First-line Antitubercular Drugs Research Articles

An observed repeat case of drug reaction with eosinophilia and systemic symptoms syndrome with modified anti-tuberculosis therapy: a case report

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome, while uncommon, presents a potentially hazardous condition. It is a drug-induced multi‑system immunological hypersensitivity reaction, characterized by the triad of fever, rash, and internal organ involvement. This is a case report of a 60-year-old Indian female who developed a repeat episode of DRESS syndrome following modified anti-tuberculosis therapy (ATT). She had a past history of DRESS syndrome caused by first-line antitubercular drugs. This case report aims to highlight the challenges in managing DRESS syndrome in the context of tuberculosis (TB) treatment, as well as to emphasize the importance of prompt withdrawal of the culprit drugs and immediate initiation of appropriate supportive care. This case report also highlights the high risk of recurrence of DRESS syndrome following the re-administration of the offending medication, especially antitubercular drugs.

Diagnostic Performance and Comparative Analysis of Conventional Drug Susceptibility Testing, Line Probe Assay, and GeneXpert in Extrapulmonary Tuberculosis Cases: A Cross-sectional Observational Study

Introduction: Tuberculosis (TB), a known threat to mankind for ages, causes a significant burden on healthcare worldwide. The alarming rise of Extrapulmonary Tuberculosis (EPTB) has led healthcare professionals to opt for molecular diagnostics. Despite the availability of rapid diagnostics, conventional culture Drug Susceptibility Testing (DST) is still considered the gold standard in diagnosing TB. Aim: To assess the diagnostic accuracy of culture DST which is considered the gold standard. Materials and Methods: This cross-sectional observational study included 150 suspected EPTB patients and was conducted over a period of one year (September 2018 to August 2019) at Lokmanya Tilak Municipal Medical College and Sion Hospital (LTMMC), a tertiary care hospital in central Mumbai, Maharashtra, India. The hospital is located adjacent to Dharavi, the largest slum area with a high population density, which contributes to the majority of patients attending clinics. Patients attending the pulmonary medicine Outpatient Department (OPD) with extrapulmonary manifestations and suspected cases of EPTB were enrolled in the study. Samples, excluding sputum, were sent to the Department of Microbiology, LTMMC, Sion Hospital for GeneXpert analysis. The samples were further evaluated by microscopy, GeneXpert, and culture DST to detect the presence of Mycobacterium tuberculosis (M. tuberculosis) and drug susceptibility, respectively. Patients positive for Pulmonary Tuberculosis (PTB) were excluded from the study. Categorical variables were described using percentages. A Chi-square test was applied, and a p-value of <0.05 was considered significant. All statistical analyses were performed using SPSS statistical software (IBM SPSS version 26.0, Armonk, N.Y.). Results: Out of the 150 extrapulmonary samples, 23 (15.33%) samples were culture positive for M. tuberculosis and were subjected to DST using the 1% proportion method and GeneXpert assay. The MDR isolates were tested using the firstline Line Probe Assay (LPA). Eleven (47.8%) showed resistance to first-line antitubercular drugs. Among the 12 new cases, only 2 (16.7%) showed resistance compared to 9 (81.8%) in previously treated cases. A discordance of 8.7% was observed between DST with GeneXpert and LPA. Additionally, a discordance of 8.7% was observed between DST and LPA for rifampicin resistance and 4.3% for isoniazid resistance. Conclusion: The paucibacillary nature of extrapulmonary samples contributes to the challenging diagnosis of EPTB cases, leading to increased drug resistance. Highlighting the importance of the conventional solid culture DST method, this study strongly recommends the use of conventional DST accompanied by LPA for extrapulmonary cases.

Development of a HPLC Method for Analysis of a Combination of Clofazimine, Isoniazid, Pyrazinamide, and Rifampicin Incorporated into a Dermal Self-Double-Emulsifying Drug Delivery System.

We describe the development and validation of a new high performance liquid chromatography (HPLC) method for analysis of a combination of the first-line anti-tubercular drugs isoniazid, pyrazinamide, and rifampicin together with clofazimine. This is a unique challenge since clofazimine and rifampicin are relatively highly lipophilic drugs, whereas isoniazid and pyrazinamide are considerably more hydrophilic. Thus, clear separation of peaks and quantification of four individual drugs can present difficulties during the development of an analytical method. Detection was established at two wavelengths-254 nm for isoniazid and pyrazinamide and 320 nm for clofazimine and rifampicin. Gradient elution was employed using 0.1% aqueous formic acid (A) and acetonitrile (B); clear separation of the four drugs was achieved within 10 min. A linear relationship was indicated by a correlation coefficient (r2) of 0.9999 for each anti-tubercular drug, respectively. The limit of detection (LOD) for the individual drugs was 0.70 µg/mL (isoniazid), 0.30 µg/mL (pyrazinamide), 0.20 µg/mL (rifampicin) and 0.20 µg/mL (clofazimine). Precision experiments rendered a mean recovery percentage of 101.25% (isoniazid), 98.70% (pyrazinamide), 99.68% (rifampicin) and 97.14% (clofazimine). This HPLC method was validated and is reliable, repeatable, and accurate for the purpose of conducting simultaneous HPLC analyses of the four anti-tubercular drugs.

A Comprehensive Investigation of the Interactions between Proteins and Ligands in the Crystal Structures of Mycobacterium Tuberculosis

Mycobacterium tuberculosis (MTB), an acid-fast aerobic bacterium that may grow on gram stain as either a gram-positive or gram-negative bacterium, is the disease-causing agent of tuberculosis (TB). Rifampin, isoniazid, pyrazinamide and ethambutol, the first-line anti-tubercular drugs, can all have hepatotoxic side effects. The new medicine needs to work through a novel mode of action or to a novel target, be more active than presently available treatments, and shorten the course of treatment for the MDR-TB and XDR-TB, also active against both active and latent bacteria, and does not interact with antiretroviral medications because many TB patients also have HIV. Additionally, it must work well with other anti-TB medications to form at least an effective three-drug regimen. This article discusses the analysis of a few FDA-approved anti-tubercular medications and their binding locations with respective targeted proteins. This mainly focuses on the amino acids of the proteins that are responsible for the formation of interactions with a drug molecule. So, researchers can modify the existing drugs or their derivatives or can construct a new molecule according to the binding sites of enzymes corresponding to mycobacterium tuberculosis.

New approach to rifampicin stability and first-line anti-tubercular drug pharmacokinetics by UPLC-MS/MS

Successful tuberculosis (TB) therapy requires achieving sufficient exposure to multiple drugs. Limited stability of several first-line anti-TB drugs might compromise reliable therapeutic drug monitoring (TDM). We developed and validated a sensitive and selective UPLC-MS/MS method for simultaneous quantification of isoniazid (INH), pyrazinamide (PZA), rifampicin (RIF), its metabolite 25-desacetylrifampicin and degradation products: rifampicin quinone and 3-formyl-rifampicin. Analysis was completed from a very small plasma volume (20 µL) using only protein precipitation with methanol. Chromatographic separation was achieved on a Kinetex Polar C18 column (2.6 µm; 150 × 3 mm) with a mobile phase consisting of 5 mM ammonium acetate and acetonitrile, both containing 0.1 % formic acid, in gradient elution. The analytes were detected using a positive ionization mode by multiple reaction monitoring. The LLOQ for RIF and its degradation products was 0.1 µg/mL, 0.05 µg/mL for INH, and 0.2 µg/mL for PZA. The method was validated based on the FDA guidance. The application of the method was confirmed in the analysis of RIF, INH, and PZA, as well as RIF metabolism/degradation products in plasma samples of patients with TB. Based on the detailed stability study of the analyzed compounds at various storage conditions, we proposed recommendations for handling the plasma and serum samples in TDM and other pharmacokinetic studies.

Correlation of N-acetyltransferase 2 genotype and acetylation status with plasma isoniazid concentration and its metabolic ratio in ethiopian tuberculosis patients

Unfavorable treatment outcomes for tuberculosis (TB) treatment might result from altered plasma exposure to antitubercular drugs in TB patients. The present study investigated the distribution of the N-Acetyltransferase 2 (NAT2) genotype, isoniazid acetylation status, genotype–phenotype concordance of NAT2, and isoniazid plasma exposure among Ethiopian tuberculosis patients. Blood samples were collected from newly diagnosed TB patients receiving a fixed dose combination of first-line antitubercular drugs daily. Genotyping of NAT2 was done using TaqMan drug metabolism assay. Isoniazid and its metabolite concentration were determined using validated liquid chromatography-tandem mass spectrometry (LC–MS/MS). A total of 120 patients (63 male and 57 female) were enrolled in this study. The mean daily dose of isoniazid was 4.71 mg/kg. The frequency of slow, intermediate, and fast NAT2 acetylators genotypes were 74.2%, 22.4%, and 3.3% respectively. The overall median isoniazid maximum plasma concentration (Cmax) was 4.77 µg/mL and the AUC0–7 h was 11.21 µg.h/mL. The median Cmax in slow, intermediate, and fast acetylators were 5.65, 3.44, and 2.47 μg/mL, respectively. The median AUC0–7 h hour in slow, intermediate, and fast acetylators were 13.1, 6.086, and 3.73 mg•h/L, respectively. The majority (87.5%) of the study participants achieved isoniazid Cmax of above 3 µg/mL, which is considered a lower limit for a favorable treatment outcome. There is 85% concordance between the NAT2 genotype and acetylation phenotypes. NAT2 genotype, female sex, and dose were independent predictors of Cmax and AUC0–7 h (p < 0.001). Our finding revealed that there is a high frequency of slow NAT2 genotypes. The plasma Cmax of isoniazid was higher in the female and slow acetylators genotype group. The overall target plasma isoniazid concentrations in Ethiopian tuberculosis patients were achieved in the majority of the patients. Therefore, it is important to monitor adverse drug reactions and the use of a higher dose of isoniazid should be closely monitored.

Drug-Induced Hypersensitivity Reaction and Re-Introduction of Anti-Tubercular Drugs (ATT): A Case Report and Review of Literature

Tuberculosis (TB) is a communicable disease caused by the bacillus Mycobacterium tuberculosis and is the leading cause of death by a single infectious agent overall. According to the WHO Global TB Report, India contributes to 26% of the global burden of TB. Currently, a four-drug regimen comprising Rifampicin, Isoniazid, Pyrazinamide, and Ethambutol is approved for the treatment of drug-sensitive TB. The management of cutaneous adverse drug reactions to anti-tubercular drugs is akin to a double-edged sword, with discontinuation of ATT increasing the risk of developing disseminated and drug-resistant tuberculosis, and continuation leading to persistence or exacerbation of the adverse drug reaction (ADR). The risk of developing an ADR to anti-tubercular therapy (ATT) varies from 8 to 85% in various studies [10]. The prevalence of rashes associated with ATT shows that the maculopapular rash (42.5%) is the most frequently observed type, followed by urticarial, lichenoid, DRESS, AGEP, and exfoliative dermatitis (17). The drugs associated with Cutaneous ADRs from the lowest to the highest risk are Isoniazid, Rifampicin, Pyrazinamide, Ethionamide, Cycloserine, Ethambutol, Para-aminosalicylic acid (PAS), and Streptomycin (25). We present a case and approach to the re-introduction of first-line anti-tubercular drugs after hypersensitivity with fixed-dose combinations.&#x0D; Keywords: Tuberculosis, Mycobacterium tuberculosis, adverse drug reaction, anti-tubercular therapy

Determinants of adverse reactions to first-line antitubercular medicines: a prospective cohort study

BackgroundThe success of tuberculosis treatment relies on patients adhering to their medication regimen consistently. However, adherence levels tend to decrease among patients who experience adverse drug reactions to antitubercular medications, leading to suboptimal treatment outcomes. Hence, this study aimed to examine the types, incidence rates, and severity of adverse reactions caused by first-line antitubercular drugs. Additionally, it aimed to identify factors associated with the development of these reactions. By doing so, the study aimed to facilitate the provision of personalized and effective treatment to patients, ultimately improving treatment outcomes.MethodsNewly diagnosed patients with active tuberculosis were monitored from the start of their treatment until the completion of therapy. Any adverse reactions to anti-TB drugs that they encountered were carefully recorded. The collected data were analyzed using appropriate statistical methods such as analysis of variance, Chi-squared test, Fisher's exact test, and independent t-tests. Logistic regression was employed to assess the association between adverse drug reactions and various socio-demographic and clinical factors of the patients, using odds ratios as a measure of association.ResultsAmong the 378 patients included in the study, 181 individuals (47.9%) reported experiencing at least one adverse drug reaction, with an incidence rate of 1.75 events per 100-person months. The majority of these reactions occurred during the intensive phase of treatment. The gastrointestinal tract was the most commonly affected system, followed by the nervous system and skin. Patients aged over 45 years (OR = 1.55, 95% CI 1.01–2.39, p = 0.046) and those with extrapulmonary tuberculosis (OR = 2.41, 95% CI 1.03–5.64) were more likely to develop gastrointestinal reactions. Female gender was a significant predictor of both skin (OR = 1.78, 95% CI 1.05–3.02, p = 0.032) and nervous system (OR = 1.65, 95% CI 1.07–2.55, p = 0.024) reactions. Additionally, alcohol use and HIV infection were identified as independent predictors of adverse drug reactions affecting all three systems.ConclusionSignificant risk factors for developing antitubercular drug adverse reactions include alcohol consumption, cigarette smoking, being HIV positive, female gender and extrapulmonary tuberculosis.

Molecular and cellular remodeling of HepG2 cells upon treatment with antitubercular drugs.

Drug-induced liver injury (DILI) is an adverse outcome of the currently used tuberculosis treatment regimen, which results in patient noncompliance, poor treatment outcomes, and the emergence of drug-resistant tuberculosis. DILI is primarily caused by the toxicity of the drugs and their metabolites, which affect liver cells, biliary epithelial cells, and liver vasculature. However, the precise mechanism behind the cellular damage attributable to first-line antitubercular drugs (ATDs), as well as the effect of toxicity on the cell survival strategies, is yet to be elucidated. In the current study, HepG2 cells upon treatment with a high concentration of ATDs showed increased perforation within the cell, cuboidal shape, and membrane blebbing as compared with control/untreated cells. It was observed that ATD-induced toxicity in HepG2 cells leads to altered mitochondrial membrane permeability, which was depicted by the decreased fluorescence intensity of the MitoRed tracker dye at higher drug concentrations. In addition, high doses of ATDs caused cell damage through an increase in reactive oxygen species production in HepG2 cells and a simultaneous reduction in glutathione levels. Further, high dose of isoniazid (50-200 mM), pyrazinamide (50-200 mM), and rifampicin (20-100 µM) causes cell apoptosis and affects cell survival during toxic conditions by decreasing the expression of potent autophagy markers Atg5, Atg7, and LC3B. Thus, ATD-mediated toxicity contributes to the reduced ability of hepatocytes to tolerate cellular damage caused by altered mitochondrial membrane permeability, increased apoptosis, and decreased autophagy. These findings further emphasize the need to develop adjuvant therapies that can mitigate ATD-induced toxicity for the effective treatment of tuberculosis.

N-Acylated Ciprofloxacin Derivatives: Synthesis and In Vitro Biological Evaluation as Antibacterial and Anticancer Agents.

A novel series of N-acylated ciprofloxacin (CP) conjugates 1-21 were synthesized and screened as potential antimicrobial agents. Conjugates 1 and 2 were 1.25-10-fold more potent than CP toward all Staphylococci (minimal inhibitory concentration 0.05-0.4 μg/mL). Most of the chloro- (3-7), bromo- (8-11), and CF3-alkanoyl (14-16) derivatives expressed higher or comparable activity to CP against selected Gram-positive strains. A few CP analogues (5, 10, and 11) were also more effective toward the chosen clinical Gram-negative rods. Conjugates 5, 10, and 11 considerably influenced the phases of the bacterial growth cycle over 18 h. Additionally, compounds 2, 4-7, 9-12, and 21 exerted stronger tuberculostatic action against three Mycobacterium tuberculosis isolates than the first-line antitubercular drugs. Amides 1, 2, 5, 6, 10, and 11 targeted gyrase and topoisomerase IV at 2.7-10.0 μg/mL, which suggests a mechanism of antibacterial action related to CP. These findings were confirmed by molecular docking studies. In addition, compounds 3 and 15 showed high antiproliferative activities against prostate PC3 cells (IC50 2.02-4.8 μM), up to 6.5-2.75 stronger than cisplatin. They almost completely reduced the growth and proliferation rates in these cells, without a cytotoxic action against normal HaCaT cell lines. Furthermore, derivatives 3 and 21 induced apoptosis/necrosis in PC3 cells, probably by increasing the intracellular ROS amount, as well as they diminished the IL-6 level in tumor cells.

Cisatracurium besylate rescues Mycobacterium Tuberculosis-infected macrophages from necroptosis and enhances the bactericidal effect of isoniazid

ObjectiveTuberculosis is the leading killer among the chronic single-source infectious diseases. Mycobacterium tuberculosis can induce necrotic-dominant multiple modes of cell death in macrophages, which accelerates bacterium dissemination and expands tissue injury in host lungs. Mining drugs to counteract Mycobacterium tuberculosis-induced cell death would be beneficial to tuberculosis patients. MethodsIn this study, the protective drug was screened out from the FDA-approved drug library in Mycobacterium tuberculosis-infected macrophages with CCK-8 assay. The death mode regulated by the drug was identified using transcriptomic sequencing, cytomorphological observation, and in the experimental mouse Mycobacterium tuberculosis-infection model. The functional mechanism was explored using western blot, co-immunoprecipitation, and DARTS assay. The intracellular bacterial survival was detected using colony forming unit assays. ResultsCisatracurium besylate was identified to be highly protective for the viability of macrophages during Mycobacterium tuberculosis infection via inhibiting necroptosis. Cisatracurium besylate prevented RIPK3 to be associated with the executive molecule MLKL for forming the necroptotic complex, resulting in the inhibition of MLKL phosphorylation and pore formation on cell membrane. However, Cisatracurium besylate did not interfere with the association between RIPK3 with its upstream kinase RIPK1 or ZBP1 but regulated RIPK3 autophosphorylation. Moreover, Cisatracurium besylate significantly inhibited the expansion of intracellular Mycobacterium tuberculosis both in vitro and in vivo, which also displayed a strong auxiliary bacteriostatic effect to support the therapeutic efficacy of isoniazid and rifampicin, the first-line anti-tubercular drugs. ConclusionCisatracurium besylate performs anti-Mycobacterium tuberculosis and anti-necroptotic roles, which potentiates its application to be an adjuvant drug for antituberculosis therapy to assist the battle against drug-resistant tuberculosis.

Rifampicin-Amlodipine Interaction: A Case Report of Hypertension Exacerbation

Introduction: Rifampicin, a first-line anti-tubercular therapy drug, is a strong inducer of hepatic cytochrome P450 (CYP). Amlodipine and metoprolol, two anti-hypertensives that are CYP substrates, have the potential to interact pharmacologically with rifampicin. Therefore, individuals with hypertension receiving rifampicin-based anti-tubercular therapy are at risk for worsening hypertension.&#x0D; Case Details: We report a case of a 63-year-old female patient, who developed accelerated hypertension after initiating rifampicin. Later, up to four antihypertensive drugs were administered as part of a gradual increase in dosage but did not successfully lower blood pressure to a desirable level. After clinical pharmacist intervention, Tab. Amlodipine+Metoprolol 5 mg+50 mg was discontinued and the blood pressure measurements gradually improved.&#x0D; Conclusion: We postulate that rifampicin diminished the therapeutic effect of amlodipine and metoprolol and hence recommend that prudent monitoring for worsening hypertension should be carried out in hypertensive patients with chronic kidney disease receiving anti-tubercular therapy.

The human proton pump inhibitors inhibit Mycobacterium tuberculosis rifampicin efflux and macrophage-induced rifampicin tolerance

Tuberculosis treatment requires months-long combination chemotherapy with multiple drugs, with shorter treatments leading to relapses. A major impediment to shortening treatment is that Mycobacterium tuberculosis becomes tolerant to the administered drugs, starting early after infection and within days of infecting macrophages. Multiple lines of evidence suggest that macrophage-induced drug tolerance is mediated by mycobacterial drug efflux pumps. Here, using assays to directly measure drug efflux, we find that M. tuberculosis transports the first-line antitubercular drug rifampicin through a proton gradient-dependent mechanism. We show that verapamil, a known efflux pump inhibitor, which inhibits macrophage-induced rifampicin tolerance, also inhibits M.tuberculosis rifampicin efflux. As with macrophage-induced tolerance, the calcium channel-inhibiting property of verapamil is not required for its inhibition of rifampicin efflux. By testing verapamil analogs, we show that verapamil directly inhibits M. tuberculosis drug efflux pumps through its human P-glycoprotein (PGP)-like inhibitory activity. Screening commonly used drugs with incidental PGPinhibitory activity, we find many inhibit rifampicin efflux, including the proton pump inhibitors (PPIs) such as omeprazole. Like verapamil, the PPIs inhibit macrophage-induced rifampicin tolerance as well as intramacrophage growth, which has also been linked to mycobacterial efflux pump activity. Our assays provide a facile screening platform for M. tuberculosis efflux pump inhibitors that inhibit invivo drug tolerance and growth.

Detection of katG and inhA Genes Mutation in Rifampicin-Resistant Mycobacterium Tuberculosis Using Line Probe Assay (LPA) In Kebbi, Nigeria

Elimination of tuberculosis remains a public health menace, due to multidrug resistant strains of Mycobacterium tuberculosis, that are resistant to the first-line anti-tubercular drugs. Consequently, detection of resistant strains depends on early diagnosis. Intervention of molecular techniques is essential to reduce mortality and morbidity rates. This study aimed to detect katG and inhA gene mutations among rifampicin resistant strain of Mycobacterium tuberculosis in Kebbi State. A cross-sectional study was conducted which covered all the five major health zones in Kebbi State. Two hundred and forty (240) acid fast bacilli confirmed sputum samples were recruited and subjected to Gene Xpert testing. Positive sputum samples were later subjected to Line Probe Assay technique. 14 sputum samples were resistant to rifampicin out of the 240 confirmed acid fast bacilli sputum samples while 226 were sensitive to rifampicin. Mutations were found at the frequency of 100% for katG gene (katG/S315T) in all the 14 rifampicin resistant samples (rpoB/S531L) at the different health zones in kebbi state using the line probe assay. The research has also detected inhA gene mutation at a frequency of 100% in all rifampicin resistant samples showing that mutation is associated with multi resistance to isoniazid and rifampicin. This study confirms that resistance due to katG and inhA mutation is a better surrogate of multidrug-resistant tuberculosis among TB patients in Kebbi State compared to the single-marker analysis. Hence, early molecular detection of rifampicin resistant strains will suffice in determining the management of multidrug resistant tuberculosis in Kebbi State.

Cartridge-based nucleic acid amplification test in drug-resistant Mycobacterium tuberculosis as compared to solid cultures: Is it time to look beyond cartridge-based nucleic acid amplification test?

Background: There is a need to study the performance, validity, and accuracy of cartridge-based nucleic acid amplification test (CB-NAAT) for accessing drug resistance among pulmonary tuberculosis (TB) compared with the solid culture drug susceptibility test (DST).Methods: Patients with symptoms of cough for more than 2 weeks with anyone symptoms such as night sweats, fever, and unintentional weight loss were studied. Cases with previously diagnosed drug-resistant pulmonary TB by sputum CB-NAAT having constitutional symptoms but not on any ATT for a minimum of 2 months were also included in the study. The patient's information, including age, immune surveillance status, clinical features, and chest X-rays, were recorded. Each sputum sample was divided into three aliquots and tested for smear microscopy, liquid culture (LC), and genotypic DST. Results of all three diagnostic modalities were compared with CB-NAAT reports.Results: Of 236 patients with sputum-positive CB-NAAT (n = 236), 49.4% (n = 117) were rifampicin resistant, while 50. 4% (n = 119) were rifampicin sensitive. The genotypic DST assays carried out of all enrolled patients showed that 76.3% (n = 181) patients were resistant to one or more first-line antitubercular drugs (FL ATTs) or second-line (SL) ATTs, while 23.7% (n = 55) patients were sensitive to all ATTs. Among all the study participants, 56.4% (n = 133) of patients had sputum smear-positive by ZN stain, while 88.6% (n = 209) showed growth on LC (BACTEC) media. On concordant analysis of CB-NAAT with DST assays, we found that among 119 CB-NAAT rifampicin-sensitive patients, 66 patients were drug-resistant (DR) TB to any of the FL or SL ATTs. The sensitivity, specificity, positive predictive value, and negative predictive value of CB-NAAT for detecting rifampicin resistance on sputum for pulmonary TB when compared with the gold-standard DST assays were 97.67%, 76.67%, 70.59%, and 98.29%, respectively.Conclusions: This study found that the use of rapid molecular technique (CB-NAAT) in screening DRTB at the community level is suboptimal compared to the gold-standard solid culture method. Although CB-NAAT's sensitivity in detecting DR pulmonary TB is significantly higher, the specificity is lower in that population who have received ATT earlier.

Chemical remodeling of the mycomembrane with chain-truncated lipids sensitizes mycobacteria to rifampicin.

The outer mycomembrane of Mycobacterium tuberculosis and related pathogens is a robust permeability barrier that protects against antibiotic treatment. Here, we demonstrate that synthetic analogues of the mycomembrane biosynthetic precursor trehalose monomycolate bearing truncated lipid chains increase permeability of Mycobacterium smegmatis cells and sensitize them to treatment with the first-line anti-tubercular drug rifampicin. The reported strategy may be useful for enhancing entry of drugs and other molecules to mycobacterial cells, and represents a new way to study mycomembrane structure and function.

Adverse drug reactions to first-line antituberculosis drugs at four DOTS centers in Goa, India

BACKGROUND: Major adverse drug reactions (ADRs) can cause significant morbidity and can compromise the treatment regimen. This can result in substantial additional cost due to added outpatient visits to the health facility or laboratory investigations or hospitalization in serious instances. Treatment is often prolonged with additional challenge of compliance. Hence, there is a need to monitor and manage these ADRs timely for better patient care and outcome. This study was carried out with the objective of studying the pattern of ADRs due to first-line antitubercular drugs and to carry out the causality and severity assessment of the reported ADRs.METHODOLOGY: A prospective observational study was conducted at four DOTS centers. All tuberculosis (TB) patients registered and receiving treatment under DOTS were enrolled for the study and were followed up at regular intervals till the end of their treatment. Patients' demographic, personal, disease, investigation, and ADRs details were entered in a predesigned patient recording form. Causality assessment of all ADRs were done using Naranjo algorithm. Severity assessment was done using modified Hartwig and Siegel scale. The study was approved by the institutional ethics committee of the institute. Statistical analysis was conducted using IBM SPSS Statistics for Windows.RESULTS: Of 186 patients, 23 patients (12.26%) developed one or more ADRs. The average number of ADRs per person was 1.43. Majority of the ADRs were reported in the 20–40 years of age group and ADRs were more likely to be among females compared to males. There was no association between type of TB, site of TB, regimen of anti-TB drugs, treatment outcomes, and ADRs. Around 84.85% and 15.15% of ADRs were classified as of mild and moderate severity, respectively, as per modified Hartwig and Siegel scale, while, as per Naranjo algorithm, 72.73% of the ADRs were classified as probable and 27.27% of ADRs as possible. No ADRs were classified as definite.CONCLUSION: Thorough understanding of the various ADRs and their management will help in the effective treatment of TB as well as designing effective counseling methods, which will help in adherence to treatment and also to have better compliance.

STUDY OF RESISTANCE TO FIRST-LINE DRUGS IN MULTIDRUG RESISTANCE TUBERCULOSIS SUSPECTS FROM SPUTUM SAMPLES BY GOLD STANDARD – STANDARD ECONOMIC VARIANT 1% PROPORTION METHOD IN NORTH COASTAL ANDHRA PRADESH

Objectives: The objectives of the study were to culture Mycobacterium tuberculosis from sputum samples of multidrug resistance (MDR) suspects on Lowenstein-Jensen (LJ) media, to test for susceptibility and resistance to first-line antitubercular drugs rifampicin (RMP), isoniazid (INH), streptomycin (SM), and ethambutol (EMB) by conventional DST on LJ media by standard economic variant proportion (1%) method and to calculate the rate of MDR and pattern of drug resistance in MDR tuberculosis (MDR-TB) suspects. Methods: A prospective, laboratory-based study was done on a total of 80 samples from cases of suspected pulmonary and extra-pulmonary TB. Identification of culture isolates as M. tuberculosis was done by susceptibility to p-nitrobenzoic acid (PNB), niacin test, and catalase activity at 68°C/pH 7. Drug sensitivity testing (DST) of M. tuberculosis cultures on LJ medium for drugs was performed by a standard economic variant of the 1% proportion method. Results: Among MDR suspects, the maximum is in the age group of 45–60 years (35%) with a mean age of 42.75±15.93 years. The sex ratio of male to female is 2:1. Out of 80 samples, 36 samples (45%) were graded 1+, 31 samples (38.7%) 2+, and 13 samples (16.3%) 3+. All 80 sputum samples showed growth on LJ media within 8 weeks. When colonies obtained on LJ medium were subjected to biochemical tests for identification, all were positive for M. tuberculosis. Out of 80 M. tuberculosis isolates tested for sensitivity against first-line drugs (except pyrazinamide), 45 (56.3%) were found to be sensitive to all four drugs (INH, RMP, EMB, and SM), and 35 (43.7%) were resistant to at least one drug. Nine isolates (11.3%) showed resistance to a single drug (monoresistance). The various MDR patterns were INH+RMP seen in 6 strains (7.5%) and INH+RMP+SM seen in 4 strains (5%). Conclusion: Drug resistance trends must be closely monitored to evaluate the efficiency of existing therapies and their effect on pulmonary tuberculosis epidemic. To design the new drug regulations, more extensive data on drug sensitivity with standardized testing protocols which is quality assured are required.

Multidrug-Resistant Musculoskeletal Tuberculosis: An Aggressive Clinical, Radiological and Molecular Confirmation With Genotypic Drug Susceptibility Testing Approach.

IntroductionIncreasing evidence suggests that musculoskeletal tuberculosis (MSTB) causes significant morbidity due to the late presentation of symptoms and lack of accurate diagnosis. We aimed to assess the utility of two modalities, viz. radiology and molecular methods, in the early diagnosis of MSTB. Also, the rate of resistance to two basic first-line antitubercular drugs in musculoskeletal TB cases among clinically suspected patients was analyzed.MethodsSamples from 119 patients with clinical suspicion of musculoskeletal TB were included. A radiological workup of patient and smear microscopy, mycobacterial culture, real-time multiplex polymerase chain reaction (PCR), cartridge based nucleic acid amplification test (CBNAAT), and line probe assay (LPA) of samples were carried out.ResultsMaximum positivity (69.74%) was observed by real-time multiplex, followed by CBNAAT and LPA (68.9%), mycobacterial culture (40.3%), and smear microscopy (19.3%). One additional advantage of using multiplex PCR was the detection of non-tuberculous mycobacteria (NTM) isolate. Forty-five strains (54.9%) on LPA were susceptible to rifampicin and isoniazid, eight (9.8%) were rifampicin mono-resistant, seven (8.5%) were isoniazid (INH) mono-resistant, and 22 (26.8%) were multidrug resistant.ConclusionsMSTB diagnosis can be expedited by the combination of radiology and molecular methods. The positivity rate escalates, turnaround time improves, and the additional advantage of detection of drug resistance is added when this algorithm is included for clinching the diagnosis of MSTB.

Prevalence of tuberculosis among HIV positive patients on anti-retroviral therapy with special emphasis on pattern of adverse events of first-line anti-tubercular drug

Background: Survival rates have been improved with concomitant use of anti-tubercular drugs in HIV subjects with tuberculosis. The use of anti-tubercular drugs combined with ART can lead to more drug interactions, non-compliance, toxicity, and adverse effects. Aim: To assess the pattern, severity, and prevalence of adverse drug reactions of first-line anti-tubercular drugs in HIV (Human Immunodeficiency Virus) positive subjects with tuberculosis. Methods: The present prospective, observational study included 391 subjects out of 19522 subjects who were diagnosed HIV Positive and scheduled for Anti-Retroviral therapy at the ART Centre. 102 subjects were enrolled as tuberculosis confirmation of HIV-TB Co-Infection disease during the study period. All the subjects were evaluated for adverse drug events including blurred vision, jaundice, neuropathy, skin infection, itching, blood urea, hepatotoxicity, tingling, numbness, pain, pancreatitis, diarrhea, skin rashes, and anemia. Results: The most prevalent side-effect noted was neuropathy reported in 26.13% (n=10) study participants followed by skin rashes reported in 21.05% (n=8) study subjects. Jaundice, vomiting, and body weakness were all reported in 15.78% (n=6) of study subjects each. Diarrhea, headache, hepatotoxicity, insomnia, mental confusion, and anorexia were all reported in 10.52% (n=4) of study participants each.