RESUMO
Bedaquiline Drug Resistance Emergence Assessment in Multidrug-resistant tuberculosis (MDR-TB) (DREAM) was a 5-year (2015 to 2019) phenotypic drug resistance surveillance study across 11 countries. DREAM assessed the susceptibility of 5,036 MDR-TB isolates of bedaquiline treatment-naive patients to bedaquiline and other antituberculosis drugs by the 7H9 broth microdilution (BMD) and 7H10/7H11 agar dilution (AD) MIC methods. Bedaquiline AD MIC quality control (QC) range for the H37Rv reference strain was unchanged, but the BMD MIC QC range (0.015 to 0.12 µg/ml) was adjusted compared with ranges from a multilaboratory, multicountry reproducibility study conforming to Clinical and Laboratory Standards Institute Tier-2 criteria. Epidemiological cutoff values of 0.12 µg/ml by BMD and 0.25 µg/ml by AD were consistent with previous bedaquiline breakpoints. An area of technical uncertainty or intermediate category was set at 0.25 µg/ml and 0.5 µg/ml for BMD and AD, respectively. When applied to the 5,036 MDR-TB isolates, bedaquiline-susceptible, -intermediate, and -resistant rates were 97.9%, 1.5%, and 0.6%, respectively, for BMD and 98.8%, 0.8%, and 0.4% for AD. Resistance rates were the following: 35.1% ofloxacin, 34.2% levofloxacin, 33.3% moxifloxacin, 1.5% linezolid, and 2% clofazimine. Phenotypic cross-resistance between bedaquiline and clofazimine was 0.4% in MDR-TB and 1% in pre-extensively drug-resistant (pre-XDR-TB)/XDR-TB populations. Coresistance to bedaquiline and linezolid and clofazimine and linezolid were 0.1% and 0.3%, respectively, in MDR-TB and 0.2% and 0.4%, respectively, in pre-XDR-TB/XDR-TB populations. Resistance rates to bedaquiline appear to be low in the bedaquiline-treatment-naive population. No treatment-limiting patterns for cross-resistance and coresistance have been identified with key TB drugs to date.
Assuntos
Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Antituberculosos/farmacologia , Diarilquinolinas/farmacologia , Resistência a Medicamentos , Humanos , Testes de Sensibilidade Microbiana , Estudos Prospectivos , Reprodutibilidade dos Testes , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologiaRESUMO
BACKGROUND: Bringing reliable and accurate tuberculosis (TB) diagnosis closer to patients is a key priority for global TB control. Molbio Diagnostics have developed the Truenat point-of-care molecular assays for detection of TB and rifampicin (RIF) resistance. METHODS: We conducted a prospective multicentre diagnostic accuracy study at 19 primary healthcare centres and seven reference laboratories in Peru, India, Ethiopia and Papua New Guinea to estimate the diagnostic accuracy of the point-of-care Truenat MTB, MTB Plus and MTB-RIF Dx assays for pulmonary TB using culture and phenotypic drug susceptibility testing as the reference standard, compared with Xpert MTB/RIF or Ultra. RESULTS: Of 1807 enrolled participants with TB signs/symptoms, 24% were culture-positive for Mycobacterium tuberculosis, of which 15% were RIF-resistant. In microscopy centres, the pooled sensitivity of Truenat MTB and Truenat MTB Plus was 73% (95% CI 67-78%) and 80% (95% CI 75-84%), respectively. Among smear-negative specimens, sensitivities were 36% (95% CI 27-47%) and 47% (95% CI 37-58%), respectively. Sensitivity of Truenat MTB-RIF was 84% (95% CI 62-95%). Truenat assays showed high specificity. Head-to-head comparison in the central reference laboratories suggested that the Truenat assays have similar performance to Xpert MTB/RIF. CONCLUSION: We found the performance of Molbio's Truenat MTB, MTB Plus and MTB-RIF Dx assays to be comparable to that of the Xpert MTB/RIF assay. Performing the Truenat tests in primary healthcare centres with very limited infrastructure was feasible. These data supported the development of a World Health Organization policy recommendation of the Molbio assays.
Assuntos
Antibióticos Antituberculose , Mycobacterium tuberculosis , Tuberculose , Antibióticos Antituberculose/uso terapêutico , Farmacorresistência Bacteriana , Humanos , Testes de Sensibilidade Microbiana , Estudos Prospectivos , Sensibilidade e Especificidade , Escarro , Tuberculose/diagnóstico , Tuberculose/tratamento farmacológicoRESUMO
Drug-resistance due to AmpC ß-lactamases represents a growing problem worldwide. In this study, a previously collected sample of 108 cefoxitin-resistant clinical isolates was assessed for AmpC ß-lactamase production through routine phenotypic testing and double-disc cefoxitin/cloxcallin (DD-CC), cefoxitin/phenylboronic acid (CDT-PBA) and AmpC disc tests. The same isolates were characterized by a novel multiplex polymerase chain reaction molecular assay to detect the presence of blaACT, blaDHA, blaCIT, blaFOX, blaMIR and blaMOX. By phenotypic analysis, 56%, 55% and 48â% were detected as being AmpC ß-lactamase producers by the CDT-PBA, DD-CC and AmpC disc tests, respectively. By molecular analysis, 57ââ% were determined to be AmpC ß-lactamase producers, including 34â% blaFOX, 8â% blaCIT and 1.6â% blaDHAas mono-AmpC producers. The production of multiple AmpC molecular types was common, including 30â% with both blaCIT+FOX and 1.6â% each of blaCIT+DHA, blaACT+MIR, blaACT+FOX, blaACT+DHA and blaMIR+FOX. Molecular characterization of AmpC would help detect the prevalence of AmpC ß-lactamase producers, facilitate proper patient management and implement infection control practices.
Assuntos
Proteínas de Bactérias/genética , Enterobacteriaceae/genética , Reação em Cadeia da Polimerase Multiplex/métodos , beta-Lactamases/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/biossíntese , Cefoxitina/farmacologia , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/isolamento & purificação , Enterobacteriaceae/metabolismo , Infecções por Enterobacteriaceae/epidemiologia , Infecções por Enterobacteriaceae/microbiologia , Genótipo , Humanos , Índia/epidemiologia , Testes de Sensibilidade Microbiana , Fenótipo , Sensibilidade e Especificidade , Atenção Terciária à Saúde , Resistência beta-Lactâmica/efeitos dos fármacos , Resistência beta-Lactâmica/genética , beta-Lactamases/biossínteseRESUMO
Extra-pulmonary TB (EPTB) is difficult to diagnose due to paucibacillary nature of disease. Current study evaluated accuracy of Truenat MTB and MTB-Rif Dx (TN), for detection of Mycobacterium tuberculosis and resistance to rifampicin. Samples were collected from 2103 treatment naive adults with presumptive EPTB, and tested by smear microscopy, liquid culture (LC) (MGIT-960) and GeneXpert MTB/RIF (GX) (Microbiological Reference Standards, MRS). TN results were compared to MRS and Composite Reference Standards (CRS, Microbiology, histopathology, radiology, clinical features prompting decision to treat, response to treatment). CRS grouped patients into 551 confirmed, 1096 unconfirmed, and 409 as unlikely TB. TN sensitivity and specificity was 73.7% and 90.4% against GX. Against LC, Overall sensitivity of GX was 67.6%, while that of TN was 62.3%. Highest sensitivity by TN was observed in pus samples (89%) and highest specificity (92%) in CSF samples, similar to GX. TN sensitivity was better in fluid and biopsy samples and slightly inferior for lymph node aspirates compared to GX. TN sensitivity for RIF resistance detection was slightly superior to GX. TN and GX results were further compared to Clinical Reference Standards. TN detected 170 TB patients initiated on treatment missed by GX, while GX detected 113 such patients missed by TN. Of 124 samples with RIF resistance discordance between GX and TN, GX reported 103/124 as sensitive, 3/124 as indeterminate and 18 as resistant (13/18 samples had low/very low DNA load) while TN reported RIF resistance indeterminate in 103/111 low/very low DNA load samples. Due to paucibacillary nature of EPTB samples, culture yield was poor and phenotypic drug susceptibility testing failed to resolve the discordance. The study establishes TN at par with GX and can be utilized for quick and accurate diagnosis of EPTB.
Assuntos
Rifampina , Sensibilidade e Especificidade , Tuberculose Extrapulmonar , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Farmacorresistência Bacteriana/genética , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/isolamento & purificação , Rifampina/uso terapêutico , Tuberculose Extrapulmonar/diagnóstico , Tuberculose Extrapulmonar/tratamento farmacológicoRESUMO
BACKGROUND: The WHO End TB Strategy requires drug susceptibility testing and treatment of all people with tuberculosis, but second-line diagnostic testing with line-probe assays needs to be done in experienced laboratories with advanced infrastructure. Fewer than half of people with drug-resistant tuberculosis receive appropriate treatment. We assessed the diagnostic accuracy of the rapid Xpert MTB/XDR automated molecular assay (Cepheid, Sunnyvale, CA, USA) to overcome these limitations. METHODS: We did a prospective study involving individuals presenting with pulmonary tuberculosis symptoms and at least one risk factor for drug resistance in four sites in India (New Delhi and Mumbai), Moldova, and South Africa between July 31, 2019, and March 21, 2020. The Xpert MTB/XDR assay was used as a reflex test to detect resistance to isoniazid, fluoroquinolones, ethionamide, amikacin, kanamycin, and capreomycin in adults with positive results for Mycobacterium tuberculosis complex on Xpert MTB/RIF or Ultra (Cepheid). Diagnostic performance was assessed against a composite reference standard of phenotypic drug-susceptibility testing and whole-genome sequencing. This study is registered with ClinicalTrials.gov, number NCT03728725. FINDINGS: Of 710 participants, 611 (86%) had results from both Xpert MTB/XDR and the reference standard for any drug and were included in analysis. Sensitivity for Xpert MTB/XDR detection of resistance was 94% (460 of 488, 95% CI 92-96) for isoniazid, 94% (222 of 235, 90-96%) for fluoroquinolones, 54% (178 of 328, 50-61) for ethionamide, 73% (60 of 82, 62-81) for amikacin, 86% (181 of 210, 81-91) for kanamycin, and 61% (53 of 87, 49-70) for capreomycin. Specificity was 98-100% for all drugs. Performance was equivalent to that of line-probe assays. The non-determinate rate of Xpert MTB/XDR (ie, invalid M tuberculosis complex detection) was 2·96%. INTERPRETATION: The Xpert MTB/XDR assay showed high diagnostic accuracy and met WHO's minimum target product profile criteria for a next-generation drug susceptibility test. The assay has the potential to diagnose drug-resistant tuberculosis rapidly and accurately and enable optimum treatment. FUNDING: German Federal Ministry of Education and Research through KfW, Dutch Ministry of Foreign Affairs, and Australian Department of Foreign Affairs and Trade.
Assuntos
Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Tuberculose , Adulto , Amicacina/farmacologia , Amicacina/uso terapêutico , Austrália , Capreomicina/farmacologia , Capreomicina/uso terapêutico , Estudos Transversais , Farmacorresistência Bacteriana , Etionamida/farmacologia , Etionamida/uso terapêutico , Fluoroquinolonas/farmacologia , Fluoroquinolonas/uso terapêutico , Humanos , Isoniazida/uso terapêutico , Canamicina/farmacologia , Canamicina/uso terapêutico , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/genética , Estudos Prospectivos , Rifampina/uso terapêutico , Sensibilidade e Especificidade , Escarro/microbiologia , Tuberculose/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológicoRESUMO
PURPOSE: Faecal carriage of carbapenemase-producing Enterobacterales (CPE) has been extensively investigated in hospitalized patients, but limited data is available on the carriage rate in healthy individuals in India. METHODS: A total of 1000 stool samples were screened for CPE from healthy individuals in Chennai (n â= â50), Hyderabad (n â= â184) and Mumbai (n â= â766). Diluted stool samples were cultured on chromID CARBA SMART plates. Growing colonies were screened for CPE by RAPIDEC® CARBA NP Test and minimum inhibitory concentration (MIC) of imipenem by E-Test. PCR was performed for confirmation of CPE genes. RESULTS: Out of the 1000 stool samples tested, 6.1% were positive for CPE. A total of 64 carbapenem resistant isolates (56 âE.coli, 4 Klebsiella pneumoniae, 3 Enterobacter cloacae and 1 Citrobacter freundii) were recovered from ChromID CARBA SMART biplate. Carbapenemase production was identified in 57/64 isolates by RAPIDEC® CARBA NP test. PCR analysis showed 28 blaNDM-1 and 33 blaOXA48. Three remaining isolates (2 âE.coli, 1 âK.pneumoniae) were negative for the tested carbapenemase genes. Interestingly, out of these 61 PCR positive isolates, 49.1% displayed imipenem MIC within the susceptibility range on the basis of CLSI interpretative criteria. CONCLUSIONS: Faecal carriage of CPE among healthy individuals was 6.1%. Comprehensive measures to improve the sanitation scenario and implementation of National AMR action plan are needed to prevent further generation and dissemination of carbapenem resistant Enterobacterales (CRE).
Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos , Infecções por Enterobacteriaceae , Proteínas de Bactérias/análise , Proteínas de Bactérias/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Carbapenêmicos/farmacologia , Enterobacteriaceae/genética , Infecções por Enterobacteriaceae/epidemiologia , Escherichia coli , Humanos , Imipenem/farmacologia , Índia/epidemiologia , Klebsiella pneumoniae , Testes de Sensibilidade Microbiana , Prevalência , beta-Lactamases/análise , beta-Lactamases/genéticaRESUMO
BACKGROUND: Timely drug resistance detection is essential to global tuberculosis management. Unfortunately, rapid molecular tests assess resistance to only a few drugs, with culture required for comprehensive susceptibility test results. METHODS: We evaluated targeted next generation sequencing (tNGS) for tuberculosis on 40 uncultured sputum samples. Resistance profiles from tNGS were compared with profiles from Xpert MTB/RIF, line probe assay (LPA), pyrosequencing (PSQ), and phenotypic testing. Concordance, sensitivity, specificity, and overall test agreement were compared across assays. RESULTS: tNGS provided results for 39 of 40 samples (97.5%) with faster turnaround than phenotypic testing (median 3 vs. 21 days, p = 0.0068). Most samples were isoniazid and rifampin resistant (N = 31, 79.5%), 21 (53.8%) were fluoroquinolone resistant, and 3 (7.7%) were also resistant to Kanamycin. Half were of the Beijing lineage (N = 20, 51.3%). tNGS from uncultured sputum identified all resistance to isoniazid, rifampin, fluoroquinolones, and second-line injectable drugs that was identified by other methods. Agreement between tNGS and existing assays was excellent for isoniazid, rifampin, and SLDs, very good for levofloxacin, and good for moxifloxacin. CONCLUSION: tNGS can rapidly identify tuberculosis, lineage, and drug resistance with faster turnaround than phenotypic testing. tNGS is a potential alternative to phenotypic testing in high-burden settings.
Assuntos
Técnicas Bacteriológicas , DNA Bacteriano/genética , Farmacorresistência Bacteriana/genética , Sequenciamento de Nucleotídeos em Larga Escala , Pulmão/microbiologia , Mycobacterium tuberculosis/genética , Tuberculose Pulmonar/microbiologia , Adolescente , Adulto , Antituberculosos/uso terapêutico , Estudos de Viabilidade , Feminino , Genótipo , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Mutação , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/crescimento & desenvolvimento , Fenótipo , Valor Preditivo dos Testes , Escarro/microbiologia , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/tratamento farmacológico , Adulto JovemRESUMO
BACKGROUND: We evaluated the performance of pyrosequencing, a genotypic test which detects TB and XDR-defining mutations within 6 h, directly on CSF samples for diagnosing TB meningitis(TBM). METHODS: This retrospective, diagnostic accuracy study was conducted in Hinduja hospital, Mumbai from May-2017 to May-2019. 107 consecutive patients with physician-suspected TBM for whom CSF pyrosequencing was requested were screened. Seven patients with incomplete data were excluded. Diagnostic accuracy of pyrosequencing was compared with Xpert MTB/Rif and TBMGIT (TB Mycobacterial Growth Indicator Tube) culture against the uniform case definition of definite or probable TBM. Susceptibility concordance rate of pyrosequencing with TBMGIT culture and Xpert MTB/Rif was determined. RESULTS: The study cohort comprised of 100 patients[Definite(n = 33), Probable(n = 20), Possible(n = 30), Alternative(n = 17)] with 50% males[median age(years):38(Range:2-87)]. Against the uniform case definition, pyrosequencing had 98·11%(95%CI 89·93-99·95; n = 52/53) sensitivity and 97·79%(86·31-99·67; n = 44/45) negative predictive value(NPV) compared with 43.39%(29·83-57·72; n = 23/53,p < 0.0001) sensitivity and 61.04%(55·31-66·48; n = 47/77) NPV for Xpert MTB/Rif and 45·28%(31·56-59·55; n = 24/53,p < 0.0001) sensitivity and 61·84%(55·92-67·43; n = 47/76) NPV for TBMGIT culture. Susceptibility concordance rate of pyrosequencing with phenotypic Drug Susceptibility Testing was 91.3%(n = 21/23) and with Xpert MTB/Rif was 95·45%(n = 21/22). CONCLUSION: CSF pyrosequencing is significantly more sensitive than Xpert MTB/Rif and TBMGIT culture for diagnosing TBM. Additionally, it facilitates early therapeutic decision-making by providing information on XDR-defining mutations.
Assuntos
Líquido Cefalorraquidiano/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose Meníngea/líquido cefalorraquidiano , Tuberculose Resistente a Múltiplos Medicamentos/líquido cefalorraquidiano , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Líquido Cefalorraquidiano/microbiologia , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular , Reprodutibilidade dos Testes , Estudos Retrospectivos , Tuberculose Meníngea/diagnóstico , Tuberculose Meníngea/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Adulto JovemRESUMO
The development and rollout of the Xpert® Mycobacterium tuberculosis/rifampicin assay for the GeneXpert platform is considered an important breakthrough in the fight against tuberculosis. Xpert though robust is known to have issues that occur with very low load of tuberculosis detection, wherein it is recommended to confirm resistance if resistance is not suspected using another genotypic test.
RESUMO
BACKGROUND: Resistance due to New Delhi metallo-ß-lactamase (NDM) and OXA-48/181 continues to emerge as a threat which is associated with nosocomial outbreaks and is a serious healthcare concern. Phenotypic detection being laborious and time-consuming requires rapid detection of NDM and OXA-48/181, which is achieved through real-time polymerase chain reaction (RT-PCR). MATERIALS AND METHODS: In this study, RT-PCR assay was developed to simultaneously detect NDM and OXA-48/181. The assay was validated on 102 non-duplicate, phenotypically characterised clinical samples. RESULTS: The assay showed a sensitivity and specificity of 97% and 100% for the detection of carbapenemases in comparison to conventional PCR. The in-house developed multiplex RT-PCR would help to rule-in the presence of NDM and OXA-48/181. CONCLUSIONS: Rapid detection of these carbapenemases would be assist in better patient management, in terms of accurate antimicrobial treatment, help in cohorting infected from uninfected patient to prevent spread.
Assuntos
Proteínas de Bactérias/análise , Reação em Cadeia da Polimerase em Tempo Real/métodos , Manejo de Espécimes/métodos , beta-Lactamases/análise , Proteínas de Bactérias/genética , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Reação em Cadeia da Polimerase Multiplex/métodos , Sensibilidade e Especificidade , Fatores de Tempo , beta-Lactamases/genéticaRESUMO
Tubercular meningitis (TBM) is a serious form of tuberculosis (TB). The diagnosis of TBM & susceptibility/resistance is difficult as TB MGIT culture lacks sensitivity & timeliness. Timely and accurate diagnosis of the TBM is the need of the hour for initiation of appropriate therapy. We have exploited pyrosequencing to detect TB and associated Multi/extensively drug resistant (MDR/ XDR-TB) directly from Cerebrospinal Fluid (CSF) specimens.
Assuntos
Técnicas Bacteriológicas , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla/genética , Tuberculose Extensivamente Resistente a Medicamentos/diagnóstico , Sequenciamento de Nucleotídeos em Larga Escala , Mycobacterium tuberculosis/genética , Análise de Sequência de DNA/métodos , Tuberculose Meníngea/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Adolescente , Adulto , Antituberculosos/uso terapêutico , Líquido Cefalorraquidiano/microbiologia , DNA Bacteriano/líquido cefalorraquidiano , Tuberculose Extensivamente Resistente a Medicamentos/líquido cefalorraquidiano , Tuberculose Extensivamente Resistente a Medicamentos/tratamento farmacológico , Tuberculose Extensivamente Resistente a Medicamentos/microbiologia , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/patogenicidade , Fenótipo , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Fatores de Tempo , Tuberculose Meníngea/líquido cefalorraquidiano , Tuberculose Meníngea/tratamento farmacológico , Tuberculose Meníngea/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/líquido cefalorraquidiano , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Fluxo de Trabalho , Adulto JovemRESUMO
Delayed diagnosis of drug resistance has been a major obstacle to proper management and control of drug-resistant tuberculosis (TB). Expanded access to rapid molecular diagnostics such as Xpert MTB/RIF has been helpful, but has generated confusion about how to interpret genotype-phenotype discordance. Optimal management is not clearly defined for patients with rifampin resistance by Xpert MTB/RIF but rifampin susceptibility by phenotypic testing. To resolve this discrepancy, we performed pyrosequencing of discordant isolates identified at a reference laboratory over a 6-month period. We present here strategies to address genotype-phenotype discordance using sequencing.
RESUMO
MGIT 960 drug susceptibility testing (DST) for Mycobacterium tuberculosis was compared for performance and speed with pyrosequencing (PSQ). Pulmonary samples (nâ¯=â¯100), from GeneXpert/MTB/Rifampicin-resistant patients receiving second-line treatment for 1-3 months, were subjected to DST and PSQ for seven drugs (isoniazid, rifampicin, kanamycin, amikacin, capreomycin, moxifloxacin, and ofloxacin). The mean time-to-result was 35 and two days for DST and PSQ, respectively. Average concordancy was 92.7%. Theoretically, PSQ showed substantial incremental value over the commercial Genotype MTBDRplus/sl. Mutations not considered in commercial molecular tests were observed by PSQ. Our findings corroborated the association between S315T (katG region) and S531L (rpoB region) and phenotypic resistance. PSQ is more rapid, can be performed from the sample, provides information about all known mutations simultaneously, allows extensive post-processing analyses, and is open to the inclusion of new mutations. It indicates the exact mutation conferring resistance to the particular drug, unlike the qualitative DST.
Assuntos
Antituberculosos/farmacologia , Tuberculose Extensivamente Resistente a Medicamentos/microbiologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Mycobacterium tuberculosis/efeitos dos fármacos , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla/genética , Estudos de Viabilidade , Genótipo , Humanos , Testes de Sensibilidade Microbiana/métodos , Mutação , Mycobacterium tuberculosis/genética , Fenótipo , Saúde Pública , Análise de Sequência de DNA/métodosRESUMO
BACKGROUND: The Xpert MTB/RIF assay is an automated molecular test that has improved the detection of tuberculosis and rifampicin resistance, but its sensitivity is inadequate in patients with paucibacillary disease or HIV. Xpert MTB/RIF Ultra (Xpert Ultra) was developed to overcome this limitation. We compared the diagnostic performance of Xpert Ultra with that of Xpert for detection of tuberculosis and rifampicin resistance. METHODS: In this prospective, multicentre, diagnostic accuracy study, we recruited adults with pulmonary tuberculosis symptoms presenting at primary health-care centres and hospitals in eight countries (South Africa, Uganda, Kenya, India, China, Georgia, Belarus, and Brazil). Participants were allocated to the case detection group if no drugs had been taken for tuberculosis in the past 6 months or to the multidrug-resistance risk group if drugs for tuberculosis had been taken in the past 6 months, but drug resistance was suspected. Demographic information, medical history, chest imaging results, and HIV test results were recorded at enrolment, and each participant gave at least three sputum specimen on 2 separate days. Xpert and Xpert Ultra diagnostic performance in the same sputum specimen was compared with culture tests and drug susceptibility testing as reference standards. The primary objectives were to estimate and compare the sensitivity of Xpert Ultra test with that of Xpert for detection of smear-negative tuberculosis and rifampicin resistance and to estimate and compare Xpert Ultra and Xpert specificities for detection of rifampicin resistance. Study participants in the case detection group were included in all analyses, whereas participants in the multidrug-resistance risk group were only included in analyses of rifampicin-resistance detection. FINDINGS: Between Feb 18, and Dec 24, 2016, we enrolled 2368 participants for sputum sampling. 248 participants were excluded from the analysis, and 1753 participants were distributed to the case detection group (n=1439) and the multidrug-resistance risk group (n=314). Sensitivities of Xpert Ultra and Xpert were 63% and 46%, respectively, for the 137 participants with smear-negative and culture-positive sputum (difference of 17%, 95% CI 10 to 24); 90% and 77%, respectively, for the 115 HIV-positive participants with culture-positive sputum (13%, 6·4 to 21); and 88% and 83%, respectively, across all 462 participants with culture-positive sputum (5·4%, 3·3 to 8·0). Specificities of Xpert Ultra and Xpert for case detection were 96% and 98% (-2·7%, -3·9 to -1·7) overall, and 93% and 98% for patients with a history of tuberculosis. Xpert Ultra and Xpert performed similarly in detecting rifampicin resistance. INTERPRETATION: For tuberculosis case detection, sensitivity of Xpert Ultra was superior to that of Xpert in patients with paucibacillary disease and in patients with HIV. However, this increase in sensitivity came at the expense of a decrease in specificity. FUNDING: Government of Netherlands, Government of Australia, Bill & Melinda Gates Foundation, Government of the UK, and the National Institute of Allergy and Infectious Diseases.
Assuntos
Antibióticos Antituberculose/farmacologia , Farmacorresistência Bacteriana , Técnicas de Diagnóstico Molecular/métodos , Mycobacterium tuberculosis/isolamento & purificação , Rifampina/farmacologia , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Pulmonar/diagnóstico , Adulto , África , Ásia , Técnicas Bacteriológicas/métodos , Brasil , Europa (Continente) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Estudos Prospectivos , Sensibilidade e Especificidade , Escarro/microbiologiaRESUMO
To prevent the spread of carbapenemases-producing Enterobacteriaceae (CPE) active surveillance, contact isolation and cohorting infected patients should be practiced. Rectal swabs for the Xpert MDRO-assay of 32 patients were included. 71.85% were positive for targets incorporated into the MDRO-assay; whereas 28% were phenotypically not CRE and Xpert negative (9.37% had different mechanism [bla OXA]). The assay identified 59.3%, 9.37% and 3.1% as bla NDM, bla NDM+VIM and bla VIM, respectively. The assay is a screening test that identifies CPE harbouring organism within an hour and can be installed at tertiary-care facilities to screen colonized patients.
Assuntos
Proteínas de Bactérias/análise , Técnicas Bacteriológicas/métodos , Infecções por Enterobacteriaceae/microbiologia , Enterobacteriaceae/enzimologia , Reação em Cadeia da Polimerase Multiplex/métodos , beta-Lactamases/análise , Proteínas de Bactérias/genética , Enterobacteriaceae/isolamento & purificação , Humanos , Programas de Rastreamento/métodos , Reto/microbiologia , beta-Lactamases/genéticaRESUMO
To evaluate the performance of TrueNAT (RT Micro PCR device) assay in comparison with GeneXpert on sputum samples from pulmonary cases of tuberculosis. 274 samples were processed to detect MTB by ZN smear examination, MGIT culture and molecular methods that included RT-PCR (ABI 7500 & TrueNAT) and GeneXpert for case detection of TB. The overall performance of the test with MGIT(Mycobacterium Growth Indicator Tube) culture as gold standard, sensitivity of smear, RT PCR/TrueNAT and Genexpert was 61.5% (CI:53.3-69.3%), 94.7% (CI:89.8-97.6%) & 96.0% (CI: 91.5-98.5%), respectively. Amongst the S+ (108) samples, RT-PCR/TrueNAT and GeneXpert showed a sensitivity of 99% (CI:94.9%-99.8%) and 100% (98.6%-100.0%), respectively. High concordance was observed between GeneXpert and TrueNAT for case detection of TB. The GeneXpert MTB/RIF test was independent on the user's skills. It has a short turn-around time and simultaneously detects RIF resistance with M. tuberculosis in less than 3h. The TrueNAT MTB has good sensitivity and specificity in case detection with hands on time of less than 3h as well as fits the requirements in resourcelimited health care settings. Larger, multi-site studies are required to obtain better estimates of the performance of TrueNAT MTB.
RESUMO
BACKGROUND: Control of the global Tuberculosis (TB) burden is hindered by the lack of a simple and effective diagnostic test that can be utilized in resource-limited settings. METHODS: We evaluated the performance of Truenat MTB™, a chip-based nucleic acid amplification test in the detection of Mycobacterium tuberculosis (MTB) in clinical sputum specimens from 226 patients with suspected pulmonary tuberculosis (TB). The test involved sputum processing using Trueprep-MAG™ (nanoparticle-based protocol run on a battery-operated device) and real-time PCR performed on the Truelab Uno™ analyzer (handheld, battery-operated thermal cycler). Specimens were also examined for presence of MTB using smear microscopy, liquid culture and an in-house nested PCR protocol. Results were assessed in comparison to a composite reference standard (CRS) consisting of smear and culture results, clinical treatment and follow-up, and radiology findings. RESULTS: Based on the CRS, 191 patients had "Clinical-TB" (Definite and Probable-TB). Of which 154 patients are already on treatment, and 37 were treatment naïve cases. Remaining 35 were confirmed "Non-TB" cases which are treatment naïve cases. The Truenat MTB test was found to have sensitivity and specificity of 91.1% (CI: 86.1-94.7) and 100% (CI: 90.0-100) respectively, in comparison to 90.58% (CI: 85.5-94.3) and 91.43% (CI: 76.9-98.2) respectively for the in-house nested PCR protocol. CONCLUSION: This preliminary study shows that the Truenat MTB test allows detection of TB in approximately one hour and can be utilized in near-care settings to provide quick and accurate diagnosis.
Assuntos
Técnicas e Procedimentos Diagnósticos/instrumentação , Mycobacterium tuberculosis/isolamento & purificação , Mycobacterium tuberculosis/fisiologia , Sistemas Automatizados de Assistência Junto ao Leito , Tuberculose Pulmonar/diagnóstico , Humanos , Mycobacterium tuberculosis/genética , Nanopartículas , Reação em Cadeia da Polimerase em Tempo Real , Escarro/microbiologia , Fatores de TempoRESUMO
BACKGROUND: The emergence of resistant tuberculosis (TB) is a major setback to the global control of the disease as the treatment of such resistance is complex and expensive. Use of direct detection of mutations by molecular methods could facilitate rapid diagnosis of resistance to offset diagnostic delays. We evaluated the performance of the Genotype MTBDRsl (Hain Life Sciences) for the detection of second line resistant TB directly from stored smear positive sputum sediments. METHODOLOGY/PRINCIPAL FINDINGS: The assay showed a diverse range of sensitivity and specificity, 91.26% [95% CI, 84-96] and 95.5% [95% CI, 87-99] for FQ (PPV â¼97% & NPV â¼ 87.67%), 56.19% [95%CI, 46-66] and 81% [95%CI, 66-91] for EMB (PPV â¼ 88.06% & NPV â¼ 43.21%) and 100% for SLD. Diagnostic accuracy for FQ, SLD and EMB was 94%, 100% and 63.51%, respectively. 1.17% (2/170) were heteroresistance strains, where the heteroresistance was linked to rrs gene. A varying rate of validity was observed 100% (170/170) for FQ, 94.11% (160/170) for EMB, 88.23% (150/170) for SLD. CONCLUSIONS/SIGNIFICANCE: Genotype MTBDRsl is simple, rapid, economical assay that can be used to detect commonly known resistance associated with Fluoroquinolone, second line injectable drugs and ethambutol. The assay detects the targeted resistance in less time as compared to phenotypic DST. But due to low NPV to FQ (88%) and EMB (43.21%), the assay results must be interpreted in coordination with the phenotypic DST.