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1.
Curr Issues Mol Biol ; 46(7): 6951-6959, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-39057056

RESUMO

Asthma is a chronic inflammatory respiratory condition, characterized by variable airflow limitation, leading to clinical symptoms such as dyspnea and chest tightness. These symptoms result from an underlying inflammatory process. The ß2 agonists are bronchodilators prescribed for the relief of the disease. Nevertheless, their efficacy exhibits substantial interindividual variability. Currently, there is widespread recognition of the association between specific genetic variants, predominantly located within the ADRB2 and ADCY9 genes and their efficacy. This association, usually represented by the presence of non-synonymous single nucleotide polymorphisms (SNPs) have a strong impact in the protein functionality. The prevalence of these mutations varies based on the ethnic composition of the population and thus understanding the profiles of variability in different populations would contribute significantly to standardizing the use of these medications. In this study, we conducted a sequence-based genotyping of the relevant SNPs within the ADRB2 and ADCY9 genes in patients undergoing treatment with bronchodilators and/or corticosteroids at two healthcare facilities in the state of Rio de Janeiro, Brazil. We investigated the presence of c.46A>G, c.79C>G, c.252G>A, and c.491C>T SNPs within the ADRB2, and c.1320018 A>G within the ADCY9. Our results were in line with existing literature data with both for individuals in Brazil and Latin American.

2.
Clin Infect Dis ; 70(10): 2054-2061, 2020 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-31260522

RESUMO

BACKGROUND: Leprosy has been treated with multidrug therapy, which has been distributed for free across the globe and regarded as highly efficient. However, the impossibility of growing Mycobacterium leprae in axenic media has historically impaired assessments of M. leprae resistance, a parameter only recently detectable through molecular methods. METHODS: A systematic, population-based search for M. leprae resistance in suspected leprosy relapse cases and contacts was performed in Prata Village, an isolated, hyperendemic, former leprosy colony located in the Brazilian Amazon. Results led to an extended active search involving the entire Prata population. Confirmed leprosy cases were investigated for bacterial resistance using a combination of in vivo testing and direct sequencing of resistance genes folP1, rpoB, and gyrA. A molecular epidemiology analysis was performed using data from 17 variable number tandem repeats (VNTR). RESULTS: Mycobacterium leprae was obtained from biopsies of 37 leprosy cases (18 relapses and 19 new cases): 16 (43.24%) displayed drug-resistance variants. Multidrug resistance to rifampicin and dapsone was observed in 8 relapses and 4 new cases. Single resistance to rifampicin was detected in 1 new case. Resistance to dapsone was present in 2 relapses and 1 new case. Combined molecular resistance and VNTR data revealed evidence of intra-familial primary transmission of resistant M. leprae. CONCLUSIONS: A comprehensive, population-based systematic approach to investigate M. leprae resistance in a unique population revealed an alarming scenario of the emergence and transmission of resistant strains. These findings may be used for the development of new strategies for surveillance of drug resistance in other populations.


Assuntos
Hanseníase , Preparações Farmacêuticas , Brasil/epidemiologia , Farmacorresistência Bacteriana , Quimioterapia Combinada , Humanos , Hansenostáticos/farmacologia , Hansenostáticos/uso terapêutico , Hanseníase/tratamento farmacológico , Hanseníase/epidemiologia , Testes de Sensibilidade Microbiana , Mycobacterium leprae/genética
4.
Lepr Rev ; 87(4): 486-500, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30226353

RESUMO

Background: This study compares the strains of genotypes of M. leprae from nasal secretions (NS) and skin biopsy (SB) in the same patient, supplementing conventional epidemiology to gain insight into the infection of leprosy in Fortaleza, Brazil. Methods: The sample consisted of 38 newly diagnosed leprosy patients attending the National Reference Center of Dermatology Dona Libania (CDERM), in Fortaleza, who tested positive for M. leprae by PCR in DNA extracts of nasal secretions. DNA was also extracted from skin biopsy (SB) scrapings of each patient and used for multiplex PCR amplification of M. leprae VNTR loci. The number of repeats at 15 loci were determined by the fragment length analysis method. Results: Locus VNTR genotypes were achieved in 38 NS, and in 38 SB specimens. M. leprae strains differed in their genotypes in paired specimens in all but two of 38 patients. The genotype similarity in the remainder ranged from 53% to 87%. Conclusion: M. leprae 15 VNTR loci genotypes of paired nasal and biopsy skin samples from five patients were identical, while as many as seven loci differed in the 33 other patients. When the NS and biopsy genotypes were pooled and compared, it was found that there was a great variability among different VNTR markers. It is important to investigate other molecular markers suitable for typing genetic variations of the bacilli.


Assuntos
Biópsia/métodos , Hanseníase/microbiologia , Repetições Minissatélites , Mycobacterium leprae/genética , Nariz/microbiologia , Pele/patologia , Brasil/epidemiologia , Estudos Transversais , DNA Bacteriano/genética , Doenças Endêmicas , Variação Genética , Genótipo , Humanos , Hanseníase/diagnóstico , Mycobacterium leprae/classificação , Mycobacterium leprae/isolamento & purificação , Reação em Cadeia da Polimerase , Polimorfismo de Nucleotídeo Único , Pele/microbiologia
5.
Emerg Infect Dis ; 21(3): 452-5, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25642998

RESUMO

We conducted a population-based study of tuberculosis (TB) cases in Dourados, Brazil, to assess the relationship between incarceration and TB in the general population. Incarceration was associated with TB in an urban population; 54% of Mycobacterium tuberculosis strains were related to strains from persons in prisons. TB control in prisons is critical for reducing disease prevalence.


Assuntos
Reservatórios de Doenças , Mycobacterium tuberculosis/genética , Prisões , Tuberculose/epidemiologia , Tuberculose/transmissão , Brasil/epidemiologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Tipagem Molecular , Mycobacterium tuberculosis/classificação , Vigilância da População , Prevalência , Fatores de Risco
6.
J Clin Microbiol ; 52(7): 2615-24, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24829250

RESUMO

Strains of the Beijing genotype family of Mycobacterium tuberculosis are a cause of particular concern because of their increasing dissemination in the world and their association with drug resistance. Phylogenetically, this family includes distinct ancient and modern sublineages. The modern strains, contrary to the ancestral counterparts, demonstrated increasing prevalence in many world regions that suggest an enhanced bacterial pathogenicity. We therefore evaluated virulence of modern versus ancient Beijing strains with similar epidemiological and genotype characteristics. For this, we selected six strains that had very similar 24-locus mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) typing profiles and belonged to the region of difference 181 (RD181) subgroup but differed using markers (mutT2 and mutT4 genes and NTF locus) that discriminate between modern and ancient Beijing sublineages. The strains were isolated from native patients in Brazil and Mozambique, countries with a low prevalence of Beijing strains. The virulence levels of these strains were determined in models of pulmonary infection in mice and in vitro macrophage infection and compared with that of a strain from Russia, part of the epidemic and hypervirulent Beijing clone B0/W148, and of the laboratory strain H37Rv. The results showed that two of the three modern Beijing strains were highly pathogenic, exhibiting levels of virulence comparable with that of the epidemic Russian strain. In contrast, all isolates of the ancient sublineage displayed intermediate or low virulence. The data obtained demonstrate that the strains of the modern Beijing sublineage are more likely to exhibit highly virulent phenotypes than ancient strains and suggest that genetic alterations characteristic of the modern Beijing sublineage favor selection of highly virulent bacteria.


Assuntos
Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/patogenicidade , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/patologia , Animais , Brasil , Células Cultivadas , Modelos Animais de Doenças , Genótipo , Humanos , Macrófagos/microbiologia , Camundongos Endogâmicos C57BL , Tipagem Molecular , Moçambique , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/isolamento & purificação , Federação Russa , Tuberculose Pulmonar/microbiologia , Tuberculose Pulmonar/patologia
8.
J Clin Microbiol ; 51(4): 1071-7, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23325819

RESUMO

Spoligotyping has shown Mycobacterium tuberculosis strains to be composed of different lineages, and some of them are not just geographically restricted but also affect specific ethnic populations and are associated with outbreaks and drug resistance. We recently described a particular subtype within the Latin American-Mediterranean (LAM) family, called RD(Rio), widespread in Brazil. Moreover, recent data also indicate that RD(Rio) is present in many countries on all continents and is associated with cavitary disease and multidrug resistance (MDR). To further explore the relationship between RD(Rio) and MDR, we conducted a study in a tuberculosis (TB) reference center responsible for the care of MDR patients in Rio Grande do Sul, the southernmost Brazilian state. From a collection of 237 clinical isolates, RD(Rio) alone was responsible for one-half of all MDR cases, including one large group composed of strains with identical IS6110-restriction fragment length polymorphism (RFLP) and having the LAM5 signature. We additionally had complete data records for 96 patients and could make comparisons between the presence and absence of RD(Rio). No difference in clinical, radiological or laboratory features was observed, but a significantly greater number of cases with MDR were described in patients infected with an RD(Rio) strain (P = 0.0015). Altogether, RD(Rio) was responsible for 38% of all TB cases. These data support and confirmed previous findings that RD(Rio) is the main agent responsible for TB in Brazil and is associated with drug resistance. Considering that RD(Rio) is a globally distributed genotype, such findings raise concern about the increase in MDR in certain human populations.


Assuntos
Farmacorresistência Bacteriana Múltipla , Tipagem Molecular , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/genética , Polimorfismo de Fragmento de Restrição , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Brasil/epidemiologia , Feminino , Genótipo , Humanos , Masculino , Epidemiologia Molecular , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/isolamento & purificação , Prevalência
9.
J Clin Microbiol ; 50(11): 3757-9, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22933595

RESUMO

We describe a multiplex PCR assay to detect the Mycobacterium tuberculosis Beijing genotype variant B0/W148, which is considered a "successful" clone of M. tuberculosis, widespread in Russia. Specificity and sensitivity of the assay were 100% based on the analysis of a collection of 516 M. tuberculosis isolates of different genotypes and origins. This assay may be used for accurate and simple detection and surveillance of this clinically and epidemiologically important variant of M. tuberculosis.


Assuntos
Técnicas Bacteriológicas/métodos , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase Multiplex/métodos , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/diagnóstico , Métodos Epidemiológicos , Genótipo , Humanos , Programas de Rastreamento/métodos , Mycobacterium tuberculosis/genética , Federação Russa , Sensibilidade e Especificidade , Tuberculose/microbiologia
10.
BMC Infect Dis ; 11: 110, 2011 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-21527037

RESUMO

BACKGROUND: The classical spoligotyping technique, relying on membrane reverse line-blot hybridization of the spacers of the Mycobacterium tuberculosis CRISPR locus, is used world-wide (598 references in Pubmed on April 8th, 2011). However, until now no inter-laboratory quality control study had been undertaken to validate this technique. We analyzed the quality of membrane-based spoligotyping by comparing it to the recently introduced and highly robust microbead-based spoligotyping. Nine hundred and twenty-seven isolates were analyzed totaling 39,861 data points. Samples were received from 11 international laboratories with a worldwide distribution. METHODS: The high-throughput microbead-based Spoligotyping was performed on CTAB and thermolyzate DNA extracted from isolated Mycobacterium tuberculosis complex (MTC) strains coming from the genotyping participating centers. Information regarding how the classical Spoligotyping method was performed by center was available. Genotype discriminatory analyses were carried out by comparing the spoligotypes obtained by both methods. The non parametric U-Mann Whitney homogeneity test and the Spearman rank correlation test were performed to validate the observed results. RESULTS: Seven out of the 11 laboratories (63%), perfectly typed more than 90% of isolates, 3 scored between 80-90% and a single center was under 80% reaching 51% concordance only. However, this was mainly due to discordance in a single spacer, likely having a non-functional probe on the membrane used. The centers using thermolyzate DNA performed as well as centers using the more extended CTAB extraction procedure. Few centers shared the same problematic spacers and these problematic spacers were scattered over the whole CRISPR locus (Mostly spacers 15, 14, 18, 37, 39, 40). CONCLUSIONS: We confirm that classical spoligotyping is a robust method with generally a high reliability in most centers. The applied DNA extraction procedure (CTAB or thermolyzate) did not affect the results in this study. However performance was center-dependent, suggesting that training is a key component in quality assurance of spoligotyping. Overall, no particular spacer yielded a higher degree of deviating results, suggesting that errors occur randomly either in the process of re-using membranes, or during the reading of the results and transferring of data from the film to a digital file. Last, the performance of the microbead-based method was excellent as previously shown by Cowan et al. (J. Clin. Microbiol. 2004) and Zhang et al. (J. Med. Microbiol. 2009) and demonstrated the proper detection of spacer 15 that is known to occasionally give weak signals in the classical spoligotyping.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Tuberculose/microbiologia , Técnicas de Tipagem Bacteriana/instrumentação , Técnicas de Tipagem Bacteriana/normas , DNA Bacteriano/genética , Genótipo , Humanos , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/genética , Reação em Cadeia da Polimerase/instrumentação , Reação em Cadeia da Polimerase/normas , Controle de Qualidade
11.
Front Microbiol ; 12: 718477, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34504483

RESUMO

Among non-tuberculous mycobacteria, Mycobacterium kansasii is one of the most pathogenic, able to cause pulmonary disease indistinguishable from tuberculosis in immunocompetent susceptible adults. The lack of animal models that reproduce human-like lung disease, associated with the necrotic lung pathology, impairs studies of M. kansasii virulence and pathogenicity. In this study, we examined the ability of the C57BL/6 mice, intratracheally infected with highly virulent M. kansasii strains, to produce a chronic infection and necrotic lung pathology. As a first approach, we evaluated ten M. kansasii strains isolated from Brazilian patients with pulmonary disease and the reference strain M. kansasii ATCC 12478 for virulence-associated features in macrophages infected in vitro; five of these strains differing in virulence were selected for in vivo analysis. Highly virulent isolates induced progressive lung disease in mice, forming large encapsulated caseous granulomas in later stages (120-150 days post-infection), while the low-virulent strain was cleared from the lungs by day 40. Two strains demonstrated increased virulence, causing premature death in the infected animals. These data demonstrate that C57BL/6 mice are an excellent candidate to investigate the virulence of M. kansasii isolates. We observed considerable heterogeneity in the virulence profile of these strains, in which the presence of highly virulent strains allowed us to establish a clinically relevant animal model. Comparing public genomic data between Brazilian isolates and isolates from other geographic regions worldwide demonstrated that at least some of the highly pathogenic strains isolated in Brazil display remarkable genomic similarities with the ATCC strain 12478 isolated in the United States 70 years ago (less than 100 SNPs of difference), as well as with some recent European clinical isolates. These data suggest that few pathogenic clones have been widely spread within M. kansasii population around the world.

12.
Transbound Emerg Dis ; 68(3): 1639-1651, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32964690

RESUMO

Armadillos are specialist diggers and their burrows are used to find food, seek shelter and protect their pups. These burrows can also be shared with dozens of vertebrate and invertebrate species and; consequently, their parasites including the zoonotics. The aim of this study was to diagnose the presence of zoonotic parasites in four wild-caught armadillo species from two different Brazilian ecosystems, the Cerrado (Brazilian savanna) and the Pantanal (wetland). The investigated parasites and their correspondent diseases were: Toxoplasma gondii (toxoplasmosis), Trypanosoma cruzi (Chagas disease), Leishmania spp., (leishmaniasis), Paracoccidioides brasiliensis (Paracoccidioidomicosis) and Mycobacterium leprae (Hansen's disease). Forty-three free-living armadillos from Pantanal and seven road-killed armadillos from the Cerrado were sampled. Trypanosoma cruzi DTU TcIII were isolated from 2 out of 43 (4.65%) armadillos, including one of them also infected with Trypanosoma rangeli. Antibodies anti-T. gondii were detected in 13 out of 43 (30.2%) armadillos. All seven armadillos from Cerrado tested positive for P. brasiliensis DNA, in the lungs, spleen, liver fragments. Also, by molecular analysis, all 43 individuals were negative for M. leprae and Leishmania spp. Armadillos were infected by T. cruzi, T. rangeli, P. brasiliensis and presented seric antibodies to T. gondii, highlighting the importance of those armadillos could have in the epidemiology of zoonotic parasites.


Assuntos
Tatus , Doença de Chagas/veterinária , Leishmaniose/veterinária , Hanseníase/veterinária , Paracoccidioidomicose/veterinária , Toxoplasmose Animal/parasitologia , Zoonoses/microbiologia , Zoonoses/parasitologia , Animais , Brasil , Doença de Chagas/parasitologia , Feminino , Leishmania/isolamento & purificação , Leishmaniose/parasitologia , Hanseníase/microbiologia , Masculino , Mycobacterium leprae/isolamento & purificação , Paracoccidioides/isolamento & purificação , Paracoccidioidomicose/parasitologia , Especificidade da Espécie , Toxoplasma/isolamento & purificação , Trypanosoma cruzi/isolamento & purificação
13.
BMC Infect Dis ; 10: 80, 2010 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-20350321

RESUMO

BACKGROUND: Mycobacterium tuberculosis is the principal etiologic agent of human tuberculosis (TB) and a member of the M. tuberculosis complex (MTC). Additional MTC species that cause TB in humans and other mammals include Mycobacterium africanum and Mycobacterium bovis. One result of studies interrogating recently identified MTC phylogenetic markers has been the recognition of at least two distinct lineages of M. africanum, known as West African-1 and West African-2. METHODS: We screened a blinded non-random set of MTC strains isolated from TB patients in Ghana (n = 47) for known chromosomal region-of-difference (RD) loci and single nucleotide polymorphisms (SNPs). A MTC PCR-typing panel, single-target standard PCR, multi-primer PCR, PCR-restriction fragment analysis, and sequence analysis of amplified products were among the methods utilized for the comparative evaluation of targets and identification systems. The MTC distributions of novel SNPs were characterized in the both the Ghana collection and two other diverse collections of MTC strains (n = 175 in total). RESULTS: The utility of various polymorphisms as species-, lineage-, and sublineage-defining phylogenetic markers for M. africanum was determined. Novel SNPs were also identified and found to be specific to either M. africanum West African-1 (Rv1332(523); n = 32) or M. africanum West African-2 (nat(751); n = 27). In the final analysis, a strain identification approach that combined multi-primer PCR targeting of the RD loci RD9, RD10, and RD702 was the most simple, straight-forward, and definitive means of distinguishing the two clades of M. africanum from one another and from other MTC species. CONCLUSION: With this study, we have organized a series of consistent phylogenetically-relevant markers for each of the distinct MTC lineages that share the M. africanum designation. A differential distribution of each M. africanum clade in Western Africa is described.


Assuntos
Técnicas de Tipagem Bacteriana , Análise por Conglomerados , Impressões Digitais de DNA , DNA Bacteriano/genética , Mycobacterium/classificação , Polimorfismo Genético , Tuberculose/microbiologia , Genótipo , Gana , Humanos , Mycobacterium/genética , Mycobacterium/isolamento & purificação , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNA
14.
Mutat Res ; 683(1-2): 43-9, 2010 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-19909761

RESUMO

N-Acetyltransferase 2 (NAT2) metabolizes a variety of xenobiotics that includes many drugs, chemicals and carcinogens. This enzyme is genetically variable in human populations and polymorphisms in the NAT2 gene have been associated with drug toxicity and efficacy as well as cancer susceptibility. Here, we have focused on the identification of NAT2 variants in Brazilian individuals from two different regions, Rio de Janeiro and Goiás, by direct sequencing, and on the characterization of new haplotypes after cloning and re-sequencing. Upon analysis of DNA samples from 404 individuals, six new SNPs (c.29T>C, c.152G>T, c.203G>A, c.228C>T, c.458C>T and c.600A>G) and seven new NAT2 alleles were identified with different frequencies in Rio de Janeiro and Goiás. All new SNPs were found as singletons (observed only once in 808 genes) and were confirmed by three independent technical replicates. Molecular modeling and structural analysis suggested that p.Gly51Val variant may have an important effect on substrate recognition by NAT2. We also observed that amino acid change p.Cys68Tyr would affect acetylating activity due to the resulting geometric restrictions and incompatibility of the functional group in the Tyr side chain with the admitted chemical mechanism for catalysis by NATs. Moreover, other variants, such like p.Thr153Ile, p.Thr193Met, p.Pro228Leu and p.Val280Met, may lead to the presence of hydrophobic residues on NAT2 surface involved in protein aggregation and/or targeted degradation. Finally, the new alleles NAT2*6H and NAT2*5N, which showed the highest frequency in the Brazilian populations considered in this study, may code for a slow activity. Functional studies are needed to clarify the mechanisms by which new SNPs interfere with acetylation.


Assuntos
Arilamina N-Acetiltransferase/química , Arilamina N-Acetiltransferase/genética , Haplótipos/genética , Modelos Moleculares , Polimorfismo de Nucleotídeo Único/genética , Tuberculose Pulmonar/genética , Acetilação , Brasil , Estudos de Casos e Controles , Humanos , Estrutura Molecular , Análise de Sequência , Tuberculose Pulmonar/enzimologia
15.
Infect Genet Evol ; 86: 104581, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33022427

RESUMO

Molecular epidemiology investigations are notoriously challenging in the leprosy field mainly because the inherent characteristics of the disease as well as its yet uncultivated causative agents, Mycobacterium leprae and M. lepromatosis. Despite significant developments in understanding the biology of leprosy bacilli through genomic approaches, the exact mechanisms of transmission is still unclear and the factors underlying pathological variation of the disease in different patients remain as major gaps in our knowledge about leprosy. Despite these difficulties, the last two decades have seen the development of genotyping procedures based on PCR-sequencing of target loci as well as by the genome-wide analysis of an increasing number of geographically diverse isolates of leprosy bacilli. This has provided a foundation for molecular epidemiology studies that are bringing a better understanding of strain evolution associated with ancient human migrations, and phylogeographical insights about the spread of disease globally. This review discusses the advantages and drawbacks of the main tools available for molecular epidemiological investigations of leprosy and summarizes various methods ranging from PCR-based genotyping to genome-typing techniques. We also describe their main applications in analyzing the short-range and long-range transmission of the disease. Finally, we summarise the current gaps and challenges that remain in the field of molecular epidemiology of leprosy.


Assuntos
Hanseníase/epidemiologia , Hanseníase/microbiologia , Mycobacterium leprae/genética , Genes Bacterianos , Genoma Bacteriano , Genômica/métodos , Humanos , Hanseníase/tratamento farmacológico , Hanseníase/transmissão , Epidemiologia Molecular , Mycobacterium leprae/efeitos dos fármacos , Filogenia , Vigilância em Saúde Pública
16.
BMC Microbiol ; 9: 39, 2009 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-19228426

RESUMO

BACKGROUND: Mutations associated with resistance to rifampin or streptomycin have been reported for W/Beijing and Latin American Mediterranean (LAM) strain families of Mycobacterium tuberculosis. A few studies with limited sample sizes have separately evaluated mutations in katG, ahpC and inhA genes that are associated with isoniazid (INH) resistance. Increasing prevalence of INH resistance, especially in high tuberculosis (TB) prevalent countries is worsening the burden of TB control programs, since similar transmission rates are noted for INH susceptible and resistant M. tuberculosis strains. RESULTS: We, therefore, conducted a comprehensive evaluation of INH resistant M. tuberculosis strains (n = 224) from three South American countries with high burden of drug resistant TB to characterize mutations in katG, ahpC and inhA gene loci and correlate with minimal inhibitory concentrations (MIC) levels and spoligotype strain family. Mutations in katG were observed in 181 (80.8%) of the isolates of which 178 (98.3%) was contributed by the katG S315T mutation. Additional mutations seen included oxyR-ahpC; inhA regulatory region and inhA structural gene. The S315T katG mutation was significantly more likely to be associated with MIC for INH >or=2 microg/mL. The S315T katG mutation was also more frequent in Haarlem family strains than LAM (n = 81) and T strain families. CONCLUSION: Our data suggests that genetic screening for the S315T katG mutation may provide rapid information for anti-TB regimen selection, epidemiological monitoring of INH resistance and, possibly, to track transmission of INH resistant strains.


Assuntos
Antituberculosos/farmacologia , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana , Isoniazida/farmacologia , Mutação de Sentido Incorreto , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose/microbiologia , Técnicas de Tipagem Bacteriana , Análise por Conglomerados , Impressões Digitais de DNA , DNA Bacteriano/genética , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/isolamento & purificação , América do Sul
17.
J Clin Microbiol ; 46(11): 3822-5, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18768653

RESUMO

This study evaluated the biodiversity of 28 clinical and 24 environmental Mycobacterium isolates from Rio de Janeiro, Brazil, by using hsp65 sequences, with the aim of contributing to a better understanding of the genetic diversity and usefulness of this marker. An extensive phylogenetic analysis was performed. The nucleotide diversity was similar between clinical (0.06508) and environmental (0.06221) isolates.


Assuntos
Proteínas de Bactérias/genética , Biodiversidade , Chaperoninas/genética , Microbiologia Ambiental , Mycobacterium/classificação , Mycobacterium/isolamento & purificação , Tuberculose/microbiologia , Animais , Brasil/epidemiologia , Bovinos , Chaperonina 60 , DNA Bacteriano/química , DNA Bacteriano/genética , Humanos , Dados de Sequência Molecular , Mycobacterium/genética , Filogenia , Análise de Sequência de DNA , Suínos , Tuberculose/epidemiologia
18.
J Clin Microbiol ; 46(4): 1259-67, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18234868

RESUMO

The Latin American-Mediterranean (LAM) family of Mycobacterium tuberculosis is believed to be the cause of approximately 15% of tuberculosis cases worldwide. Previously, we defined a prevalent sublineage of the LAM family in Brazil by a single characteristic genomic deletion designated RD(Rio). Using the Brazilian strains, we pinpoint an Ag85C(103) single nucleotide polymorphism (SNP) (screened by restriction fragment length polymorphism [RFLP] analysis) that correctly identified all LAM family strains. Importantly, all RD(Rio) strains concomitantly possessed the RD174 deletion. These genetic signatures, along with a newly developed multiplex PCR for rapid differentiation between "wild-type" and RD(Rio) strains, were then used to analyze an international collection of M. tuberculosis strains. RD(Rio) M. tuberculosis was identified from four continents involving 11 countries. Phylogenetic analysis of the IS6110-RFLP patterns from representative RD(Rio) and LAM strains from Brazil, along with all representative clusters from a South African database, confirmed their genetic relatedness and transcontinental transmission. The Ag85C(103) SNP RFLP, as compared to results obtained using a PCR method targeting a LAM-restricted IS6110 element, correctly identified 99.8% of LAM spoligotype strains. Together, these tests were more accurate than spoligotyping at categorizing strains with indefinable spoligotypes and segregated true LAM strains from those with convergent spoligotypes. The fact that RD(Rio) strains were identified worldwide highlights the importance of this LAM family sublineage and suggests that this strain is a global threat that should be specifically targeted by public health resources. Our provision of simple and robust molecular methods will assist the evaluation of the LAM family and the RD(Rio) sublineage.


Assuntos
Saúde Global , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/genética , Oligonucleotídeos/análise , Polimorfismo de Nucleotídeo Único/genética , Tuberculose/epidemiologia , Tuberculose/transmissão , Aciltransferases/genética , Antígenos de Bactérias/genética , Códon , Elementos de DNA Transponíveis/genética , Evolução Molecular , Ácido Graxo Sintases/genética , Humanos , América Latina , Região do Mediterrâneo , Mycobacterium tuberculosis/isolamento & purificação , Filogenia , Reação em Cadeia da Polimerase/métodos , Sensibilidade e Especificidade , Tuberculose/microbiologia
19.
Mem Inst Oswaldo Cruz ; 103(5): 489-92, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18797764

RESUMO

The frequency of the Beijing genotype of Mycobacterium tuberculosis as a cause of tuberculosis (TB) in South America was determined by analyzing genotypes of strains isolated from patients that had been diagnosed with the disease between 1997 and 2003 in seven countries of the subcontinent. In total, 19 of the 1,202 (1.6%) TB cases carried Beijing isolates, including 11 of the 185 patients from Peru (5.9%), five of the 512 patients from Argentina (1.0%), two of the 252 Brazilian cases (0.8%), one of the 166 patients from Paraguay (0.6%) and none of the samples obtained from Chile (35), Colombia (36) and Ecuador (16). Except for two patients that were East Asian immigrants, all cases with Beijing strains were native South Americans. No association was found between carrying a strain with the Beijing genotype and having drug or multi-drug resistant disease. Our data show that presently transmission of M. tuberculosis strains of the Beijing genotype is not frequent in Latin America. In addition, the lack of association of drug resistant TB and infection with M. tuberculosis of the Beijing genotype observed presently demands efforts to define better the contribution of the virulence and lack of response to treatment to the growing spread of Beijing strains observed in other parts of the world.


Assuntos
Mycobacterium tuberculosis/genética , Tuberculose Pulmonar/microbiologia , Impressões Digitais de DNA , Genótipo , Humanos , Mycobacterium tuberculosis/classificação , Polimorfismo de Fragmento de Restrição , América do Sul/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos , Tuberculose Pulmonar/epidemiologia
20.
Tuberculosis (Edinb) ; 110: 36-43, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29779771

RESUMO

Tuberculosis (TB) remains a major public health problem in the world and Brazil is among the countries with the highest incidence and prevalence rates, and Rio Grande do Sul, a Brazilian state, occupy a prominent position. Multidrug-resistant Mycobacterium tuberculosis (MDR-TB) further aggravates this scenario, making it more difficult to treat and control the disease. Isoniazid monoresistance (IMR) may increase the risk of progression to MDR-TB and treatment failure. However, most drug resistance molecular tests only focus on detecting rifampicin (RIF) resistance.In the present study, we characterized a total of 63 drug resistant isolates of M. tuberculosis (35 MDR, 26 IMR and two isolates monoresistant to rifampicin [RMR]) of the Rio Grande do Sul state by MIRU-VNTR (24 loci), spoligotyping, presence of RDRio, fbpC103, pks15/1 and sequencing of the katG, rpoB and inhA genes. We observed a higher proportion of the LAM family 30/63 (47.61%). In IMR, mutations were found in the katG gene (98% at codon 315) in 72.5%, and mutations in the promoter region of the inhA gene in 6.25% of the isolates. In MDR-TB and RMR-TB isolates, 92.1% had mutations in the rpoB gene (57% at codon 531). The presence of a 12 bp insertion between codons 516 and 517 of the rpoB gene in MDR-TB isolates was found in five isolates. In conclusion, we observed that the highest frequency of IMR-TB and MDR-TB strains belong to the LAM and Haarlem genotypes in Rio Grande do Sul state. A significant number of isolates previously characterized as Mycobacterium pinnipedi2 through spoligotyping were found to belong to the M. tuberculosis LAM family. This was responsible for a number of significant cases and the molecular profile of this strain and the pattern of mutations related to drug resistance were analyzed. These findings may contribute to a better understanding about the spread of M. tuberculosis resistant in southern of Brazil.


Assuntos
Antituberculosos/farmacologia , Isoniazida/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Tuberculose/microbiologia , Técnicas de Tipagem Bacteriana/métodos , Farmacorresistência Bacteriana/genética , Farmacorresistência Bacteriana Múltipla/genética , Genes Bacterianos/genética , Variação Genética , Genótipo , Humanos , Testes de Sensibilidade Microbiana/métodos , Repetições Minissatélites/genética , Mycobacterium tuberculosis/classificação , Fenótipo , Tuberculose/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia
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