International Journal of Mycobacteriology最新文献

Background: Drug-resistant tuberculosis (DR-TB) poses a significant threat to global TB control and remains a major public health issue. This study aims to evaluate treatment outcomes and identify risk factors for unfavorable outcomes in patients with multi-DR-TB (MDR-TB) treated at a major reference hospital in Istanbul.

Methods: We conducted a retrospective analysis of 413 patients with rifampicin-resistant and MDR-TB who received treatment between January 1, 2013, and December 31, 2023, at the University of Health Sciences Süreyyapaşa Chest Diseases Training and Research Hospital. Patients were treated following the World Health Organization and national guidelines, with regimens tailored to individual drug resistance profiles and side effect management. Demographic data, comorbidities, microbiological follow-up, drug resistance patterns, treatment regimens, and radiological findings were analyzed.

Results: Treatment success was achieved in 350 patients (84.74%). Thirty-two patients (7.74%) were lost to follow-up, and 32 patients (7.74%) died. Logistic regression analysis identified several factors associated with unfavorable treatment outcomes: comorbidities (odds ratio [OR]: 7.555, P = 0.001), quinolone resistance (OR: 3.695, P = 0.030), and bronchiectasis (OR: 4.126, P = 0.013). Additional significant factors included male gender (P = 0.007), foreign-born status (P = 0.013), age over 35 years (P = 0.002), previous treatment history (P = 0.058), and drug side effects (P = 0.012).

Conclusion: The long-term regimen for MDR-TB was found to be highly successful, with an 84.74% treatment success rate. Effective treatment regimens, close patient follow-up, early recognition of side effects, and comprehensive management are crucial for achieving successful outcomes. Identifying and addressing risk factors such as comorbidities, drug resistance, and specific patient demographics can further improve treatment success rates. This study underscores the importance of tailored treatment strategies and robust patient management in combating MDR-TB.

Background: Nontuberculous mycobacteria (NTM) infections are an emerging global health concern with increasing incidence. Conventional identification methods for NTM species in clinical settings are prone to errors. This study evaluates a newer method, polymerase chain reaction-restriction enzyme analysis (PCR-REA) of the rpoB gene, for NTM species identification. The study identified NTM species in clinical samples using conventional biochemical techniques and compared the results with PCR-REA of the rpoB gene. This cross-sectional study was conducted at a tertiary health-care center in North India over 18 months, analyzing both pulmonary and extrapulmonary samples.

Methods: Two hundred and forty-seven NTM isolates were identified using phenotypic and biochemical methods. The same isolates were subjected to rpoB gene amplification by PCR followed by REA using Msp I and Hae III enzymes.

Results: Conventional methods identified 12 different NTM species (153 slow-growing and 94 rapid-growing), whereas PCR-REA identified 16 species (140 slow-growing, 107 rapid-growing). The Mycobacterium avium intracellulare complex was the most common species isolated. PCR-REA demonstrated higher resolution in species identification, particularly in differentiating within species complexes.

Conclusions: PCR-REA of the rpoB gene proves to be a simple, rapid, and more discriminative tool for NTM species identification compared to conventional methods. This technique could significantly improve the diagnosis and management of emerging NTM infections in clinical settings.

Background: Multidrug-resistant tuberculosis (MDR-TB) is a serious threat to global tuberculosis (TB) control efforts. This study aims to investigate the trend of MDR-TB prevalence in Iran over 20 years.

Methods: A systematic literature search was conducted in various databases, including PubMed, Embase, and Web of Science, from 1981 to 2023. Studies reporting the prevalence of MDR-TB in Iran were included in the meta-analysis. Statistical analysis was performed using Comprehensive Meta-Analysis software.

Results: A total of 58 studies from different provinces of Iran were included in the meta-analysis. The majority of studies were from Tehran (n = 33), Kermanshah (n = 5), Mashhad (n = 4), and Tabriz (n = 4) provinces. Overall, 1885 cases of MDR-TB were reported in Iran during the study period. The highest number of MDR-TB cases was reported in 2000 (582 cases) and the lowest in 2001 (1 case). An increasing trend in MDR-TB prevalence was observed, particularly between 2018 and 2019. The pooled prevalence of MDR-TB in Iran was 12.31% (95% CI: 11.83-12.80) using the fixed-effects model and 20.21% (95% CI: 15.70-26.01) using the random-effects model. No evidence of publication bias was found.

Conclusion: The results of this comprehensive meta-analysis highlight the increasing trend of MDR-TB in Iran over the past two decades. This underscores the urgent need for strengthening TB control strategies, including improved surveillance, case detection, treatment, and management of MDR-TB in the country. Developing diagnostic and treatment approaches for MDR-TB should be prioritized by Iranian medical universities and public health authorities.

Background: Tuberculous meningitis (TBM) is a challenging condition to diagnose, and current laboratory methods have limitations, especially in developing countries. This study evaluated the diagnostic utility of the Lancet consensus scoring (LCS) system in suspected TBM cases at a tertiary care center in India.

Methods: The clinical manifestations of 75 patients with suspected TBM were prospectively evaluated using the LCS system, which categorizes cases as "definite" (laboratory confirmed), "probable" (>10 points without imaging or > 12 points with imaging), and "possible" (6-9 points without imaging or 6-11 points with imaging). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the LCS system were compared to GeneXpert and mycobacterial growth indicator tube (MGIT) liquid culture, which are considered the gold standard tests.

Results: Out of 75 recruited cases, 11 were confirmed as definite TBM cases. The LCS system correctly identified 8 of these as "probable" and 3 as "possible" cases. Compared to GeneXpert, the LCS system had a specificity of 100%, sensitivity of 54.55%, NPV of 92.7%, and PPV of 100%. Compared to MGIT liquid culture, the LCS system had a specificity of 100%, sensitivity of 81.82%, NPV of 96.97%, and PPV of 100%. The diagnostic accuracy was higher for MGIT liquid culture (97.33%) than GeneXpert (93.33%).

Conclusion: The LCS system is a practical and easily applicable tool that can aid the diagnosis of suspected TBM cases, particularly in resource-limited settings. Despite some limitations, the LCS system demonstrated good diagnostic performance, suggesting its potential utility in improving TBM diagnosis and management.

Background: Tuberculosis (TB) is a leading cause of death in patients with human immunodeficiency virus (HIV)/AIDS. About 60% of HIV-positive individuals with latent TB infection (LTBI) develop active TB. Isoniazid preventive therapy (IPT) is recommended by the World Health Organization to prevent the progression of active TB in people living with HIV/AIDS (PLWHA). However, IPT implementation has been limited in some countries like Indonesia. The objective of this study was to assess the effect of IPT administration on the incidence of active TB in HIV patients with latent TB.

Methods: This was a quasi-experimental prospective cohort study conducted in an academic hospital in Indonesia. Interferon-gamma release assay-positive HIV-TB patients were randomly divided into an IPT group (received 6 months of IPT) and a non-IPT group. The incidence of active pulmonary TB was compared between the two groups after 6 months of follow-up.

Results: Of the 23 eligible patients, 22 were enrolled (10 in the IPT group, 12 in the non-IPT group). The incidence of active pulmonary TB was 0% in both groups. Factors associated with the absence of TB in both groups were the use of antiretroviral therapy for >4 years and a CD4+ T lymphocyte count >200 cells/μL. IPT was found to be safe with minimal adverse effects.

Conclusions: In this setting, the use of long-term antiretroviral therapy and higher CD4+ counts, rather than just IPT, were the key factors associated with preventing active TB in latent HIV-TB patients. These findings suggest that comprehensive HIV management may be more important than IPT alone for TB control in PLWHA. Further research is needed to optimize TB prevention strategies in this high-risk population.

Background: Phenotypic drug susceptibility testing (DST) is considered the gold standard for detecting linezolid (LZD) resistance in Mycobacterium tuberculosis (MTB), but it is time-consuming. Nanopore sequencing offers a potentially faster alternative approach. This study evaluated the agreement between phenotypically detected LZD resistance and mutations in the rrl and rplC genes of MTB isolates using nanopore sequencing.

Methods: Consecutive drug-resistant MTB isolates from pulmonary samples collected in 2021 underwent liquid culture (LC) DST for LZD. All resistant isolates and an equal number of susceptible isolates were subjected to targeted sequencing of the rrl and rplC genes using nanopore technology.

Results: Sequencing identified a C154R mutation in the rplC gene in only one LZD-resistant isolate. No mutations were detected in the rrl gene. The agreement between sequencing and LC-DST for detecting LZD resistance was poor (Cohen's kappa: 0.03571, 95% confidence interval [CI]: -0.034-0.105). Additionally, no significant association was found between LZD resistance and clinical or microbiological outcomes at 6-month follow-up.

Conclusion: This study revealed a considerable discrepancy between phenotypic and genotypic detection of LZD resistance in MTB. Further research is needed to better understand the genetic mechanisms underlying LZD resistance and to develop reliable molecular diagnostics for rapid resistance detection.

Background: Tuberculosis (TB) is caused due to the infection of Mycobacterium tuberculosis (MTB) and it can infect the various parts of the human body. The disease is highly prevalent and is the second most common cause of death worldwide after COVID-19. Apart from sputum specimen, it is exceedingly difficult to diagnose due to its paucibacillary nature. The current study was intended to evaluate the accuracy of Smart Sure™ MTB and multidrug-resistant-TB (MDR-TB) kits (Genetix Biotech Asia Pvt. Ltd., India) with Xpert ultra and Mycobacterium growth indicator tube (MGIT) culture on nonsputum specimens from TB suspects.

Methods: A total of 205 nonsputum specimens were received between October 2023 and May 2024 at Intermediate Reference Laboratory, Department of Medicine, All India Institute of Medical Sciences, New Delhi, India. Xpert ultra and Smart Sure™ MTB and MDR-TB tests were done directly on samples. However, processed specimens were used for MGIT culture and drug-susceptibility testing (DST). Invalid and MGIT contaminated specimens were excluded from the final calculation.

Results: Overall, sensitivity and specificity of Smart Sure™ MTB screening kit was 71.59% and 98.28%, respectively, with Xpert ultra and 68.35% and 90.83%, respectively, with MGIT culture. While comparing with both Xpert ultra and MGIT-DST to detect rifampicin (RIF) resistant, Smart Sure™ MDR-TB kits showed sensitivity of 75.0% and 100% of specificity. However, for isoniazid (INH) resistance, Smart Sure™ MDR-TB kits showed 100% of sensitivity and specificity with MGIT-DST.

Conclusion: For the detection of MTB and its drug-resistance patterns (RIF and INH) in the specimens other than sputum, Smart Sure™ MTB and MDR-TB kits could play a vital role in TB endemic countries. While comparing the set-ups and skilled staffs, it required almost same as compared with previously approved WHO diagnostics used in resource-limited countries.

Background: The objective is to assess lung compliance and identify the optimal positive end-expiratory pressure (PEEP) levels in patients with tuberculosis-associated Acute Respiratory Distress Syndrome (TB-ARDS) compared to non-TB-ARDS patients.

Methods: This observational case-control study utilized electrical impedance tomography to evaluate lung mechanics in 20 TB-ARDS and 20 non-TB-ARDS patients. Participants underwent PEEP titration from 23 to 5 cm H2O in 2 cm H2O decrements. Lung compliance and the rates of hyperdistention and collapse were assessed at each PEEP level.

Results: Delta impedance values showed higher amounts in a PEEP range of 11-17 cm H2O and in patients with TB-ARDS (P > 0.05). In addition, both hyperdistention and collapse rates were nonsignificantly higher in TB-ARDS patients (P > 0.05), and the compromised levels of hyperdistention and collapse rates were at 15-17 cm H2O, indicating the most favorable PEEP level.

Conclusions: The observed patterns of hyperdistention and collapse rates across various PEEP levels provide valuable insights into the susceptibility of TB-ARDS patients to barotrauma. Notably, the identified optimal PEEP range between 15 and 17 cm H2O may guide ventilator management strategies in mitigating both hyperdistention and collapse; nonetheless, due to the high variability of lung compliances within groups, we strongly recommend individualized consideration for tailored respiratory support and evaluation.

Bacteria other than Mycobacterium tuberculosis and Mycobacterium leprae are known as nontuberculous mycobacteria (NTM), and the frequency of clinically symptomatic forms is increasing day by day. Mycobacterium fortuitum, a rapidly reproducing NTM, causes various clinical signs such as skin soft-tissue infection, surgical site infection, and disseminated infection in immunosuppressed patients. Although progress can be made in terms of diagnosis when growth is detected in culture, it is quite difficult to distinguish between infection and contamination. There is no place for antituberculosis treatment in the treatment of M. fortuitum. Antibiotics such as quinolones, trimethoprim-sulfamethoxazole, linezolid, doxycycline, clarithromycin, azithromycin, imipenem, tigecycline, linezolid, and amikacin are recommended at least in dual combination therapy. In this case presentation, the diagnosis and treatment of a 2-year skin soft-tissue infection with M. fortuitum growth in culture will be discussed.

To systematize published laboratory methods to inactivate Mycobacterium tuberculosis (MTB) and to describe their effectiveness. We carried out a review of the scientific literature to identify the publications that reported methods for the inactivation of MTB, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations. The search addressed inactivation methodologies used in Public health laboratories for the treatment of biological material and only included studies reporting the efficacy of the method. The database used were PubMed (National Library of Medicine) and LILACS (Latin American and Caribbean Literature in Health Sciences). We evaluated the quality of the studies with the JBI (Joanna Briggs Institute) Critical Instrument Appraisal Checklist. We included 14 publications meeting the established inclusion and exclusion criteria. These 14 studies actually described a total of 35 inactivation methods. Most of them combined heat treatment with some chemical or enzymatic agent, and there were very few applying a single strategy. Twenty-four (68.57%) methods demonstrated significant efficacy in inactivating MTB. The systematic review identified 35 methods of inactivation of MTB, published in 14 studies. Most of the methods combined physical treatment techniques, especially heat, with chemical and/or enzymatic treatment techniques, obtaining mostly good results in preventing the reproduction of the microorganism. PROSPERO (International Prospective Register of Ongoing Systematic Reviews) (Code CRD42024503621).