Search Results (124)

Background: Isoniazid (INH) remains a cornerstone of tuberculosis (TB) prevention and treatment, administered either as monotherapy or in combination with rifamycin-containing regimens. In this study, the preventive regimens analyzed included 6 months of daily INH monotherapy (6H), 3 months of daily INH plus rifampicin (3HR), and 3 months of twice-weekly INH plus rifapentine (3H2P2). Despite the adoption of shorter-course regimens, substantial inter-individual variability (IIV) in INH exposure persists, potentially impacting both therapeutic efficacy and toxicity. A quantitative, regimen-specific characterization of INH pharmacokinetics is therefore critical to support model-informed dosing strategies. Methods: Population pharmacokinetic models were developed separately for INH administered as 6H, 3HR, and 3H2P2. The models characterized absorption, clearance, and IIV of INH, while accounting for co-administered rifamycin. The effects of N-acetyltransferase 2 (NAT2) acetylator phenotype and relevant clinical covariates were systematically evaluated. Model performance was assessed using goodness-of-fit diagnostics, posterior predictive checks, and visual predictive checks. Population pharmacokinetic models were developed using a Bayesian nonlinear mixed-effects framework implemented in Stan through CmdStanR version 0.9.0, with additional data processing, statistical summaries, and visualization performed using R version 4.2.3. Results: INH pharmacokinetics were adequately described by regimen-specific models, revealing distinct differences in absorption and variability across regimens. Typical INH apparent oral clearance (CL/F) estimates were 21.83 L/h for 6H, 26.32 L/h for 3HR, and 25.98 L/h for 3H2P2. NAT2 phenotype was a major determinant of INH clearance across regimens: compared with intermediate acetylators, slow acetylators showed 35.4% lower CL/F, whereas fast acetylators showed 48.4% higher CL/F, indicating higher INH exposure in slow acetylators and lower exposure in fast acetylators. Body weight also influenced INH pharmacokinetics. Co-administration with rifampicin or rifapentine influenced INH pharmacokinetics in a manner consistent with reduced exposure in rifamycin-containing regimens, particularly among fast acetylators. Conclusions: Regimen-specific population pharmacokinetic modeling elucidated clinically relevant differences in INH exposure across commonly used preventive and treatment regimens. These findings highlight the importance of accounting for regimen- and genotype-specific effects when optimizing INH dosing and provide a quantitative framework for future model-informed precision dosing approaches in TB care. Full article

Isoniazid (INH) targets cell wall biosynthesis and is a potent antimycobacterial agent. Elucidating the regulatory networks that govern drug susceptibility in mycobacterial models is fundamental to understanding intrinsic resistance in pathogenic species. The iniBAC operon plays a crucial role in INH tolerance and envelope permeability, yet the transcriptional regulatory mechanisms controlling its expression in response to INH-induced stress remain incompletely understood. The second messenger cyclic di-GMP (c-di-GMP) regulates drug susceptibility in several bacteria, but its downstream receptors and regulatory pathways in mycobacteria have not been explored. Here, we demonstrate that c-di-GMP reduces INH susceptibility via the receptor HpoR. Mechanistically, c-di-GMP alleviates HpoR-mediated repression of the iniBAC operon in a concentration-dependent manner, which decreases envelope permeability and consequently modulates multidrug susceptibility in both M. bovis BCG and M. smegmatis. This regulatory paradigm is likely conserved in pathogenic mycobacteria. Full article

This investigation focused on isoniazid (INH)—saccharin (SAC) salts. One hydrate and one anhydrous INH-SAC salt form were synthesized and characterized spectroscopically by Raman and infrared spectroscopy. Solvent (methanol, acetone, acetonitrile)-assisted synthesis in the presence of water, or in water, resulted in production of the monohydrated form of the salt (MH: (INH+H)⁺/(SAC–H)⁻.H₂O). The anhydrous form (A: (INH+H)⁺/(SAC–H)⁻) was obtained using the same synthesis method but in the absence of water or, together with the hydrate, in the presence of traces of water. Differential scanning calorimetry studies revealed that the hydrate can be converted into the anhydrous form of the salt upon heating, with the latter melting at a T_m (onset) of 131.7 ± 0.5 °C. Melting was followed by a reaction between isoniazid and saccharin leading to saccharin ring opening and formation of a new covalent hydrazide–amide derivative, via nucleophilic acyl substitution at the saccharin carbonyl. The newly formed adduct, 2-[2-(pyridine-4-carbonyl)hydrazine-1-carbonyl] benzene-1-sulfonamide, melts at T_m (onset) = 204.4 ± 0.5 °C. The crystal structures of the hydrate and of the anhydrous form were determined by single-crystal X-ray diffraction, and the dominant intermolecular interactions in the crystalline INH-SAC salts were evaluated using Hirshfeld surface analysis. To complement the experimental results, density functional theory (DFT) calculations were performed both on relevant isolated structural units and on the two salts, employing fully periodic DFT methods. Full article

(1) Background: Indonesia faces the dual challenge of a high tuberculosis (TB) burden and increasing drug resistance. Conventional molecular diagnostics frequently fail to detect isoniazid resistance and nontuberculous mycobacteria (NTM). This study evaluates a domestic multiplex Open PCR system in Medan, Indonesia. (2) Methods: From July to November 2025, 1569 sputum specimens from suspected TB patients were analysed using the Indigen MTB/NTM/DR-TB Real-time PCR Kit Gen 2. (3) Results: Mycobacterial DNA was detected in 421 specimens (26.8%). Among these, 396 (94.1%) were drug-susceptible TB, while 16 (3.8%) showed resistance, predominantly INH mono-resistance (n = 14; 0.89% of total). Additionally, 9 cases (2.1%) involved NTM or TB-NTM co-infections. Tertiary hospitals showed significantly higher positivity rates (33.5%) than primary care (18.9%; p < 0.001). TB status was significantly associated with male (p = 0.0052) and older age (p = 0.006), whereas resistance profiles and NTM distribution were consistent across all demographic groups (p > 0.80). (4) Conclusions: This study describes the implementation and diagnostic yield of a domestic multiplex Open PCR system in Medan, Indonesia. By bridging diagnostic gaps across a decentralized referral network, this facilitates rapid and targeted therapy. Integrating multiplex domestic innovations into national diagnostic algorithms is essential for achieving Indonesia’s TB elimination targets. Full article

A series of INH–pyrazole molecular hybrids (6a–o) was synthesized and evaluated for in vitro anti-tubercular activity against drug-susceptible, multidrug-resistant (MDR), and extensively drug-resistant (XDR) Mycobacterium tuberculosis strains, alongside their corresponding precursors (4a–o), using isoniazid (INH) as the reference drug. Overall, the hybrid compounds exhibited inhibitory activity comparable to or exceeding that of INH against the drug-susceptible strain. Among the series, compounds 6a, 6d–6f, and 6m demonstrated the highest potency, with a minimum inhibitory concentration (MIC) of 0.9 µM, corresponding to an approximately 4.3-fold enhancement relative to INH. Compounds 6b,c, 6g–i, and 6l,m also showed noticeable activity (MIC = 1.95 µM), representing an approximate twofold improvement over INH and significantly outperforming their respective precursors. Notably, compound 6o exhibited enhanced activity against the XDR strain (MIC = 121 µM), reflecting an approximately 2.8-fold improvement compared to precursor 4o (MIC > 341 µM), thereby highlighting the advantage of molecular hybridization. However, all compounds displayed diminished activity relative to INH against the resistant strains. Against the MDR strain, compounds 4h, 6e, and 6g displayed measurable activity, with MIC values of 76, 125, and 112 µM, respectively. Cytotoxicity assessment using THP-1 human monocytic cells revealed low toxicity, with all tested compounds maintaining acceptable cell viability at 10 µg/mL. In addition, in silico ADME analysis indicated that the hybrid molecules comply with key drug-likeness criteria. Collectively, these findings suggest that INH–pyrazole hybrids represent promising lead scaffolds for the development of next-generation anti-tubercular agents. Full article

Background: The global burden of drug-resistant Mycobacterium tuberculosis continues to threaten tuberculosis control efforts, largely due to the emergence and transmission of resistance-associated genetic mutations. Molecular epidemiology provides critical insights into mutation profiles and resistance associations, yet the interplay among key mutations and their contributions to complex resistance patterns remains poorly understood, particularly in high-burden settings. Methods: A retrospective, cross-sectional, laboratory-based design was used to analyze 111 phenotypically confirmed drug-resistant isolates. Molecular drug susceptibility testing (DST) for first- and second-line anti-tuberculosis drugs was performed at the National Health Laboratory Service (NHLS) TB reference laboratory. Drug-resistance profiles were classified according to World Health Organization (WHO) definitions. Descriptive and inferential statistical analyses were conducted to determine mutation frequencies, co-occurrence patterns, and associations with resistance profiles. Results: rpoB (D435V 38.7%; S450L 36.0%) and katG (S315T 80.2%) mutations predominated, forming the core molecular basis of MDR-TB, while 15% harbored inhA promoter mutations associated with low-level isoniazid resistance. The most frequent combinations included rpoB S450L with katG S315T and rpoB D435V with katG S315T, consistent with multidrug-resistant tuberculosis (MDR-TB) profiles. Nearly 48% showed dual resistance to fluoroquinolones and second-line injectables. Conclusion: This study highlights the predominance of resistance-associated mutations and their co-occurrence patterns in shaping MDR-TB profiles in the study setting. The observed burden of second-line drug resistance underscores the importance of comprehensive resistance testing. These findings support the use of mutation profiling for rapid diagnosis and informed treatment decisions, while emphasizing the need for ongoing local surveillance to guide TB control efforts. Full article

Background: Drug-resistant tuberculosis (TB) remains a major challenge in high-burden settings, where timely identification of emerging resistance and effective governance responses are critical. While routine molecular diagnostics generate large volumes of resistance-associated mutation data, these outputs are typically used for individual patient management and remain underutilized for population-level surveillance and for the application of clinical governance approaches for improved TB care. Methods: We conducted a retrospective cross-sectional analysis of 1386 molecular diagnostic records for Mycobacterium tuberculosis, collected between March 2021 and December 2024, from 30 health facilities in the King Sabata Dalindyebo (K.S.D.) Local Municipality of Oliver Reginald (O.R.) Tambo District. Resistance-associated mutation proxies were identified for loci associated with isoniazid (katG, inhA), fluoroquinolone (gyrA), and second-line injectable agents (amikacin, kanamycin, and capreomycin) through mutations in the rrs locus. Mutation proxy prevalence was examined overall, by age group, over time, and across facilities. Persistence of resistance detection was assessed using consecutive-month analyses to characterize temporal continuity at the facility level. Results: At least one resistance-associated mutation proxy was detected in 72.7% of the analyzed records. Isoniazid resistance predominated, with katG mutation proxies identified in 52.2% and inhA in 20.2% of cases. Mutation proxies associated with fluoroquinolone and second-line injectable resistance were less frequently observed. Temporal analysis demonstrated variability over the study period, with a general decline in overall mutation proxy prevalence alongside a relative increase in inhA-associated mutations. Substantial heterogeneity in resistance patterns was observed across health facilities, with high-volume sites contributing the greatest absolute burden and selected facilities demonstrating sustained persistence of mutation detection over consecutive months. These findings highlight the magnitude, distribution, and persistence of resistance-associated mutation proxies within routine programmatic data. Conclusions: Routine molecular diagnostic data revealed a substantial and heterogeneous burden of drug-resistant Mycobacterium tuberculosis in K.S.D. Local Municipality, characterized by age-specific patterns, temporal shifts, and sustained facility-level persistence. Beyond descriptive epidemiology, routinely generated mutation proxy data can serve as early-warning indicators of clinical governance stress, signaling emerging pressures on TB care systems when resistance patterns persist or worsen. Interpreting these trends can support more anticipatory clinical governance, strengthen resistance surveillance, and guide prioritized interventions in high-burden, resource-constrained settings. Full article

Background: Resistance to first-line anti-tuberculosis drugs in Mycobacterium tuberculosis represents a significant public health challenge, particularly in high-burden tuberculosis (TB) settings such as Pakistan, where multidrug-resistant (MDR) forms further complicate disease control efforts. Drug resistance is primarily associated with mutations in rpoB, inhA, katG, embA, embB, embC, and pncA. The emergence of novel, region-specific variants underscores the urgent need for integrating genomic surveillance into routine TB diagnostics and regional control programs. This study aimed to identify the spectrum of mutations contributing to first-line drug resistance in MDR-TB isolates from Khyber Pakhtunkhwa, Pakistan. Methods: Whole-genome sequencing was performed on 16 clinical isolates (12 MDR and 4 drug-susceptible) to identify resistance-associated mutations in rpoB, inhA, katG, embA, embB, embC, and pncA. Detected variants were interpreted using the World Health Organization (WHO) mutation catalogue to determine their association with drug resistance. Phylogenetic relationships were inferred using the Bacterial and Viral Bioinformatics Resource Center (BV-BRC) platform. Results: A total of 16 M. tuberculosis isolates were analyzed to evaluate resistance to first-line anti-tuberculosis drugs. In rpoB, 76 distinct variants were identified, including canonical mutations such as Ser450Leu and His445Arg, as well as a potentially novel substitution, Ser431Phe, predicted to confer high-level rifampicin resistance. The katG and inhA genes harbored 24 and 27 mutations, respectively, including well-characterized substitutions such as Ser315Thr and Ala114Glu, which are strongly associated with isoniazid resistance. Mutations in embA and embB were linked to ethambutol resistance, with several variants localized within conserved transmembrane domains critical for drug interaction. Phylogenetic analysis revealed substantial genetic diversity and evidence of local transmission among MDR-TB isolates. Conclusions: This study suggests that the genetic landscape of drug resistance in M. tuberculosis is highly dynamic in endemic regions. The findings highlight the importance of integrating region-specific mutation profiles into molecular diagnostic frameworks to enhance early detection, guide individualized therapeutic interventions, and strengthen strategies aimed at controlling the transmission of MDR-TB. Full article

Background: Drug-resistant tuberculosis remains a major challenge in resource-limited settings, particularly in rural regions of the Eastern Cape Province, where limited laboratory infrastructure, constrained access to advanced molecular diagnostics, shortages of specialized healthcare personnel, and prolonged diagnostic turnaround times can delay appropriate treatment initiation. This study examined whether routinely detectable genomic resistance markers could be integrated with parsimonious machine learning approaches to support early risk stratification for isoniazid (INH) and/or rifampicin (RIF) resistance and multidrug-resistant tuberculosis (MDR-TB). Methods: We conducted a retrospective analysis of clinical, demographic, and genomic data from 207 Mycobacterium tuberculosis isolates representing 207 unique patients. Resistance was classified as INH and/or RIF resistance or MDR-TB (concurrent resistance to both drugs). Predictors included age, sex, and canonical resistance-associated mutations (katG S315T, inhA −15C>T, and rpoB codon substitutions). Logistic regression was used to estimate adjusted odds ratios (aORs), while Random Forest models were applied to assess non-linear feature importance. Internal validation was performed using 10-fold cross-validation. A systems network analysis mapped the integration of model-derived risk bands into Clinical Governance structures and Community-Engaged Education pathways, including interventions delivered by Community Health Workers (CHWs). Results: INH and/or RIF resistance was identified in 58.9% of isolates, with 21.7% classified as MDR-TB. The most frequently detected mutations were katG S315T (29.0%) and rpoB S450L (26.6%). Logistic regression identified rpoB S450L (aOR 4.20; 95% CI: 2.10–8.45) and katG S315T (aOR 2.85; 95% CI: 1.40–5.80) as the strongest independent predictors, while age and sex were not statistically significant. Models demonstrated strong internal discrimination (AUCs of 0.96 for INH and/or RIF resistance and 0.99 for MDR-TB). Risk stratification categorized 18% of patients as high risk. Scenario-based modelling suggested that prioritizing high-risk patients for reflex Line Probe Assay testing could reduce the median time to appropriate treatment from 14 to 3 days and may reduce progression from isoniazid-resistant TB to MDR-TB under specified operational assumptions. Conclusions: Mutation-informed predictive modelling demonstrates strong internally validated discrimination and provides a structured framework for risk-stratified intervention. Integrating probability-based risk thresholds within Clinical Governance systems and community-level support structures, including CHW-led adherence and education strategies, may support earlier treatment optimization in high-burden rural settings. External validation and prospective implementation studies are required before broader programmatic adoption. Full article

Background: Bedside manipulation of adult anti-tuberculosis tablets for paediatric dosing is common in low-resource settings, yet it can compromise drug stability. This study investigated how grinding and multi-drug co-suspension affect the supramolecular organisation, thermal stability, and dissolution of isoniazid (INH). Methods: INH raw, INH branded tablets (whole and ground), and multi-drug combination mixtures (MCMs) that simulate paediatric multi-drug-resistant tuberculosis (MDR-TB) regimens were assessed. Samples were analysed as solids and aqueous suspensions using hot-stage microscopy (HSM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Raman spectroscopy, FTIR-ATR, USP dissolution, and HPLC (LOD 0.0015 mg mL⁻¹; LOQ 0.005 mg mL⁻¹). Results: Grinding and co-mixing lowered melting points and masked typical INH events. Spectroscopy revealed the broadening and shifting of OH/NH and pyridine-ring bands, consistent with the formation of new hydrogen-bonding networks, correlative with supramolecular rearrangements. In multi-drug suspensions, INH fell below the HPLC quantification limit in both pH 1.2 and 6.8 media, despite visible residue, suggesting the formation of non-dissociable supramolecular complexes. Using a validated HPLC assay, no quantifiable INH was detected from the crushed multi-drug suspensions in either pH 1.2 or pH 6.8, whereas intact API/tablets showed measurable release. Conclusions: Co-suspension of INH with companion tuberculosis (TB) drugs disrupts its supramolecular integrity, leading to pre-administration degradation and a loss of quantifiable drug. Dissolution testing showed minimal INH release at pH 1.2 and none at pH 6.8, contrasting with intact tablets/API. These observations highlight that converting an immediate-release tablet into an aqueous suspension fundamentally alters its physicochemical environment and requires rational formulation design to preserve molecular stability, differentiating true resistance from formulation failure. Full article

The lack of reliable diagnostic tools and relapse monitoring for latent tuberculosis infection (LTBI) constitutes a major obstacle to global tuberculosis (TB) control. This highlights an urgent need for robust animal models and predictive biomarkers. To address this, we report the successful establishment of a rapid murine model of recapitulating the active, latent, and relapse phases of TB within a compressed ten-week timeframe—hence termed the rapid multi-stage TB murine model. In this model, mice were first intravenously infected with Mycobacterium tuberculosis, followed by a four-week isoniazid (INH) regimen starting at two weeks post-infection. By week six, pulmonary bacterial loads in most mice dropped below the detection limit, signifying the establishment of latency. Reactivation was subsequently triggered by a four-week administration of anti-TNF-α (Tumor Necrosis Factor-α) monoclonal antibody. Leveraging this reproducible and time-efficient model, we performed transcriptomic profiling of peripheral blood and identified a distinct sixteen-gene signature (including Ets2, Fam111a, Fosl2, Gadd45b, Nfkbid, Rgs1, Bhlhe40, Il1r2, Clec2d, Kmo, Lynx1, Papd4, Trim34a, Wrb, Nlrp12, Spns1) that dynamically tracks disease progression. Collectively, these findings not only provide a valuable and efficient preclinical tool but also deliver transformable candidate biomarkers with immediate potential to guide the development of novel diagnostic strategies for LTBI surveillance and management. Full article

Isoniazid (INH) is an antitubercular drug that exhibits high toxicity in dogs due to the absence of N-acetyltransferase activity in this species. Consequently, it has been implicated in both accidental and intentional poisonings in dogs. The aim of this study was to develop and validate an analytical method for the quantification of INH in canine liver samples and to apply it in the forensic investigation of seven suspected poisoning cases. The method, based on liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC-QTOF-MS), enabled both accurate INH measurement and analysis of the molecular pattern of its metabolite formation. In addition, histopathological examination of the stomach, pancreas, liver, and brain was performed. Liver INH concentrations ranged from 11.822 to 30.484 μg/g and were associated with extensive necrotic lesions across all examined tissues. A strong signal for isonicotinic acid was observed in all samples, whereas the acetylated metabolite was negligible. The developed method allows precise quantification of INH in canine liver and facilitates identification of the characteristic molecular profile of its metabolites. Full article

Background/Objectives: Patients with rheumatic immune-mediated inflammatory diseases (R-IMID) require latent tuberculosis infection screening and, in case of positivity, chemoprophylaxis. Isoniazid INH remains the standard regimen, but hepatotoxicity is an underrecognized concern. To describe the characteristics of R-IMID patients developing hepatotoxicity during INH therapy and identify potential risk factors through clinical analysis and literature review. Methods: Retrospective study of 64 R-IMID who developed hepatotoxicity with INH. Mean age was 53.4 ± 10.5 years; 70.3% female. Diagnoses included spondyloarthritis/psoriatic arthritis (56.3%), rheumatoid arthritis (32.8%), systemic sclerosis (4.7%), connective tissue diseases (4.7%), and other IMIDs (3.2%). All patients showed ≥ 2 × upper limit of normality (ULN) liver enzyme elevation, 34.4% ≥ 3 ULN, 20.3% ≥ 4 ULN. Literature review (19 studies) revealed INH-related hepatotoxicity rates of 1–41%, exacerbated by concurrent methotrexate, sulfasalazine, TNF inhibitors, and prior drug-induced liver injury. Results: Hepatotoxicity was frequent when INH was combined with other hepatotoxic drugs, especially methotrexate. Conclusions: INH prophylaxis in R-IMID patients carries substantial hepatotoxic risk. Careful hepatic monitoring and individualized risk stratification are essential to prevent liver injury in immunosuppressed populations. Full article

Drug-resistant tuberculosis (DR-TB) threatens global TB control. We investigated the prevalence and molecular characteristics of second-line drug resistance among rifampicin (RIF)- and/or isoniazid (INH)-resistant Mycobacterium tuberculosis complex (MTBC) isolates in São Paulo, Brazil, using the MTBDRsl v. 2.0 line-probe assay. MTBC isolates RIF- and/or INH-resistant by GenoType MTBDRplus or phenotypic testing (2019–2021) were subsequently tested by MTBDRsl for fluoroquinolone (FQ) and injectable drugs (capreomycin, amikacin, kanamycin) resistance. Isolates with inferred mutations underwent Sanger sequencing. Of 13,557 isolates, 728 (5.4%) were RIF- and/or INH-resistant (297 INH-R, 235 RIF-R, 196 MDR). Among them, 623 (85.6%) were tested by MTBDRsl; 582 (93.4%) showed no additional resistance, while 41 (6.6%) carried mutations. FQ resistance was detected in 38 isolates (92.7%), mostly in gyrA (n = 35). Three isolates with gyrB mutations were wild-type by sequencing. Two MDR isolates harbored the rrs a1401g mutation, and one also harbored gyrA D94G. Sequencing confirmed resistance in 38 of 41 isolates. Most MDR strains with second-line mutations (n = 32/33; 97%) were pre-XDR. Affected patients were predominantly male (68.4%), with pulmonary TB (92.1%), and unfavorable outcomes (39.5%). Second-line resistance prevalence was low overall, but FQ resistance was high among MDR isolates. Findings support integrating molecular and sequencing-based tools for accurate detection and management of DR-TB. Full article

Background/Objectives: Accurate and rapid detection of Mycobacterium tuberculosis complex (MTBC) and drug resistance is essential for effective tuberculosis (TB) management, particularly in high-burden settings. The Cobas^® MTB and Cobas MTB/RIF-INH assays are moderate-complexity nucleic acid amplification tests that detect MTBC and resistance to rifampicin (RIF) and isoniazid (INH). Methods: This study evaluated the clinical diagnostic performance of the Cobas assays on sputum, using liquid culture as the reference standard and Xpert MTB/RIF Ultra (Xpert Ultra) for comparison. Diagnostic accuracy of the Cobas MTB assay on tongue swabs (TS) was also assessed. Results: In a study population (n = 354) with 56% HIV prevalence, the overall sensitivity and specificity of Cobas MTB on sputum was 93.8% (95% CI: 84.8–98.3) and 100% (95% CI: 98.7–100) compared with culture. The assay showed almost perfect agreement with Xpert Ultra (Cohen’s kappa = 0.904). Among HIV-positive participants, sensitivity was 88.2% (95% CI: 72.5–96.7). RIF resistance profiling by Cobas MTB/RIF-INH was fully concordant with culture and Xpert Ultra. Three INH-resistant cases were missed, likely due to genotypic–phenotypic discordance. Although specimen numbers were small, TS demonstrated better diagnostic accuracy when using a diluted (66%) microbial inactivation solution. Conclusions: The Cobas MTB and MTB/RIF-INH assays demonstrated high diagnostic accuracy compared to culture and Xpert Ultra on sputum. Findings support TS as an alternative specimen type for MTBC detection using an optimized protocol. These findings underscore the potential of the Cobas assays as reliable alternatives for TB and resistance diagnostics, particularly in settings where rapid, accurate detection of MTBC and RIF or INH resistance is crucial. Full article