 was independently found to be highly prevalent in Mozambique, which suggests a migration history from East-Africa to Brazil during the 16th-18th slave trade period to Northern Brazil.


Assuntos
Variação Genética/genética , Mycobacterium tuberculosis/genética , População Negra/genética , Brasil , Genótipo , Humanos , Madagáscar , Moçambique , Países Baixos , Filogenia , Polimorfismo de Nucleotídeo Único/genética , Tuberculose/microbiologia
3.
Mem Inst Oswaldo Cruz ; 112(11): 769-774, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29091137

RESUMO

BACKGROUND: The accurate detection of multidrug-resistant tuberculosis (MDR-TB) is critical for the application of appropriate patient treatment and prevention of transmission of drug-resistant Mycobacterium tuberculosis isolates. The goal of this study was to evaluate the correlation between phenotypic and molecular techniques for drug-resistant tuberculosis diagnostics. Molecular techniques used were the line probe assay genotype MTBDRplus and the recently described tuberculosis-spoligo-rifampin-isoniazid typing (TB-SPRINT) bead-based assay. Conventional drug susceptibility testing (DST) was done on a BACTECTM MGIT 960 TB. METHOD: We studied 80 M. tuberculosis complex (MTC) clinical isolates from Minas Gerais state, of which conventional DST had classified 60 isolates as MDR and 20 as drug susceptible. FINDINGS: Among the 60 MDR-TB isolates with MGIT as a reference, sensitivity, specificity, accuracy, and kappa for rifampicin (RIF) resistance using TB-SPRINT and MTBDRplus, were 96.7% versus 93.3%, 100.0% versus 100.0%, 97.5% versus 95.0% and 0.94 versus 0.88, respectively. Similarly, the sensitivity, specificity, accuracy, and kappa for isoniazid (INH) resistance were 85.0% and 83.3%, 100.0% and 100.0%, 88.8% and 87.5% and 0.74 and 0.71 for both tests, respectively. Finally, the sensitivity, specificity, accuracy, and kappa for MDR-TB were 85.0% and 83.3%, 100.0% and 100.0%, 88.8% and 87.5% and 0.74 and 0.71 for both tests, respectively. MAIN CONCLUSIONS: Both methods exhibited a good correlation with the conventional DST. We suggest estimating the cost-effectiveness of MTBDRplus and TB-SPRINT in Brazil.


Assuntos
Técnicas Bacteriológicas/métodos , Mycobacterium tuberculosis/genética , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Brasil , Genótipo , Humanos , Técnicas de Diagnóstico Molecular , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia
4.
Mem. Inst. Oswaldo Cruz ; 112(11): 769-774, Nov. 2017. tab
Artigo em Inglês | LILACS | ID: biblio-894852

RESUMO

BACKGROUND The accurate detection of multidrug-resistant tuberculosis (MDR-TB) is critical for the application of appropriate patient treatment and prevention of transmission of drug-resistant Mycobacterium tuberculosis isolates. The goal of this study was to evaluate the correlation between phenotypic and molecular techniques for drug-resistant tuberculosis diagnostics. Molecular techniques used were the line probe assay genotype MTBDRplus and the recently described tuberculosis-spoligo-rifampin-isoniazid typing (TB-SPRINT) bead-based assay. Conventional drug susceptibility testing (DST) was done on a BACTECTM MGIT 960 TB. METHOD We studied 80 M. tuberculosis complex (MTC) clinical isolates from Minas Gerais state, of which conventional DST had classified 60 isolates as MDR and 20 as drug susceptible. FINDINGS Among the 60 MDR-TB isolates with MGIT as a reference, sensitivity, specificity, accuracy, and kappa for rifampicin (RIF) resistance using TB-SPRINT and MTBDRplus, were 96.7% versus 93.3%, 100.0% versus 100.0%, 97.5% versus 95.0% and 0.94 versus 0.88, respectively. Similarly, the sensitivity, specificity, accuracy, and kappa for isoniazid (INH) resistance were 85.0% and 83.3%, 100.0% and 100.0%, 88.8% and 87.5% and 0.74 and 0.71 for both tests, respectively. Finally, the sensitivity, specificity, accuracy, and kappa for MDR-TB were 85.0% and 83.3%, 100.0% and 100.0%, 88.8% and 87.5% and 0.74 and 0.71 for both tests, respectively. MAIN CONCLUSIONS Both methods exhibited a good correlation with the conventional DST. We suggest estimating the cost-effectiveness of MTBDRplus and TB-SPRINT in Brazil.


Assuntos
Humanos , Técnicas Bacteriológicas/métodos , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Mycobacterium tuberculosis/genética , Brasil , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Patologia Molecular , Genótipo
5.
BMC Infect Dis ; 15: 306, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-26231661

RESUMO

BACKGROUND: We aimed to characterize the genetic diversity of drug-resistant Mycobacterium tuberculosis (MTb) clinical isolates and investigate the molecular epidemiology of multidrug-resistant (MDR) tuberculosis from Minas Gerais State, Brazil. METHODS: One hundred and four MTb clinical isolates were assessed by IS6110-RFLP, 24-locus mycobacterial interspersed repetitive units variable-number tandem repeats (MIRU-VNTR), TB-SPRINT (simultaneous spoligotyping and rifampicin-isoniazid drug-resistance mutation analysis) and 3R-SNP-typing (analysis of single-nucleotide polymorphisms in the genes involved in replication, recombination and repair functions). RESULTS: Fifty-seven different IS6110-RFLP patterns were found, among which 50 had unique patterns and 17 were grouped into seven clusters. The discriminatory index (Hunter and Gaston, HGDI) for RFLP was 0.9937. Ninety-nine different MIRU-VNTR patterns were found, 95 of which had unique patterns and nine isolates were grouped into four clusters. The major allelic diversity index in the MIRU-VNTR loci ranged from 0.6568 to 0.7789. The global HGDI for MIRU-VNTR was 0.9991. Thirty-two different spoligotyping profiles were found: 16 unique patterns (n = 16) and 16 clustered profiles (n = 88). The HGDI for spoligotyping was 0.9009. The spoligotyped clinical isolates were phylogenetically classified into Latin-American Mediterranean (66.34 %), T (14.42 %), Haarlem (5.76 %), X (1.92 %), S (1.92 %) and U (unknown profile; 8.65 %). Among the U isolates, 77.8 % were classified further by 3R-SNP-typing as 44.5 % Haarlem and 33.3 % LAM, while the 22.2 % remaining were not classified. Among the 104 clinical isolates, 86 were identified by TB-SPRINT as MDR, 12 were resistant to rifampicin only, one was resistant to isoniazid only, three were susceptible to both drugs, and two were not successfully amplified by PCR. A total of 42, 28 and eight isolates had mutations in rpoB positions 531, 526 and 516, respectively. Correlating the cluster analysis with the patient data did not suggest recent transmission of MDR-TB. CONCLUSIONS: Although our results do not suggest strong transmission of MDR-TB in Minas Gerais (using a classical 100 % MDR-TB identical isolates cluster definition), use of a smoother cluster definition (>85 % similarity) does not allow us to fully eliminate this possibility; hence, around 20-30 % of the isolates we analyzed might be MDR-TB transmission cases.


Assuntos
Variação Genética , Mycobacterium tuberculosis/genética , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Alelos , Antituberculosos/uso terapêutico , Proteínas de Bactérias/genética , Brasil/epidemiologia , Análise por Conglomerados , DNA Bacteriano/análise , RNA Polimerases Dirigidas por DNA , Genótipo , Humanos , Isoniazida/uso terapêutico , Repetições Minissatélites/genética , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/isolamento & purificação , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo Genético , Rifampina/uso terapêutico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA