TB drug susceptibility testing in high fluoroquinolone resistance settings.

BACKGROUND: The insurgence of resistance to key drugs of the BPaLM (bedaquiline + pretomanid + moxifloxacin) regimen is a major concern. In settings with widespread resistance to fluoroquinolones (FQs), like Pakistan, new technologies, such as Xpert® MTB/XDR, may ensure drug resistance upfront screening. This study aims to assess MTB/XDR's performance in detecting FQs and isoniazid resistance, proposing a renewed diagnostic algorithm for drug-resistant TB (DR-TB). METHODS: This cross-sectional prospective study, approved by the local ethical committee, collected samples from people newly and previously diagnosed with TB over 6 months. Xpert® MTB/RIF Ultra, MTB/XDR, Genotype® MTBDRplus, Genotype® MTBDRsl, culture, and phenotypic drug susceptibility testing (pDST) for relevant drugs (including bedaquiline and levofloxacin) were performed. Next-generation sequencing (NGS) resolved discordances between MTB/XDR and pDST results. RESULTS: The analysis showed that MTB/XDR has 91.5% and 88.2% sensitivity and 99.5% and 97.7% specificity in detecting respectively isoniazid (INH) and resistance to FQs, demonstrating that MTB/XDR meets the WHO targets for INH resistance detection at the peripheral level. NGS effectively resolved discordances between MTB/XDR and pDST results. CONCLUSIONS: The obtained results allowed designing the proposed diagnostic algorithm for rapid identification of DR-TB, ensuring rapid and equitable access to drug susceptibility testing for TB, ultimately improving TB care and control.

CONTEXTE: La recrudescence de la résistance aux médicaments clés du régime BPaLM (bédaquiline + prétomanide + moxifloxacine) est une préoccupation majeure. Dans les contextes où la résistance aux fluoroquinolones (FQ) est répandue, comme le Pakistan, de nouvelles technologies, telles que Xpert® MTB/XDR, peuvent assurer un dépistage initial de la résistance aux médicaments. Cette étude vise à évaluer la performance de MTB/XDR dans la détection des FQ et de la résistance à l'isoniazide, en proposant un algorithme de diagnostic renouvelé pour la TB pharmacorésistante (DR-TB, pour l'anglais «drug-resistant TB ¼ ). MÉTHODES: Cette étude prospective transversale, approuvée par le comité d'éthique local, a recueilli des échantillons de personnes nouvellement diagnostiquées et précédemment diagnostiquées avec la TB pendant 6 mois. Xpert® MTB/RIF Ultra, MTB/XDR, le GenoType® MTBDRplus, le GenoType® MTBDRsl, la culture et des tests phénotypiques de sensibilité aux médicaments (pDST, pour l'anglais «phenotypic drug susceptibility testing ¼ ) pour les médicaments pertinents (y compris la bédaquiline et la lévofloxacine) ont été effectués. Le séquençage de nouvelle génération (NGS, pour l'anglais «next-generation sequencing ¼ ) a résolu les discordances entre les résultats MTB/XDR et pDST. RÉSULTATS: L'analyse a montré que le MTB/XDR a une sensibilité de 91,5% et 88,2% et une spécificité de 99,5% et 97,7% dans la détection respectivement de l'isoniazide et de la résistance aux FQ, démontrant que le MTB/XDR répond aux objectifs de l'OMS pour la détection de la résistance à l'isoniazide au niveau périphérique. NGS a efficacement résolu les discordances entre les résultats MTB/XDR et pDST. CONCLUSIONS: Les résultats obtenus ont permis de concevoir l'algorithme de diagnostic proposé pour l'identification rapide de la DR-TB, garantissant un accès rapide et équitable aux tests de sensibilité aux médicaments pour la TB, améliorant ainsi la prise en charge et le contrôle de la TB.

Intracranial tuberculomas diagnosed with Xpert MTB/RIF Ultra assay of formalin-fixed paraffin-embedded brain tissues and treated with an optimized antituberculosis regimen: A case report.

Diagnosis of intracranial tuberculoma remains a challenge due to its rarity, non-specific clinical presentation, and radiological findings. Herein, we describe a case of intracranial tuberculomas in a male diabetic patient who presented headache and vomiting on admission. Neuroimaging findings indicated multiple ring contrast-enhanced lesions with extensive perilesional edema. However, a cerebrospinal fluid (CSF) examination was normal. When a biopsy of brain lesions was performed, pathological characteristics of tuberculosis were absent and acid-fast staining was negative. A tuberculosis diagnosis was subsequently obtained from an Xpert MTB/RIF Ultra assay of formalin-fixed paraffin-embedded brain tissue. The patient was treated with an optimized anti-tuberculosis regimen which included high-dose intravenous administration of rifampicin and isoniazid, and oral administration of linezolid. The patient recovered well and exhibited marked clinical improvement. This case report demonstrates that when CSF analysis does not indicate the presence of intracranial tuberculomas, analysis of formalin-fixed paraffin-embedded brain tissue specimens with the Xpert MTB/RIF Ultra assay may be able to confirm a diagnosis. Furthermore, a high dose of rifampicin and isoniazid plus linezolid may improve patient outcome.

Diagnostic accuracy of the Xpert® MTB/XDR assay for detection of Isoniazid and second-line antituberculosis drugs resistance at central TB reference laboratory in Tanzania.

INTRODUCTION: Early diagnosis of tuberculosis (TB) and universal access to drug-susceptibility testing (DST) are critical elements of the WHO End TB Strategy. Current rapid tests (e.g., Xpert® MTB/RIF and Ultra-assays) can detect rifampicin resistance-conferring mutations, but cannot detect resistance to Isoniazid and second-line anti-TB agents. Although Line Probe Assay is capable of detecting resistance to second-line anti-TB agents, it requires sophisticated laboratory infrastructure and advanced skills which are often not readily available in settings replete with TB. A rapid test capable of detecting Isoniazid and second-line anti-TB drug resistance is highly needed. METHODS: We conducted a diagnostic accuracy study to evaluate a new automated Xpert MTB/XDR 10-colour assay for rapid detection of Isoniazid and second-line drugs, including ethionamide, fluoroquinolones, and injectable drugs (Amikacin, Kanamycin, and Capreomycin). Positive Xpert MTB/RIF respiratory specimens were prospectively collected through routine diagnosis and surveillance of drug resistance at the Central TB Reference Laboratory in Tanzania. Specimens were tested by both Xpert XDR assay and LPA against culture-based phenotypic DST as the reference standard. FINDINGS: We analysed specimens from 151 TB patients with a mean age (SD) of 36.2 (12.7) years. The majority (n = 109, 72.2%) were males. The sensitivity for Xpert MTB/XDR was 93.5% (95% CI, 87.4-96.7); for Isoniazid, 96.6 (95% CI, 92.1-98.6); for Fluoroquinolone, 98.7% (95% Cl 94.8-99.7); for Amikacin, 96.6%; and (95% CI 92.1-98.6) for Ethionamide. Ethionamide had the lowest specificity of 50% and the highest was 100% for Fluoroquinolone. The diagnostic performance was generally comparable to that of LPA with slight variations between the two assays. The non-determinate rate (i.e., invalid M. tuberculosis complex detection) of Xpert MTB/XDR was 2·96%. CONCLUSION: The Xpert MTB/XDR demonstrated high sensitivity and specificity for detecting resistance to Isoniazid, Fluoroquinolones, and injectable agents. This assay can be used in clinical settings to facilitate rapid diagnosis of mono-isoniazid and extensively drug-resistant TB.

Mycobacterium tuberculosis and rifampicin-resistant tuberculosis among tuberculosis presumptive patients in selected zones of Tigray, Northern Ethiopia, 2016-2019.

Introduction: Tuberculosis (TB) is the second leading cause of mortality from an infectious disease worldwide. Multidrug-resistant tuberculosis (MDR-TB), where rifampicin-resistant TB is the biggest contributor, remains a global health threat. There is scant data on MTB and rifampicin resistance (RR-MTB) using Gene Xpert MTB/RIF assay in Ethiopia. This study aimed to determine the prevalence of MTB and RR-MTB among presumptive TB patients in Tigray, Northern Ethiopia. Methods: A multi-center retrospective cross-sectional study was conducted from October 2019 to December 2019 among presumptive MTB patients from four hospitals in Tigray. Records of sputum sample results of presumptive MTB patients analyzed with Gene Xpert MTB/RIF assay from January 2016 to December 2019 were investigated. Data were extracted using a data-extraction tool from registration books and analyzed using SPSS ver.21. Statistically significant was set at p-value ≤0.05. Results: From 17,329 presumptive adult MTB patients who had submitted sputum samples for TB diagnosis, 16,437 (94.9 %) had complete records and were included in the study. More than half (60.2 %) of them were males and ages ranged from 18 to 98 years. Majority of the participants: 15,047(91.5 %) were new cases and 11,750 (71.5 %) were with unknown HIV status. Prevalence of MTB was 9.7 % (95 % CI: 9.2-10.2 %) of these, rifampicin resistant-MTB was 8.7 % (95 % CI: 7.32-10.09 %). Age (being >29 years) [p < 0.001] and new cases [AOR = 0.46; 95%CI = 0.39, 0.53, p < 0.001] were associated with low TB infection. Age groups of 18-29 years were associated with higher RR-MTB [AOR = 3.08; 95 % CI = 1.07, 8.72, p = 0.036]. Conclusion: Nearly one-tenth of the presumptive tuberculosis patients tested positive for MTB; out of these, 8.7 % were RR-MTB. The high prevalence of TB and RR-MTB at a young age and previously treated cases calls for a concerted effort to improve and monitor TB treatment to reduce the problem.

Navigating Diagnostic Pitfalls: False Positivity in GeneXpert Mycobacterium Tuberculosis/Rifampicin Assay.

Tuberculosis (TB), which is predominantly caused by Mycobacterium tuberculosis (MTB), poses severe diagnostic hurdles, especially with pulmonary tuberculosis (PTB), which spreads by aerosols. Sputum culture, the gold standard for MTB diagnosis, is time-consuming, expensive, and easily contaminated. The GeneXpert MTB/RIF (Xpert) assay, a molecular diagnostic tool, can quickly detect MTB and rifampicin (RIF) resistance. However, the ability to identify both live and non-viable MTB DNA, for example, in patients with a previous history of pulmonary tuberculosis or sampling from a contaminated bronchoscope, can result in false positives, as demonstrated in this case series. We present three cases of PTB diagnosed with Xpert, each with no conventional TB symptoms.

Diagnostic Yield of Urine Xpert MTB/RIF Ultra in Adults With Suspected Extrapulmonary Tuberculosis.

We assessed the diagnostic yield of urine GeneXpert MTB/RIF Ultra and factors associated with a positive test among adult patients suspected to have extrapulmonary tuberculosis. Urine Ultra was positive in 14% of participants with definite or probable tuberculosis. Hospitalization, disseminated tuberculosis, and human immunodeficiency virus infection were associated with a positive result.

Peritoneal tuberculosis, an underestimated diagnosis: a case report.

Tuberculosis is an infectious disease that most often affects the lungs, caused by human-to-human transmission of Mycobacterium tuberculosis. Peritoneal tuberculosis is an extra-pulmonary form of the disease that usually manifests as an ascitic syndrome, with or without fever, in a context of altered general condition, often in endemic areas. The diagnosis of peritoneal tuberculosis is not always easy, as the clinical signs are often insidious and unspecific. We report a case of peritoneal tuberculosis in an 18-year-old female, who had presented for 10 days with a progressive increase in abdominal volume associated with vomiting and diarrhoea.

Diagnostic performance analysis of Xpert MTB/RIF in lymph node tuberculosis: A retrospective study.

AIMS: To retrospectively analyze the diagnostic efficacy of Xpert MTB/RIF (Xpert) in lymph node tuberculosis (LNTB). METHODS: Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and area under the curve (AUC) of Xpert, pathological examination and culture for LNTB were calculated. RESULTS: 421 suspected LNTB cases were categorized into the LNTB group (377 cases) and non-LNTB group (44 cases). The sensitivities of Xpert, pathological examination, and culture were 72.15%, 20.69%, 30.24%, respectively, with NPVs of 29.53%, 12.83%, 14.33%. The AUC values were 0.861, 0.603, 0.651, respectively. The sensitivity of Xpert varied across sample types: tissue (64.73%), puncture fluid (74.42%), and pus (96.05%). For specific lymph node locations, the sensitivity was head-and-neck (72.51%), mediastinal (84.21%), and axillary (45.83%). CONCLUSIONS: Xpert demonstrates high diagnostic value for LNTB, particularly in pus samples. It also performs better in mediastinal and head-and-neck lymph node samples compared to axillary lymph node samples.

Second Time's the Charm? Assessing the Sensitivity and Yield of Inpatient Diagnostic Algorithms for Pulmonary Tuberculosis in a Low-Prevalence Setting.

Background: For persons with suspected pulmonary tuberculosis, the guidelines of the Centers for Disease Control and Prevention recommend collecting 3 respiratory specimens 8 to 24 hours apart for acid-fast bacilli (AFB) smear and culture, in addition to 1 nucleic acid amplification test (NAAT). However, data supporting this approach are limited. Our objective was to estimate the performance of 1, 2, or 3 AFB smears with or without NAATs to detect pulmonary tuberculosis in a low-prevalence setting. Methods: We conducted a retrospective study of hospitalized persons at 8 Massachusetts acute care facilities who underwent mycobacterial culture on 1 or more respiratory specimens between July 2016 and December 2022. We evaluated percentage positivity and yield on serial AFB smears and NAATs among people with growth of Mycobacterium tuberculosis on mycobacterial cultures. Results: Among 104 participants with culture-confirmed pulmonary tuberculosis, the first AFB smear was positive in 41 cases (39%). A second AFB smear was positive in 11 (22%) of the 49 cases in which it was performed. No third AFB smears were positive following 2 initial negative smears. Of 52 smear-negative cases, 36 had a NAAT performed, leading to 23 additional diagnoses. Overall sensitivity to detect tuberculosis prior to culture positivity was higher in any strategy involving 1 or 2 NAATs (74%-79%), even without AFB smears, as compared with 3 smears alone (60%). Conclusions: Tuberculosis diagnostic testing with 2 AFB smears offered the same yield as 3 AFB smears while potentially reducing laboratory burden and duration of airborne infection isolation. Use of 1 or 2 NAATs increased sensitivity to detect culture-positive pulmonary tuberculosis when added to AFB smear-based diagnostic testing alone.

Impact of Xpert MTB/RIF implementation in tuberculosis case detection and control in Brazil: a nationwide intervention time-series analysis (2011-2022).

Background: Since 2014, Brazil has gradually implemented the Xpert MTB/RIF (Xpert) test to enhance early tuberculosis (TB) and drug-resistant (DR-TB) detection and control, yet its nationwide impact remains underexplored. Our study conducts an intervention time-series analysis (ITSA) to evaluate how the Xpert's implementation has improved TB and DR-TB detection nationwide. Methods: 1,061,776 cases from Brazil's National TB Registry (2011-2022) were reviewed and ITSA (2011-2019) was used to gauge the impact of the Xpert's adoption on TB and DR-TB notification. Granger Causality and dynamic regression modelling determined if incorporating Xpert testing as an external regressor enhanced forecasting accuracy for Brazil's future TB trends. Findings: Xpert implementation resulted in a 9.7% increase in TB notification and substantial improvements in DR-TB (63.6%) and drug-susceptible TB (92.1%) detection compared to expected notifications if it had not been implemented. Xpert testing counts also presented a time-dependent relationship with DR-TB detection post-implementation, and improved predictions in forecasting models, which depicted a potential increase in TB and DR-TB detection in the next six years. Interpretation: This study underscores the critical role of Xpert's adoption in boosting TB and DR-TB detection in Brazil, reinforcing the case for its widespread use in disease control. Improvements in prediction accuracy resulting from integrating Xpert data are crucial for allocating resources and reducing the incidence of TB. By acknowledging Xpert's role in both disease control and improving predictions, we advocate for its expanded use and further research into advanced molecular diagnostics for effective TB and DR-TB control. Funding: FIOCRUZ.

Performance of fine needle aspiration cytology and Ziehl-Neelsen staining technique in the diagnosis of tuberculosis lymphadenitis.

INTRODUCTION: Proper diagnosis of tuberculosis (TB) lymphadenitis is critical for its treatment and prevention. Fine needle aspirate cytology (FNAC) is the mainstay method for the diagnosis of TB lymphadenitis in Ethiopia; however, the performance of FNAC has not been evaluated in the Eastern Region of Ethiopia. This study aimed to evaluate the performance of FNAC and Ziehl-Neelsen (ZN) staining compared with that of GeneXpert for the diagnosis of TB lymphadenitis. METHODS: Fine needle aspiration (FNA) specimens collected from 291 patients suspected of having TB lymphadenitis were examined using FNAC, ZN, and GeneXpert to diagnose TB lymphadenitis. Gene-Xpert was considered the reference standard method for comparison. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and kappa coefficient were determined using SPSS version 25. RESULTS: The sensitivity, specificity, PPV, and NPV of ZN for diagnosing TB lymphadenitis were 73.2%, 97.4%, 96.2%, and 80.1% respectively. There was poor agreement between ZN and GeneXpert (Kappa=-0.253). The sensitivity, specificity, PPV, and NPV of FNAC were 83.3%, 94.8%, 93.5%, and 86.3% respectively. There was moderate agreement between the FNAC and GeneXpert (Kappa = 0.785). CONCLUSION: The fine needle aspiration cytology (FNAC) is a more sensitive test for the diagnosis of TB lymphadenitis than ZN. The FNAC showed a moderate agreement with the GeneXpert assay. This study recommends the FNA GeneXpert MTB/RIF test in preference to FNAC for the diagnosis of TB lymphadenitis to avoid a missed diagnosis of smear-negative TB lymphadenitis.

Rapid detection of Mycobacterium tuberculosis based on cyp141 via real-time fluorescence loop-mediated isothermal amplification (cyp141-RealAmp).

Background: The rapid detection of Mycobacterium tuberculosis (MTB) is essential for controlling tuberculosis. Methods We designed a portable thermocycler-based real-time fluorescence loop-mediated isothermal amplification assay (cyp141-RealAmp) using six oligonucleotide primers derived from cyp141 to detect MTB. A combined number of 213 sputum samples (169 obtained from clinically diagnosed cases of pulmonary TB and 44 from a control group without tuberculosis) underwent Acid-fast bacillus (AFB) smear, culture, Xpert MTB/RIF assays, and cyp141-RealAmp assay. Results: By targeting MTB cyp141, this technique could detect as low as 10 copies/reaction within 30 min, and it was successfully rejected by other mycobacteria and other bacterial species tested. Of the 169 patients, there was no statistical difference between the detection rate of cyp141-RealAmp (92.90%, 95% CI: 89.03-96.07) and that of Xpert MTB/RIF (94.67%, 95% CI: 91.28-98.06) (P > 0.05), but both were statistically higher than that of culture (65.68%, 95% CI: 58.52-72.84) (P< 0.05) and AFB (57.40%, 95% CI: 49.94-64.86) (P< 0.05). Both cyp141-RealAmp and Xpert MTB/RIF had a specificity of 100%. Furthermore, a high concordance between cyp141-RealAmp and Xpert MTB/RIF was found (Kappa = 0.89). Conclusion: The cyp141-RealAmp assay was shown to be effective, responsive, and accurate in this study. This method offers a prospective strategy for the speedy and precise detection of MTB.

Establishment and evaluation of a new fluorescent probe method based on loop-mediated isothermal amplification for the detection of Mycobacterium tuberculosis complex.

We aimed to develop a novel diagnostic method called multiplex fluorescence of loop primer upon self-dequenching loop-mediated isothermal amplification (mFLOS-LAMP) for the rapid detection of Mycobacterium tuberculosis complex (MTBC). A set of specific primers was designed to target the detection of IS1081 and IS6110 genes, which are insertion sequences within the MTBC. The 110 sputum specimens collected were assessed using the established mFLOS-LAMP method, multiplex polymerase chain reaction, Xpert MTB/RIF, and smear microscopy. The optimal reaction temperature and duration for mFLOS-LAMP were determined to be 65°C and 30 min, respectively, by optimizing the entire system. The detection sensitivity of mFLOS-LAMP was 6.0 × 101 CFU/mL, by Bacillus Calmette-Guerin, and the mFLOS-LAMP sensitivity of M. tuberculosis H37Rv genomic DNA was 500 fg, and the specificity was 100%. The sensitivity of mFLOS-LAMP was 94.2% and the specificity was 96.6%, when Xpert MTB/RIF was used as the reference method. There was no statistically significant difference in their detection rate (χ2 = 0, P = 1.000), and the consistency was good (kappa = 0.909, P < 0.001). The receiver operating characteristic analysis yielded the maximum area under the curve of 0.954. The mFLOS-LAMP method demonstrated high sensitivity and specificity, allowing for swift and accurate detection of MTBC.

Comparative evaluation of the STANDARD M10 and Xpert C. difficile assays for detection of toxigenic Clostridioides difficile in stool specimens.

This study compared the performance of two commercial molecular assays, the STANDARD M10 Clostridioides difficile assay (M10) and the Xpert C. difficile assay (Xpert), for detecting toxigenic C. difficile in stool specimens. A total of 487 consecutive stool specimens submitted for routine C. difficile testing between June and November 2023 were included. Following routine testing using C. DIFF QUIK CHEK COMPLETE (QCC), M10 and Xpert were tested in parallel, alongside toxigenic culture (reference standard). Additionally, two-step algorithms, using QCC on the first step and either M10 or Xpert on the second step, were assessed. Both M10 and Xpert demonstrated a sensitivity and negative predictive value (NPV) of 100%. M10 exhibited significantly higher specificity and positive predictive value (PPV; 91.9% and 64.2%, respectively) than Xpert (90.3% and 59.8%, respectively). Both two-step algorithms showed a sensitivity and NPV of 98.4% and 99.8%, respectively. The specificity and PPV of the two-step algorithm using M10 (95.2% and 75.0%, respectively) were slightly higher than those of the one using Xpert (94.8% and 73.2%, respectively), without statistical significance. Receiver operating characteristic curve analysis, assessing the predictive ability of cycle threshold (Ct) values for the detection of free toxin, exhibited an area under the curve of 0.825 for M10 and 0.843 for Xpert. This indicates the utility of Ct values as predictors for the detection of free toxin in both assays. In conclusion, M10 proves to be an effective diagnostic tool with performance comparable to Xpert, whether utilized independently or as part of a two-step algorithm.

Trend of pulmonary tuberculosis and rifampicin-resistance among tuberculosis presumptive patients in Central Tigray, Ethiopia; 2018 -2023: a six-year retrospective study.

BACKGROUND: Tuberculosis (TB) is a major public health concern in the developing countries. Moreover, the emergence of multidrug-resistant tuberculosis is challenging. However, there are no organized data on the trends of pulmonary tuberculosis and rifampicin-resistant Mycobacterium tuberculosis in the study area. METHODS: A retrospective cross-sectional study was conducted to fill the information gap in Central Tigray at St. Mary General Hospital between 2018 and 2023. Data were collected from the GeneXpert™ tuberculosis registration logbooks using standard checklists and analyzed using Statistical Package for Social Science version 22. After performing logistic regression, a p-value < 0.05 with a corresponding 95% confidence interval was considered statistically significant. Moreover, chi square test for trend was performed to assess the percentage of annual detection of pulmonary tuberculosis and rifampicin-resistant Mycobacterium tuberculosis during the study years. RESULT: Presumptive pulmonary tuberculosis patients with complete data (n = 3696) were included in the study. The overall prevalence of pulmonary tuberculosis was 11.7%, of which 8.1% were resistant to rifampicin. The study revealed that the incidence of pulmonary tuberculosis has been increasing, mainly in the recent four years. Likewise, an increase in rifampicin-resistant Mycobacterium tuberculosis was observed with considerable fluctuations. Age, human immunodeficiency virus infection, and presumptive rifampicin-resistant Mycobacterium tuberculosis infection were significantly associated with the presence of pulmonary tuberculosis. Moreover, pulmonary tuberculosis was more prevalent among participants in the productive-age group. CONCLUSION: Although there have been fluctuations, an increasing of pulmonary tuberculosis and rifampicin-resistant Mycobacterium tuberculosis has been observed in recent years. Hence, prevention and treatment strategies for tuberculosis should be strengthened to alleviate the burden of pulmonary tuberculosis and rifampicin-resistant Mycobacterium tuberculosis in the study area.

Diagnostic Value of Combined-Diagnostic Methods of Brain Tuberculoma Tissue Specimens: A Case Series.

Background: The diagnosis of brain tuberculoma (BT) is sometimes challenging. Herein, we presented a case series to evaluate the combined-diagnostic methods, including acid-fast bacilli (AFB) stain, polymerase chain reaction (PCR), Gene Xpert, and histopathology, of tuberculoma tissue specimens (TTSs). Patients and Methods: A total of 16 patients (11 human immunodeficiency virus [HIV]-positive, 5 HIV-negative) with BT confirmed by combined-diagnostic methods of TTS were included in this study. Clinical data, including clinical symptoms, laboratory tests, neuroimaging features, histopathology, treatment, and prognosis, were assessed in all patients. Results: There were 10 male and 6 female patients (range, 18-73 years). Acid-fast bacilli stain and PCR of TTSs were positive in 11 and 10 patients, respectively. The sensitivity of Gene Xpert of TTSs was (80.0%; 8/10). Nine (56.3%; 9/16) patients were diagnosed with BT by histopathology. After receiving antituberculosis treatment, 12 (75.0%; 12/16) patients improved clinically to a considerable extent. Conclusions: The combined-diagnostic methods of TTS may improve the diagnostic efficiency of BT.

Discordant results between Xpert MTB/RIF assay and Bactec MGIT 960 culture system regarding the detection of rifampin-resistant Mycobacterium tuberculosis isolates in Wenzhou, China.

This study aimed to assess the possible causes of discordant results between Xpert MTB/RIF (Xpert) and Bactec MGIT 960 Culture System (MGIT960) regarding rifampicin (RIF) susceptibility in Mycobacterium tuberculosis. Patients with previous RIF-resistant tuberculosis who were admitted to Wenzhou Central Hospital from January 2020 to December 2022 were enrolled. The isolates obtained from these patients were subjected to RIF susceptibility tests using Xpert and MGIT960, and the minimum inhibitory concentration (MIC) of RIF was determined by the MYCOTB MIC plate test. Additionally, molecular docking and molecular dynamics (MD) simulations were performed to evaluate the binding efficacy of rpoB and RIF based on rpoB mutations detected in the isolates with discordant RIF susceptibility results. A total of 28 isolates with discordant RIF susceptibility test results were detected, 15 of them were RIF susceptible with MICs ≤ 0.5 µg/mL. Twelve out of 15 isolates contained borderline RIF resistance-associated mutations [L430P (n = 6), H445N (n = 6)], 1 isolate had D435Y and Q429H double mutation, and the remaining 2 isolates had a silent (Q432Q) mutation. Compared with the affinity of RIF toward the wild type (WT) (-45.83 kcal/mol) by MD, its affinity toward L452P (-55.52 kcal/mol), D435Y (-47.39 kcal/mol), L430P (approximately -69.72 kcal/mol), H445N (-49.53 kcal/mol), and Q429H (-55.67 kcal/mol) increased. Borderline RIF resistance-associated mutations were the main cause for the discordant RIF susceptibility results between Xpert and MGIT960, and the mechanisms of the resistance need further investigated.IMPORTANCEThis study is aimed at assessing discordant results between Xpert MTB/RIF (Xpert) assay and Bactec MGIT 960 Culture System (MGIT960) regarding the detection of rifampicin (RIF)-resistant Mycobacterium tuberculosis isolates in Wenzhou, China. The discordant results of RIF between these two assays were mainly caused by borderline RIF resistance-associated mutations, subsequently by silent mutations of rpoB. Borderline RIF resistance- associated mutations detected in our study were demonstrated to not be affected by the affinity of rpoB and RIF by molecular dynamics, and the mechanism of resistance was needed to be clarified. For the discordant results of RIF by Xpert and MGIT960 that occurred, rpoB DNA sequencing was recommended to investigate its association with resistance to RIF.

Primary Rifampicin Mono-Resistant Extrapulmonary Tuberculosis of the Scapula With Cold Abscesses: A Report of a Rare Case.

Extrapulmonary tuberculosis is rare. Tuberculous involvement of the scapula is an infrequently reported entity. Such cases are exceptionally rare, as there is no documented case of an isolated primary rifampicin mono-resistant extrapulmonary tuberculosis of the scapula with cold abscesses in the medical literature. This case report features a 25-year-old Indian male patient whose main complaint was a painful swelling with a discharging sinus in his left shoulder that limited his range of motion. A thorough blood workup, clinical assessment, and scans led to a definitive diagnosis. The patient was commenced on antituberculous therapy.

Advancements in Tuberculosis Diagnostics: A Comprehensive Review of the Critical Role and Future Prospects of Xpert MTB/RIF Ultra Technology.

Tuberculosis remains a persistent global health challenge, demanding swift and accurate diagnostic methods for effective treatment. The emergence of the Xpert MTB/RIF Ultra system marks a significant milestone in combating tuberculosis, streamlining the identification of Mycobacterium tuberculosis, and advancing our pursuit of eradicating the disease. Delving into the therapeutic landscape of tuberculosis and rifampicin resistance, this scientific narrative review offers a comprehensive exploration. It begins by delving into the historical backdrop and the hurdles encountered with traditional tuberculosis diagnostics. From there, it traces the journey of the Xpert MTB/RIF technology, underscoring its molecular underpinnings. In this narrative review, the performance of the Xpert MTB/RIF Ultra system undergoes thorough scrutiny, encompassing investigations into sensitivity, specificity, and comparisons with alternative diagnostic methods. The spotlight shines on its clinical applications across diverse scenarios, from diagnosing pulmonary and extrapulmonary tuberculosis to its pivotal role in identifying rifampicin resistance. The study also evaluates its clinical efficacy in enhancing patient outcomes and supporting global tuberculosis control initiatives. However, the review does not shy away from discussing the challenges and limitations associated with the Xpert MTB/RIF Ultra system. It meticulously addresses concerns regarding cost, infrastructure requirements, and potential diagnostic inaccuracies. Offering a panoramic view, the review assesses the system's impact in resource-constrained settings and its potential to bolster tuberculosis elimination endeavors worldwide. Peering into the future, it explores ongoing research avenues and potential enhancements in Xpert MTB/RIF Ultra technology, envisioning a landscape of improved performance, broader applications, and emerging diagnostic innovations in the realm of tuberculosis diagnostics.

Impact of the Stool-Based Xpert Test on Childhood Tuberculosis Diagnosis in Selected States in Nigeria.

BACKGROUND: In Nigeria, most children with tuberculosis (TB) present at primary health clinics where there are limited personnel skilled in collecting appropriate respiratory specimens from those who cannot produce sputum. KNCV Nigeria, in collaboration with the National Tuberculosis Control Program, implemented a modified simple, one-step (SOS), stool-based Xpert MTB/RIF method for diagnosis of TB in children who cannot expectorate sputum. We evaluated the impact of its implementation on childhood TB diagnosis. METHOD: A cross-sectional study was conducted across 14 selected states using secondary data of children presumed to have TB. Stool was collected from children presumed to have TB and processed using Xpert. RESULT: Out of 52,117 presumptive TB cases, 52% were male and 59.7% were under 5 years old. A total of 2440 (5%) cases were diagnosed with TB, and 2307 (95%) were placed on treatment. Annual TB notifications increased significantly after the introduction of the stool-based Xpert test when compared to those in the pre-implementation period. Increasing contributions from stool testing were observed throughout the implementation period, except in 2020 during the COVID-19 era. Overall, stool Xpert testing improved childhood TB notification in the studied states. Interventions aimed at awareness creation, capacity building, and active case finding improved the performance of the test.