Diagnostic performance of whole-genome sequencing for identifying drug-resistant TB in Thailand

2021 ◽  
Vol 25 (9) ◽  
pp. 754-760
Author(s):  
P. Kamolwat ◽  
D. Nonghanphithak ◽  
A. Chaiprasert ◽  
S. Smithtikarn ◽  
P. Pungrassami ◽  
...  

BACKGROUND: Whole-genome sequencing (WGS) is a promising tool for the detection of drug-resistant TB (DR-TB). To date, there have been few comparisons of diagnostic performance of WGS and phenotypic drug susceptibility testing (DST) in DR-TB.METHODS: We compared drug resistance-conferring mutations identified by WGS analysis using TB-Profiler and Mykrobe with phenotypic DST profiles based on the Löwenstein-Jensen proportion method using drug-resistant Mycobacterium tuberculosis (n = 537) isolates from across Thailand. Based on available phenotypic DST results, diagnostic performance was analysed for resistance against isoniazid, rifampicin, ethambutol (EMB), streptomycin, ethionamide (ETH), kanamycin, capreomycin (CPM), para-aminosalicylic acid, ofloxacin and levofloxacin.RESULTS: High agreement between the two methods was observed for most drugs (>91%), except EMB (57%, 95% CI 53–61) and ETH (70%, 95% CI 66–74). Also, low specificity was observed for EMB (49%, 95% CI 44–54) and ETH (66%, 95% CI 61–71). Sensitivity was high for most drugs (range 83–98%), except CPM (77%, 95% CI 59–88).CONCLUSION: Low agreement between WGS and phenotypic tests for drug resistance was found for EMB and ETH. The current genomic database is insufficient for the identification of CPM resistance. Challenges remain for routine usage of WGS-based DST, especially for second-line anti-TB drugs.

2020 ◽  
Author(s):  
Martina L. Reichmuth ◽  
Kathrin Zürcher ◽  
Marie Ballif ◽  
Chloé Loiseau ◽  
Sonia Borrell ◽  
...  

AbstractBackgroundDrug-resistant Mycobacterium tuberculosis (Mtb) strains threaten tuberculosis (TB) control. We compared data on drug resistance obtained at clinics in seven high TB burden countries during routine care with whole-genome sequencing (WGS) carried out centrally.MethodsWe collected pulmonary Mtb isolates and clinical data from adult TB patients in Africa, Latin America, and Asia, stratified by HIV status and drug resistance, from 2013 to 2016. Participating sites performed drug susceptibility testing (DST) locally, using routinely available methods. WGS was done using Illumina HiSeq 2500 at laboratories in the USA and Switzerland. We used TBprofiler to analyse the genomes. We used multivariable logistic regression adjusted for sex, age, HIV-status, history of TB, sputum positivity, and Mtb-lineage to analyse mortality.FindingsWe included 582 TB patients. The median age was 32 years (interquartile range: 27-43 years), 225 (39%) were female, and 247 (42%) were HIV-positive. Based on WGS, 339 (58%) isolates were pan-susceptible, 35 (6%) monoresistant, 146 (25%) multidrug-resistant, and 24 (4%) pre-/ extensively drug-resistant (pre-XDR/XDR-TB). The local DST results were discordant compared to WGS results in 130/582 (22%) of patients. All testing methods identified isoniazid and rifampicin resistance with relatively high agreement (kappa 0.69 for isoniazid and 0.88 rifampicin). Resistance to ethambutol, pyrazinamide, and second-line drugs was rarely tested locally. Of 576 patients with known treatment, 86 (15%) patients received inadequate treatment according to WGS results and the World Health Organization treatment guidelines. The analysis of mortality was based on 530 patients; 63 patients (12%) died and 77 patients (15%) received inadequate treatment. Mortality ranged from 6% in patients with pan-susceptible Mtb (18/310) to 39% in patients with pre-XDR/XDR-TB (9/23). The adjusted odds ratio for mortality was 4.82 (95% CI 2.43-9.44) for under-treatment and 0.52 (95% CI 0.03-2.73) for over-treatment.InterpretationIn seven high-burden TB countries, we observed discrepancies between drug resistance patterns from local DST and WGS, which resulted in inadequate treatment and higher mortality. WGS can provide accurate and detailed drug resistance information, which is required to improve the outcomes of drug-resistant TB in high burden settings. Our results support the WHO’s call for point-of-care tests based on WGS.


2020 ◽  
Vol 9 (2) ◽  
pp. 465 ◽  
Author(s):  
Jalil Kardan-Yamchi ◽  
Hossein Kazemian ◽  
Simone Battaglia ◽  
Hamidreza Abtahi ◽  
Abbas Rahimi Foroushani ◽  
...  

Accurate and timely detection of drug resistance can minimize the risk of further resistance development and lead to effective treatment. The aim of this study was to determine the resistance to first/second-line anti-tuberculosis drugs in rifampicin/multidrug-resistant Mycobacterium tuberculosis (RR/MDR-MTB) isolates. Molecular epidemiology of strains was determined using whole genome sequencing (WGS)-based genotyping. A total of 35 RR/MDR-MTB isolates were subjected to drug susceptibility testing against first/second-line drugs using 7H9 Middlebrook in broth microdilution method. Illumina technology was used for paired-end WGS applying a Maxwell 16 Cell DNA Purification kit and the NextSeq platform. Data analysis and single nucleotide polymorphism calling were performed using MTBseq pipeline. The genome-based resistance to each drug among the resistant phenotypes was as follows: rifampicin (97.1%), isoniazid (96.6%), ethambutol (100%), levofloxacin (83.3%), moxifloxacin (83.3%), amikacin (100%), kanamycin (100%), capreomycin (100%), prothionamide (100%), D-cycloserine (11.1%), clofazimine (20%), bedaquiline (0.0%), and delamanid (44.4%). There was no linezolid-resistant phenotype, and a bedaquiline-resistant strain was wild type for related genes. The Beijing, Euro-American, and Delhi-CAS were the most populated lineage/sublineages. Drug resistance-associated mutations were mostly linked to minimum inhibitory concentration results. However, the role of well-known drug-resistant genes for D-cycloserine, clofazimine, bedaquiline, and delamanid was found to be more controversial.


2022 ◽  
Vol 98 (6) ◽  
pp. 697-705
Author(s):  
V. Tolchkov ◽  
Y. Hodzhev ◽  
B. Tsafarova ◽  
E. Bachiyska ◽  
Yu. Atanasova ◽  
...  

Introduction. Mycobacterium tuberculosis is the causative agent of tuberculosis. Drug susceptibility testing is performed by phenotypic and molecular tests. Commonly used for phenotypic drug susceptibility testing is the automated BACTEC system in a liquid culture medium. Drug susceptibility by line probe molecular tests was introduced almost 15 years ago. Recently whole genome sequencing (WGS) analysis of M. tuberculosis strains demonstrated that genotyping of drug-resistance could be accurately performed. Several software tools were developed.Our study aimed to perform whole-genome sequencing on phenotypically confirmed multi-drug resistant (MDR) M. tuberculosis strains, to identify drug-resistant mutations and to compare whole-genome sequencing profiles with line probe assay and phenotypic results.Materials and methods. We performed analysis on 34 MDR M. tuberculosis Bulgarian strains. Phenotypic drug susceptibility testing was performed on the BACTEC system. For molecular testing of drug susceptibility to first- and second-line tuberculostatics, we applied line probe assay Geno Type MTBDR plus v.1.0 и Geno Type MTBDR sl v.1.0. Sequencing was performed on MiSeq. Generated FASTQ files were analyzed for known drugresistant mutations with the software platform Mykrobe v.0.8.1.Results. All three methods — phenotypic analysis using the BACTEC system, genetic analysis of strains applying the Geno Type test and Mykrobe software gave comparable sensitivity/resistance results for the studied strains. All phenotypically proven rifampicin and isoniazid-resistant strains were 100% confirmed using Mykrobe software. The C-15T mutation is a marker for isoniazid resistance in strains of the SIT41 spoligotype. We observed a 75% (21/28) agreement between BACTEC and Mykrobe for ethambutol resistance. Phenotypically, 87% (n = 27) of the strains are resistant to streptomycin, but only 59% (n = 19) are proven by Mykrobe software. Comparing phenotypic and genotypic resistance to ofloxacin, amikacin and kanamycin, we observed 100% coincidence of results.Conclusions. Whole-genome sequencing approach is relatively expensive and laborious but useful for detailed analysis such as epidemiological genotyping and molecular drug susceptibility testing.


2018 ◽  
Author(s):  
Sebastian M. Gygli ◽  
Peter M. Keller ◽  
Marie Ballif ◽  
Nicolas Blöchliger ◽  
Rico Hömke ◽  
...  

AbstractWhole genome sequencing allows rapid detection of drug-resistant M. tuberculosis isolates. However, high-quality data linking quantitative phenotypic drug susceptibility testing (DST) and genomic data have thus far been lacking.We determined drug resistance profiles of 176 genetically diverse clinical M. tuberculosis isolates from Democratic Republic of the Congo, Ivory Coast, Peru, Thailand and Switzerland by quantitative phenotypic DST for 11 antituberculous drugs using the BD BACTEC MGIT 960 system and 7H10 agar dilution to generate a cross-validated phenotypic DST readout. We compared phenotypic drug susceptibility results with predicted drug resistance profiles inferred by whole genome sequencing.Both phenotypic DST methods identically classified the strains into resistant/susceptible in 73-99% of the cases, depending on the drug. Changes in minimal inhibitory concentrations were readily explained by mutations identified by whole genome sequencing. Using the whole genome sequences we were able to predict quantitative drug resistance levels where wild type and mutant MIC distributions did not overlap. The utility of genome sequences to predict quantitative levels of drug resistance was partially limited due to incompletely understood mechanisms influencing the expression of phenotypic drug resistance. The overall sensitivity and specificity of whole genome-based DST were 86.8% and 94.5%, respectively.Despite some limitations, whole genome sequencing has high predictive power to infer resistance profiles without the need for time-consuming phenotypic methods.One sentence summaryWhole genome sequencing of clinical M. tuberculosis isolates accurately predicts drug resistance profiles and may replace culture-based drug susceptibility testing in the future.


Author(s):  
Joseph Shea ◽  
Tanya A. Halse ◽  
Donna Kohlerschmidt ◽  
Pascal Lapierre ◽  
Herns A. Modestil ◽  
...  

Rapid and reliable detection of rifampin (RIF) resistance is critical for the diagnosis and treatment of drug-resistant and multi-drug resistant (MDR) tuberculosis. Discordant RIF phenotype/genotype susceptibility results remain a challenge due to the presence of rpoB mutations which do not confer high levels of RIF resistance as have been exhibited in strains with mutations such as Ser450Leu. These strains, termed low-level RIF resistant, exhibit elevated RIF minimum inhibitory concentrations (MICs) compared to fully susceptible strains, however remain phenotypically susceptible by mycobacteria growth indicator tube (MGIT) testing and have been associated with poor patient outcomes. Here we assess RIF resistance prediction by whole-genome sequencing (WGS) among a set of 1779 prospectively tested strains by both prevalence of rpoB gene mutation and phenotype as part of routine clinical testing during a 21/2-year period. During this time, 139 strains were found to have nonsynonymous rpoB mutations, 53 of which were associated with RIF resistance, including both low-level and high-level resistance. Resistance to RIF (1.0 μg/mL in MGIT) was identified in 43 (81.1%) isolates. The remaining 10 (18.9%) strains were susceptible by MGIT, however were confirmed to be low-level RIF resistant by MIC testing. Full rpoB gene sequencing overcame the limitations of critical concentration phenotyping, probe-based genotyping, and partial-gene sequencing methods. Universal clinical WGS with concurrent phenotypic testing provided a more complete understanding of the prevalence and type of rpoB mutations and their association with RIF resistance in New York.


2019 ◽  
Vol 63 (4) ◽  
Author(s):  
Sebastian M. Gygli ◽  
Peter M. Keller ◽  
Marie Ballif ◽  
Nicolas Blöchliger ◽  
Rico Hömke ◽  
...  

ABSTRACTWhole-genome sequencing allows rapid detection of drug-resistantMycobacterium tuberculosisisolates. However, the availability of high-quality data linking quantitative phenotypic drug susceptibility testing (DST) and genomic data have thus far been limited. We determined drug resistance profiles of 176 genetically diverse clinicalM. tuberculosisisolates from the Democratic Republic of the Congo, Ivory Coast, Peru, Thailand, and Switzerland by quantitative phenotypic DST for 11 antituberculous drugs using the BD Bactec MGIT 960 system and 7H10 agar dilution to generate a cross-validated phenotypic DST readout. We compared DST results with predicted drug resistance profiles inferred by whole-genome sequencing. Classification of strains by the two phenotypic DST methods into resistotype/wild-type populations was concordant in 73 to 99% of cases, depending on the drug. Our data suggest that the established critical concentration (5 mg/liter) for ethambutol resistance (MGIT 960 system) is too high and misclassifies strains as susceptible, unlike 7H10 agar dilution. Increased minimal inhibitory concentrations were explained by mutations identified by whole-genome sequencing. Using whole-genome sequences, we were able to predict quantitative drug resistance levels for the majority of drug resistance mutations. Predicting quantitative levels of drug resistance by whole-genome sequencing was partially limited due to incompletely understood drug resistance mechanisms. The overall sensitivity and specificity of whole-genome-based DST were 86.8% and 94.5%, respectively. Despite some limitations, whole-genome sequencing has the potential to infer resistance profiles without the need for time-consuming phenotypic methods.


2017 ◽  
Vol 1 (Special Issue-Supplement) ◽  
pp. 267-267
Author(s):  
Kayzad S. Nilgiriwala ◽  
Louise Pankhurst ◽  
Ali Vaughan ◽  
Zamin Iqbal ◽  
Derrick Crook ◽  
...  

2021 ◽  
Vol 25 (12) ◽  
pp. 995-1000
Author(s):  
A. Nikolenka ◽  
M. Mansjö ◽  
A. Skrahina ◽  
H. Hurevich ◽  
V. Grankov ◽  
...  

BACKGROUND: Distinguishing TB relapse from re-infection is important from a clinical perspective to document transmission patterns. We investigated isolates from patients classified as relapse to understand if these were true relapses or re-infections. We also investigated shifts in drug susceptibility patterns to distinguish acquired drug resistance from re-infection with resistant strains.METHODS: Isolates from pulmonary TB patients from 2009 to 2017 were analysed using whole-genome sequencing (WGS).RESULTS: Of 11 patients reported as relapses, WGS results indicated that 4 were true relapses (single nucleotide polymorphism difference ≤5), 3 were re-infections with new strains, 3 were both relapse and re-infection and 1 was a suspected relapse who was later categorised as treatment failure based on sequencing. Of the 9 patients who went from a fully susceptible to a resistant profile, WGS showed that none had acquired drug resistance; 6 were re-infected with new resistant strains, 1 was probably infected by at least two different genotype strains and 2 were phenotypically misclassified.CONCLUSIONS: WGS was shown to distinguish between relapse and re-infection in an unbiased way. The use of WGS minimises the risk of false classification of treatment failure instead of re-infection. Furthermore, our study showed that strains without major genetic differences can cause re-infection.


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