scholarly journals Evaluation of the GenoType MTBDRplusand MTBDRslfor the detection of drug-resistantMycobacterium tuberculosison isolates from Beijing, China

2018 ◽  
Author(s):  
Jiyong Jian ◽  
Xinyu Yang ◽  
Jun Yang ◽  
Liang Chen

ABSTRACTThe incidence of tuberculosis (TB) and especially multidrug-resistant TB (MDR) and extreme drug resistance (XDR-TB) continue to increase alarmingly worldwide and reliable and fast diagnosis of MDR-TB and XDR-TB is essential for the adequate treatment of patients. So molecular line probe assays (LPAs) for detection of MDR-TB and XDR-TB have been endorsed by the World Health Organization (WHO). We analyzed 96 isolates from Beijing comparing culture-based drug susceptibility testing (DST) to LPAs detecting rifampicin (RFP), isoniazid (INH), and levofloxacin (LFX), amikacin (AM), capreomycin (CMP), ethambutol (EMB) resistance. Compared to phenotypic DST, the GenoType MTBDRplusand MTBDRslshowed a sensitivity of 98.7% and a specificity of 88.9% for detection of RFP resistance, 82.1% and 94.4% for INH, 89.7% and 94.4% for LFX, 60.0% and 98.7% for AM/CPM, 57.5% and 98.2% for EMB, respectively. The sensitivity and specificity of LPAs for MDR-TB and XDR-TB were 80.8%, 100% and 50.0%, 97.6%. Mutations in codon S531L of therpoBgene and S315T1 ofKatGgene were dominated in MDR-TB strains. The most frequently observed mutations were in codon A90V of thegyrAgene, A1401G of therrsgene and M306V of theembBgene, according to the MTBDRslresults. Our study showed that, in combination to phenotypic DST, application of the LPAs might be an efficient and reliable supplementary DST assay for rapid susceptibility screening of MDR-TB and XDR-TB. Using LPAs in high MDR/XDR burden countries allows for appropriate and timely treatment, which will reduce transmission rates, morbidity and improve treatment outcomes in patients.


2021 ◽  
Author(s):  
◽  
Alexander S Lachapelle

Rapid and up-to-date drug susceptibility testing is urgently needed to address the threat of multidrug resistant tuberculosis. We developed a composite machine learning system to predict susceptibility from whole-genome sequences for 13 anti-tuberculosis drugs. We trained, validated and externally tested the system, and assessed its performance against a previously validated mutation catalogue, existing molecular assays, and World Health Organization Target Product Profiles. 174,492 phenotypes and 26,328 isolates from 15 countries were studied. The sensitivity of the model was greater than 90% for all drugs except ethionamide, clofazimine and linezolid. Specificity was greater than 95% for all drugs except ethambutol, ethionamide, and bedaquiline, delamanid and clofazimine. The machine learning system was more sensitive than the catalogue and assay (all p<0.01), and correctly predicted a pan-susceptible regimen with 98% accuracy in MDR-TB samples. The proposed system can help guide therapy and be updated automatically as new resistance emerges.



2020 ◽  
Vol 24 (3) ◽  
pp. 329-339 ◽  
Author(s):  
J-C. S. Ngabonziza ◽  
Y. M. Habimana ◽  
T. Decroo ◽  
P. Migambi ◽  
A. Dushime ◽  
...  

SETTING: In 2005, in response to the increasing prevalence of rifampicin-resistant tuberculosis (RR-TB) and poor treatment outcomes, Rwanda initiated the programmatic management of RR-TB, including expanded access to systematic rifampicin drug susceptibility testing (DST) and standardised treatment.OBJECTIVE: To describe trends in diagnostic and treatment delays and estimate their effect on RR-TB mortality.DESIGN: Retrospective analysis of individual-level data including 748 (85.4%) of 876 patients diagnosed with RR-TB notified to the World Health Organization between 1 July 2005 and 31 December 2016 in Rwanda. Logistic regression was used to estimate the effect of diagnostic and therapeutic delays on RR-TB mortality.RESULTS: Between 2006 and 2016, the median diagnostic delay significantly decreased from 88 days to 1 day, and the therapeutic delay from 76 days to 3 days. Simultaneously, RR-TB mortality significantly decreased from 30.8% in 2006 to 6.9% in 2016. Total delay in starting multidrug-resistant TB (MDR-TB) treatment of more than 100 days was associated with more than two-fold higher odds for dying. When delays were long, empirical RR-TB treatment initiation was associated with a lower mortality.CONCLUSION: The reduction of diagnostic and treatment delays reduced RR-TB mortality. We anticipate that universal testing for RR-TB, short diagnostic and therapeutic delays and effective standardised MDR-TB treatment will further decrease RR-TB mortality in Rwanda.



2018 ◽  
Vol 51 (3) ◽  
pp. 1702467 ◽  
Author(s):  
Cheon Tae Kim ◽  
Tae-Ok Kim ◽  
Hong-Joon Shin ◽  
Young Chun Ko ◽  
Yeong Hun Choe ◽  
...  

Relatively little is known about the efficacy and safety of the programmatic use of bedaquiline and delamanid in multidrug-resistant tuberculosis (MDR-TB) treatment.This study evaluated 61 patients with MDR-TB treated with bedaquiline (n=39), delamanid (n=11) or both, either sequentially (n=10) or in coadministration (n=1), for >1 month, combined with a World Health Organization-recommended regimen.Of these, 49 (80.3%) were male and 12 (19.7%) were female. The median (interquartile range (IQR)) age was 53 (38.5–61.0) years. 42 (68.9%) patients had fluoroquinolone-resistant MDR-TB and 16 (26.2%) had extensively drug-resistant TB. The median (IQR) duration of treatment with bedaquiline and/or delamanid was 168 (166.5–196.5) days, with 33 (54.1%) receiving linezolid for a median (IQR) of 673 (171–736) days. Of the 55 patients with positive sputum cultures at the start of bedaquiline and/or delamanid treatment, 39 (70.9%) achieved sputum culture conversion within a median of 119 days. Treatment was halted in four patients (6.6%) because of prolonged Fridericia's corrected QT interval.Bedaquiline and delamanid were effective and safe for treating MDR-TB, with initial evidence of sequential administration of these two drugs as a viable treatment strategy for patients when an adequate treatment regimen cannot be constructed.



2010 ◽  
Vol 15 (11) ◽  
Author(s):  
I Devaux ◽  
D Manissero ◽  
K Fernandez de la Hoz ◽  
K Kremer ◽  
D van Soolingen ◽  
...  

This paper describes the results of second-line drug (SLD) susceptibility tests among multidrug-resistant tuberculosis (MDR TB) cases reported in 20 European countries aiming to identify extensively drug-resistant tuberculosis (XDR TB) cases. A project on molecular surveillance of MDR TB cases was conducted by EuroTB and the National Institute for Public Health and the Environment (RIVM) from 2005 to 2007. Information on drug susceptibility testing (DST) was provided to this project and case-based data on MDR TB cases were reported on a quarterly basis by 20 countries of the World Health Organization’s European Region, including 15 European Union Member States. Data included SLD susceptibility test results, enabling a retrospective description of XDR TB cases notified between 2003 and 2007 .In 18 countries DST was performed for two or more of the SLD included in the XDR TB definition. The proportion of MDR TB isolates tested for SLD varied widely between countries (range 20 to 100 percent). In the 18 countries, 149 (10%) XDR TB cases were reported among MDR TB cases with available DST results for SLD. Sixteen additional MDR TB cases were reported by the MDR TB surveillance system when compared with the number of routinely reported MDR TB cases to EuroTB in ten countries with representative data reported during three consecutive years (2003-2005). To counter the threat of XDR TB in Europe, a standardised approach to XDR TB surveillance and DST for SLD is needed, as well as increased laboratory capacity across European countries.



Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 797
Author(s):  
Vichita Ok ◽  
Alexandra Aubry ◽  
Florence Morel ◽  
Isabelle Bonnet ◽  
Jérôme Robert ◽  
...  

The MDR/MTB ELITe MGB® kit (ELITech) carried on the ELITe InGenius® platform is a new real-time PCR assay allowing automated extraction and detection of DNA of the Mycobacterium tuberculosis complex (MTB) and mutations in the rpoB and katG genes and inhA promoter region (pro-inhA) associated to resistance to rifampicin and isoniazid, the two markers of multidrug-resistant TB (MDR). We assessed the performances of the test on a collection of strains (n = 54) and a set of clinical samples (n = 242) from routine practice, comparatively to TB diagnosis and genotypic drug susceptibility testing (gDST) as references. Regarding the 242 clinical samples, the sensitivity and specificity of MTB detection by ELITe were 90.9% and 97.5%, respectively. For the detection of resistance-conferring mutations on positive clinical samples, we observed perfect agreement with gDST for katG and pro-inhA (κ = 1.0) and two discordant results for rpoB (κ = 0.82). Considering the 54 cultured strains, very good agreement with gDST was observed for the detection of the 25 distinct mutations in rpoB, katG, and pro-inhA, (κ = 0.95, 0.88, and 0.95, respectively). In conclusion, the automated MDR/MTB ELITe MGB® assay shows great promise and appears to be a valuable tool for rapid detection of pre-MDR- and MDR-TB directly from clinical specimens.



2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Natasha F. Sabur ◽  
Mantaj S. Brar ◽  
Lisa Wu ◽  
Sarah K. Brode

Abstract Background The World Health Organization recommends intravenous amikacin for the treatment of MDR-TB at a dose of 15 mg/kg. However, higher doses are associated with significant toxicity. Methods Patients with MDR-TB treated at our institution receive amikacin at 8–10 mg/kg, with dose adjustment based on therapeutic drug monitoring. We conducted a retrospective cohort study of patients with MDR-TB who received amikacin between 2010 and 2016. Results Forty-nine patients were included in the study. The median starting dose of amikacin was 8.9 mg/kg (IQR 8, 10), and target therapeutic drug levels were achieved at a median of 12 days (IQR 5, 26). The median duration of amikacin treatment was 7.2 months (IQR 5.7, 8), and median time to sputum culture conversion was 1 month (IQR 1,2). Six patients (12.2%) experienced hearing loss based on formal audiometry testing (95% CI 4.6–24.8%); 22.2% had subjective hearing loss (95% CI 11.2–37.1%) and 31.9% subjective tinnitus (95% CI 19.1–47.1%). Ten patients (23%) had a significant rise in serum creatinine (95% CI 11.8–38.6%), but only 5 patients had a GFR < 60 at treatment completion. 84% of patients had a successful treatment outcome (95% CI 84–99%). Conclusions Low dose amikacin is associated with relatively low rates of aminoglycoside-related adverse events. We hypothesize that low-dose amikacin can be used as a safe and effective treatment for MDR-TB in situations where an adequate regimen cannot be constructed with Group A and B drugs, and where careful monitoring for adverse events is feasible.



2020 ◽  
Vol 6 (4) ◽  
pp. 00329-2020
Author(s):  
Roland Diel ◽  
Albert Nienhaus

BackgroundA total of 5429 new cases of tuberculosis (TB) were reported in Germany in 2018; out of the 3780 TB cases for whom drug susceptibility testing was available, the proportion of multidrug-resistant TB (MDR-TB) cases was only 3.1% (118 cases).MethodsOn the basis of the current therapy guidelines of the German Central Committee against Tuberculosis, this study estimates the mean direct outpatient and combined in- and outpatient costs per non-MDR-TB patient from the perspective of the German statutory health insurance (SHI) system, together with costs arising from productivity losses and costs due to public health screening for TB in close contacts.ResultsFrom the insurance perspective, the mean outpatient costs (rounded) per case were €1628 for adults and €1179 for children for standard therapy; the mean cost of inpatient treatment amounted to €8626. The mean combined inpatient/outpatient cost was €8756 for adults and €8512 for children. As 95% of all TB patients were adults, the weighted treatment cost per patient in Germany in 2018 was €8746. These are in addition to the mean cost arising from productivity losses (€1839) and, weighted by pulmonary infectivity, cost of contact investigations (€368), coming to a total of €10 953.ConclusionGiven the clear increase in the number of non-MDR-TB cases since 2015, TB is still a disease of significant economic impact in Germany.



2021 ◽  
Author(s):  
◽  
Joshua J Carter

AbstractThe World Health Organization goal of universal drug susceptibility testing for patients with tuberculosis is most likely to be achieved through molecular diagnostics; however, to date these have focused largely on first-line drugs, and always on predicting binary susceptibilities. Here, we used whole genome sequencing and a quantitative microtiter plate assay to relate genomic mutations to minimum inhibitory concentration in 15,211 Mycobacterium tuberculosis patient isolates from 27 countries across five continents.This work identifies 449 unique MIC-elevating genetic determinants across thirteen drugs, as well as 91 mutations resulting in hypersensitivity for eleven drugs. Our results provide a guide for further implementation of personalized medicine for the treatment of tuberculosis using genetics-based diagnostics and can serve as a training set for novel approaches to predict drug resistance.



2020 ◽  
Vol 10 (7) ◽  
pp. 2605 ◽  
Author(s):  
Christian Lienhardt ◽  
Mario C. Raviglione

The World Health Organization (WHO) End Tuberculosis (TB) Strategy has set ambitious targets to reduce 2015 TB incidence and deaths by 80% and 90%, respectively, by the year 2030. Given the current rate of TB incidence decline (about 2% per year annually), reaching these targets will require new transformational tools and innovative ways to deliver them. In addition to improved tests for early and rapid detection of TB and universal drug-susceptibility testing, as well as novel vaccines for improved prevention, better, safer, shorter and more efficacious treatments for all forms of TB are needed. Only a handful of new drugs are currently in phase II or III clinical trials, and a few combination regimens are being tested, mainly for drug-resistant TB. In this article, capitalising on an increasingly rich medicine pipeline and taking advantage of new methodological designs with great potential, the main areas where progress is needed for a transformational improvement of treatment of all forms of TB are described.



2019 ◽  
Vol 147 ◽  
Author(s):  
R. S. Salvato ◽  
S. Schiefelbein ◽  
R. B. Barcellos ◽  
B. M. Praetzel ◽  
I. S. Anusca ◽  
...  

AbstractTuberculosis (TB) is the leading cause of death among infectious diseases worldwide. Among the estimated cases of drug-resistant TB, approximately 60% occur in the BRICS countries (Brazil, Russia, India, China and South Africa). Among Brazilian states, primary and acquired multidrug-resistant TB (MDR-TB) rates were the highest in Rio Grande do Sul (RS). This study aimed to perform molecular characterisation of MDR-TB in the State of RS, a high-burden Brazilian state. We performed molecular characterisation of MDR-TB cases in RS, defined by drug susceptibility testing, using 131Mycobacterium tuberculosis (M.tb)DNA samples from the Central Laboratory. We carried out MIRU-VNTR 24loci, spoligotyping, sequencing of thekatG,inhA andrpoB genes and RDRiosublineage identification. The most frequent families found were LAM (65.6%) and Haarlem (22.1%). RDRiodeletion was observed in 42 (32%) of theM.tbisolates. Among MDR-TB cases, eight (6.1%) did not present mutations in the studied genes. In 116 (88.5%)M.tbisolates, we found mutations associated with rifampicin (RIF) resistance inrpoB gene, and in 112 isolates (85.5%), we observed mutations related to isoniazid resistance inkatG andinhA genes. An insertion of 12 nucleotides (CCAGAACAACCC) at the 516 codon in therpoB gene, possibly responsible for a decreased interaction of RIF and RNA polymerase, was found in 19/131 of the isolates, belonging mostly to LAM and Haarlem families. These results enable a better understanding of the dynamics of transmission and evolution of MDR-TB in the region.



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