Active contact tracing beyond the household in multidrug resistant tuberculosis in Vietnam: a cohort study.

BACKGROUND: Currently in Vietnam contact tracing for multidrug-resistant tuberculosis (MDR-TB) entails passive case finding among symptomatic household contacts who present themselves for diagnosis. Close contacts of MDR-TB cases are therefore not identified adequately. We assessed the added value of active contact tracing within and beyond households using social network questionnaires to identify close contacts of MDR-TB patients in Vietnam. METHODS: We conducted a cohort study using social network questionnaires in which contacts were identified by MDR-TB patients, including contacts from 'high risk' places like work. Contacts of MDR-TB patients were followed up and screened over a period of at least 6 months. This included two active screenings and any unscheduled passive screening of self-referred contacts during the study period. RESULTS: Four hundred seventeen contacts of 99 index cases were recruited, 325 (77.9%) and 160/417 (38.4%) contacts participated in the first and second screenings, respectively. The first screening detected one TB case but the bacteria were not MDR. From passive screening, a household contact was diagnosed with TB meningitis but not through our active approach. Social network analysis showed that only 1/17 (5.9%) high-risk places agreed to cooperate and were included in the screening, and no MDR-TB cases were detected. There were two pairs of index cases (identified separately) who were found to be contacts of each other and who had been diagnosed before the study started. CONCLUSIONS: No new MDR-TB cases were detected using social network analysis of nearly 100 MDR-TB index cases, likely due to a relatively short follow up time, and loss to follow up (lack of cooperation from contacts or high risk places and lack of available resources in the National Tuberculosis Control Programme).

Treatment outcomes of the drug resistant tuberculosis cases previously exposed to second line anti Tuberculosis drugs in Pakistan: A multi-center cross-sectional study.

OBJECTIVE: To determine the treatment outcomes of the drug-resistant tuberculosis patients who were previously exposed to second line drugs. METHODS: The retrospective study was conducted at eight Programmatic Management of Drug Resistant Tuberculosis (PMDT) sites in Sindh and Balochistan. Data of patients who were previously exposed to second line drugs and re-enrolled in the drug-resistant tuberculosis register at PMDT sites in Sindh and Balochistan between 2008 and 2016 was included for analysis. Data of those still under treatment or transferred to another treatment site was excluded. Association was explored between treatment outcomes and other independent variables, while in order to identify the risk factors associated with poor treatment outcomes univariate and multivariate logistic regression was used. RESULTS: Overall, there were 3645 patients and 288(8%) were previously exposed to second line drugs. Of them, 95(33%) were excluded, and the final sample stood at 193; 99(51.3%) males and 94(48.7%) females. The median age of the sample was 29 years (inter-quartile range: 22-41 years). The mean duration of treatment was 20}11.14 months. Overall success rate of the re-treatment of previously treated patients was 105(54.4%). Observed relapse rate was 9(4.7%).. CONCLUSIONS: The success rate for re-treatment drug-resistant tuberculosis patients was found to be unacceptably low. New drugs and novel regimens should be made widely available.

Predictor of multidrug resistant tuberculosis in southwestern part of Ethiopia: a case control study.

BACKGROUND: Curable disease tuberculosis is becoming incurable or difficult to treat due to drug resistance. Multi drug resistance tuberculosis is a major health problem for less developed countries. Development of drug resistance is mainly as result of man related factors and poor lifestyle. Identifying predictors of drug resistance and working on them is the important way of reducing the expansion in high burden countries. Ethiopia is one of TB, TB/HIV, and multi-drug resistant tuberculosis (MDR-TB) high burden country globally. This study was aimed to assess predictor of MDR-TB in southwest part of Ethiopia. METHODS: Unmatched case control study was conducted in case to control ratio of 1:1.2 in southwest part of Ethiopia. The cases were recruited from confirmed MDR-TB patient enrolled on second line treatment in Shenen Gibe Hospital (MDR-TB treatment center of the prefecture) and the controls were recruited from previously TB patients who cured or patient with smear negative at the end of treatment month during the study period in the same area. The data was collected by structured questionnaire by interview and logistic regression analyses were used to identify predictors of MDR-TB. Odds ratios with 95% CI were computed to determine the predictors. RESULT: From the total 132 participants about 45% of them were cases. None disclosed tuberculosis infected to relatives [AOR = 3.4, 95% CI (1.2-9.8)], insufficient instruction on how to take anti-TB drug [AOR = 4.7, 95% CI (1.4-14.6)], contact history with MDR-TB [AOR = 8.5, 95% CI (2.9-25.5)], interruption of first-line anti-TB treatment for at list 1 day [AOR = 7.9, 95% CI (2.5-24.9)], and having alcohol drinking habits [AOR = 5.1, 95% CI (1.4-18.7)] were identified predictors for MDR-TB infection in study area. CONCLUSION: TB infection disclosure status, insufficient instruction on drug usage, contact history with MDR-TB, interruption of first-line anti-TB drugs, and alcohol drinking habits were identified predictor of MDR-TB case. Therefore, early detection and proper treatment of drug susceptible TB, strengthening directly observed treatment, short-course on daily bases, community involvement, and supporting the patient to intervene identified factors is paramount.

High-resolution melting analysis for molecular detection of multidrug resistance tuberculosis in Peruvian isolates.

BACKGROUND: The emergence of multidrug-resistant strains is a major health problem especially for countries with high TB incidence such as Peru. In this study, we evaluated High Resolution Melting (HRM) assay in Peruvian isolates for the detection of mutations within rpoB, katG genes and promoter region inhA to determine isoniazid and rifampicin resistance in Mycobacterium tuberculosis (Mtb). METHODS: DNA samples extracted from a total of 167 clinical isolates of Mtb, 89 drug-sensitive and 78 multidrug-resistant, were blindly analyzed by HRM analysis and verified by DNA sequencing. RESULTS: The HRM analysis generated patterns that were specific to distinguish between sensitive and resistance isolates. The sensitivity and specificity of the HRM assays in comparison with drug susceptibility testing (DST) for detection of rifampicin resistance were 98.7 % and 97.5 %, and for isoniazid resistance were 98.7 % and 100 %. CONCLUSION: This study suggests that HRM Analysis could help with rapid diagnosis of MDR-TB cases in Peru.

Telemedicine as a tool to prevent multi-drug resistant tuberculosis in poor resource settings: Lessons from Nigeria.

Background: This mini review aims to provide an overview of the role of telemedicine in preventing multi-drug resistant tuberculosis (MDR-TB) in Nigeria. The specific objectives include examining the potential benefits of telemedicine, identifying the challenges associated with its implementation, and highlighting the importance of addressing infrastructure limitations and data privacy concerns. Methods: This minireview is based on a comprehensive analysis of existing literature, including scholarly articles, and reports,. A systematic search was conducted using electronic databases, such as PubMed and Google Scholar, to identify relevant publications related to telemedicine and MDR-TB prevention in Nigeria. The selected articles were assessed for their relevance, and key findings were synthesized to provide an overview of the role of telemedicine in addressing the challenges of MDR-TB in Nigeria. Results: The review demonstrates that telemedicine has the potential to significantly contribute to MDR-TB prevention efforts in Nigeria. The benefits of telemedicine include improved access to specialized care, enhanced patient adherence to treatment, and potential cost savings. However, challenges such as infrastructure limitations and data privacy concerns need to be addressed for successful implementation. Integrating telemedicine into the healthcare system has the potential to strengthen MDR-TB prevention, particularly in underserved areas, including within Nigeria. Specifically, the integration of telemedicine into the healthcare system can enhance access to specialized care, improve patient adherence, and potentially reduce costs associated with MDR-TB management. Conclusions: Addressing infrastructure challenges, ensuring data privacy and security, and fostering trust among healthcare providers and patients are critical for successful implementation of telemedicine. Further research and policy frameworks are needed to guide the effective implementation and scale-up of telemedicine in MDR-TB prevention efforts in Nigeria.

Drug hypersensitivity in drug-resistant tuberculosis.

Objective: To evaluate drug resistant tuberculosis patients who developed drug hypersensitivity to antituberculosis drug. Methods: This was a retrospective study. The primary aim of the study is to determine the demographic and clinical characteristics of patients who develop drug hypersensitivity in drug resistant tuberculosis patients. The secondary aim of the study is to examine the treatment results. Demographic features, tuberculosis diagnostic indicator, clinical signs of developing hypersensitivity reaction, reaction time, and treatment were evaluated. Results: A total of 25 patients were included in the study. The prevalence of hypersensitivity in drug resistance patients was 11.9%. Twelve (48%) of the cases were women. Mean age (mean ± SD) was 37.24 ± 14.44 years; early type hypersensitivity reaction in 13 (52%). Three patients were isoniazid resistant; 19 patients were multidrug-resistant (MDR); 2 patients were pre-extensive drug resistant (Pre-XDR), 1 patient was extensive drug resistance (XDR) tuberculosis. The most common skin findings were maculopapular eruption and urticaria. But also we had seen isole angiodema, urticaria and angioedema, erythema multiforme, lichenoid drug eruption and drug rash with eosinophilia and systemic symptoms. In patients who developed a hypersensitivity reaction, the responsible agent was identified in 14 cases in total. Among the drugs, pyrazinamide, ethambutol, moxifloxacin, amikacin, para amino salicylic, prothionamide, and cycloserine are the responsible agents. When evaluated in terms of treatment results, 15 (60%) patients successfully completed the treatment. Conclusion: Our study is the first study in the literature that evaluated the drug hypersensitivity in drug resistance tuberculosis patients. Drug hypersensitivity that develops with tuberculosis treatment may lead to discontinuation or change in treatment. It can cause treatment failure, drug resistance, relapse, and even death. In resistant tuberculosis, the already existing resistance pattern may become more difficult to treat. Success can be achieved with the right management in these patients who have few treatment options, more drug side effects, and high treatment failure rates. The established regimen should be curative and prevent recurrence.

Development of Bedaquiline-Loaded SNEDDS Using Quality by Design (QbD) Approach to Improve Biopharmaceutical Attributes for the Management of Multidrug-Resistant Tuberculosis (MDR-TB).

Background: The ever-growing emergence of antibiotic resistance associated with tuberculosis (TB) has become a global challenge. In 2012, the USFDA gave expedited approval to bedaquiline (BDQ) as a new treatment for drug-resistant TB in adults when no other viable options are available. BDQ is a diarylquinoline derivative and exhibits targeted action on mycobacterium tuberculosis, but due to poor solubility, the desired therapeutic action is not achieved. Objective: To develop a QbD-based self-nanoemulsifying drug delivery system of bedaquiline using various oils, surfactants, and co-surfactants. Methods: The quality target product profile (QTPP) and critical quality attributes (CQAs) were identified with a patient-centric approach, which facilitated the selection of critical material attributes (CMAs) during pre-formulation studies and initial risk assessment. Caprylic acid as a lipid, propylene glycol as a surfactant, and Transcutol-P as a co-surfactant were selected as CMAs for the formulation of bedaquiline fumarate SNEDDS. Pseudo-ternary phase diagrams were constructed to determine the optimal ratio of oil and Smix. To optimize the formulation, a Box-Benkhen design (BBD) was used. The optimized formulation (BDQ-F-SNEDSS) was further evaluated for parameters such as droplet size, polydispersity index (PDI), percentage transmittance, dilution studies, stability studies, and cell toxicity through the A549 cell. Results: Optimized BDQ-F-SNEDDS showed well-formed droplets of 98.88 ± 2.1 nm with a zeta potential of 21.16 mV. In vitro studies showed enhanced drug release with a high degree of stability at 25 ± 2 °C, 60 ± 5% and 40 ± 2 °C, 75 ± 5%. Furthermore, BDQ-F-SNEDDS showed promising cell viability in A549 cells, indicating BDQ-F-SNEDDS as a safer formulation for oral delivery. Conclusion: Finally, it was concluded that the utilization of a QbD approach in the development of BDQ-F-loaded SNEDDS offers a promising strategy to improve the biopharmaceutical properties of the drug, resulting in potential cost and time savings.

Frequency and Management of Adverse Drug Reactions Among Drug-Resistant Tuberculosis Patients: Analysis From a Prospective Study.

Drug-resistant tuberculosis (DR-TB) management is often linked with a higher rate of adverse drug reactions (ADRs) needing effective and timely management of these ADRs, which, if left untreated, may result in a higher rate of loss to follow-up of drug-resistant patients. Study objective: The study was aimed at prospectively identifying the nature, frequency, suspected drugs, and management approaches for ADRs along with risk factors of ADRs occurrence among DR-TB patients at Nishtar Medical University, Hospital, Multan, Pakistan. Materials and Methods: The prospective study included all the DR-TB patients enrolled for treatment from January 2016 to May 2017 at the study site. Patients were evaluated for the treatment-induced ADRs as per standard criteria of the National Tuberculosis Program, Pakistan. Multivariate logistic regression was used to assess the independent variables associated with the occurrence of ADRs. Results: Out of 271 DR-TB patients included in the final analysis, it was observed that 55 patients (20.3%) experienced at least three ADRs. A total of 50 (18.5%) patients experienced zero adverse effects, while 15 (5.5%), 33 (12.2%), and 53 (19.6%) patients experienced one, two, and four ADRs, respectively. Gastrointestinal disturbances (66.7%), nervous system disorders (59.4%), and electrolyte disturbances (55.7%) remained the highest reported ADRs during therapy, followed by arthralgia (49.1%), ototoxicity (24%), pruritic reactions/rash (12.9%), dyspnoea (12.5%), and tinnitus (8.8%). Pulmonary cavitation at the baseline visit (p-value 0.001, OR 3.419; 95% CI (1.694-6.902) was significantly associated with the occurrence of ADRs among DR-TB patients. Conclusion: The frequency of ADRs was high among the study cohort; however, these were managed effectively. Patients with recognized risk factors for ADRs occurrence need continuous clinical management efforts.

Drug resistance pattern and mutation pattern in pediatric tuberculosis: Study from north India.

BACKGROUND: The emergence of multidrug-resistant MDR-TB and extensively drug-resistant XDR-TB are serious threats to global TB control. Molecular tests like GenoType MTBDRplus has revolutionized MDR-TB diagnosis by rapid detection of resistance, leading to early and appropriate management of DR-TB. Information about common mutations imparting resistance to RIF and INH, helps in understanding the disease epidemiology in various regions. The study was conducted to determine the genetic mutation in drug resistant tuberculosis in children less than 12 years with pulmonary or extrapulmonary tuberculosis. MATERIALS/METHODS: Retrospective analysis was done over a period of 54 months from January 2015 to June 2019 to study the resistance pattern and mutations present in DR-TB in children less than 12 years with suspected pulmonary or extrapulmonary tuberculosis using Hain's GenoType MTBDRplus VER 2.0. RESULTS: Over a period of 54 months, samples from 3461 patients with suspected TB were received for MGIT culture, out of which, 347 were positive for Mycobacterium tuberculosis. 250 of these 347 isolated were tested for drug resistance by Hain's GenoType MTBDRplus VER 2.0.61.1% were sensitive to isoniazid and rifampicin while 15.2% were DR-TB (38 out of 250). Out of these 38, 22 were MDR TB, 13 were isoniazid monoresistant (34.2%) and 3 were rifampicin monoresistant. The most common genotypic resistance for rifampicin was absence of rpoB WT8 band and presence of rpoB MUT 3 band (88%). 84.6% of the INH monoresistant isolates showed high level isoniazid resistant. All these isolates showed presence of katG MUT 1 band. On comparing Hain's GenoType MTBDRplus VER 2.0 with Xpert MTB/Rif Assay, most common mutation for rifampicin resistance at S531L which can be detected by Xpert MTB/Rif Assay (probe E). However, two cases with rifampicin resistance had mutation in codon region 509-513 and 513-519 which could be missed by Xpert MTB/Rif Assay. CONCLUSIONS: We cannot solely rely on Xpert MTB/Rif Assay for detection of drug resistance due to the risk of missing the isoniazid monoresistance. GenoType MTBDRplus has revolutionized MDR-TB diagnosis by substantially reducing turn around time and leading to early management of DR-TB cases.

Evaluation of the postal service for referral of specimen of drug resistance tuberculosis in Amhara region, Ethiopia; mixed method.

BACKGROUND: In Ethiopia, specimens of presumptive drug resistant tuberculosis cases are transported by courier system from district sample collection centers to reference laboratories. It is essential to track the effectiveness of the referral system and identify challenges in order to take timely and appropriate actions. We assessed turnaround time and quality of specimens, and explored challenges of the specimen referral system in Amhara region, Ethiopia, 2017. METHODS: With mixed methods, we retrospectively examined 385 randomly selected presumptive drug resistance TB specimens, and interviewed 53 purposively selected key informants from laboratories and post offices. We calculated median TAT and proportion of acceptable quality. We analyzed qualitative data thematically. RESULTS: Of the 385 specimens, 94.5% (364/385) had acceptable quality at arrival in the reference laboratories. All the 364 specimens had result. Three - fourth (76.1%) of results were dispatched to the referring health facilities within the recommended turnaround time. Ineffective communication and lack of feedback among institutions were mentioned as challenges. CONCLUSION: The postal service was effective in keeping quality and majority of test results were timely delivered. Yet, there were operational challenges. Therefore, effective communication, using dedicated vehicle for specimen shipment and awareness creation on specimen collection and handling are recommended.

Prediction of the Complication Risk in Drug-Resistant Tuberculosis After Surgery: Development and Assessment of a Novel Nomogram.

Background: Surgery is increasingly accepted as an adjunctive approach to treat multidrug-resistant tuberculosis (MDR-TB) or extensively drug-resistant tuberculosis (XDR-TB). However, a model that includes all factors to predict the risk of postoperative complications is lacking. Methods: We developed a prediction model based on 138 patients who had undergone surgery as treatment for drug-resistant tuberculosis (DR-TB) after 24 months. Clinical features on the lesion type (L), treatment history (T), physiologic status of the body (B), and surgical approach (S) were evaluated. Multivariable logistic regression analysis was conducted by clinical features selected in the least absolute shrinkage and selection operator (LASSO) to build a nomogram. The discrimination, calibration, and clinical usefulness of the nomogram were assessed using the C-Index, calibration plots, and decision curves. Internal validation was assessed using bootstrapping. Results: The nomogram contained the features L, B, T, cavitary, recurrent chest infection (RCI) and MDR-TB/XDR-TB. The model displayed good discrimination with a C-Index of 0.879 (95% CI: 0.799-0.967). A high C-Index of 0.824 was achieved in the interval validation. Decision-curve analysis showed that the nomogram was clinically useful if intervention was decided at the non-adherence possibility threshold of 4%. Conclusion: Our novel nomogram could be used conveniently to predict postoperative complication risk in DR-TB patients.

Evaluation of risk factors associated with the development of MDR- and XDR-TB in a tertiary care hospital: a retrospective cohort study.

BACKGROUND: Drug resistant tuberculosis (DR-TB) infringes substantial burden in terms of longer treatment duration, morbidity and mortality. Timely identification of patients at risks of DR-TB will aid individualized treatment. Current study was aimed to ascertain several factors associated with DR-TB among patients attending a tertiary care hospital. METHODS: This retrospective study was conducted among patients with confirmed diagnosis of DR-TB and drug susceptible TB (DS-TB) seeking medical care from a tertiary care hospital during 2014-2019. The types of DR-TB included were rifampicin resistant tuberculosis (RR-TB), Multidrug resistant tuberculosis (MDR-TB) and extensively drug resistant tuberculosis (XDR-TB). Appropriate statistical methods were implied to evaluate the factors associated with DR-TB. RESULTS: Out of 580 patients, DS-TB was diagnosed in 198 (34.1%) patients while DR-TB was present in 382 patients. Of resistance cases, RR-TB, MDR-TB and XDR-TB were diagnosed in 176 (30.3%), 195 (33.6%) and 11 (1.9%) patients, respectively. Significant differences (P < 0.05) in demographics and clinico-laboratory characteristics were observed between patients with DS-TB and DR-TB. Logistic regression analysis revealed age ≤38 years (OR: 2.5), single marital status (OR: 11.1), tobacco use (OR: 2.9), previous treatment (OR: 19.2), treatment failure (OR: 9.2) and cavity on chest X-ray (OR: 30.1) as independent risk factors for MDR-TB. However, XDR-TB was independently associated with age group of ≤38 years (OR: 13.6), students (OR: 13.0), previous treatment (OR: 12.5), cavity on chest X-ray (OR: 59.6). The independent risk factors associated with RR-TB are age ≤38 years (OR: 2.8), females (OR: 5.7), unemployed (OR: 41.5), treatment failure (OR: 4.9), previous treatment (OR: 38.2) and cavity on chest X-ray (OR: 4.3). ROC curve analysis accentuate the excellent predictive accuracy of all logistic regression models as shown by AUC (0.968, P < 0.001) for MDR-TB, AUC (0.941, P < 0.001) for XDR-TB and AUC (0.962, P < 0.001) for RR-TB. CONCLUSIONS: Current study demonstrates a sizeable extent of resistant cases among pulmonary TB patients. This study presaged significant risk of DR-TB among females, young adults, unemployed, smokers, patients with previous treatment failure and cavitation on chest X-ray. Timely identification of high risk patients will give pronounced advantages regarding appropriate choices of prevention, treatment and disease control.

Abbott RealTime MTB and MTB RIF/INH assays for the diagnosis of tuberculosis and rifampicin/isoniazid resistance.

BACKGROUND: The Abbott RealTime MTB (Abbott-RT) and Abbott RealTime MTB RIF/INH Resistance (Abbott-RIF/INH) assays have been introduced for the detection of tuberculosis (TB) and drug-resistant tuberculosis (DR-TB). We performed a systematic review and meta-analysis to assess the accuracy of Abbott-RT and Abbott-RIF/INH for the detection of TB and DR-TB. METHODS: The Ovid MEDLINE, EMBASE, Cochrane and Web of Science databases were searched to identify eligible articles for the systematic review. The pooled analyses were calculated with a bivariate model. Hierarchical summary receiver operating characteristic curves and the area under the curve (AUC) were used to summarize overall diagnostic performance. Deeks' test was performed to evaluate potential publication bias. RESULTS: For the Abbott-RT assay, 9 studies including 3, 640 patients met the study criteria. The pooled sensitivity of Abbott-RT for detecting TB was 0.96 (95% CI: 0.88-0.99) and specificity was 0.97 (95% CI: 0.93-0.99). For DR-TB, four studies were included to evaluate the diagnosis accuracy of Abbott-RIF/INH. The pooled sensitivity was 0.88 (95% CI, 0.82-0.93) and specificity was 0.99 (95% CI, 0.96-0.99). No publication bias was found. CONCLUSION: Both Abbott-RT and Abbott-RIF/INH assays have good sensitivity, specificity and accuracy for the diagnosis of TB and DR-TB.

Validation of the GenoType® MTBDRplus Ver 2.0 assay for detection of rifampicin and isoniazid resistance in Mycobacterium tuberculosis complex isolates at UZCHS-CTRC TB research laboratory.

BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB) is a public health concern globally. MDR-TB is defined as resistance to rifampicin (RIF) and isoniazid (INH), the two-major anti-TB first-line TB treatment drugs. Rapid identification of MDR-TB can contribute significantly to the control of TB. The GenoType® MTBDRplus Ver 2.0 assay is a molecular assay used to detect genetic mutations that result in RIF and INH resistance. The aim of this study was to validate the performance of the GenoType® MTBDRplus Ver 2.0 assay for the detection of INH and RIF resistance. METHODS: Fifty-five stored Mycobacterium tuberculosis isolates were tested using both the mycobacterial growth indicator tube (MGIT), antimicrobial susceptibility testing (AST), and the GenoType® MTBDRplus Ver 2.0 assay. The MGIT AST was done according to the BBL MGIT AST SIRE system with RIF and INH final critical concentrations of 1.0 µg/ml and 0.1 µg/ml, respectively. The GenoType® MTBDRplus assay (Hain Lifescience, Germany) was performed following the manufacturer's instructions. RESULTS: The GenoType® MTBDRplus Ver 2.0 assay had a sensitivity, specificity, positive predictive value, and negative predictive value of 100% for INH and RIF resistance. The intra-assay precision for the assay was 100%. CONCLUSION: The GenoType® MTBDRplus Ver 2.0 assay's sensitivity and specificity show that the assay is highly accurate for the detection of RIF and INH resistance and thus can be used as an alternate platform due to its shorter results turnaround time.

Evaluation of thin-layered agar for Mycobacterium tuberculosis isolation and drug susceptibility testing.

Background: Tuberculosis (TB) is India's major public health problem. According to the WHO, India harbors the largest number of cases, and TB control remains a challenge in diagnosis, drug resistance, and treatment. We undertook this study to compare the isolation rates of Mycobacterium tuberculosis (MTB) in agar, egg-based media, incidence of multidrug-resistant (MDR), and extended drug resistance (XDR) in MTB. This study aimed to compare and evaluate thin-layered agar (TLA) for the cultivation and drug susceptibility pattern of MTB with the conventional egg-based Lowenstein-Jensen's (LJ) medium and to differentiate atypical Mycobacterium by incorporating para-nitrobenzoic acid (PNB) in the TLA medium. This cross-sectional study was conducted in Sri Ramachandra Medical College and Research Institute, Porur, Chennai. Methods: A total of 68 smear-positive samples were inoculated into TLA (Middle Brook 7H 11) and LJ media with and without antibiotics (rifampicin, isoniazid, and ofloxacin) simultaneously after decontamination by the modified Petroff's method. TLA with PNB was also used to differentiate the growth of nontuberculous mycobacterium (NTM). Incubation was done at 37°C, and reading was taken every 3rd day for 6 weeks in case of TLA and for 8 weeks in case of LJ medium. Results: Out of the 68 samples, 64 (94.1%) grew in LJ, and the growth observed at the end of the 1st, 2nd, 3rd, 4th, 5th, and 6-10th weeks was 0, 12 (18.8%), 10 (15.6%), 14 (21.9%), 15 (23.4%), and 13 (20.3%), respectively. Similarly, in TLA, 65 (95.5%) samples were grown, among which 22 (33.8%) grew in the 1st week and the rest (43 [66.2%]) in the 2nd week. MDR and XDR were observed in 4 (5.8%) and 3 (4.4%) samples, respectively. Seven of them were NTM. Conclusions: TLA is a better medium, with time to positivity ranging from 1 to 2 weeks with drug susceptibility and the pattern is also comparable with LJ medium. Incorporation of PNB in TLA helps in differentiating NTM.

Cycloserine Induced Suicidal Tendencies and Kanamycin Induced Ototoxicity in Indian MDR-TB Patient: A Case Report.

INTRODUCTION: Cycloserine and Kanamycin are approved for treatment of multidrug-resistant tuberculosis with good tolerability in Tuberculosis patients and have various labeled adverse reactions but the neuropsychiatric adverse drug reactions with cycloserine are rarely explained. CASE REPORT: We present a case report on Cycloserine induced Suicidal tendencies and Kanamycin induced decrease in hearing sensation in Indian MDR-TB patient. A 55-year-old male patient who was diagnosed with MDR-TB was prescribed with category IV anti-tubercular therapy. Within one month of initiation of therapy, he developed repeated suicidal thoughts, joint pain, restlessness, depression, constipation, insomnia, tinnitus and a decrease in hearing sensation. RESULTS AND DISCUSSION: Cycloserine and kanamycin were closely associated with suicidal tendency and tinnitus followed by a decrease in hearing sensations respectively. On causality assessment using WHO-UMC Causality assessment scale, Adverse Drug Reaction with Cycloserine was found to be certain and for kanamycin, ADR was found to be possible. CONCLUSION: Early management of such fatal ADR can improve the compliance, thus preventing the relapse of infection as well as improving therapeutic outcome in Tuberculosis patients.

Repurposing and Revival of the Drugs: A New Approach to Combat the Drug Resistant Tuberculosis.

Emergence of drug resistant tuberculosis like multi drug resistant tuberculosis (MDR-TB), extensively drug-resistant tuberculosis (XDR-TB) and totally drug resistant tuberculosis (TDR-TB) has created a new challenge to fight against these bad bugs of Mycobacterium tuberculosis. Repurposing and revival of the drugs are the new trends/options to combat these worsen situations of tuberculosis in the antibiotics resistance era or in the situation of global emergency. Bactericidal and synergistic effect of repurposed/revived drugs along with the latest drugs bedaquiline and delamanid used in the treatment of MDR-TB, XDR-TB, and TDR-TB might be the choice for future promising combinatorial chemotherapy against these bad bugs.

Best approaches to drug-resistance surveillance at the country level.

In 2014, the World Health Organization (WHO) recommendation to include the endorsed rapid molecular technologies (Xpert MTB/RIF, line probe assays) into surveillance systems and surveys allowed the testing of more tuberculosis (TB) patients for drug resistance at country level than ever before. The whole genome sequencing (WGS) approach is emerging as a more powerful tool for epidemiological and drug-resistant routine surveillances, promising a rapid and simultaneous screening of all the clinically-relevant mutations for the determination of resistance to the first-, second-line, and new anti-TB drugs. In addition, WGS can support the conventional contact tracing for epidemiological studies with high discriminatory power by tracking the circulating strains and their relatedness. These features make WGS, moreso than the conventional molecular tools, an ideal tool to monitor transmission and drug resistance trends in countries, providing deep and wide information in a standardized way. WGS technologies have already been adopted in many supranational and reference laboratories at the centralized level, and several research groups are working to reduce the complexity and costs of these platforms, from sample preparation to the downstream analysis and interpretation of sequencing reads, with the final aim to expand the use of WGS to all laboratory levels. The landscape of the platforms available for next-generation sequencing (NGS) is rapidly enriching. It includes high-throughput instruments that can be used for centralized surveillance studies on a large scale, and "benchtop" sequencers that conversely can reach more peripheral settings for rapid and non-extensive surveys. Traditionally, WGS is performed on genomic DNA samples extracted from clinical isolates to ensure the required high DNA quality and quantity for the following library preparation and sequencing reaction steps. Nevertheless, the researchers are trying to apply the WGS to early primary cultures and in particular directly to sputum samples, including specific procedures to remove non-mycobacterial genetic material and to enrich the Mycobacterium tuberculosis (MTB) genome. The targeted NGS approach that takes advantage of the amplification of selected regions of the MTB genome for genotyping and drug resistance determination could represent the most effective method to avoid the need of culturing MTB prior to sequencing, also enabling the implementation of NGS for surveillance purposes in resource-limited settings without infrastructures and equipment for growing TB cultures. Classical sequencing and NGS approaches have been successfully used in a recent study conducted in five countries with high burden of TB and multidrug resistant tuberculosis (MDR-TB) and aimed at investigating levels of resistance to pyrazinamide among patients with TB by pncA sequencing [doi: 10.1016/S1473-3099(16)30190-6]. This work innovatively demonstrated that the establishment of strong links between national (peripheral and reference laboratories) and supranational laboratories, with the former possibly processing indirect or direct samples and generating sequencing data, and the latter supporting them for bioinformatics analysis and data interpretation, will soon make WGS and targeted NGS the preferred tools to conduct public health surveillances in TB field, thus helping the strategies adopted by TB control programs at local and national levels.

Nanocarrier-based interventions for the management of MDR/XDR-TB.

Emergence of multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB over the past decade presents an unprecedented public health challenge to which countries of concern are responding far too slowly. Global Tuberculosis Report 2014 marks the 20th anniversary of the Global Project on Anti-Tuberculosis Drug Resistance Surveillance, indicating the highest global level of drug-resistance ever recorded detection of 97 000 patients with MDR-TB resulting in 170 000 deaths in 2013. Treatment of MDR-TB is expensive, complex, prolonged (18-24 months) and associated with a higher incidence of adverse events. In this context, nanocarrier delivery systems (NDSs) efficiently encapsulating considerable amounts of second-line anti tubercular drugs ((s)ATDs), eliciting controlled, sustained and more profound effect to trounce the need to administer (s)ATDs at high and frequent doses, would assist in improving patient compliance and avoid hepatotoxicity and/or nephrotoxicity/ocular toxicity/ototoxicity associated with the prevalent (s)ATDs. Besides, NDSs are also known to inhibit the P-glycoprotein efflux, reduce metabolism by gut cytochrome P-450 enzymes and circumnavigate the hepatic first-pass effect, facilitating absorption of drugs via intestinal lymphatic pathways. This review first provides a holistic account on MDR-TB and discusses the molecular basis of Mycobacterium tuberculosis resistance to anti-tubercular drugs. It also provides an updated bird's eye view on current treatment strategies and laboratory diagnostic test for MDR-TB. Furthermore, a relatively pithy view on patent studies on second-line chemotherapy using NDSs will be discussed.

Prevalence,diagnosis and treatment status of pediatric drug-resistant tuberculosis / 中华实用儿科临床杂志

Tuberculosis is a chronic infectious disease caused by Mycobacterium tuberculosis,which threats the health of children worldwide.Accompany with the increase of drug-resistance tuberculosis,great challenging has arose in the prevention and treatment of tuberculosis.Nowadays,the diagnosis and treatment of drug-resistance tuberculosis is still difficult in pediatric patients.Based on molecular diagnosis,fast detect as well as reliable treatment of drug-re-sistance tuberculosis become available.Currently,the principle of drug-resistant tuberculosis treatment in children is essentially similar to adults.In this review,the mechanism,diagnosis and treatment of pediatric drug resistance tuberculosis were discussed.