Distribution of common and rare drug resistance patterns in Mycobacterium tuberculosis clinical isolates revealed by GenoType MTBDRplus and MTBDRsl assay.

Background: Tuberculosis (TB) remains a significant global health emergency caused by Mycobacterium tuberculosis (Mtb). The epidemiology, transmission, genotypes, mutational patterns, and clinical consequences of TB have been extensively studied worldwide, however, there is a lack of information regarding the epidemiology and mutational patterns of Mtb in Pakistan, specifically concerning the prevalence of multi-drug resistant TB (MDR-TB). Methods: This study aimed to investigate the incidence of Mtb and associated mutational patterns using the line probe assay (LPA). Previous studies have reported a high frequency of mutations in the rpoB, inhA, and katG genes, which are associated with resistance to rifampicin (RIF) and isoniazid (INH). Therefore, the current study utilized LPA to detect mutations in the rpoB, katG, and inhA genes to identify multi-drug resistant Mtb. Results: LPA analysis of a large pool of Mtb isolates, including samples from 241 sputum-positive patients, revealed that 34.85% of isolates were identified as MDR-TB, consistent with reports from various regions worldwide. The most prevalent mutations observed were rpoB S531L and inhA promoter C15T, which were associated with resistance to RIF and INH, respectively. Conclusions: This study highlights the effectiveness of GenoType MTBDRplus and MTBDRsl assays as valuable tools for TB management. These assays enable rapid detection of resistance to RIF, INH, and fluoroquinolones (FQs) in Mtb clinical isolates, surpassing the limitations of solid and liquid media-based methods. The findings contribute to our understanding of MDR-TB epidemiology and provide insights into the genetic profiles of Mtb in Pakistan, which are essential for effective TB control strategies.

Treatment of latent tuberculosis in a child with mucopolysaccharidosis type I receiving enzyme replacement therapy: A case report.

Mucopolysaccharidosis type I S (MPS IS) is a rare autosomal recessive lysosomal storage disorder caused by mutations in the IDUA gene, leading to a deficiency of the enzyme alpha-L-iduronidase. Enzyme replacement therapy (ERT) reduces lysosomal storage in the liver and improves clinical manifestations. To date, there are no published reports of tuberculosis (TB) treatment in MPS IS patients receiving ERT and as such it is not known whether both conditions can be treated simultaneously. Here, we report the case of a 14-year-old male with MPS IS receiving ERT with laronidase who was diagnosed with a latent TB infection after being in contact with a multi-drug-resistant TB patient. He received prophylactic TB treatment with moxifloxacin for 6 months. No complications were reported and there has been no active TB disease. Our case report demonstrates that TB and MPS IS can be treated simultaneously without serious adverse effects.

Comparative genomic analyses of multi-drug resistant Mycobacterium tuberculosis from Nepal and other geographical locations.

Nepal exhibits a tuberculosis (TB) incidence rate that is comparable to neighbouring high TB incidence countries. In addition, it records >500 cases of multi-drug resistant (MDR) TB each year. The objective of this study was to perform whole-genome bioinformatic analysis on MDR-TB isolates from Nepal (n = 19) to identify the specific mutations underlying their phenotypic resistance. In addition, we examined the dominant genotype among the Nepal MDR-TB isolates, the East-Asian Beijing sub-lineage, to determine its relatedness to a panel of 1274 genomes of international strains available from public databases. These analyses provided evidence that the XDR-TB isolates in our collection were not derived from importation of primary XDR-TB to Nepal but were more likely the result of acquisition of second-line drug resistance in Nepal. Resistance to fluoroquinolones was detected among a high proportion of the Nepal isolates. This has implications for the management of TB, including appropriate antimicrobial stewardship and susceptibility testing for fluoroquinolones and other second-line TB drugs, to minimise the development of XDR-TB among Nepal TB cases.

Effect of Xpert MTB/RIF on the treatment of multi-drug-resistant or rifampicin-resistant tuberculosis screened out from re-treatment pulmonary tuberculosis patients, a prospective cohort study.

BACKGROUND: Re-treatment pulmonary tuberculosis (PTB) has a high risk of being multi-drug- or rifampicin-resistant tuberculosis (MDR/RR-TB). The Xpert MTB/RIF assay possesses high efficacy for the evaluation of rifampicin resistance. The aim of the present study was to assess the benefit of the Xpert MTB/ RIF assay in the screening and treatment of MDR/RR-TB in re-treatment PTB patients. METHODS: Patients with suspected re-treatment PTB were prospectively enrolled and divided into Xpert MTB/RIF and mycobacterial tuberculosis (MTB) culture groups. No Xpert MTB/RIF assay was carried out in the MTB culture group. The diagnostic performance and turn-around time (TAT) of MDR/RRTB detection and the culture results of MDR/RR-TB patients following two-month chemotherapy in two groups were calculated and compared. RESULTS: Using phenotypic DST as a reference standard, the positive predictive value of Xpert MTB/RIF for the detection of RR-TB and MDR-TB among re-treatment PTB patients was 90.72% and 77.32%, respectively. The Xpert MTB/RIF group had a significantly shorter interval for the initiation of anti-MDR/ RR-TB treatment {1 [1-1] vs. 52 [47-57] days, P<0.0001}; and following two-month chemotherapy, the percentage of positive culture MDR/RR-TB patients in the Xpert MTB/RIF group was significantly reduced (24.18% vs. 50%, P=0.0003). CONCLUSIONS: Xpert MTB/RIF can accurately screen MDR/RR-TB among re-treatment PTB patients, reducing both the turn-around time for therapy initiation and the percentage of positive culture MDR/ RR-TB patients following two-month chemotherapy. This is not only beneficial for treatment but also for reducing MDR-TB transmission. We recommend that re-treatment PTB patients receive anti-RR/TB chemotherapy following a positive RFP resistance result in the Xpert MTB/RIF assay.

Assessment of GeneXpert GxAlert platform for multi-drug resistant tuberculosis diagnosis and patients' linkage to care in Tanzania.

OBJECTIVE: The gap between patients diagnosed with multi-drug resistant tuberculosis (MDR-TB) and enrolment in treatment is one of the major challenges in tuberculosis control programmes. A 4-year (2013-2016) retrospective review of patients' clinical data and subsequent in-depth interviews with health providers were conducted to assess the effectiveness of the GeneXpert GxAlert platform for MDR-TB diagnosis and its impact on linkage of patients to care in Tanzania. RESULTS: A total of 782 new rifampicin resistant cases were notified, but only 242 (32.3%) were placed in an MDR-TB regimens. The remaining 540 (67.07%) patients were not on treatment, of which 103 patients had complete records on the GxAlert database. Of the 103 patients: 39 were judged as untraceable; 27 died before treatment; 12 were treated with first-line anti-TBs; 9 repeat tests did not show rifampicin resistance; 15 were not on treatment due to communication breakdown, and 1 patient was transferred outside the country. In-depth interviews with health providers suggested that the pre-treatment loss for the MDR-TB patients was primarily attributed to health system and patients themselves. We recommend strengthening the health system by developing and implementing well-defined interventions to ensure all diagnosed MDR-TB patients are accurately reported and timely linked to treatment.

A patient with central nervous system tuberculomas and a history of disseminated multi-drug-resistant tuberculosis.

Tuberculosis (TB) is one of the leading causes of death worldwide, particularly in low- and middle-income countries. The global rates and numbers of drug resistant TB are rising. With increasing globalization, the spread of drug-resistant strains of TB has become a mounting global public health concern. We present a case of a young man previously treated for multi-drug resistant (MDR) TB in India who presented with neurological symptoms and central nervous system TB in the United States. His case highlights unique diagnostic and treatment challenges that are likely to become more commonplace with the increase of patients infected with drug-resistant TB and complicated extrapulmonary disease.

Nuevas perspectivas terapéuticas en tuberculosis / New perspectives in tuberculosis treatment

To advance in the control and elimination of tuberculosis (TB) we must achieve a high level of effectiveness in the prevention of TB in populations infected by Mycobacterium tuberculosis. Latent TB prevention success with current therapies (single isoniazid or in combination with rifampicin) is close to 60%. We also must offer a high level of treatment success in first-line drugs sensitive TB patients. With currently available drugs (isoniazid, rifampicin, ethambutol and pyrazinamide) treatment success should reach at least 95%. Drug side reactions together with the lengthen treatment of infection and disease (6 months) decrease the compliance to these therapies. In Multi-Drug-Resistant TB (MDR-TB), therapies are even longer (20 months according to WHO's recommendation) and much less tolerated, with rates of success under 50%. New trials for latent TB using rifapentin and isoniacid; combined fixed-dose offirst-line drugs in sensible TB, and the addition of new drugs (fluorquinolones, bedaquiline, delamanid and linezolid) in multi-drug resistant TB, together with shorter regimens of 12 months duration which include Clofazimine (experience in Cameroon with modification of a 9 months trial previously used in Bangladesh showing 89% cure) are discussed in this article.

Para el control y eliminación de la tuberculosis se debe lograr un alto grado de eficacia en la prevención del desarrollo de tuberculosis en la población infectada por Mycobacterium tuberculosis. Esta prevención, con las terapias actuales de la tuberculosis latente (isoniazida sola o combinada con rifampicina), es cercana al 60%. También debemos alcanzar una alta tasa de curación para los enfermos con tuberculosis sensible a los fármacos de primera línea (vírgenes a tratamiento). Con los fármacos actualmente disponibles (isoniazida, rifampicina, etambutol y pirazinamida) esta curación debería alcanzar a no menos del 95%. La regular tolerancia y reacciones colaterales de los fármacos y el largo tiempo que demandan las terapias de la infección y de la enfermedad (6 meses) atenta contra su adherencia. En el caso de la Tuberculosis Multi-Drogo-Resistente (TB-MDR), los tratamientos son aún más prolongados (20 meses según recomienda la OMS actualmente) y menos tolerados, siendo sus tasas de curación inferiores a 50%. Se analizan nuevos esquemas para el tratamiento de la tuberculosis latente usando rifapentina asociada a isoniacida; dosis fijas combinadas de fármacos de primera línea para tuberculosis sensibles, y asociación de fármacos antiguos y nuevos (fluoroquinolonas, bedaquilina, delamanid y linezolid) para el tratamiento de las tuberculosis multirresistentes. También se presentan nuevos esquemas acortados, de 12 meses de duración, que incluyen clofazimina (experiencia en Camerún con modificación del esquema de 9 meses usado previamente en Bangladesh, con tasas de curación de 89%).

Homeopathic treatment in addition to standard care in multi drug resistant pulmonary tuberculosis: a randomized, double blind, placebo controlled clinical trial.

BACKGROUND: Multi drug resistant-tuberculosis (MDR-TB) [resistant to Isoniazid and Rifampicin] is a major global public health problem. In India the incidence is rising in spite of implementation of Revised National Tuberculosis Control Program. Standard MDR-TB drugs are second generation antibiotics taken for 24-27 months. The present study was undertaken to evaluate the efficacy of add on homeopathic intervention to the standard MDR-TB regimen (SR). METHODS: A randomized, double blind, placebo controlled study was conducted from 2003 to 2008. 120 diagnosed MDR-TB patients (both culture positive and negative) were enrolled and randomized to receive Standard Regimen + individualized homeopathic medicine (SR + H) or Standard Regimen + identical placebo (SR + P). The medicines have been used in infrequent doses. The outcome measures were sputum conversion, changes in chest X-ray (CXR), hemoglobin, erythrocyte sedimentation rate (ESR), weight gain, and clinical improvement. RESULTS: There was an improvement in all the outcome measures as per intention to treat (ITT) and per protocol (PP) analyses. ITT analyses revealed sputum culture conversion from positive to negative in 23 (38.3%) in SR + H; 23 (38.3%) patients in SR + P group; (p = 0.269) and 27 (55.1); 21 (42.8%), p = 0.225 as PP analyses. The mean weight gain in SR + H group was 2.4 ± 4.9 and in SR + P was 0.8 ± 4.4; [p = 0.071], reduction in ESR in SR + H was -8.7 ± 13.2; SR + P was 3.9 ± 15.4 [p = 0.068]. The mean increase in hemoglobin was by 0.6 ± 1.7 in SR + H & 0.3 ± 2.3 [p = 0.440] in SR + P group at 95% confidence interval. Statistically significant improvement was seen in CXR in 37 (61.7%) in SR + H and 20 (33.3%) patients in SR + P group (p = 0.002). Subgroup analyses of culture positive patients showed statistically significant improvement in CXR (p = 0.0005), weight gain (p = 0.026), increase in hemoglobin (p = 0.017) and reduction in ESR (p = 0.025) with add on homeopathy. The cure rate was 11.4% more in SR + H group as compared to placebo group. Change in sputum culture conversion, was not statistically significant. CONCLUSION: Add on homeopathy in addition to standard therapy appears to improve outcome in MDR-TB. Larger scale studies using a standardized homeopathic treatment regime should be conducted.

Multidrug and extensively drug-resistant tuberculosis management: Evidences and controversies.

Multi-drug and extensively drug resistant tuberculosis (M/XDR-TB) has been an area of growing concern among clinicians, epidemiologists, and public health workers worldwide. Lack of controlled trials in M/XDR-TB patients hinders the optimal management of such patients, and guidelines that have been developed based largely on expert opinion are controversial. Lack of new effective drugs, improper regimens prescribed by poorly trained doctors and unreliable drug susceptibility testing add to the magnitude of the problem. M/XDR-TB is mostly a man made problem and its emergence can be checked by prompt diagnosis and effective use of first-line drugs in every new patient. DOTS-Plus proposed by World Health Organization (WHO) has highlighted the comprehensive management strategy to control multi-drug resistant tuberculosis (MDR-TB). Laboratory services must be strengthened for adequate and timely diagnosis of M/extensively drug resistant tuberculosis (XDR-TB) and programmatic management of M/XDR-TB must be scaled up as per target set by global plan to stop TB 2011-2015. In MDR-TB patients with localized disease, surgery, as an adjunct to chemotherapy, can improve outcomes and should be considered when there is poor response to appropriate chemotherapy. Proper use of second-line drugs must be ensured to cure existing MDR-TB, to reduce its transmission and to prevent emergence of XDR-TB.

Rapid molecular testing for multi-resistant tuberculosis in Mongolia: A diagnostic accuracy study.

OBJECTIVE: The aim of this study was to assess the performance of a molecular line probe assay, GenoType® MTBDRplus, for rapid detection of rifampicin and isoniazid resistance in the Mongolian situation. The sensitivity and specificity of GenoType® MTBDRplus to detect rifampicin and isoniazid resistance-associated mutations in culture specimens and directly in smear-positive clinical specimens was examined. METHOD: 218 MDR-TB subjects aged between 14 and 75years old from eight districts in Ulaanbaatar city (between July 2009 and May 2010) were included in this study .The GenoType Mycobacterium tuberculosis drug resistance first line (MTBDR plus) assay (Hain Life-science, Nehren, Germany) was tested on 109 clinical isolates and directly on 41 sputum specimens for the ability to detect the resistances. Results were compared with conventional culture and drug susceptibility testing on solid medium. RESULTS: The high correlation of the results from GenoType® MTBDRplus and conventional drug susceptibility testing was obtained from this study. The results clearly showed a high performance of GenoType® MTBDRplus with almost 100% accuracy for all the important indicators, such as sensitivity, specificity, positive and negative predictive values and detection of rifampicin resistance. Discrepancies were obtained in comparison with DNA sequencing results. CONCLUSIONS: The Genotype® MTBDRplus assay was demonstrated as a rapid, reliable and highly accurate tool for early detection of MDR-TB through examining smear positive cases.

Results of molecular genetic study of m. Tuberculosis strains isolated from specimens of mdr-tb suspects in Ulaanbaatar, Mongolia in 2009-2010 / Монголын Анагаах Ухаан

Bacground: DST by conventional methods takes several weeks, while early diagnosis of the disease and the rapid identification of resistant strains are essential for efficient treatment and control of the MDR strains. Rapid molecular testing of detecting MDR-TB is needed.Objective: The aim of this study was to assess performance of molecular line probe assay, Genotype16 MTBDRp/us, for rapid detection of RIF and INH resistance for M.Tuberculosis in Mongolia. The sensitivity and specificity of Genotype® MTBDRp/us to detect RIF and INH resistance-associated mutations in culture specimens and directly in smear-positive clinical specimens was examined and compared with conventional culture and drug susceptibility testing on solid medium.Material and Methods: The subjects of this study were 218 MDR-TB suspects aged 14-75 years from 8 districts in Ulaanbaatar city. The study was conducted from July 2009 to May 2010. The Genotype M. Tuberculosis drug resistance first line (MTBDR plus) assay (Hain Life-science, Nehren, Germany) was tested on directly on 41 sputum specimens and 109 clinical isolates.Results: The high correlation of the results from Genotype® MTBDRp/us and conventional drug susceptibility testing was obtained from this study. The results clearly show high performance of Genotype® MTBDRp/us with almost 100% accuracy for all the important indicators, such as sensitivity, specificity, positive and negative predictive values of detection of RIF and INH resistance. Some minor discrepancies were obtained in comparison with DNA sequencing results.Our study found that among high proportion for detection of RIF resistance, S531L mutation (MUT3 band) occurred the most commonly, with 80.0% of all RIF-resistant strains (83.6% of MDR) having the mutation. Other mutation in the 530-533 regions was common, as detected by the lack of binding to the WT8 probe in the absence of S531L mutation.In this study we observed that mutations in the promoter region of inhA gene played a major role (67.6 % (63.9% of MDR strains and 90% of INH-mono-resistant strains) had a mutation in the inhA.Conclusion: The Genotype® MTBDRp/us assay was demonstrated as a rapid, reliable and highly accurate tool for early detection of MDR-TB through examining smear positive cases enabling early start of appropriate therapeutic and public health measures to control of the spread of drug resistant M.tuberculosis in the population.

Detection of Rifampin Resistant Mycobacterium tuberculosis complex using Denaturing HPLC / 대한진단검사의학회지

BACKGROUND: Tuberculosis (TB) remains an important cause of morbidity and mortality throughout the world. The surge of TB has been accompanied by an increase in multi-drug-resistant tuberculosis (MDR-TB). In this study, we developed a denaturing HPLC (DHPLC) method for detecting rpoB gene mutation as a rifampin resistance based on sequence. METHODS: In this study, we used 99 mycobacterial isolates grown in Ogawa media. At first, we used a PCR method that can amplify the 235 bp and 136 bp rpoB DNAs of Mycobacterium tuberculosis complex (MTB) and Non-tuberculous mycobacteria (NTM). And then, PCR-restriction fragment length polymorphism (RFLP) of rpoB DNA (342 bp), which comprises the Rif(T) region, was used for the differential identification of Mycobacteria. Finally, we detected these amplicons by DHPLC, compared to PCR-RFLP results, and performed sequencing. RESULTS: Among 99 mycobacterial isolates, 80 (81%) were MTB and 19 (19%) were NTM. NTM were identified to 7 different species by DHPLC and PCR-RFLP. rpoB mutation was detected in 9 (11%) of the MTB specimens. These results were confirmed by using sequencing. CONCLUSIONS: DHPLC provided a rapid, simple, and automatable performance for detection of rifampin resistant Mycobacterium tuberculosis complex and would be helpful as a supplemental method in high-throughput clinical laboratories.