Tuberculosis Complex Research Articles

Dual-centre evaluation of the FluoroType MTBDR version 2 assay for detection of Mycobacterium tuberculosis complex and resistance-conferring mutations in pulmonary and extrapulmonary samples from Denmark, Germany and Sierra Leone

ObjectivesWe evaluated the ability of FluoroType MTBDR version 2 (FTv2; Hain Lifescience), a second-step real-time PCR assay, to simultaneously detect Mycobacterium tuberculosis complex (MTBC) DNA and mutations conferring resistance to rifampicin (RIF) and isoniazid (INH), in pulmonary and extrapulmonary samples from patients and compared them with corresponding cultures. MethodsFTv2 MTBC was evaluated on 1815 and 432 samples from Denmark (DK) and Germany (DE), respectively. RIF and INH resistance mutations were assessed in the German samples and 110 samples from Sierra Leone and subsequently compared to phenotypic antimicrobial susceptibility testing and a composite reference DNA (CRD) based on the GenoType MTBDR line-probe assay and Sanger sequencing or whole-genome sequencing. ResultsOf the 584 (557 smear-negative) Danish and 277 (85 smear-negative) German sputum samples, 42 (16) and 246 (54) were culture positive, and 44 (18) and 222 (35) were FTv2 positive, providing an FTv2 sensitivity and specificity of 0.86 (0.63) and 0.98 (DK), 0.90 (0.65) and 1.00 (DE), respectively. The count, sensitivities, and specificities for all pulmonary samples were 1434, 0.79, and 0.99 (DK) and 347, 0.86, and 1.00 (DE), respectively; for extrapulmonary samples, 381, 0.33, 0.99 (DK) and 83, 0.50, and 1.00 (DE). The valid count, sensitivity, and specificity compared with CRD for detecting resistance mutations were RIF 355, 0.99, 0.96, and INH 340, 1.00, and 0.98, respectively. DiscussionFTv2 reliably detects MTBC DNA in pulmonary and extrapulmonary samples and detects resistance mutations for INH and RIF resistance in inhA promoter, katG, and rpoB genes.

Retrospective and prospective evaluation of the FluoroType®-Mycobacteria VER 1.0 assay for the identification of mycobacteria from cultures in a French center.

Rapid, reliable identification of mycobacteria from positive cultures is essential for patient management, particularly for the differential diagnosis of Mycobacterium tuberculosis complex (MTBC) and nontuberculous mycobacteria (NTM) species. The aim of the present study was to evaluate a new "In-Vitro-Diagnostic"-certified PCR kit, FluoroType®-Mycobacteria VER1.0 (Hain Lifescience GmbH) for NTM and MTBC identification from cultures. Mycobacteria identification isolated from positive cultures during routine practice at the Lyon university hospital mycobacteria laboratory obtained by hsp65 amplification/sequencing were compared retrospectively and prospectively to those obtained by and the FluoroType®-Mycobacteria VER1.0kit. The overall agreement between hsp65 amplification/sequencing and the FluoroType®-Mycobacteria VER1.0kit was 88.4% (84/95); 91.2% (52/57) for the retrospective period and 84.2% (32/38) for the prospective period. There were 9 (9.5%) minor discrepancies (species in the FluoroType®-Mycobacteria VER1.0database and identified at genus level): 4 during the retrospective period, 5 during the prospective period; and 2 (2.1%) major discrepancies (species in the FluoroType®-Mycobacteria VER1.0database and identified incorrectly to species level): 1 during the retrospective period (M. kumamotonense identified as M. abscessus subsp massiliense by the kit) and 1 during the prospective period (M. chimaera identified as M. smegmatis by the kit). Including concordant results at genus level and minor discrepancies, 17.9% (17/95) of strains were identified as Mycobacterium sp. by the FluoroType®-Mycobacteria-VER1.0kit. The good performance of the FluoroType®-Mycobacteria-VER1.0kit with few major discrepancies could enable its use for first-line identification of positive mycobacteria cultures. However, an alternative identification method at least for reference laboratories is needed owing to the non-negligible proportion of NTM strains were identified at genus level.

Mycobacterium tuberculosis complex and detection of rifampicin and isoniazid resistance, with phenotypic study and massive genome sequencing

Objective: The objective of this study is to compare the results obtained from the detection of MTBC (Mycobacterium tuberculosis Complex) and drug resistances between two commercial molecular methods, phenotypic Drug Susceptibility Testing (DST) and whole-genome sequencing. Materials and methods: Clinical samples positive for MTBC were selected. Identification and study of mutations associated with rifampicin and isoniazid resistance were carried out using 2 commercial molecular techniques and phenotypic DST, using critical concentration in liquid medium. In parallel, the analysis of Mycobacterium tuberculosis complex genome was performed by sequencing complete genomes.

Mycobacterium tuberculosis complex in domestic goats in Southern Spain

Tuberculosis (TB) is a zoonotic infectious disease caused by bacteria belonging to the Mycobacterium tuberculosis complex (MTC), which can affect a wide variety of domestic and wild animal species. Although the role of goats as a reservoir of MTC bacteria has been evidenced, information about the circulation of MTC strains in this species is still very scarce. The aim of the present study was to determine the seroprevalence, spatial distribution, risk factors and MTC spoligotypes circulating in goats from Andalusia (Southern Spain), the Spanish region with the largest goat census and a hotspot area of TB in both cattle and wild ungulates. A total of 2155 serum samples from 80 goat flocks were analyzed by an in-house ELISA using the P22 protein complex as a coating antigen. Antibodies against MTC were detected in 473 goats (21.9%, 95% CI: 20.2–23.7) and the true seroprevalence was 22.3% (95% CI: 20.6–24.1). Seropositivity was found in 72 (90.0%) of the 80 flocks analyzed. The generalized estimating equation model showed that the management system (higher seroprevalence on intensive and semi-intensive farms), and the presence of hospital pens inside the regular stables, were risk factors potentially associated with MTC exposure in goats in Southern Spain. The spatial analysis identified a significant spatial cluster (p < 0.001) in Eastern Andalusia. A total of 16 different MTC spoligotypes, including five of M. caprae and eleven of M. bovis, were identified in goats between 2015 and 2022 in the study area, with SB0157 as the most frequently isolated. The results obtained indicate widespread and non-homogeneous spatial distribution of MTC in goat herds from Southern Spain. The high individual and herd-level seroprevalence values found suggest that goats could play a significant role in the maintenance and transmission of MTC in the study area. Our results highlight the importance of implementing control measures in this species.

Genotypic Characterization of Mycobacterium Tuberculosis Strains Resistant to Rifampicin, Isoniazid and Second-Line Antibiotics in Chad

Monitoring drug resistance and identifying the genetic basis of resistance to first- and second-line anti-tuberculosis (anti-TB) drugs provides important information to optimize patient care. The present study was an observational, cross-sectional and analytical study aimed at determining the prevalence of resistance genes to rifampicin, isoniazid and resistant and multi-resistant genes with mutations associated with second-line anti-tuberculosis drugs (Levofloxacin Amikacin, Kanamycin and Capreomycin) among strains of Mycobacterium tuberculosis in nine hospitals in four provinces of Chad with three new molecular techniques. The TB-LAMP molecular technique made it possible to detect 264 (25.14%) strains of Mycobacterium tuberculosis complex among 1050 people referred for tuberculosis research, including 37 cases in relapse and 237 new cases under treatment or not without clinical improvement. The average age of the patients was 34.15 years with the extremes ranging from 12 to 77 years. The sex ratio was 3.33 in favor of men. The GeneXpert made it possible to confirm the 264 positive cases of Mycobacterium tuberculosis (MTB+) of which 76% of men and 24% of women had the MTB+ profile sensitive to rifampicin, and 80% of men and 20% of women harbored the Mycobacterium complex. rifampicin-resistant tuberculosis. The determination of resistance genes including 13% (rpoB) to rifampicin, 4% (inhA) to isoniazid and 8% (rpoB/KatG and/or KatG/inhA) multi-resistant (MDR) genes was carried out using the Line Probe Assay technique. This technique also made it possible to determine resistance genes with associated mutations including 13.6% (gyrA and gyrB), 7.6% (eis), 6.1% (rrs and eis) and 10.6% being mutations affecting the different alleles on the chromosomes of the Mycobacterium tuberculosis complex. This study highlighted the emergence of resistance to rifampicin and isoniazid as well as resistance with mutations associated with second-line anti-tuberculosis drugs. It raises the need to implement an effective surveillance system to detect the resistance of Mycobacterium tuberculosis to anti-tuberculosis drugs in Chad and even in Central Africa.

Incipient tuberculosis: a comprehensive overview.

In the context of the evolving global health landscape shaped by the COVID-19 pandemic, tuberculosis (TB) is gaining renewed attention as a reemerging threat even in low-endemic countries. Immunological tests such as the tuberculin skin test (TST) and interferon-gamma release assay (IGRA) are pivotal in identifying tuberculosis infection (TBI). However, their inability to distinguish between past and ongoing infection poses a diagnostic challenge, possibly leading to the unnecessary treatment of a significant portion of the population with potential side effects. This review delves into the concept of incipient tuberculosis (ITB), a dynamic, presymptomatic stage characterized by heightened Mycobacterium tuberculosis complex (MTC) metabolic activity and replication that result in minimal radiological changes, signifying a transitional state between TBI and TB. Key focus areas include epidemiological factors, underlying pathogenesis, imaging findings, and the ongoing challenges in the identification of individuals with ITB through the development of new biomarkers and the use of whole-genome sequencing-based analyses to implement early treatment strategies.

Diagnosing adult and pediatric extrapulmonary tuberculosis by MPT64 antigen detection with immunohistochemistry and immunocytochemistry using reproduced polyclonal antibodies.

Diagnosing extrapulmonary tuberculosis (EPTB) is challenging. Immunohistochemistry or immunocytochemistry has been used to diagnose tuberculosis (TB) by detection of MPT64 antigen from various extrapulmonary specimens and has shown good diagnostic performance in our previous studies. The test can distinguish between disease caused by Mycobacterium tuberculosis (Mtb) complex and nontuberculous mycobacteria and can be applied on formalin-fixed paraffin-embedded tissue. As the antibodies previously used were in limited supply, a new batch of polyclonal antibodies was developed for scale-up and evaluated for the first time in this study. Our aim was to assess the diagnostic accuracy of the MPT64 test with reproduced antibodies in the high burden settings of Pakistan and India. Patients were enrolled prospectively. Samples from suspected sites of infection were collected and subjected to histopathologic and/or cytologic evaluation, routine TB diagnostics, GeneXpert MTB/RIF (Xpert), and the MPT64 antigen detection test. Patients were followed until the end of treatment. Based on a composite reference standard (CRS), 556 patients were categorized as TB cases and 175 as non-TB cases. The MPT64 test performed well on biopsies with a sensitivity and specificity of 94% and 75%, respectively, against a CRS. For cytology samples, the sensitivity was low (36%), whereas the specificity was 81%. Overall, the MPT64 test showed higher sensitivity (73%) than Xpert (38%) and Mtb culture (33%). The test performed equally well in adults and children. We found an additive diagnostic value of the MPT64 test in conjunction with histology and molecular tests, increasing the yield for EPTB. In conclusion, immunochemical staining with MPT64 antibodies improves the diagnosis of EPTB in high burden settings and could be a valuable addition to routine diagnostics.

Tuberculosis: Implications for Dentistry

Tuberculosis (TB) is an airborne infection caused by Mycobacterium tuberculosis complex and is highly infectious. Therefore, precautionary measures should be implemented prior to dental treatment to reduce the risk of infection to staff and other patients. Dental history and examination have a role in identification of TB infection. Complex medical history poses a challenge to safe patient management in a dental setting, and close liaison between different disciplines in managing these patients is of paramount importance. This article explores the classical clinical features of pulmonary TB, its oral manifestations and the dental management of patients with active and latent TB. CPD/Clinical Relevance: Clinicians should be aware of the clinical features and dental management of patients with active and latent TB.

Rapid and accurate identification and differentiation of Mycobacterium tuberculosis and non-tuberculous mycobacteria using PCR kits available in a high-burden setting.

Infections caused by mycobacteria, including Mycobacterium tuberculosis complex (MTBC) and non-tuberculous mycobacteria (NTM), are a major public health issue worldwide. An accurate diagnosis of mycobacterial species is a challenge for surveillance and treatment, particularly in high-burden settings usually associated with low- and middle-income countries. In this study, we analyzed the clinical performance of two commercial PCR kits designed for the identification and differentiation of MTBC and NTM, available in a high-burden setting such as Ecuador. A total of 109 mycobacteria isolates were included in the study, 59 of which were previously characterized as M. tuberculosis and the other 59 as NTM. Both kits displayed great clinical performance for the identification of M. tuberculosis, with 100% sensitivity. On the other hand, for NTM, one of the kits displayed a good clinical performance with a sensitivity of 94.9% (CI 95%: 89-100%), while the second kit had a reduced sensitivity of 77.1% (CI 95%: 65-89%). In conclusion, one of the kits is a fast and reliable tool for the identification and discrimination of MTBC and NTM from clinical isolates.

Evaluation of Colorimetric Nitrate Reductase Assay in Liquid Medium for Detection of Resistance to First-line Antitubercular Drugs.

On a global scale, India holds the distinction of having the greatest number of tuberculosis (TB) cases caused by Mycobacterium tuberculosis (MTB) complex. The study aimed at evaluating the sensitivity, specificity, accuracy, cost, rapidity, and feasibility of the performance of the colorimetric nitrate reductase-based antibiotic susceptibility (CONRAS) test against the indirect proportion method (IPM) on Lowenstein-Jensen media as the gold standard. A comparative cross-sectional study was performed on 51 MTB isolates. Fresh subcultures were used for drug susceptibility testing by IPM on the Lowenstein-Jensen medium and the CONRAS method in liquid medium. Quality control for drug susceptibility testing was done using a known sensitive strain of MTB (H37Rv) and strains resistant to both isoniazid (INH) and rifampicin (RIF) - multidrug-resistant (MDR), mono-resistant to RIF, streptomycin (STM), and ethambutol (EMB). Statistical analysis was performed using MedCalc software (Version 20.027). CONRAS, carried out in microfuge tubes, was cost-efficient and easy to perform/interpret with most results being available in 10 days compared to 42 days in the case of IPM. The sensitivity, specificity, and accuracy of RIF and INH were 100%, 97.37%, and 98.04 and 93.33%, 97.59%, and 96.08%, respectively, which translates into an almost perfect agreement between the two methods as indicated by κ value of 0.905 and 0.949, respectively, for the two drugs. The performance of CONRAS was less satisfactory for STM and EMB when compared to IPM. CONRAS may serve as a useful test for the detection of MDR-TB because of its accuracy, low cost, ease of performance/interpretation, and rapidity when compared to IPM on LJ medium. It does not involve the use of expensive reagents and equipment, as is the case with molecular methods like GeneXpert and line probe assay, making it a suitable option for the detection of MDR-TB in resource-poor settings.

Bovine Tuberculosis in Wild Boar (Sus scrofa) in Slovenia.

Mycobacteria of the Mycobacterium tuberculosis complex (MTC) are capable of infecting a wide variety of animals. Wild boar (Sus scrofa) has been recognized as an important wildlife reservoir for bovine tuberculosis. We screened wild boar in Slovenia for the presence of (1) Mycobacterium bovis in tissues and (2) antibodies to M. bovis in blood samples. In 2016 and 2017, 1284 tissue samples from 676 wild boar were subjected to cultivation. In 2018 and 2019, blood samples from 132 wild boar were examined using an ELISA kit. None of the MTC species were isolated from the tissue samples, and no antibodies to M. bovis were detected in the blood samples. Several nontuberculous mycobacteria (NTM), identified by 16S rRNA sequencing and/or matrix-assisted laser desorption ionization time-of-flight mass spectrometry, were found in the tissues of 9.8% of the wild boar: Mycobacterium nonchromogenicum, Mycobacterium peregrinum/Mycobacterium septicum, Mycobacterium avium, Mycobacterium engbaekii, Mycobacterium arupense, Mycobacterium algericum, Mycobacterium bohemicum, Mycobacterium confluentis, Mycobacterium flavescens, Mycobacterium fortuitum, Mycobacterium thermoresistibile, and Mycobacterium vaccae. Species-level identification was not possible for 21.2% of the isolates. At the time of the study, wild boar in Slovenia were not at risk from bTB; the significance of the presence of NTM in wild boar remains to be clarified and evaluated from a One Health perspective.

A Case of Multidrug-Resistant Tuberculosis in an Active Duty Military Health Care Worker.

Cases of active tuberculosis (TB) in the U.S. Military have fallen over the last century in large part due to improved screening and treatment options. The subset of multidrug-resistant TB (MDR-TB) is almost nonexistent within the U.S. Military. We present a case of MDR-TB in an active duty U.S. Military health care worker and discuss several considerations for treatment that may present challenges for U.S. Military medical practitioners. A 30-year-old active duty Soldier was referred to Army public health services after a bronchoscopy sample was positive for Mycobacterium tuberculosis complex. Sputum smears were negative for acid-fast bacilli, suggesting lower risk for community spread. One month after initiation of the standard 4-drug regimen for active TB, genetic susceptibility testing found the patient's M. tuberculosis isolate to be resistant to rifampin, isoniazid, and pyrazinamide. Contact investigation efforts among co-workers and family members fortunately found no new interferon-gamma release assay conversions. Coordination of public health assets to ensure a successful treatment regimen occurred across varied local, state, and federal agencies. Atypical medications required coordination with the FDA for procurement. An extensive surveillance plan for medication adverse effects was required. Finally, questions of public health authority versus patient autonomy arose requiring multidisciplinary input and ethical discussions.

Cross Sectional Study on the Prevalence of Tuberculosis among the District of Sudhnuti, Azad Jammu and Kashmir

Globally, tuberculosis (TB) is a major health risk that is mostly caused by Mycobacterium tuberculosis, a member of the Mycobacterium Tuberculosis Complex (MTC). Ten million cases of tuberculosis and 1.3 million deaths from the disease occur each year, making Mycobacterium tuberculosis one of the leading causes of death globally. Pakistan is ranked fifth among high-burden countries for tuberculosis (TB) and is expected to rank fourth for the prevalence of multi-drug resistant (MDR) TB. As a result, tuberculosis poses a serious threat to public health in Pakistan. Tuberculosis is a common occurrence in Azad Jammu and Kashmir. Aims: The current study aimed to find out the prevalence of tuberculosis in the defined population. Study Design: The study was conducted in the District and Tehsil Headquarters Hospitals of District Sudhnuti AJK. Place and Duration of Study: Samples were collected from all the District and Tehsil headquarters hospitals of Sudhnuti district from January 2019 to December 2019. Methodology: Samples of sputum from suspected cases were gathered from district Sudhnuti hospitals and TB centers from January 2019 to December 2019. All the suspected cases were examined by sputum smear microscopy and then bacteriologically positive cases were further confirmed by GeneXpert. All positive cases were examined for multi-drug resistance by using GeneXpert. Results: In the current study during the year 2019, 201 TB cases were reported from district Sudhnuti out of which 107 (53.23%) were males and 94 (46.76%) were females. The value of P=0.51 which is &gt;0.05 is insignificant shows that Tuberculosis has no selective effect on a specific gender. Pulmonary cases were 131 in number with 81 bacteriologically positive and 50 clinically diagnosed negative cases. Extra Pulmonary cases were 70 in number with 1 bacteriologically positive and 69 clinically diagnosed negative cases. Only 2 (0.99%) MDR cases were diagnosed and the case notification rate during 2019 was 66. Conclusion: The current study shows that males are slightly more prone to TB in district Sudhnuti AJK as compared to females. Individuals with age &gt;64 are more susceptible to TB when compared to individuals with age &lt;15. The CNR during 2019 is 66 which is far away from the WHO set criteria. The CNR indicates that there is a need for improvement in the surveillance system.

Corrigendum: Lack of methoxy-mycolates characterizes the geographically restricted lineage 7 of Mycobacterium tuberculosis complex.

Corrigendum: Lack of methoxy-mycolates characterizes the geographically restricted lineage 7 of Mycobacterium tuberculosis complex.

Risk Factors Associated with Prevalence of Zoonotic Tuberculosis in Small Ruminants in Chhattisgarh, India

This study carried out in 2021-22 and 2022-23 at the College of Veterinary Science &amp; A.H., Anjora, Durg, and ICAR-NIBSM, Baronda, Raipur, Chhattisgarh, India focused on examining molecular detection and determining risk factors associated with infections of Bovine tuberculosis (BTB) in small ruminants within the Chhattisgarh region. Zoonotic tuberculosis, a global threat emerging from the Mycobacterium tuberculosis complex, impacts humans, livestock, and wildlife. A total of 795 samples from small ruminants, including blood, aborted fetuses, vaginal swabs, and placental tissues, were collected. DNA extraction and multiplex PCR targeting Mycobacteria RD1 and RD4 genes were performed. Statistical analyses explored individual animal-level and herd-level risk factors using SPSS. Results revealed a 0.75% prevalence of BTB in Small ruminants. Herd-level analysis demonstrated 2.6% prevalence. The statistical analysis assessing individual animal-level risk factors associated with BTB prevalence showed no significant associations with species, age, sex, or sample type. Herd-level risk factors included the number of small ruminants (OR=1.158, p =0.003) and introducing new animals (OR=1.090, p=0.034). In a multivariable logistic regression analysis, the variable “Number of small ruminants kept” emerged as a significant predictor (OR=1.155, p=0.004).Other factors like vaccination, biosecurity measures, and history of reproductive disorders did not reach statistical significance. This study provides comprehensive insights into the multifaceted risk factors associated with zoonotic tuberculosis transmission in small ruminants. The findings underscore the importance of ongoing research to formulate effective control strategies considering the nuanced nature of BTB.

Transmissibility of Mycobacterium pinnipedii in a murine model.

The causative agent of tuberculosis in pinnipeds is Mycobacterium pinnipedii, a member of the Mycobacterium tuberculosis complex (MTC). The natural hosts are pinnipeds; however, other non-marine mammals, including humans, can also be infected. The transmissibility of a pathogen is related to its virulence. The transmissibility of a M. pinnipedii strain (i.e., 1856) was investigated in a murine model and compared with that of two Mycobacterium bovis strains (i.e., 534 and 04-303) with different reported virulence. Non-inoculated mice (sentinels) were co-housed with intratracheally inoculated mice. Detailed inspection of mice to search for visible tuberculosis lesions in the lungs and spleen was performed, and bacillus viability at 30, 60, and 90 days post-inoculation (dpi) was assayed. A transmissibility of 100% was recorded at 30 dpi in sentinel mice co-housed with the inoculated mice from the M. pinnipedii and M. bovis 04-303 groups, as evidenced by the recovery of viable M. pinnipedii and M. bovis from the lungs of sentinel mice. Mice inoculated with M. pinnipedii (1856) and M. bovis (534) survived until euthanized, whereas five of the M. bovis 04-303-inoculated mice died at 17 dpi. This study constitutes the first report of the transmissibility of a M. pinnipedii strain in mice and confirms the utility of this experimental model to study virulence features such as the transmission of poorly characterized MTC species.

The use of Kudoh method for culture of Mycobacterium tuberculosis and Mycobacterium africanum in The Gambia.

Mycobacterium tuberculosis culturing remains the gold standard for laboratory diagnosis of tuberculosis. Tuberculosis remains a great public health problem in developing countries like The Gambia, as most of the methods currently used for bacterial isolation are either time-consuming or costly. To evaluate the Kudoh swab method in a West African setting in Gambia, with a particular focus on the method's performance when culturing Mycobacterium africanum West Africa 2 (MAF2) isolates. 75 sputum samples were collected in the Greater Banjul Area and decontaminated in parallel with both the standard N-acetyl-L-Cysteine-NaOH (NALC-NaOH) and the Kudoh swab method in the TB diagnostics laboratory in the Medical Research Council Unit The Gambia between 30th December 2017 and 25th February 2018. These samples were subsequently cultured on standard Löwenstein-Jensen and Modified Ogawa media respectively and incubated at 37°C for mycobacterial growth. Spoligotyping was done to determine if the decontamination and culture methods compared could equally detect Mycobacterium tuberculosis, Mycobacterium africanum West Africa 1 and Mycobacterium africanum West Africa 2. Among the 50 smear positives, 35 (70%) were culture-positive with Kudoh and 32 (64%) were culture positive with NALC-NaOH, whilst 7(28%) of the 25 smear negative samples were culture positive with both methods (Table 2). There was no significant difference in recovery between both methods (McNemar's test, p-value = 0.7003), suggesting that the overall positivity rate between the two methods is comparable. There were no differences in time-to-positivity or contamination rate between the methods. However, Kudoh yielded positive cultures that were negative on LJ and vice versa. All findings were irrespective of mycobacterial lineages. The Kudoh method has comparable sensitivity to the NALC-NaOH method for detecting Mycobacterium tuberculosis complex isolates. It is easy to perform and could be an add on option for mycobacterial culture in the field in The Gambia, since it requires less biosafety equipment.

Profile of non-tuberculous mycobacteria amongst tuberculosis presumptive people in Cameroon

BackgroundCameroon is a tuberculosis (TB) burden country with a 12% positivity among TB presumptive cases. Of the presumptive cases with a negative TB test, some are infected with Non-tuberculous Mycobacteria (NTM). However, the diagnosis of NTM infections remains difficult due to the lack of tools in many laboratories, particularly in resource limited laboratories and remote setting. The present study was undertaken to determine NTM profile and associated comorbidities among TB presumptive people.MethodsA retrospective study was conducted from December 2018 to December 2019 in the Tuberculosis-National Reference Laboratory (TB-NRL) for Bacteriological analysis of samples and Jamot Hospital of Yaounde (JHY) for clinical evaluation of confirmed NTM patients.We included in this study data of 5267 TB presumptive people previously diagnosed using three consecutive samples and having culture and SD Bioline results with or without Microscopy and reverse hybridization-based Line Probe Assay(LPA) results. The data on co-morbidities or history of people infected with NTM were then collected from the three participants with available clinical data.ResultsWe collected data of 5267 presumptive TB people. Among them, 3436 (65.24%), have a positive culture with 3200 (60.75%) isolates belong to Mycobacterium tuberculosis Complex (MBTC) and 236 (4.48%) to NTM. Our results showed that, 123 (52.11%) NTM were isolated from people with negative microscopy and 113 (47.88%) from people with positive microscopy. Among the 236 NTM, 108 (45.8%) isolates were identified using LPA. M. fortuitum was the most represented species (32.41%) followed by M. intracellulare (19.44%). Sputum had the highest proportion of NTM (56%), followed by bronchial aspirations (31%). The extra-pulmonary samples presented lower proportions of isolates compared to pulmonary samples. Some patients affected with NTM presented comorbidities as HIV infection, Pulmonary tuberculosis, Type 2 diabetes, Chronic bronchitis and Alveolar pneumonia.ConclusionsOur study showed the presence of NTM strains among presumptive TB people with a predominance of M. fortuitum and M. intracellulare. It is important to implement a surveillance system of NTM in TB burden country and also to develop a point-of-care test for NTM identification in limited-resource settings.

Mycobacterium tuberculosis sepsis with multiple intermuscular abscesses and respiratory failure as the main manifestations: a case report

BackgroundTuberculous sepsis is uncommon in individuals without human immunodeficiency virus (HIV) infection, and some patients may not exhibit clinical signs and symptoms of suspected sepsis upon admission, leading to delayed diagnosis and treatment.Case presentationThis report present the case of a 60-year-old female patient who presented with erythema, edema, and pain in her right upper limb accompanied by fever and chills. Further evaluation revealed multiple intermuscular abscesses caused by suspected gram-positive bacteria. Despite receiving anti-infection treatment, the patient rapidly progressed to septic shock and respiratory failure. Metagenomic next-generation sequencing (mNGS) analysis of blood samples detected Mycobacterium tuberculosis complex groups (11 reads). Additionally, mNGS analysis of fluid obtained from puncture of the abscess in the right upper extremity also suggested Mycobacterium tuberculosis complex groups (221 981 reads). Consequently, the patient was diagnosed with tuberculous sepsis resulting from hematogenous dissemination of Mycobacterium tuberculosis. Following the administration of anti-tuberculosis treatment, a gradual recovery was observed during the subsequent follow-up period.ConclusionIt is noteworthy that atypical hematogenous disseminated tuberculosis can be prone to misdiagnosis or oversight, potentially leading to septic shock. This case illustrates the importance of early diagnosis and treatment of tuberculosis sepsis. Advanced diagnostic techniques such as mNGS can aid clinicians in the early identification of pathogens for definitive diagnosis.

Performance of metagenomic next-generation sequencing in cerebrospinal fluid for diagnosis of tuberculous meningitis.

Purpose. Metagenomic next-generation sequencing (mNGS) has been widely used in the diagnosis of infectious diseases, while its performance in diagnosis of tuberculous meningitis (TBM) is incompletely characterized. The aim of this study was to assess the performance of mNGS in the diagnosis of TBM, and illustrate the sensitivity and specificity of different methods.Methods. We retrospectively recruited TBM patients between January 2021 and March 2023 to evaluate the performance of mNGS on cerebrospinal fluid (CSF) samples, in comparison with conventional microbiological testing, including culturing of Mycobacterium tuberculosis (MTB), acid-fast bacillus (AFB) stain, reverse transcription PCR and Xpert MTB/RIF.Results. Of the 40 enrolled, 34 participants were diagnosed with TBM, including 15(44.12 %) definite and 19(55.88 %) clinical diagnosis based upon clinical manifestations, CSF parameters, brain imaging, pathogen evidence and treatment response. The mNGS method identified sequences of Mycobacterium tuberculosis complex (MTBC) in 11 CSF samples. In patients with definite TBM, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of mNGS were 78.57, 100, 100, 66.67 and 85 %, respectively. Compared to conventional diagnostic methods, the sensitivity of mNGS (78.57 %) was higher than AFB (0 %), culturing (0 %), RT-PCR (60 %) and Xpert MTB/RIF (14.29 %).Conclusions. Our study indicates that mNGS of CSF exhibited an overall improved sensitivity over conventional diagnostic methods for TBM and can be considered a front-line CSF test.