Mycobacterium Tuberculosis Complex Research Articles

Disseminated nontuberculous mycobacteriosis due to Mycobacterium avium subsp. hominissuis infection in a reindeer from a zoo.

Bacteria in the Mycobacterium tuberculosis complex and nontuberculous mycobacteria may affect a variety of animal species under human care and pose public health risks as zoonotic pathogens. A case of sudden onset of lethargy and increased respiratory effort in a 5-y-old, intact female reindeer (Rangifer tarandus) under managed care had progressed to severe dyspnea despite aggressive treatment. The animal was euthanized due to poor prognosis. Postmortem findings included: disseminated miliary nodules in the lungs, pleura, small intestine, liver, and spleen; enlarged mesenteric lymph nodes; dilated mesenteric and serosal lymphatic vessels; and renal infarcts. Histologically, granulomatous lymphadenitis and lymphangitis with intrahistiocytic acid-fast bacilli were observed. Mycobacterium sp. DNA was detected in lung via real-time PCR. Mycobacterial culture and sequencing identified Mycobacterium avium subsp. hominissuis (MAH) within pulmonary lesions. Infection with MAH has been reported in humans and many animal species; this nontuberculous mycobacterial infection may be an emerging concern in animals under managed care. To our knowledge, MAH infection has not been reported previously in reindeer.

Clinical Evaluation of a Rapid Reciprocal-Flow PCR Assay and Real-Time PCR Assay with Quenching Probe for Detection of Mycobacterium tuberculosis Complex.

This study investigated the diagnostic efficiencies of two assays for the detection of Mycobacterium tuberculosis complex: (1) the reciprocal-flow real-time polymerase chain reaction (PCR)-based GeneSoC assay and (2) the real-time PCR based GENECUBE MTB assay with quenching probe. These assays were performed for stored clinical samples and results were compared with the confirmed results based on culture and COBAS TaqMan MTB assay. A total of 53 samples (20 confirmed positives and 33 confirmed negatives) were included in the performance analysis. The GeneSoC assay showed concordance in all 53 samples, regardless of specimen type, while the GENECUBE MTB assay showed concordance in 19 of the 20 confirmed positive samples and all 33 confirmed negative samples. The overall agreement was 100.0% for the GeneSoC assay and 98.1% for the GENECUBE MTB assay. Positive and negative percent agreements were 100.0% each for the GeneSoC assay and 95.0% and 100.0%, respectively, for the GENECUBE MTB assay. Both the GeneSoC and GENECUBE MTB assays exhibited excellent performance in detecting M. tuberculosis complex. The GeneSoC assay is useful for independent assays of individual samples, whereas the GENECUBE MTB assay is suitable for batch assays of multiple samples.

Effects of different vaccination regimes on the immunodiagnosis of tuberculosis in goats and evaluation of defined antigens

Tuberculosis (TB) in goats is a chronic infectious disease caused by Mycobacterium tuberculosis complex (MTBC) organisms that pose a great health and economic challenge for the caprine industry in some European and developing countries. It is also a zoonotic disease posing a risk for public health. The control programs of the disease are based on a test-and-slaughter strategy, and vaccination is not feasible with available vaccines due to its interferences with the current TB immunodiagnosis. There is still a need for the development of an effective TB vaccine and, concurrently, diagnostic methods that allow differentiation between infected and vaccinated animals (DIVA approach). In this study, we investigated the interferences caused by the tuberculin (PPD)-based TB diagnostic tests in goats immunized by different mucosal and parenteral vaccination strategies: three single-dose strategies based on intranasal administration of BCG and two heat-inactivated M. bovis (HIMB) vaccines, and two prime-boost strategies based on parenteral BCG or HIMB priming and intranasal HIMB boosting. In addition, the defined antigens ESAT-6, CPF10, and EspC were evaluated as alternative diagnostic reagents to PPDs. At week 14 after prime vaccination of the animals, skin tests, IFN-γ release assay, and antibody detection assays were performed. The two prime-boosted and the single-dose intranasal BCG groups displayed greater cell-mediated immune responses to PPDs than the two single-dose intranasal HIMB vaccines. However, the use of reagents based on the defined antigens eliminated or reduced the vaccine-induced diagnostic interferences in all groups. Based on these results, the use of defined antigens in the current immunodiagnostic tests appears to be suitable in a future goat TB vaccination scenario.

Epidemiological and clinical profile of rifampicin-sensitive and -resistant pulmonary tuberculosis in sites of displaced persons due to the 2022-2024 floods in N'Djamena, Chad

Patients with rifampicin-resistant tuberculosis (RR-TB) may remain a source of infection longer than rifampicin-susceptible tuberculosis (RS-TB). The objective of this study was to detect active cases of rifampicin-susceptible and -resistant tuberculosis in displaced persons sites in the 9th District of N’Djamena. This observational, cross-sectional and analytical study was conducted among 418 contacts of the displaced persons, including 285 in the Walia site and 133 in the Toukra site. Data were collected using a pre-tested, semi-structured questionnaire administered by an interviewer. The identification of active cases of tuberculosis among the displaced persons was carried out by an interview to verify the presence or absence of TB symptoms. The TB-LAMP molecular technique was used to detect active tuberculosis among symptomatic and asymptomatic contacts. Instead, a GeneXpert analysis was carried out to detect cases of tuberculosis sensitive and resistant to rifampicin. TB-LAMP detected 76 (5.5%) cases of active TB among 418 displaced persons, including 11 lost to follow-up and 65 new cases. Female patients were more dominant (59.21%) than males (40.78%), and the age of patients ranged from 12 to 65 years, with a mean age of 38.5 years with a sex ratio of 1.45 in favor of females. Loss of appetite (31%), asthenia (20.0%) and cough (16%) were the most common symptoms. GeneXpert confirmed the 76 positive cases of Mycobacterium tuberculosis, of which 8 (10.52%) were resistant and 69 (90.78%) were sensitive to rifampicin. HIV1/2 immunochromatographic tests detected 12 (15.78%) cases of HIV/tuberculosis coinfection among the positive cases. This study highlighted the emergence of strains of the Mycobacterium tuberculosis complex resistant and sensitive to rifampicin. Regular and effective screening of RR-TB contacts is necessary to stop transmission in displaced persons sites in Chad, Africa and even worldwide. Keywords: Flood, displaced person, Mycobacterium tuberculosis, resistance, rifampicin, molecular technique, Chad.

Functions of nitroreductases in mycobacterial physiology and drug susceptibility.

Tuberculosis is a respiratory infection that is caused by members of the Mycobacterium tuberculosis complex, with M. tuberculosis (Mtb) being the predominant cause of the disease in humans. The approval of pretomanid and delamanid, two nitroimidazole-based compounds, for the treatment of tuberculosis encourages the development of more nitro-containing drugs that target Mtb. Similar to the nitroimidazoles, many antimycobacterial nitro-containing scaffolds are prodrugs that require reductive activation into metabolites that inhibit the growth of the pathogen. This reductive activation is mediated by mycobacterial nitroreductases, leading to the hypothesis that these nitroreductases contribute to the specificity of the nitro prodrugs for mycobacteria. In addition to their prodrug-activating activities, these nitroreductases have different native activities that support the growth of the bacteria. This review summarizes the activities of different mycobacterial nitroreductases with respect to their activation of different nitro prodrugs and highlights their physiological functions in the bacteria.

Recovery of Mycobacterium tuberculosis Complex Isolates Including Pre-Extensively Drug-Resistant Strains From Cattle at a Slaughterhouse in Chennai, India.

India has the highest global burden of human tuberculosis (TB) and the largest cattle herd with endemic bovine TB (bTB). However, the extent of cross-species transmission and the zoonotic spillover risk, including drug-resistant Mycobacterium tuberculosis complex (MTBC) strains circulating in cattle, remain uncharacterized. To address this major knowledge gap, we investigated tissue samples from 500 apparently healthy cattle at a slaughterhouse in Chennai, India. Whole genome sequencing was performed to characterize the isolates. Sixteen animals (32 per 1000 [95% confidence interval, 16-47]) were MTBC-positive, a rate that is nearly an order of magnitude greater than the reported human TB incidence in the region. Thirteen isolates were identified as Mycobacterium orygis and 3 were M tuberculosis: 1 was a mixed infection of M tuberculosis lineage 1 and M orygis, and the other 2 had pure growth of M tuberculosis lineage 2, in both cases pre-extensively drug-resistant (pre-XDR) with identical resistance patterns and separated by 7 single-nucleotide polymorphisms. The results confirm that bTB in this region is primarily due to M orygis and M tuberculosis, and not Mycobacterium bovis. The detection of pre-XDR M tuberculosis in cattle highlights a potential public health concern, since controlling human TB alone may be insufficient without addressing bovine TB. Overall, our findings underscore an urgent need for targeted interventions to mitigate zoonotic tuberculosis transmission in regions where bTB is endemic.

Harnessing miRNAs: A Novel Approach to Diagnosis and Treatment of Tuberculosis.

Mycobacterium tuberculosis (Mtb) complex, responsible for tuberculosis (TB) infection, continues to be a predominant global cause of mortality due to intricate host-pathogen interactions that affect disease progression. MicroRNAs (miRNAs), essential posttranscriptional regulators, have become pivotal modulators of these relationships. Recent findings indicate that miRNAs actively regulate immunological responses to Mtb complex by modulating autophagy, apoptosis, and immune cell activities. This has resulted in increased interest in miRNAs as prospective diagnostic indicators for TB, especially in differentiating active infection from latent or inactive stages. Variations in miRNA expression during Mtb infection indicate disease progression and offer insights into the immune response. Furthermore, miRNAs present potential as therapeutic targets in host-directed therapy (HDT) techniques for TB infection. This work examines the function of miRNAs in TB pathogenesis, with the objective of identifying particular miRNAs that regulate the immune response to the Mtb complex, evaluating their diagnostic value and exploring their therapeutic implications in host-directed therapy for TB infection. The objective is to enhance comprehension of how miRNAs can facilitate improved diagnosis and treatment of TB.

Incidence of mycobacteria in pulmonary granulomatous lesions.

Mycobacteria infections are caused by species of the Mycobacterium tuberculosis complex (MTB) and other species called Non-Tuberculosis Mycobacteria (NTM). Identification of mycobacteria species is very important to define treatment and it can be achieved by direct culture. However, the lack of clear protocols regarding the use of culture or molecular tests on specimens diagnosed with granulomatous lesions causes delays in the diagnosis of the etiological agents and, consequently, the definition of the right treatment. This work aimed to characterize the incidence of mycobacteria species in pulmonary granulomatous lesions and the contribution of Polymerase Chain Reaction (PCR) in Formalin-Fixed Paraffin-Embedded Tissue (FFPE), direct culture, and Ziehl-Neelsen histological stain to the diagnosis. The authors performed an observational, centralized, and retrospective study in a cohort of 336 cases with pulmonary granulomatous lesions. Mycobacteria were detected by ZNS in 54/323 (16.72 %) and by direct culture in 40/198 (20.20 %). MTB DNA was detected by PCR in 10/57 (17.54 %). Mycobacterial culture results revealed MTB in 26/40 (65.00 %), whereas NTM was detected in 13/40 (32.50 %). NTM was represented by M. avium (n = 4), M. intracellulare (n = 3), M. kansasii (n = 3), M. colombiense (n = 1), M. paraffinicum (n = 1), and M. abscessus subsp. massiliense (n = 1). In conclusion, this study demonstrated that mycobacteria are detected in 16.72 % to 20.20 % of pulmonary granulomatous lesions. Moreover, MTB and NTM were detected in these lesions. The use of different methods for mycobacteria detection, in addition to culture, is complementary and contributes to fastening and increasing the detection of mycobacteria in these lesions.

Diagnostic accuracy of self-collected tongue swabs for Mycobacterium tuberculosis complex detection in individuals being assessed for TB in South Africa using the Xpert MTB/RIF Ultra assay

Diagnostic accuracy of self-collected tongue swabs for Mycobacterium tuberculosis complex detection in individuals being assessed for TB in South Africa using the Xpert MTB/RIF Ultra assay

Persistent Axillary Lymphadenitis in a Toddler Post BCG vaccination: A Case Report

Bacillus Calmette-Guérin (BCG) vaccine, a live attenuated vaccine derived from Mycobacterium bovine, has been used as a part of routine immunization programs. One of the complications of this vaccination is BCG adenitis, which is the enlargement of the regional lymph node in the axillary or supraclavicular area. Normally, this condition resolves approximately 6 weeks after vaccination, and persistent BCG adenitis is rarely seen in children with immunocompetence. Herein, a 5-month-old boy presented with complaints of left axillary lymphadenopathy after 2 weeks of BCG vaccination. Ultrasonography revealed a nontender mobile lymph node measuring approximately 2.5 × 2 cm, which persisted beyond 12 months of age. The parents insisted on removing the swelling surgically at the age of 18 months as it did not resolve on its own. The lesion was removed and sent for HPE examination, acid-fast bacilli (AFB) staining, and GeneXpert for Mycobacterium tuberculosis (MTB). In the current case, the HPE revealed epithelioid cell granulomatous lesions, with no AFB or necrosis. The GeneXpert MTB/RIF (Cepheid) test was positive, which detected the MTB complex (including MTB and BCG), suggestive of BCG adenitis without active tuberculosis. This case shows that BCG adenitis can persist even beyond the age of 12 months. Careful history taking and timely adequate investigation along with the knowledge that GeneXpertMtb detects MTB complex will aid in the correct diagnosis.

Analysis of complete genomes of Mycobacterium tuberculosis sublineage 2.1 (Proto-Beijing) revealed the presence of three pe_pgrs3-pe_pgrs4-like genes

Mycobacterium tuberculosis Complex (MTBC), the etiological agent of tuberculosis (TB), demonstrates considerable genotypic diversity with distinct geographic distributions and variable virulence profiles. The pe-ppe gene family is especially noteworthy for its extensive variability and roles in host immune response modulation and virulence enhancement. We sequenced an Mtb genotype L2.1 isolate from Chiangrai, Northern Thailand, using second and third-generation sequencing technologies. Comparative genomic analysis with two additional L2.1 isolates and two L2.2.AA3 (Asia Ancestral 3 Beijing) isolates revealed significant pe-ppe gene variations. Notably, all L2.1 isolates harbored three copies of pe_pgrs3-pe_pgrs4-like genes (pe_pgrs3*, pe_pgrs4*, and pe_pgrs4), different from L2.2.AA3 and H37Rv strains. Additionally, ppe53 was duplicated in all but H37Rv, and ppe50 was deleted in L2.1 isolates, contrasting with an extended ppe50 in an L2.2 isolate (Mtb 18b), which contains an additional SVP motif. Complete deletion of ppe66 and loss of wag22 were observed in L2.1 isolates. These findings highlight the high structural variability of the pe-ppe gene family, emphasizing its complex roles in Mtb-host immune interactions. This genetic complexity offers potentially critical insights into mycobacterial pathogenesis, with significant implications for vaccine development and diagnostics.

Evaluation of a Commercial Multiplex Real-Time PCR with Melting Curve Analysis for the Detection of Mycobacterium tuberculosis Complex and Five Nontuberculous Mycobacterial Species.

Accurate and timely diagnosis of mycobacterial infections, including Mycobacterium tuberculosis complex (MTBC) and nontuberculous mycobacteria (NTM), is crucial for effective disease management. This study evaluated the performance of the NeoPlex TB/NTM-5 Detection Kit (NeoPlex assay, Seongnam, Republic of Korea), a multiplex real-time PCR assay that incorporates melting curve analysis, compared with the line-probe assay (LPA). The NeoPlex assay could simultaneously detect and differentiate MTBC from five other NTM species: Mycobacterium intracellulare, Mycobacterium avium, Mycobacterium kansasii, Mycobacterium abscessus, and Mycobacterium massiliense. A total of 91 acid-fast bacillus culture-positive samples, comprising 36 MTBC and 55 NTM isolates, were collected from the Korea University Anam Hospital. The NeoPlex assay successfully detected nucleic acids in 87 of the 91 isolates (95.6%). Notably, it identified additional mycobacterial nucleic acids not detected by the LPA in eight isolates. These findings were confirmed via DNA sequencing. The assay had 100% sensitivity and specificity for M. intracellulare, M. abscessus, M. massilense, NTM, and MTBC, whereas it had 100% specificity and sensitivity of 90.9% and 75.0% for M. avium and M. kansasii, respectively. These results highlight the potential of the NeoPlex assay to enhance rapid and accurate diagnosis of mycobacterial infections, particularly in settings in which prompt treatment initiation is essential.

Predicting Tuberculosis Risk in Cattle, Buffaloes, Sheep, and Goats in China Based on Air Pollutants and Meteorological Factors.

Tuberculosis is a zoonotic chronic respiratory infectious disease caused by the Mycobacterium tuberculosis complex. The outbreak and epidemic of tuberculosis can seriously threaten human and veterinary health. To investigate the effects of environmental factors on tuberculosis in domestic ruminants, we collected data regarding the prevalence of tuberculosis in cattle, buffaloes, sheep, and goats in China (1956-2024) from publicly published literature and available databases. We identified the key risk factors among six major air pollutants and 19 bioclimatic variables; simulated the risk distribution of tuberculosis in cattle, buffaloes, sheep, and goats in China using the maximum entropy ecological niche model; and evaluated the effects of environmental factors. The area under the curve of the model was 0.873 (95% confidence interval, 0.851-0.895). The risk factors that most significantly influenced the prevalence of tuberculosis were the nitrogen dioxide (NO2) level, mean temperature of the coldest quarter, cattle distribution density, sheep distribution density, ozone (O3) level, and precipitation of the driest month. The predicted map of tuberculosis risk in cattle, buffaloes, sheep, and goats indicated that the high-risk regions were mainly distributed in South, North, East, and Northwest China. Improved surveillance is needed in these high-risk areas, and early preventive measures must be implemented based on the risk factors identified to reduce the future prevalence of tuberculosis in cattle, buffaloes, sheep, and goats.

Development and Comprehensive Evaluation of Culture-Independent, Long Amplicon-Based Targeted Next-Generation Sequencing Methods for Predicting Antimicrobial Resistance in Tuberculosis.

The great variety of antimicrobial resistance (AMR) profiles among tuberculosis (TB) patients necessitates a comprehensive detection method. This study developed culture-independent, long amplicon-based targeted next-generation sequencing (tNGS) methods for predicting AMR across 16 drugs within the Mycobacterium tuberculosis complex (MTBC). Multiplex PCR amplification was employed to enrich 20 gene regions, with sequencing performed on either the Oxford Nanopore Technologies (ONT) or Illumina platforms. Customized bioinformatics pipelines provide a streamlined process from raw data to clinician-friendly reports. The ONT tNGS method has been optimized, and its performance has been thoroughly evaluated, utilizing Q20+ chemistry in combination with the R10.4.1 flow cell. It requires only 15 high-quality reads per target gene to accurately identify all variants, with the turnaround time taking 4 h and 50 min. Studies confirmed that this method effectively identifies Mycobacterium species and was highly resistant to interference from other clinical pathogens. To ensure optimal coverage, it is recommended to input at least 500 copies of the genome and sequence 500MB of high-quality FASTQ data. Diagnostic performance evaluations demonstrate that this method achieves 98.35% concordance with phenotypic drug susceptibility testing (pDST) and is consistent with the results obtained from Xpert MTB/RIF assays. The design of long amplicons not only ensures comprehensive coverage of target regions but also simplifies primer design, facilitating compatibility with various sequencing platforms. Compared with previous studies, the optimized ONT tNGS method in this study significantly improves turnaround time, detection accuracy, and the comprehensive coverage of mutations associated with AMR.

Performance of a broth microdilution assay for routine minimum inhibitory concentration determination of 14 anti-tuberculous drugs against the Mycobacterium tuberculosis complex based on the EUCAST reference protocol.

This comparative study aimed at qualifying a broth microdilution (BMD) assay for phenotypic drug susceptibility testing (pDST) of Mycobacterium tuberculosis complex (MTBC) strains for implementation in a routine DST workflow. The assay was developed based on the EUCAST (European Committee on Antimicrobial Susceptibility Testing) reference protocol for determination of the minimum inhibitory concentration (MIC) of 14 anti-tuberculous drugs (isoniazid [INH], rifampicin [RIF], ethambutol [EMB], amikacin [AMI], moxifloxacin [MFX], levofloxacin [LFX], bedaquiline [BDQ], clofazimine [CFZ], delamanid [DLM], pretomanid [PA], para-aminosalicylic acid [PAS], linezolid [LZD], ethionamide [ETH], and cycloserine [CS]). Forty MTBC strains with various drug resistance profiles were tested to determine the agreement between MIC results and genotypic drug susceptibility testing (gDST) results derived from whole-genome sequencing (WGS). The agreement between the BMD and gDST results was solid for the majority of the drugs (average agreement 98%, range 90%-100%), including key drugs such as INH, RIF, MFX, LFX, BDQ, DLM, and PA. Ten discrepancies were identified (corresponding to 1.8% of the total number of MIC determinations) and most (8/10) were characterized by MICs equal or close to the potential critical concentration (pCC) applied in the BMD assay. Importantly, the assay can be adjusted to new drug recommendations and concentrations, tailored to local needs. We conclude that the BMD assay provides reliable results, and its implementation in our MTBC routine workflow will produce valuable data that improve our understanding and management of MTBC drug resistance.

Prevalence of non-tuberculous mycobacteria among people with acid-fast positive presumptive tuberculosis in Mali.

Non-tuberculous mycobacteria (NTM) are environmental agents that can cause opportunistic pulmonary disease in humans and animals, often misdiagnosed as tuberculosis (TB). In this study, we describe the cases of NTM identified during the first national anti-TB drug resistance survey conducted in Mali and explore associated risk factors. Sputum was collected from people presenting for pulmonary TB diagnosis from April to December 2019, regardless of age. Microscopy-positive patients were enrolled and tested using the Xpert MTB/RIF assay. A patient who tested negative for the Mycobacterium tuberculosis complex (MTBC) was tested for the presence of mycobacteria by amplification of the IS6110 and 16SrRNA (16S) genes through double quantitative real-time PCR, followed by nested PCR and Sanger sequencing of the IS6110-negative samples for NTM species identification. 1,418 sputum smear-positive patients were enrolled, including 1,199 new cases, 211 previously treated cases, and 8 whose previous treatment history was unknown. Based on the results of Xpert MTB/RIF assay and in-house PCR methods, 1,331 (93.9%) patients were positive for MTBC, 48 (3.4%) for NTM, and no species identification was possible for 39 (2.7%). Advanced age of 65 and over with an OR 8.8 (95% CI 2.3-33.2 and p = 0.001) and previous TB treatment with an OR 3.4 (95% CI 1.2-9.6 and p = 0.016) were the risk factors statistically associated with NTM detection. M. avium complex (MAC) was the predominant NTM species, detected in 20 cases. Detection of NTM in people presumed to have TB is an ongoing challenge, confounding correct TB diagnosis. Concomitant use of microscopy and GeneXpert testing among at-risk individuals could improve patient management.

The new gamma interferon (IFN-γ) algorithm for tuberculosis diagnosis in cynomolgus macaques.

Tuberculosis (TB) is the first infectious disease to be screened-out from specified pathogen-free cynomolgus macaques (Macaca fascicularis; Mf) using in human pharmaceutical testing. Being in either latent or active stage after exposure to the Mycobacterium tuberculosis complex (MTBC), the monkey gamma-interferon release assay (mIGRA) was previously introduced for early TB detection. However, a notable incidence of indeterminate results was observed. In this study, we compared two positive mitogen references, phytohemagglutinin (PHA) that is used in the QuantiFERON-TB Gold Plus kit (QFT-PHA) and a combination of Concanavalin A and Pokeweed mitogen (ConA+PWM), in a cohort of 316 MTBC-exposed Mf. Following a 29-month follow-up of 100 selected animals, we established a new mIGRA interpretation algorithm that demonstrated a significant shift in the negative and indeterminate cases regardless of whether the QFT-PHA or ConA+PWM was used as a mitogen. That is, if the ODNIL value was ≤0.18, ODMIT-NIL > ODNIL, and the ODTB1/2-NIL were ≥0.05 and ≥25% of individual ODNIL, the mIGRA result was interpreted as 'positive'. If the ODNIL value was ≤0.18, ODMIT-NIL > ODNIL, and the ODTB-NIL was <0.05, the mIGRA result was interpreted as 'negative'. If the ODNIL value was >0.18 or the OD of mitogen references [OD(QFT-PHA) and OD(ConA+PWM)] were ≤0.18, the mIGRA result was interpreted as 'indeterminate'. As a result, negative cases increased by 10-50%, indeterminate cases decreased by 40-80%, and the number of TB-positive cases remained unchanged. Our findings highlight the critical role of mitogens as positive controls in mIGRA interpretation. This study provides the mIGRA value for the TB screening of cynomolgus macaques that enables the identification of true positive and suspicious TB cases for quarantine programs.

Diagnostic accuracy of LiquidArray MTB-XDR VER1.0 for the detection of Mycobacterium tuberculosis complex, fluoroquinolone, amikacin, ethambutol, and linezolid susceptibility.

Drug susceptibility testing (DST) is essential for starting people on effective tuberculosis (TB) regimens. No published data exists for the high-throughput LiquidArray MTB-XDR (LA-XDR) test, which detects Mycobacterium tuberculosis complex (MTBC) and fluoroquinolone, amikacin, ethambutol, and linezolid susceptibility (latter two have no rapid DSTs available). We enrolled people (n=720) with presumptive TB who provided two sputa for a Xpert MTB/RIF Ultra and a culture (MTBC reference standard). Phenotypic DST and Sanger sequencing were the composite reference standards. LA-XDR on the manual FluoroLyse and automated GenoXtract-fleXT (fleXT) DNA extraction methods were compared. For MTBC, LA-XDR had similar sensitivities (85-87%) and specificities (99%) using each extraction method. Drug susceptibility sensitivities varied: 94% (95% CI: 86, 98) for fluoroquinolones, 64% (45, 80) for amikacin, and 88% (79, 93) for ethambutol (specificities 97-100%). 6/7 (86%) resistant linezolid isolates were detected. LA-XDR with fleXT had indeterminate proportions of 21/251 (8%), 2/251 (1%), 63/251 (25%), and 93/251 (37%) for fluoroquinolones, ethambutol, amikacin, and linezolid, respectively (amikacin and linezolid indeterminates higher with Fluorolyse-extracted DNA). In a hypothetical population of 100 smear-negative people with fluoroquinolone-resistant TB undergoing fleXT DNA extraction, 24/100 (24%) would be missed (one extraction error, two invalid results, 15 MTBC-negative, six fluoroquinolone-indeterminate, one false-susceptible). LA-XDR met the minimum WHO target product profile for a next-generation sputum-based moderate complexity DST with high fluoroquinolones and ethambutol resistance sensitivity, moderate amikacin resistance sensitivity, and promise for linezolid resistance, for which more data are needed. Improved LA-XDR MTBC detection would reduce missed resistance.

Collaborative learning in the digital age: empowering tuberculosis researchers through virtual training.

Integrating whole genome sequencing (WGS) of the Mycobacterium tuberculosis complex into routine care, surveillance, and research in high tuberculosis burden settings remains challenging due to limited resources and skills. While technological platforms for scaling WGS are emerging, scaling wet lab and analytic components often depends on partnerships where such skills have been established. To address this, a virtual training program was developed. Over 12 weeks, 21 trainees from five Southern African institutes engaged in learning from curated theoretical content and interactive virtual meetings with experienced instructors. The training program, developed by a diverse team of experts in molecular biology, biomedical research, microbiology, and tuberculosis research, provided comprehensive coverage aligned with the latest advancements. Teaching strategies included interactive mentor-led sessions and real-time feedback, together with facilitated knowledge exchange and understanding. The virtual training program yielded several successes. Of note, trainees submitted three scientific articles for peer review, based on their acquired knowledge and its application in research. The program also fostered collaborations on Mycobacterium tuberculosis WGS among participants, showcasing the potential for networking and future joint projects. While the virtual training program encountered challenges related to the pandemic, limited resources, trainee engagement, and language barriers, these were creatively mitigated. To improve future training sessions, a platform assessing participant engagement and information retention is recommended. Wider collaborative efforts among experts and institutions in collating resources will lead to more comprehensive training programs. Addressing challenges such as internet connectivity issues and language barriers is crucial for ensuring inclusivity and enhancing the overall learning experience. In conclusion, the virtual training program successfully provided knowledge and skill training in WGS to trainees, leading to scientific article submissions and collaborations. Furthermore, content creators benefited from improved science communication and training opportunities.

Gastrointestinal: Direct Visualization of Biliary Tuberculosis.

Biliary tuberculosis is a rare type of hepatobiliary tuberculosis. Clinical presentation, imaging, or cholangiogram are difficult to distinguish from other common causes of cholangiopathy or malignancy. Direct visualization of bile duct via cholangioscopy and targeted biopsy was introduced as one of effective investigations for tissue acquisition and diagnosis. We present a case of biliary tuberculosis presented with pruritus, progressive painless jaundice and significant weight loss. Laboratory findings showed an obstructive jaundice. MRI showed multifocal bile duct stricture and intrahepatic duct stone. Single operator cholangioscopy revealed ductal stricture with papillary projection at common hepatic duct and pigmented stone. Targeted biopsy was performed, which showed non-necrotizing granulomatous inflammation and detection of Mycobacterium tuberculosis complex DNA. Direct visualization via cholangioscopy can aid and increase diagnostic yield of biliary tuberculosis.