Genetic Characterization of Second-Line Drug-Resistant and Extensively Drug-Resistant 
						<i>Mycobacterium tuberculosis</i> from the Northern Region of India

Yadav, Rakesh; Saini, Aastha; Mankotia, Jureka; Khaneja, Rajiv; Agarwal, Priyanka; Sethi, Sunil

doi:10.2991/j.jegh.2018.02.100

Cited by 3 publications

(1 citation statement)

References 15 publications

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“…The detection of resistance to fluoroquinolones and aminoglycosides by molecular methods is becoming increasingly complex given the cross-resistance between these drugs. The molecular characterization of resistance was achieved by sequencing the gyrA gene DNA for fluoroquinolone (FQ) and using the polymerase chain reaction technique (PCR) and the PCR restriction fragment length polymorphism (RFLP) for rrs genes associated with aminoglycosides [ 80 ].…”

Section: Molecular Methodsmentioning

confidence: 99%

Evolution of Laboratory Diagnosis of Tuberculosis

Zaporojan,

Negrean,

Hodișan

et al. 2024

Clinics and Practice

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Tuberculosis (TB) is an infectious disease of global public health importance caused by the Mycobacterium tuberculosis complex. Despite advances in diagnosis and treatment, this disease has worsened with the emergence of multidrug-resistant strains of tuberculosis. We aim to present and review the history, progress, and future directions in the diagnosis of tuberculosis by evaluating the current methods of laboratory diagnosis of tuberculosis, with a special emphasis on microscopic examination and cultivation on solid and liquid media, as well as an approach to molecular assays. The microscopic method, although widely used, has its limitations, and the use and evaluation of other techniques are essential for a complete and accurate diagnosis. Bacterial cultures, both in solid and liquid media, are essential methods in the diagnosis of TB. Culture on a solid medium provides specificity and accuracy, while culture on a liquid medium brings rapidity and increased sensitivity. Molecular tests such as LPA and Xpert MTB/RIF have been found to offer significant benefits in the rapid and accurate diagnosis of TB, including drug-resistant forms. These tests allow the identification of resistance mutations and provide essential information for choosing the right treatment. We conclude that combined diagnostic methods, using several techniques and approaches, provide the best result in the laboratory diagnosis of TB. Improving the quality and accessibility of tests, as well as the implementation of advanced technologies, is essential to help improve the sensitivity, efficiency, and accuracy of TB diagnosis.

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Section: Molecular Methodsmentioning

confidence: 99%

Evolution of Laboratory Diagnosis of Tuberculosis

Zaporojan,

Negrean,

Hodișan

et al. 2024

Clinics and Practice

View full text Add to dashboard Cite

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Revisiting the methods for detecting Mycobacterium tuberculosis: what has the new millennium brought thus far?

Campelo

Sousa

Nogueira

et al. 2021

Access Microbiology

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Tuberculosis (TB) affects around 10 million people worldwide in 2019. Approximately 3.4 % of new TB cases are multidrug-resistant. The gold standard method for detecting Mycobacterium tuberculosis , which is the aetiological agent of TB, is still based on microbiological culture procedures, followed by species identification and drug sensitivity testing. Sputum is the most commonly obtained clinical specimen from patients with pulmonary TB. Although smear microscopy is a low-cost and widely used method, its sensitivity is 50–60 %. Thus, owing to the need to improve the performance of current microbiological tests to provide prompt treatment, different methods with varied sensitivity and specificity for TB diagnosis have been developed. Here we discuss the existing methods developed over the past 20 years, including their strengths and weaknesses. In-house and commercial methods have been shown to be promising to achieve rapid diagnosis. Combining methods for mycobacterial detection systems demonstrates a correlation of 100 %. Other assays are useful for the simultaneous detection of M. tuberculosis species and drug-related mutations. Novel approaches have also been employed to rapidly identify and quantify total mycobacteria RNA, including assessments of global gene expression measured in whole blood to identify the risk of TB. Spoligotyping, mass spectrometry and next-generation sequencing are also promising technologies; however, their cost needs to be reduced so that low- and middle-income countries can access them. Because of the large impact of M. tuberculosis infection on public health, the development of new methods in the context of well-designed and -controlled clinical trials might contribute to the improvement of TB infection control.

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Molecular characterisation of second-line drug resistance among drug resistant tuberculosis patients tested in Uganda: a two and a half-year’s review

et al. 2022

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Background Second-line drug resistance (SLD) among tuberculosis (TB) patients is a serious emerging challenge towards global control of the disease. We characterized SLD-resistance conferring-mutations among TB patients with rifampicin and/or isoniazid (RIF and/or INH) drug-resistance tested at the Uganda National TB Reference Laboratory (NTRL) between June 2017 and December 2019. Methods This was a descriptive cross-sectional secondary data analysis of 20,508 M. tuberculosis isolates of new and previously treated patients’ resistant to RIF and/or INH. DNA strips with valid results to characterise the SLD resistance using the commercial Line Probe Assay Genotype MTBDRsl Version 2.0 Assay (Hain Life Science, Nehren, Germany) were reviewed. Data were analysed with STATAv15 using cross-tabulation for frequency and proportions of known resistance-conferring mutations to injectable agents (IA) and fluoroquinolones (FQ). Results Among the eligible participants, 12,993/20,508 (63.4%) were male and median (IQR) age 32 (24–43). A total of 576/20,508 (2.8%) of the M. tuberculosis isolates from participants had resistance to RIF and/or INH. These included; 102/576 (17.7%) single drug-resistant and 474/576 (82.3%) multidrug-resistant (MDR) strains. Only 102 patients had test results for FQ of whom 70/102 (68.6%) and 01/102 (0.98%) had resistance-conferring mutations in the gyrA locus and gyrB locus respectively. Among patients with FQ resistance, gyrAD94G 42.6% (30.0–55.9) and gyrA A90V 41.1% (28.6–54.3) mutations were most observed. Only one mutation, E540D was detected in the gyrB locus. A total of 26 patients had resistance-conferring mutations to IA in whom, 20/26 77.0% (56.4–91.0) had A1401G mutation in the rrs gene locus. Conclusions Our study reveals a high proportion of mutations known to confer high-level fluoroquinolone drug-resistance among patients with rifampicin and/or isoniazid drug resistance. Utilizing routinely generated laboratory data from existing molecular diagnostic methods may aid real-time surveillance of emerging tuberculosis drug-resistance in resource-limited settings.

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Genetic Characterization of Second-Line Drug-Resistant and Extensively Drug-Resistant Mycobacterium tuberculosis from the Northern Region of India

Cited by 3 publications

References 15 publications

Evolution of Laboratory Diagnosis of Tuberculosis

Evolution of Laboratory Diagnosis of Tuberculosis

Revisiting the methods for detecting Mycobacterium tuberculosis: what has the new millennium brought thus far?

Molecular characterisation of second-line drug resistance among drug resistant tuberculosis patients tested in Uganda: a two and a half-year’s review

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