Direct tuberculosis drug susceptibility testing: time-saving and cost-effective in detecting MDR-TB

2016 ◽  
Vol 20 (3) ◽  
pp. 323-328 ◽  
Author(s):  
T. Zhang ◽  
C-F. Lv ◽  
J. Wang ◽  
W-B Zheng ◽  
L-Z. Lu ◽  
...  
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.


2021 ◽  
Vol 14 (7) ◽  
Author(s):  
Sulaiman A Al Yousef ◽  
Khalid AbdelRahim ◽  
Ahmed Mohamed Ali

Background: Fast, reliable, and cost-effective tests are recommended for tuberculosis diagnosis and drug susceptibility testing, especially in resource-limited settings. Objectives: This study aimed to evaluate the performance of thin-layer agar for tuberculosis diagnosis and drug susceptibility testing. Methods: Samples were collected from patients with presumptive tuberculosis and tested using thin-layer agar for tuberculosis and drug susceptibility testing in parallel with Lowenstein Jensen culture method for tuberculosis diagnosis and proportion method for drug susceptibility testing as the gold standard. Receiver operating characteristic curve analysis was performed to calculate the performance parameters. Results: Thin-layer agar method showed sensitivity and specificity values of 96.63% and 62.50%, respectively, for the isolation of Mycobacterium tuberculosis directly from specimens. Drug susceptibility results using thin-layer agar showed sensitivity values for isoniazid, rifampicin), ethambutol and streptomycin were 94.74%, 86.84%, 94.74% and 81.58%, respectively, while the specificity values were 100%, 100%, 86.27% and 100% for isoniazid, rifampicin, ethambutol and streptomycin, respectively. Results were available in a median time of 16 days for thin-layer agar and 25 days for the conventional method. Conclusions: The thin-layer agar method is a relatively rapid, simple, and cost-effective method for the diagnosis and drug susceptibility testing of M. tuberculosis. It may be a useful tool for establishing tuberculosis laboratories in resource-limited settings because it does not require expensive equipment and a high level of training. Our study may help in choosing the appropriate treatment and control of tuberculosis.


1970 ◽  
Vol 10 (2) ◽  
pp. 45-47 ◽  
Author(s):  
Mostafizur Rahman ◽  
SM Mostafa Kamal ◽  
Fazle Rabbi Mohammed ◽  
Md Billal Alam ◽  
HAM Nazmul Ahasan

Background: Anti-Tuberculosis (TB) drug resistance is emerging as a new global health problem. No national data on drug resistance is available in Bangladesh. The absolute number of multidrug resistant TB (MDR-TB) is expected to be high considering high TB burden. This study was aimed to determine the resistance pattern of mycobacterium tuberculosis (MTB) isolates among different category of patient. Method: A total 1123 randomly selected patients having clinical and or radiological features of tuberculosis attending out patients department of NIDCH were enrolled in this study during January to December, 2008. Sputum were collected and processed for culture by digestion, decontamination and concentration following modified Petroff's method and were inoculated on to two slopes of Lowenstein- Jensen (L-J) media for six weeks. The identity of the isolates was made by growth rate, colony morphology, P-nitrobenzoic acid (PNB) susceptibility, catalase and nitrate reduction tests. Ultimately drug susceptibility testing (DST) were performed. Result: Drug susceptibility testing for Isoniazid (INH), Rifampicin (RIF), Ethambutol (EMB) and Streptomycin (SM) was done among 363 cases. Resistance rates for INH, RIF, EMB and SM were 76.03%, 71.63%, 27.55% and 55.65% respectively. According to DST report, total 221 cases were detected as multi drug resistant TB (MDR-TB). Among them, 87% cases were MDR-TB in category II (CAT - II) failure and 13% were MDR-TB in category I (CAT - I) failure and it was 0% in new cases. Conclusion: Pattern of anti TB drug resistance was identified in this study. More surveillance and immediate therapeutic interventions should be performed in order to combat the threat of MDR-TB to the general population. Keywords: Tuberculosis, Multi drug resistance, Drug susceptibility testing.   doi: 10.3329/jom.v10i2.2812 J MEDICINE 2009; 10 : 45-47


2021 ◽  
Vol 25 (10) ◽  
pp. 839-845
Author(s):  
M. Ejo ◽  
A. Van Deun ◽  
A. Nunn ◽  
S. Meredith ◽  
S. Ahmed ◽  
...  

OBJECTIVES: To assess the performance of the GenoType MTBDRsl v1, a line-probe assay (LPA), to exclude baseline resistance to fluoroquinolones (FQs) and second-line injectables (SLIs) in the Standard Treatment Regimen of Anti-tuberculosis Drugs for Patients With MDR-TB 1 (STREAM 1) trial.METHODS: Direct sputum MTBDRsl results in the site laboratories were compared to indirect phenotypic drug susceptibility testing (pDST) results in the central laboratory, with DNA sequencing as a reference standard.RESULTS: Of 413 multidrug-resistant TB (MDR-TB) patients tested using MTBDRsl and pDST, 389 (94.2%) were FQ-susceptible and 7 (1.7%) FQ-resistant, while 17 (4.1%) had an inconclusive MTBDRsl result. For SLI, 372 (90.1%) were susceptible, 5 (1.2%) resistant and 36 (8.7%) inconclusive. There were 9 (2.3%) FQ discordant pDST/MTBDRsl results, of which 3 revealed a mutation and 5 (1.3%) SLI discordant pDST/MTBDRsl results, none of which were mutants on sequencing. Among the 17 FQ- and SLI MTBDRsl-inconclusive samples, sequencing showed 1 FQ- and zero SLI-resistant results, similar to frequencies among the conclusive MTBDRsl. The majority of inconclusive MTBDRsl results were associated with low bacillary load samples (acid-fast bacilli smear-negative or scantily positive) compared to conclusive results (P < 0.001).CONCLUSION: MTBDRsl can facilitate the rapid exclusion of FQ and SLI resistances for enrolment in clinical trials.


2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Elina Maharjan ◽  
Narayan Dutt Pant ◽  
Sanjeev Neupane ◽  
Jyoti Amatya ◽  
Bhawana Shrestha

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.


Biomedicine ◽  
2021 ◽  
Vol 41 (2) ◽  
pp. 472-476
Author(s):  
Chandan Kumar Poddar ◽  
Narmata Kumari ◽  
Rakesh Kumar ◽  
Shivendra Kumar Shahi ◽  
Naresh Kumar ◽  
...  

Introduction and Aim: India has the uppermost trouble of Multidrug resistant tuberculosis (MDR-TB) is a major challenge controlling resistance, reducing transmission and improving handling outcomes in MDR-TB patients is dependent on susceptibility testing. Isoniazid (INH) and rifampicin (Rif) are the key first-line antituberculosis drugs, and resistance to these drugs i.e., MDR-TB, is likely to result in treatment failure and poor clinical outcomes. The present study was done to compare the performance of line probe assay test (GenoType® MTBDRplus) with liquid culture (MGIT 960) system for the detection of resistance to first-line drugs.   Materials and Methods: We estimate the performance of LPAs to BACTEC MGIT 960 system for susceptibility testing of bacterial resistance to first-line drugs: rifampicin (RIF), isoniazid (INH).   Results: We performing Drug susceptibility testing (DST), 219/258 MTB cultures were viable after subculture the results of DST using the MGIT 960 system were compared to those obtained by line probe assay. LPA detected a total 46/258 (17.81%) samples as drug resistant, of which 35/258 (13.70%) were resistant to both rifampicin and isoniazid (MDR), 6/258 (2.28%) were rifampicin mono?resistant samples and 11/258 (4.11%) were isoniazid mono?resistant. Out of the culture?positive samples (219), LPA detected 39/219 (17.83%) as drug?resistant, of which 31/219 (14.2%) were resistant to both rifampicin and isoniazid, 5/193 (2.08%) were rifampicin mono?resistant and 8/219 (3.7%) were isoniazid mono?resistant. Conclusion: Drug resistant TB poses an enormous threat to TB control programs worldwide. Effective treatment of MDR-TB is very expensive, particularly in middle income countries such as India.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yong Chen ◽  
Zhengan Yuan ◽  
Xin Shen ◽  
Jie Wu ◽  
Zheyuan Wu ◽  
...  

Introduction. Second-line antituberculosis drugs (SLDs) are used for treating multidrug-resistant tuberculosis (MDR-TB). Prolonged delays before confirming MDR-TB with drug susceptibility testing (DST) could result in transmission of drug-resistant strains and inappropriate use of SLDs, thereby increasing the risk of resistance to SLDs. This study investigated the diagnostic delay in DST and prevalence of baseline SLD resistance in Shanghai and described the distribution of SLD resistance with varied delays to DST.Methods. All registered patients from 2011 to 2013 in Shanghai were enrolled. Susceptibility to ofloxacin, amikacin, kanamycin, and capreomycin was tested. Total delay in DST completion was measured from the onset of symptoms to reporting DST results.Results. Resistance to SLDs was tested in 217 of the 276 MDR-TB strains, with 118 (54.4%) being resistant to at least one of the four SLDs. The median total delay in DST was 136 days. Patients with delay longer than median days were roughly twice more likely to have resistance to at least one SLD (OR 2.22, 95% CI 1.19–4.11).Conclusions. During prolonged delay in DST, primary and acquired resistance to SLDs might occur more frequently. Rapid diagnosis of MDR-TB, improved nosocomial infection controls, and regulated treatment are imperative to prevent SLD resistance.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yang Che ◽  
Dingyi Bo ◽  
Xiang Lin ◽  
Tong Chen ◽  
Tianfeng He ◽  
...  

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
S. Siva Kumar ◽  
S. Ashok Kumar ◽  
Gomathi Sekar ◽  
K. Devika ◽  
M. Bhasker ◽  
...  

Geographically, most tuberculosis (TB) cases in 2018 were reported from India. This TB burden is compounded by MDR-TB and XDR-TB. The strategies for the management and control of TB in the community depend on an understanding of the mode of spread of the different strains of TB isolates in the community. To determine the distribution and trends of M. tb strains over the time period in the community due to treatment, we carried out the present study on changes over two decades. Design/Methods. A total of 1218  M. tb isolates (year: 2001–2018) from Tiruvallur, India, were genotyped by spoligotyping after DNA extraction and subjected to anti-TB drug susceptibility testing for the first-line anti-TB drugs. Results. On analysis with the SpolDB4 database, majority (2001–2003: 53.32% and 2015–2018: 46.3%) of the isolates belonged to East African Indian (EAI) lineage, and the orphans designated in comparison to SpolDB4 stood 33% among 2001–2003 strain collection and 46.3% among 2015–2018 strain collection. 10.2% (2001–2003) and 9.26% (2015 to 2018) of isolates were monoresistant to isoniazid (H). MDR strains were less common among EAI strains (3.2%) compared to non-EAI strains (10.32%). Conclusions. EAI is the most predominant lineage in Tiruvallur, despite the presence of highly transmissible lineages like Beijing for the last two decades. The prevalence of MDR-TB is below the national average of 2-3% among the new TB cases in the last two decades. The reason can be attributed to the well-established nature of the locally circulating strains in this region which are not associated with drug resistance.


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