RESUMO
PURPOSE: To describe katG and inhA mutations, clinical characteristics, treatment outcomes and clustering of drug-resistant tuberculosis (TB) in the State of São Paulo, southeast Brazil. METHODS: Mycobacterium tuberculosis isolates from patients diagnosed with drug-resistant TB were screened for mutations in katG and inhA genes by line probe assay and Sanger sequencing, and typed by IS6110-restriction fragment-length polymorphism for clustering assessment. Clinical, epidemiological and demographic data were obtained from surveillance information systems for TB. RESULTS: Among the 298 isolates studied, 127 (42.6%) were isoniazid-monoresistant, 36 (12.1%) polydrug-resistant, 93 (31.2%) MDR, 16 (5.4%) pre-extensively drug-resistant (pre-XDR), 9 (3%) extensively drug-resistant (XDR) and 17 (5.7%) susceptible after isoniazid retesting. The frequency of katG 315 mutations alone was higher in MDR isolates, while inhA promoter mutations alone were more common in isoniazid-monoresistant isolates. Twenty-six isolates phenotypically resistant to isoniazid had no mutations either in katG or inhA genes. The isolates with inhA mutations were found more frequently in clusters (75%) when compared to the isolates with katG 315 mutations (59.8%, p = 0.04). In our population, being 35-64 years old, presenting MDR-, pre-XDR- or XDR-TB and being a retreatment case were associated with unfavourable TB treatment outcomes. CONCLUSION: We found that katG and inhA mutations were not equally distributed between isoniazid-monoresistant and MDR isolates. In our population, clustering was higher for isolates with inhA mutations. Finally, unfavourable TB outcomes were associated with specific factors.
Assuntos
Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Humanos , Adulto , Pessoa de Meia-Idade , Isoniazida/farmacologia , Isoniazida/uso terapêutico , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Farmacorresistência Bacteriana Múltipla/genética , Brasil/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Mutação , Testes de Sensibilidade Microbiana , Proteínas de Bactérias/genéticaRESUMO
We analysed mutations in katG, inhA and rpoB genes, and isoniazid phenotypic resistance levels in Mycobacterium tuberculosis isolates from drug-resistant TB patients from São Paulo state, Brazil. Isolates resistant to the critical concentration of isoniazid in MGIT (0.1 µg/mL) were screened for mutations in katG 315 codon, inhA promoter region and rpoB RRDR by MTBDRplus assay and subjected to determination of isoniazid resistance levels by MGIT 960. Discordances were resolved by Sanger sequencing. Among the 203 isolates studied, 109 (54%) were isoniazid-monoresistant, 47 (23%) MDR, 29 (14%) polydrug-resistant, 12 (6%) pre-XDR and 6 (3%) XDR. MTBDRplus detected isoniazid mutations in 75% (153/203) of the isolates. Sequencing of the entire katG and inhA genes revealed mutations in 18/50 wild-type isolates by MTBDRplus (10 with novel mutations), resulting in a total of 32/203 (16%) isolates with no mutations detected. 81/83 (98%) isolates with katG 315 mutations alone had intermediate resistance. Of the 66 isolates with inhA C-15T mutation alone, 51 (77%) showed low-level, 14 (21%) intermediate and 1 (2%) high-level resistance. 5/6 (83%) isolates with mutations in both katG and inhA had high-level resistance. Inferred mutations corresponded to 22% (16/73) of all mutations found in rpoB. Mutations detected in katG regions other than codon 315 in this study might be potential new isoniazid resistance markers and could explain phenotypic resistance in some isolates without katG and inhA classic mutations. In our setting, 16% of isoniazid-resistant isolates, some with high-level resistance, presented no mutations either in katG or inhA.
Assuntos
Antituberculosos/farmacologia , Isoniazida/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Brasil , Catalase/genética , Catalase/metabolismo , RNA Polimerases Dirigidas por DNA/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Mutação , Mycobacterium tuberculosis/isolamento & purificação , Oxirredutases/genética , Oxirredutases/metabolismo , Estudos ProspectivosRESUMO
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 GenomaRESUMO
BACKGROUND Tuberculosis (TB) is an infectious disease caused by the bacterium Mycobacterium tuberculosis, and the number of new cases of multidrug resistant TB (MDR-TB), pre extensively drug-resistant TB (pre-XDR-TB) and extensively drug-resistant TB (XDR-TB) has increased considerably worldwide. OBJECTIVES Herein, using 156 M. tuberculosis isolates from 106 patients previously classified as MDR or pre-XDR or XDR isolates, we investigated the genetic mutation profiles associated with phenotypic resistances in patients with MDR-TB, pre-XDR-TB and XDR-TB, treatment outcomes and resistance evolution. METHODS Molecular analyses were performed by partial sequencing of the rpoB, katG, gyrA, gyrB, rrs genes and analysis of the fabG-inhA promoter region. Clinical, epidemiologic and demographic data were obtained from the TB Notification database system of São Paulo (TB-WEB) and the Information System for Special Tuberculosis Treatments (SITE-TB). FINDINGS Drug resistance was attributed to previously known mutations and a novel Asp449Val mutation in gyrB was observed in four isolates from the same patient. Ten patients had more than one isolate evaluated and eight of these patients displayed resistance progression. MAIN CONCLUSIONS The present study is the first to report the frequency of mutations related to second-line drug resistance in MDR-TB, pre-XDR-TB and XDR-TB isolates. The results could lead to the improvement of available technologies for the rapid detection of drug resistant TB.
Assuntos
Antituberculosos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Mutação/genética , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Adolescente , Adulto , Brasil , Tuberculose Extensivamente Resistente a Medicamentos/microbiologia , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Mycobacterium tuberculosis/isolamento & purificação , Fatores Socioeconômicos , Adulto JovemRESUMO
BACKGROUND: Little is known about the impact of growing migration on the pattern of tuberculosis (TB) transmission in middle-income countries. We estimated TB recent transmission and its associated factors and investigated the presence of cross-transmission between South American migrants and Brazilians. METHODS: We studied a convenient sample of cases of people with pulmonary TB in a central area of São Paulo, Brazil, diagnosed between 2013 and 2014. Cases with similar restriction fragment length polymorphism (IS6110-RFLP) patterns of their Mycobacterium tuberculosis complex isolates were grouped in clusters (recent transmission). Clusters with both Brazilian and South American migrants were considered mixed (cross-transmission). Risk factors for recent transmission were studied using logistic regression. RESULTS: Isolates from 347 cases were included, 76.7% from Brazilians and 23.3% from South American migrants. Fifty clusters were identified, which included 43% South American migrants and 60.2% Brazilians (odds ratio = 0.50, 95% confidence interval = 0.30-0.83). Twelve cross-transmission clusters were identified, involving 24.6% of all clustered cases and 13.8% of all genotyped cases, with migrants accounting for either an equal part or fewer cases in 11/12 mixed clusters. CONCLUSIONS: Our results suggest that TB disease following recent transmission is more common among Brazilians, especially among those belonging to high-risk groups, such as drug users. Cross-transmission between migrants and Brazilians was present, but we found limited contributions from migrants to Brazilians in central areas of São Paulo and vice versa.
Assuntos
Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/transmissão , Adulto , Brasil , Estudos Transversais , Feminino , Humanos , Masculino , Mycobacterium tuberculosis/patogenicidade , Fatores de Risco , Classe SocialRESUMO
BACKGROUND: Mycobacterium abscessus group has heterogeneous susceptibility pattern among species. The species is most common cause of nosocomial infections. Macrolides minimum Inhibitory concentration (MIC) determination is essential for the treatment. METHODS: Thirty-six strains were randomly selected for performing Resazurin Microtiter Assay (REMA) for clarithromycin testing in comparison to MIC test according to Clinical and Laboratory Standards Institute (2011) recommendation. REMA has been used for detection of drug resistance in M. tuberculosis. Extended incubation was performed to detect induced resistance. RESULTS: Thirty microliters of resazurin (0.01%) was added after visually taking MIC reading. Resistance was observed in 11.1% of M. bolletti and 4.8% of M. abscessus strains; and induced resistance was detected in 77.8% and 95.2% of M. bolletti and M. abscessus strains, respectively. All strains of M. massiliense were susceptible. The samples presented same MIC value both by visual reading and through resazurin. CONCLUSION: The present study showed 100% concordance between both readings, with REMA providing easier to read and report results benefit. This change in reading can also reflect on the MIC determination and report, improving the test.
Assuntos
Claritromicina/farmacologia , Testes de Sensibilidade Microbiana/métodos , Mycobacterium/isolamento & purificação , Oxazinas/metabolismo , Xantenos/metabolismo , HumanosRESUMO
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 RiscoRESUMO
Approximately 10% of the Brazilian indigenous population lives in the state of Mato Grosso do Sul (MS), where a large number of new cases of tuberculosis (TB) are reported. This study was conducted to assess TB occurrence, transmission and the utility of TB diagnosis based on the Ogawa-Kudoh (O-K) culture method in this remote population. The incidence of TB was estimated by a retrospective review of the surveillance data maintained by the Notifiable Diseases Surveillance System for the study region. The TB transmission pattern among indigenous people was assessed by genotyping Mycobacterium tuberculosis isolates using the IS 6110 restriction fragment length polymorphism (RFLP) technique. Of the 3,093 cases identified from 1999-2001, 610 (~20%) were indigenous patients (average incidence: 377/100,000/year). The use of the O-K culture method increased the number of diagnosed cases by 34.1%. Of the genotyped isolates from 52 indigenous patients, 33 (63.5%) belonged to cluster RFLP patterns, indicating recently transmitted TB. These results demonstrate high, on-going TB transmission rates among the indigenous people of MS and indicate that new efforts are needed to disrupt these current transmissions.
Assuntos
Indígenas Sul-Americanos/estatística & dados numéricos , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/transmissão , Adulto , Brasil/epidemiologia , Feminino , Genótipo , Técnicas de Genotipagem/métodos , Humanos , Incidência , Masculino , Polimorfismo de Fragmento de Restrição/genética , Estudos Retrospectivos , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/etnologiaRESUMO
We assessed the performance of MTBDRsl for detection of resistance to fluoroquinolones, aminoglycosides/cyclic peptides, and ethambutol compared to BACTEC MGIT 960 by subjecting simultaneously to both tests 385 phenotypically multidrug-resistant-Mycobacterium tuberculosis isolates from Sao Paulo, Brazil. Discordances were resolved by Sanger sequencing. MTBDRsl correctly detected 99.7% of the multidrug-resistant isolates, 87.8% of the pre-XDR, and 73.9% of the XDR. The assay showed sensitivity of 86.4%, 100%, 85.2% and 76.4% for fluoroquinolones, amikacin/kanamycin, capreomycin and ethambutol, respectively. Specificity was 100% for fluoroquinolones and aminoglycosides/cyclic peptides, and 93.6% for ethambutol. Most fluoroquinolone-discordances were due to mutations in genome regions not targeted by the MTBDRsl v. 1.0: gyrA_H70R and gyrB_R446C, D461N, D449V, and N488D. Capreomycin-resistant isolates with wild-type rrs results on MTBDRsl presented tlyA mutations. MTBDRsl presented good performance for detecting resistance to second-line drugs and ethambutol in clinical isolates. In our setting, multidrug-resistant. isolates presented mutations not targeted by the molecular assay.
Assuntos
Aminoglicosídeos , Antituberculosos , Farmacorresistência Bacteriana Múltipla , Etambutol , Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Humanos , Aminoglicosídeos/farmacologia , Antituberculosos/farmacologia , Brasil , Capreomicina/farmacologia , Etambutol/farmacologia , Fluoroquinolonas/farmacologia , Genótipo , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Técnicas de GenotipagemRESUMO
BACKGROUND: We aimed to evaluate the costs of GenoType® MTBDRplus and MTBDRsl incurred during the diagnosis of first- and second-line drug-resistant tuberculosis (TB) in São Paulo, Brazil. METHODS: Mean and activity-based costs of GenoType® were calculated in a referral laboratory for TB in Brazil. RESULTS: The mean cost value and activity-based cost of GenoType® MTBDRplus were USD 19.78 and USD 35.80 and those of MTBDRsl were USD 54.25 and USD 41.85, respectively. CONCLUSIONS: The cost of GenoType® MTBDRplus was reduced owing to the high number of examinations performed and work optimization.
Assuntos
Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Humanos , Mycobacterium tuberculosis/genética , Brasil , Sensibilidade e Especificidade , Testes de Sensibilidade Microbiana , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Genótipo , Custos e Análise de Custo , Antituberculosos/uso terapêuticoRESUMO
Monitoring the extent of and trends in multidrug-resistant tuberculosis (MDR-TB) is a priority of the Brazilian National Tuberculosis Control Programme. The current study aimed to estimate the incidence of MDR-TB, describe the profile of TB drug resistance in risk groups and examine whether screening for MDR-TB adhered to the recommended guidelines. A descriptive study that examined diagnosed cases of pulmonary TB was conducted in the city of Santos, Brazil, between 2000-2004. Of the 2,176 pulmonary TB cases studied, 671 (30.8%) met the criteria for drug sensitivity testing and, of these cases, 31.7% (213/671) were tested. Among the tested cases, 9.4% were resistant to one anti-TB drug and 15% were MDR. MDR was observed in 11.6% of 86 new TB cases and 17.3% of 127 previously treated cases. The average annual incidence of MDR-TB was 1.9 per 100,000 inhabitants-years. The extent of known MDR-TB in the city of Santos is high, though likely to be underestimated. Our study therefore indicates an inadequate adherence to the guidelines for MDR-TB screening and suggests the necessity of alternative strategies of MDR-TB surveillance.
Assuntos
Antibióticos Antituberculose/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Vigilância da População , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Pulmonar/epidemiologia , Adolescente , Adulto , Brasil/epidemiologia , Feminino , Fidelidade a Diretrizes , Humanos , Incidência , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Mycobacterium tuberculosis/isolamento & purificação , Fatores de Risco , Adulto JovemRESUMO
The World Health Organization advocates that sputum specimens submitted to tuberculosis (TB) diagnostic should be processed within 48 h after collection and be stored under cooling. We aimed to assess the performance of OMNIgene ⢠SPUTUM reagent in maintaining viable specimens of Mycobacterium tuberculosis complex (MTBC) during transportation of sputum samples without refrigeration, in comparison to the standard protocol of the National TB Control Program. Sputum samples obtained in southeastern Brazil (June 2017 to July 2018) from 100 sequential patients with positive acid-fast bacillus smear microscopy were divided into two portions. Portion 1 continued to be cooled (standard protocol, STA), but portion 2 was added to OMNIgene ⢠SPUTUM reagent (alternative protocol, OMS) until concomitant further processing. Both portions of all samples were cultured using MGIT and tested by Xpert MTB/RIF assay. Growth of MTBC in the first 42 days was detected in 96% of the cultures under the STA and 88% under the OMS. Intervals between processing and detecting MTBC growth in the two portions significantly differed (p = 0.0001). Portions under the two protocols showed similar results in the MTBC detection by Xpert assay and culture contamination by non-MTBC. The OMNIgene reagent liquefies and decontaminates sputum leading to a decrease in processing time. Although there was a small delay in mycobacterial growth, the OMNIgene reagent can be useful in specimens transported from collection sites over a long distance to centralized testing centers, maintaining viable MTBC for at least 8 days at room temperature.
Assuntos
Técnicas Bacteriológicas , Viabilidade Microbiana , Mycobacterium tuberculosis , Escarro , Tuberculose , Técnicas Bacteriológicas/instrumentação , Técnicas Bacteriológicas/métodos , Humanos , Indicadores e Reagentes , Mycobacterium tuberculosis/genética , Sensibilidade e Especificidade , Escarro/microbiologia , Tuberculose/diagnóstico , Tuberculose/microbiologiaRESUMO
There is a little-noticed trend involving human immunodeficiency virus (HIV)-infected patients suspected of having tuberculosis: the triple-treatment regimen recommended in Brazil for years has been potentially ineffective in over 30% of the cases. This proportion may be attributable to drug resistance (to at least 1 drug) and/or to infection with non-tuberculous mycobacteria. This evidence was not disclosed in official statistics, but arose from a systematic review of a few regional studies in which the diagnosis was reliably confirmed by mycobacterial culture. This paper clarifies that there has long been ample evidence for the potential benefits of a four-drug regimen for co-infected patients in Brazil and it reinforces the need for determining the species and drug susceptibility in all positive cultures from HIV-positive patients.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Antituberculosos/administração & dosagem , Infecções por Mycobacterium não Tuberculosas/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Brasil/epidemiologia , Quimioterapia Combinada/métodos , Humanos , Prevalência , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológicoRESUMO
We conducted a cross-sectional, hospital-based study between January 2006-March 2008 to estimate the resistance of Mycobacterium tuberculosis to first-line drugs in patients with tuberculosis at a Brazilian hospital. We evaluated the performance of the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide] (MTT) microplate assay compared with the Bactec-MGIT 960 system for mycobacteria testing. The prevalence of resistance in M. tuberculosis was 6.7%. Multidrug-resistance [resistance to rifampicin (RMP) and isoniazid (INH)], INH-resistance and streptomycin (SM)-resistance accounted for 1%, 3.8% and 3.8% of all resistance, respectively, and all isolates were susceptible to ethambutol (EM). The resistance was primary in four cases and acquired in three cases and previous treatment was associated with resistance (p = 0.0129). Among the 119 M. tuberculosis isolates, complete concordance of the results for INH and EM was observed between the MTT microplate and Bactec-MGIT 960TM methods. The observed agreement for RMP was 99% (sensitivity: 90%) and 95.8% for SM (sensitivity 90.9%), lower than those for other drugs. The MTT colourimetric method is an accurate, simple and low-cost alternative in settings with limited resources.
Assuntos
Antibacterianos/farmacologia , Corantes , Testes de Sensibilidade Microbiana/métodos , Mycobacterium tuberculosis/efeitos dos fármacos , Sais de Tetrazólio , Tiazóis , Tuberculose/microbiologia , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Mycobacterium tuberculosis/isolamento & purificação , Estudos Retrospectivos , Tuberculose Resistente a Múltiplos Medicamentos/microbiologiaRESUMO
INTRODUCTION: We aimed to estimate the prevalence and transmission of drug-resistant tuberculosis in a high-burden Brazilian setting under directly observed therapy short-course strategy. METHODS: Isolates of culture-confirmed pulmonary tuberculosis patients from Guarulhos, Brazil, diagnosed in October 2007-2011 were subjected to drug susceptibility and IS6110-restriction fragment length polymorphism testing. RESULTS: The overall resistance prevalence was 11.5% and the multi-drug resistance rate was 4.2%. Twenty-six (43.3%) of 60 drug-resistant isolates were clustered. Epidemiological relationships were identified in 11 (42.3%) patients; 30.8% of the cases were transmitted in households. CONCLUSIONS: Drug-resistant tuberculosis was relatively low and transmitted in households and the community.
Assuntos
Terapia Diretamente Observada/métodos , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Adolescente , Adulto , Brasil/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Mycobacterium tuberculosis/genética , Polimorfismo de Fragmento de Restrição , Prevalência , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/transmissão , Adulto JovemRESUMO
BACKGROUND: Since the implementation of the Xpert MTB/RIF in Sao Paulo, Brazil, numerous Mycobacterium tuberculosis isolates presenting "rifampicin-resistant genotype with rifampicin-susceptible phenotype" were observed. OBJECTIVE: To evaluate the prevalence, rpoB mutations and transmission of M. tuberculosis resistant to rifampicin on Xpert MTB/RIF but susceptible on BACTEC MGIT system, in Sao Paulo state. METHODS: Patients' isolates with this pattern of rifampicin discordance, collected from 2014 to 2017, had their rpoB predominant rifampicin-resistance-determining region sequenced and were genotyped by IS6110 restriction fragment-length polymorphism. FINDINGS: The prevalence of rifampicin-discordant M. tuberculosis with genotypic resistance was 55.1% (156/283). Among the sequenced and genotyped isolates, 75.5% (111/147) were in clusters, largely associated with the type of rpoB mutation. Most isolates (98.6%; 72/73) harbouring the predominant mutation, His445Asn, were pooled into the two largest clusters, SP2ga (42/72; 58.3%) and SP5o (12/72; 16.7%). Ranking second, isolates carrying the silent mutation Phe433Phe were mostly (92.3%; 24/26) gathered into four groups of the family SP25. CONCLUSION: These findings suggest that this unusual high rifampicin discrepancy proportion was greatly influenced by few actively circulating clusters. Further studies on many of the rpoB mutations identified in our setting are needed to elucidate their association with phenotypic rifampicin resistance.
Assuntos
Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/genética , Epidemias/estatística & dados numéricos , Mutação , Mycobacterium tuberculosis/genética , Rifampina/farmacologia , Tuberculose Resistente a Múltiplos Medicamentos/transmissão , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibióticos Antituberculose/farmacologia , Brasil/epidemiologia , Estudos Transversais , RNA Polimerases Dirigidas por DNA/genética , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/isolamento & purificação , Fenótipo , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Adulto JovemRESUMO
OBJECTIVE: Pulmonary nontuberculous mycobacterial infections are caused by nontuberculous mycobacteria (NTM), the microbiological diagnosis of which involves the isolation and identification of the same species in at least two sputum samples, one BAL fluid sample, or one lung biopsy sample. The objective of the present study was to determine the frequency at which the various NTM species are identified among selected individuals and in potential cases of pulmonary nontuberculous mycobacterial infection. METHODS: This was a retrospective analysis of the data on species isolated from respiratory specimens collected from 2,843 individuals between 2011 and 2014. Potential NTM infection cases were identified on the basis of the international microbiological criteria adopted in the state of São Paulo. RESULTS: A total of 50 species were identified using the molecular method PCR-restriction enzyme analysis. Samples collected from 1,014 individuals were analyzed in relation to the microbiological criteria, and 448 (44.18%) had a presumptive diagnosis of pulmonary nontuberculous mycobacterial infection, the species identified most frequently being, in descending order, Mycobacterium kansasii, M. abscessus, M. intracellulare, M. avium, and M. szulgai. CONCLUSIONS: Although various NTM species were identified among the individuals studied, those presumptively identified most frequently on the basis of the microbiological criteria adopted in the state of São Paulo were the ones that are most commonly associated with pulmonary nontuberculous mycobacterial infection worldwide or in specific geographic regions.
Assuntos
Infecções por Mycobacterium não Tuberculosas/diagnóstico , Infecções por Mycobacterium não Tuberculosas/microbiologia , Micobactérias não Tuberculosas/isolamento & purificação , Brasil/epidemiologia , Feminino , Humanos , Pulmão/microbiologia , Masculino , Infecções por Mycobacterium não Tuberculosas/epidemiologia , Reação em Cadeia da Polimerase , Mapeamento por Restrição , Estudos RetrospectivosRESUMO
OBJECTIVE: To evaluate the rapid diagnosis of multidrug-resistant tuberculosis, by using a commercial line probe assay for rifampicin and isoniazid detection (LPA-plus), in the routine workflow of a tuberculosis reference laboratory. METHODS: The LPA-plus was prospectively evaluated on 341 isolates concurrently submitted to the automated liquid drug susceptibility testing system. RESULTS: Among 303 phenotypically valid results, none was genotypically rifampicin false-susceptible (13/13; 100% sensitivity). Two rifampicin-susceptible isolates harboured rpoB mutations (288/290; 99.3% specificity) which, however, were non-resistance-conferring mutations. LPA-plus missed three isoniazid-resistant isolates (23/26; 88.5% sensitivity) and detected all isoniazid-susceptible isolates (277/277; 100% specificity). Among the 38 (11%) invalid phenotypic results, LPA-plus identified 31 rifampicin- and isoniazid-susceptible isolates, one isoniazid-resistant and six as non-Mycobacterium tuberculosis complex. CONCLUSIONS: LPA-plus showed excellent agreement (≥91%) and accuracy (≥99%). Implementing LPA-plus in our setting can speed up the diagnosis of multidrug-resistant tuberculosis, yield a significantly higher number of valid results than phenotypic drug susceptibility testing and provide further information on the drug-resistance level.
Assuntos
Técnicas de Diagnóstico Molecular/métodos , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antituberculosos/farmacologia , Criança , Pré-Escolar , DNA Bacteriano , Diagnóstico Precoce , Feminino , Humanos , Lactente , Isoniazida/farmacologia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico/métodos , Fenótipo , Estudos Prospectivos , Reprodutibilidade dos Testes , Rifampina/farmacologia , Sensibilidade e Especificidade , Fatores de Tempo , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Adulto JovemRESUMO
BACKGROUND: Identification of nontuberculous mycobacteria (NTM) based on phenotypic tests is time-consuming, labor-intensive, expensive and often provides erroneous or inconclusive results. In the molecular method referred to as PRA-hsp65, a fragment of the hsp65 gene is amplified by PCR and then analyzed by restriction digest; this rapid approach offers the promise of accurate, cost-effective species identification. The aim of this study was to determine whether species identification of NTM using PRA-hsp65 is sufficiently reliable to serve as the routine methodology in a reference laboratory. RESULTS: A total of 434 NTM isolates were obtained from 5019 cultures submitted to the Institute Adolpho Lutz, Sao Paulo Brazil, between January 2000 and January 2001. Species identification was performed for all isolates using conventional phenotypic methods and PRA-hsp65. For isolates for which these methods gave discordant results, definitive species identification was obtained by sequencing a 441 bp fragment of hsp65. Phenotypic evaluation and PRA-hsp65 were concordant for 321 (74%) isolates. These assignments were presumed to be correct. For the remaining 113 discordant isolates, definitive identification was based on sequencing a 441 bp fragment of hsp65. PRA-hsp65 identified 30 isolates with hsp65 alleles representing 13 previously unreported PRA-hsp65 patterns. Overall, species identification by PRA-hsp65 was significantly more accurate than by phenotype methods (392 (90.3%) vs. 338 (77.9%), respectively; p < .0001, Fisher's test). Among the 333 isolates representing the most common pathogenic species, PRA-hsp65 provided an incorrect result for only 1.2%. CONCLUSION: PRA-hsp65 is a rapid and highly reliable method and deserves consideration by any clinical microbiology laboratory charged with performing species identification of NTM.
Assuntos
Proteínas de Bactérias/genética , Chaperoninas/genética , Genes Bacterianos , Infecções por Mycobacterium/microbiologia , Mycobacterium/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Mapeamento por Restrição/métodos , Algoritmos , Chaperonina 60 , Humanos , Mycobacterium/química , Mycobacterium/classificação , Infecções por Mycobacterium/diagnóstico , Padrões de Referência , Sensibilidade e Especificidade , Especificidade da EspécieRESUMO
To highlight the transmission and major phylogenetic clades of Mycobacterium tuberculosis, a retrospective study was carried out at two health facilities in a small agro-industrial area in Sao Paulo, Brazil, that has a low tuberculosis incidence rate. IS6110-RFLP and spoligotyping were performed on the isolates, with the former revealing that 31.3% (35/112) of strains were clustered. Epidemiological links were found in 16 of the 35 clustered patients and were associated with transmission among patients living in public housing. Spoligotyping grouped 62.8% of the strains. The T genetic family predominated among the isolates. Of interest is that five strains had a pattern characteristic of African or Asian origin (ST535), and two others were of the rare localized type ST1888 (BRA, VEN). In addition, three new types--1889, 1890, and 1891--were identified. Spoligotyping showed that some ST may be circulating to or from Brazil, and RFLP revealed ongoing transmission in inadequately ventilated public-housing buildings. This may point to a failure in tuberculosis control policy.