scholarly journals Phenotypic and Genotypic Characterization of Pyrazinamide Resistance among Multidrug-Resistant Mycobacterium tuberculosis Isolates in Zhejiang, China

2015 ◽  
Vol 59 (3) ◽  
pp. 1690-1695 ◽  
Author(s):  
Qiang Xia ◽  
Li-li Zhao ◽  
Feng Li ◽  
Yu-mei Fan ◽  
Yuan-yuan Chen ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Dna Sequencing ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Zhejiang Province ◽  
Phenotypic Data ◽  
Genotypic Characterization ◽  
Mdr Tb ◽  
Phenotypic And Genotypic Characterization

ABSTRACTTo explore the phenotypic and genotypic characterization of pyrazinamide (PZA) resistance among multidrug-resistantMycobacterium tuberculosis(MDR-TB) isolates in Zhejiang province, a total of 274 MDR-TB isolates were collected. Drug susceptibility testing and spoligotyping were performed on all clinical isolates. In addition, the mutated features of PZA-resistant loci, includingpncAandrpsA, were also analyzed by DNA sequencing. Our results showed that the prevalence of PZA resistance among MDR-TB strains in Zhejiang province was 43.07% and that PZA resistance was associated with concomitant resistance to streptomycin. The majority of PZA-resistant MDR-TB isolates belonged to the Beijing family. Mutations withinpncA, notrpsA, constituted the primary mechanism of PZA resistance. Among 118 PZA-resistant isolates, 53 different mutations were observed inpncA, and most of them were point mutations. Compared with the phenotypic data, DNA sequencing ofpncAhas sensitivity and specificity of 77.97% and 96.79%, respectively. Analysis ofpncAprovided a robust tool for rapid detection of PZA drug resistance.

scholarly journals Phenotypic and molecular characterization of pyrazinamide resistance among multidrug-resistant Mycobacterium tuberculosis isolates in Ningbo, China

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yang Che ◽  
Dingyi Bo ◽  
Xiang Lin ◽  
Tong Chen ◽  
Tianfeng He ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Dna Sequencing ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Mdr Tb ◽  
Resistant Group ◽  
Susceptible Group

Abstract Background Detection of pyrazinamide (PZA) resistance in Mycobacterium tuberculosis (TB) patients is critical, especially in dealing with multidrug-resistant Mycobacterium tuberculosis (MDR-TB) case. Up to date, PZA drug susceptibility testing (DST) has not been regularly performed in China. The prevalence and molecular characteristics of PZA resistance in M.tuberculosis isolates, especially MDR-TB have not been studied in Ningbo, China. This study aimed to analyze the phenotypic and molecular characterization of PZA resistance among MDR-TB isolates in Ningbo. Methods A total of 110 MDR-TB isolates were collected from the TB patients who were recorded at local TB dispensaries in Ningbo. All clinical isolates were examined by drug susceptibility testing and genotyping. DNA sequencing was used to detect mutations in the pncA gene associated with PZA resistance. Results The prevalence of PZA resistance among MDR-TB strains in Ningbo was 59.1%. With regard to the history and the outcome of treatments among MDR-TB cases, the percentages of re-treated MDR-TB patients in the PZA-resistant group and of successful patients in PZA-susceptible group were significantly higher than the ones in the PZA-susceptible group and in the PZA-resistant group, respectively (P = 0.027, P = 0.020). The results showed that the resistance of streptomycin (67.7% vs 46.7%, P = 0.027), ethambutol (56.9% vs 33.3%, P = 0.015), ofloxacin (43.1% vs 11.1%, P = 0.000), levofloxacin (43.1% vs 11.1%, P = 0.000), pre-XDR (pre-Xtensively Drug Resistance) (38.5% vs 15.6%, P = 0.009), were more frequently adverted among PZA-resistant isolates compared with PZA-susceptible isolates. In addition, 110 MDR-TB was composed of 87 (PZA resistant, 78.5%) Beijing strains and 23 (PZA resistant, 21.5%) non-Beijing strains. Fifty-four out of 65 (83.1%) PZA-resistant MDR strains harbored a mutation located in the pncA gene and the majority (90.7%) were point mutations. Compared with the phenotypic characterization, DNA sequencing of pncA has sensitivity and specificity of 83.1 and 95.6%. Conclusion The mutations within pncA gene was the primary mechanism of PZA resistance among MDR-TB and DNA sequencing of pncA gene could provide a rapid detection evidence in PZA drug resistance of MDR-TB in Ningbo.

scholarly journals Characterization of katG, inhA, rpoB and pncA in Mycobacterium tuberculosis isolates from MDR-TB risk patients in Thailand

2020 ◽  
Vol 14 (03) ◽  
pp. 268-276
Author(s):  
Krairerk Suthum ◽  
Worada Samosornsuk ◽  
Seksun Samosornsuk
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Dna Sequencing ◽  
Susceptibility Testing ◽  
Gene Mutations ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Common Mutation ◽  
Mdr Tb ◽  
Risk Patients

Introduction: Multidrug-resistant tuberculosis (MDR-TB) is commonly found in Thailand especially in the public health region 5, the Western region of Thailand. This study’s aim was to characterize katG, inhA, rpoB and pncA genes in Mycobacterium tuberculosis. Methodology: One hundred strains of Mycobacterium tuberculosis (MTB) were isolated from sputum samples of MDR-TB risk patients in the laboratory of the Office of Disease Prevention and Control 5th Ratchaburi province, Thailand from January to December 2015. Drug susceptibility testing (DST) was performed using a BACTEC MGIT 960 system. Furthermore, the genes katG, inhA, rpoB and pncA were characterized by DNA sequencing. Results: Of a total of 100 MTB samples which underwent drug susceptibility testing, 42% showed isoniazid (INH) and rifampicin (RIF) resistance, and a further 25% showed INH mono-resistance (25%). The most common gene mutations found using DNA sequencing were katG_Ser315Thr (70%), rpoB_Ser531leu (81%) and pncA_Ile31Thr (84%). The common mutation of pncA_Ile31Thr substitution was detected in 26 of 91 (29%) pyrazinamide (PZA) susceptible isolates. Conclusion: Using DNA sequencing to screen for gene mutations conferring drug resistance may be feasible and use less time than using DST to detect resistance patterns.

scholarly journals Molecular Characterization of Multidrug-Resistant Mycobacterium tuberculosis Isolates from China

2014 ◽  
Vol 58 (4) ◽  
pp. 1997-2005 ◽  
Author(s):  
Li-Li Zhao ◽  
Yan Chen ◽  
Hai-Can Liu ◽  
Qiang Xia ◽  
Xiao-Cui Wu ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Multidrug Resistant ◽  
Diagnostic Methods ◽  
Molecular Diagnostic ◽  
Beijing Family ◽  
Phenotypic Data ◽  
Resistant Tuberculosis ◽  
Multidrug Resistant Tuberculosis ◽  
Mdr Tb

ABSTRACTTo investigate the molecular characterization of multidrug-resistant tuberculosis (MDR-TB) isolates from China and the association of specific mutations conferring drug resistance with strains of different genotypes, we performed spoligotyping and sequenced nine loci (katG,inhA, theoxyR-ahpCintergenic region,rpoB,tlyA,eis,rrs,gyrA, andgyrB) for 128 MDR-TB isolates. Our results showed that 108 isolates (84.4%) were Beijing family strains, 64 (59.3%) of which were identified as modern Beijing strains. Compared with the phenotypic data, the sensitivity and specificity of DNA sequencing were 89.1% and 100.0%, respectively, for isoniazid (INH) resistance, 93.8% and 100.0% for rifampin (RIF) resistance, 60.0% and 99.4% for capreomycin (CAP) resistance, 84.6% and 99.4% for kanamycin (KAN) resistance, and 90.0% and 100.0% for ofloxacin (OFX) resistance. The most prevalent mutations among the MDR-TB isolates werekatG315,inhA15,rpoB531, -526, and -516,rrs1401,eis-10, andgyrA94, -90, and -91. Furthermore, there was no association between specific resistance-conferring mutations and the strain genotype. These findings will be helpful for the establishment of rapid molecular diagnostic methods to be implemented in China.

scholarly journals Drug susceptibility patterns of Mycobacterium tuberculosis from adults with multidrug-resistant tuberculosis and implications for a household contact preventive therapy trial

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Anne-Marie Demers ◽  
◽  
Soyeon Kim ◽  
Sara McCallum ◽  
Kathleen Eisenach ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Sputum Sample ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Preventive Therapy ◽  
Drug Susceptibility Testing ◽  
Study Entry ◽  
Resistant Tuberculosis ◽  
Mdr Tb ◽  
Therapy Trial

Abstract Background Drug susceptibility testing (DST) patterns of Mycobacterium tuberculosis (MTB) from patients with rifampicin-resistant tuberculosis (RR-TB) or multidrug-resistant TB (MDR-TB; or resistant to rifampicin and isoniazid (INH)), are important to guide preventive therapy for their household contacts (HHCs). Methods As part of a feasibility study done in preparation for an MDR-TB preventive therapy trial in HHCs, smear, Xpert MTB/RIF, Hain MTBDRplus, culture and DST results of index MDR-TB patients were obtained from routine TB programs. A sputum sample was collected at study entry and evaluated by the same tests. Not all tests were performed on all specimens due to variations in test availability. Results Three hundred eight adults with reported RR/MDR-TB were enrolled from 16 participating sites in 8 countries. Their median age was 36 years, and 36% were HIV-infected. Routine testing on all 308 were confirmed as having RR-TB, but only 75% were documented as having MDR-TB. The majority of those not classified as having MDR-TB were because only rifampicin resistance was tested. At study entry (median 59 days after MDR-TB treatment initiation), 280 participants (91%) were able to produce sputum for the study, of whom 147 (53%) still had detectable MTB. All but 2 of these 147 had rifampicin DST done, with resistance detected in 89%. Almost half (47%) of the 147 specimens had INH DST done, with 83% resistance. Therefore, 20% of the 280 study specimens had MDR-TB confirmed. Overall, DST for second-line drugs were available in only 35% of the 308 routine specimens and 15% of 280 study specimens. Conclusions RR-TB was detected in all routine specimens but only 75% had documented MDR-TB, illustrating the need for expanded DST beyond Xpert MTB/RIF to target preventive therapy for HHC.

scholarly journals Transmission patterns of rifampicin resistant Mycobacterium tuberculosis complex strains in Cameroon: a genomic epidemiological study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Matthias Merker ◽  
Nkongho F. Egbe ◽  
Yannick R. Ngangue ◽  
Comfort Vuchas ◽  
Thomas A. Kohl ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Prolonged Exposure ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
High Dose ◽  
Factors Affecting ◽  
Recent Transmission ◽  
Mdr Tb

Abstract Background Determining factors affecting the transmission of rifampicin (RR) and multidrug-resistant (MDR) Mycobacterium tuberculosis complex strains under standardized tuberculosis (TB) treatment is key to control TB and prevent the evolution of drug resistance. Methods We combined bacterial whole genome sequencing (WGS) and epidemiological investigations for 37% (n = 195) of all RR/MDR-TB patients in Cameroon (2012–2015) to identify factors associated with recent transmission. Results Patients infected with a strain resistant to high-dose isoniazid, and ethambutol had 7.4 (95% CI 2.6–21.4), and 2.4 (95% CI 1.2–4.8) times increased odds of being in a WGS-cluster, a surrogate for recent transmission. Furthermore, age between 30 and 50 was positively correlated with recent transmission (adjusted OR 3.8, 95% CI 1.3–11.4). We found high drug-resistance proportions against three drugs used in the short standardized MDR-TB regimen in Cameroon, i.e. high-dose isoniazid (77.4%), ethambutol (56.9%), and pyrazinamide (43.1%). Virtually all strains were susceptible to fluoroquinolones, kanamycin, and clofazimine, and treatment outcomes were mostly favourable (87.5%). Conclusion Pre-existing resistance to high-dose isoniazid, and ethambutol is associated with recent transmission of RR/MDR strains in our study. A possible contributing factor for this observation is the absence of universal drug susceptibility testing in Cameroon, likely resulting in prolonged exposure of new RR/MDR-TB patients to sub-optimal or failing first-line drug regimens.

scholarly journals Whole-genome sequencing analysis of multidrug-resistant Mycobacterium tuberculosis from Java, Indonesia

2020 ◽  
Vol 69 (7) ◽  
pp. 1013-1019
Author(s):  
Tryna Tania ◽  
Pratiwi Sudarmono ◽  
R. Lia Kusumawati ◽  
Andriansjah Rukmana ◽  
Wahyu Agung Pratama ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Public Health Problem ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Major Public Health Problem ◽  
Whole Genome ◽  
Sequencing Analysis ◽  
Mdr Tb

Introduction. Multidrug-resistant tuberculosis (MDR-TB) is a major public health problem globally, including in Indonesia. Whole-genome sequencing (WGS) analysis has rarely been used for the study of TB and MDR-TB in Indonesia. Aim. We evaluated the use of WGS for drug-susceptibility testing (DST) and to investigate the population structure of drug-resistant Mycobacterium tuberculosis in Java, Indonesia. Methodology. Thirty suspected MDR-TB isolates were subjected to MGIT 960 system (MGIT)-based DST and to WGS. Phylogenetic analysis was done using the WGS data. Results obtained using MGIT-based DST and WGS-based DST were compared. Results. Agreement between WGS and MGIT was 93.33 % for rifampicin, 83.33 % for isoniazid and 76.67 % for streptomycin but only 63.33 % for ethambutol. Moderate WGS–MGIT agreement was found for second-line drugs including amikacin, kanamycin and fluoroquinolone (73.33–76.67 %). MDR-TB was more common in isolates of the East Asian Lineage (63.3%). No evidence of clonal transmission of DR-TB was found among members of the tested population. Conclusion. Our study demonstrated the applicability of WGS for DST and molecular epidemiology of DR-TB in Java, Indonesia. We found no transmission of DR-TB in Indonesia.

scholarly journals Use of Genotype MTBDRplus Assay for Diagnosis of Multidrug-Resistant Tuberculosis in Nepal

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Elina Maharjan ◽  
Narayan Dutt Pant ◽  
Sanjeev Neupane ◽  
Jyoti Amatya ◽  
Bhawana Shrestha
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Resistant Tuberculosis ◽  
Multidrug Resistant Tuberculosis ◽  
Conventional Drug ◽  
Mdr Tb ◽  
Genotype Mtbdrplus

The main aims of this study were to study the patterns of mutations in rpoB, katG, and inhA genes in Mycobacterium tuberculosis strains isolated from patients from Nepal and to evaluate the performance of genotype MTBDRplus assay, taking conventional drug susceptibility testing as gold standard for diagnosis of MDR-TB. A total of 69 Mycobacterium tuberculosis strains isolated from 73 smear positive sputum samples from patients suspected of suffering from multidrug-resistant tuberculosis were used in our study. The drug susceptibility pattern of Mycobacterium tuberculosis isolated from these sputum specimens was determined by using genotype MTBDRplus assay taking conventional drug susceptibility testing as reference. The sensitivity and specificity of the genotype MTBDRplus assay for the detection of MDR-TB were found to be 88.7% and 100%, respectively. 88.7% of the rifampicin resistant isolates had mutations in rpoB gene. Similarly, 79.7% and 9.4% of isoniazid resistant isolates had mutations in katG and inhA genes, respectively. Genotype MTBDRplus assay was found to be very rapid and highly sensitive and specific method for diagnosis of MDR-TB and will be very helpful for early diagnosis of MDR-TB in high tuberculosis burden countries.

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