anti-TB Regimen Research Articles

Silicosis predicts drug resistance and retreatment among tuberculosis patients in India: a secondary data analysis from Khambhat, Gujarat (2006–2022)

BackgroundIndia, with the highest global burden of tuberculosis (TB) and drug-resistant TB, aims to eliminate TB by 2025. Yet, limited evidence exists on drug resistance patterns and retreatment among patients with silico-tuberculosis. This study explores these patterns and assesses the impact of silicosis on TB retreatment in India.MethodsThis secondary data analysis stems from a larger retrospective cohort study conducted in Khambhat, Gujarat, between January 2006 and February 2022. It included 138 patients with silico-tuberculosis and 2,610 TB patients without silicosis. Data from the Nikshay TB information portal were linked with silicosis diagnosis reports from the Pneumoconiosis Board using the unique Nikshay ID as the linking variable. Drug-resistant TB was defined as resistance to any anti-TB drug recorded in Nikshay. Retreatment refers to TB patients who have previously undergone anti-TB treatment for one month or more and need further treatment. Recurrent TB denotes patients who were previously declared cured or had completed treatment but later tested positive for microbiologically confirmed TB. Multivariable logistic regression was used to determine the impact of co-prevalent silicosis on drug resistance and retreatment.ResultsPatients with silico-tuberculosis showed a higher proportion of retreatment compared to those without silicosis (55% vs. 23%, p < 0.001). Notably, 28% of patients with silico-tuberculosis were recurrent TB cases, compared to 11% among those without silicosis. Regarding drug resistance, the silico-tuberculosis group exhibited a higher rate (6% vs. 3%), largely due to rifampicin resistance (5% vs. 2%, p = 0.022). Co-prevalent silicosis was associated with a 2.5 times greater risk of drug-resistant TB (adjusted OR 2.5, 95% CI, 1.1–5.3; p = 0.021). Additionally, patients with silico-tuberculosis had a fourfold increased risk of retreatment for TB (adjusted OR 4, 95% CI, 3–6; p < 0.001).ConclusionsCo-prevalent silicosis significantly elevates the risk of drug resistance, recurrence, and retreatment among TB patients in India. This study indicates a need for improved treatment protocols and suggests that future research should focus on randomized controlled trials to evaluate appropriate anti-TB regimen and duration of therapy for this high-risk group. Given India’s goal to eliminate TB by 2025, addressing the challenges posed by silico-tuberculosis is critical.

Treatment of acute myeloid leukemia with active pulmonary tuberculosis with venetoclax‑based anti‑acute myeloid leukemia regimen combined with an intensive and then individualized anti‑tuberculosis regimen: A report of two cases.

Patients with concurrent acute myeloid leukemia (AML) and active pulmonary tuberculosis (TB) exhibit certain characteristics; cough, phlegm, fever, hemoptysis, weight loss and dyspnea are common symptoms of both diseases. These patients often cannot tolerate traditional intensive chemotherapy regimens, and finding the optimal timing in the treatment of both AML and active pulmonary TB is complex. Neglecting timely treatment can lead to serious complications and even fatal outcomes. The present paper reports two cases of patients with AML who were diagnosed with active pulmonary TB. The patients received intensive anti-TB treatment with isoniazid, rifampicin, pyrazinamide and ethambutol for 10-15 days. After three consecutive negative sputum smears, the patients in cases 1 and 2 were treated with a venetoclax, homoharringtonine and cytarabine regimen; and a venetoclax and azacitidine regimen for anti-AML therapy, respectively, as well as individualized anti-TB regimens of isoniazid, pyrazinamide, ethambutol and quinolone. Subsequently, both patients achieved complete remission of AML and their active TB was well controlled.

Whole-genome sequencing drug susceptibility testing is associated with positive MDR-TB treatment response.

<sec><title>BACKGROUND</title>Until recently, multidrug-resistant TB (MDR-TB) was treated with lengthy and toxic regimens. New three-drug anti-TB regimens raise the question of whether they are sufficiently active for MDR-TB in Central Asia, an MDR-TB hotspot region.</sec><sec><title>METHODS</title>In a cohort of rifampicin-resistant (RR) and MDR-TB patients in the Kyrgyz Republic, we investigated the impact of the number of drugs that were tested susceptible by whole-genome sequencing (WGS) and conventional drug susceptibility testing (DST) and used for treatment on the treatment response, defined as 'matches'. Logistic regressions were performed to assess the effect of having ≥ 4 susceptible drugs in a regimen at baseline and at Month 2 on the treatment response.</sec><sec><title>RESULTS</title>The study included 227 participants with RR/MDR-TB (30.8% female; median age 30.4 years). The age- and sex-adjusted analysis showed an association between a regimen with ≥ 4 WGS matches at baseline (adjusted odds ratio [aOR] 2.10, 95% CI 1.00-4.41). No association was found when using conventional DST to define matches.</sec><sec><title>CONCLUSION</title>Our study confirms that the inclusion of four efficacious anti-TB drugs in an MDR-TB regimen increases the chances of a positive treatment response. Susceptibility of at least four drugs in WGS-DST predicts a positive treatment response.</sec>.

Diabetes Mellitus Associated with Sputum Conversion Time in Drug-Resistant Pulmonary TB Patients at Dr. Soebandi Regional General Hospital, Jember

Introduction: Diabetes mellitus (DM) comorbidity in drug-resistant (DR) pulmonary tuberculosis (TB) patients can be associated with the treatment outcome. In DR-TB patients with DM, the immune system is impaired, which will decrease the success of treatment. Sputum conversion time is an indicator used to predict the treatment outcome. However, there is still no further study related to the association between DM comorbidity and the sputum conversion time in DR-TB patients, especially in Jember. This study aimed to determine the association between DM and sputum conversion time in DR-TB patients at Dr. Soebandi Regional General Hospital, Jember. Methods: This was an analytic observational study with a cross-sectional design. A total of 122 samples of DR-TB patients were taken using the purposive sampling method in 2018-2023 at Dr. Soebandi Regional General Hospital, Jember. The data were analyzed using the Chi-square and logistic regression statistical test. Results: Chi-square analysis showed that DM (p = 0.015; OR = 2.604; 95% CI 1.195-5.674) and age (p = 0.021; OR = 0.377; 95% CI 0.162-0.878) were associated with sputum conversion time. Logistic regression showed that DM was the most associated variable with the sputum conversion time (p = 0.016; OR = 2.604; 95% CI 1.195-5.674) compared to gender, age, TB resistance type, and anti-TB regimen. Conclusion: DM is associated with prolonged sputum conversion time in DR-TB patients at Dr. Soebandi Regional General Hospital, Jember. DM was also the most associated variable with the sputum conversion time compared to gender, age, TB resistance type, and anti-TB regimen.

Challenges and potential solutions for cycloserine dosing in patients with sepsis undergoing continuous renal replacement therapy

Continuous kidney replacement therapy (CRRT) is a special form of dialysis, which has more significant advantages than traditional intermittent hemodialysis in treating critically ill patients. The impact of CRRT and disease complexity on drug clearance in critically ill patients has been reported in several studies, nevertheless, the pharmacokinetic changes of cycloserine in patients with sepsis undergoing CRRT have not been reported. Here, we report a case of a 52-year-old man with septic shock and severe multidrug-resistant tuberculosis who underwent anti-TB therapy. The patient's anti-TB regimen included linezolid, clofazimine, cycloserine, and bedaquiline. Following continuous administration for 14 days, the patient was treated with CRRT due to acid-base imbalance and acute renal failure. Blood samples were collected at 0, 2, 4, 6, 10, and 12 hours following cycloserine administration (CRRT was initiated two hours after administration). Changes in plasma concentration of cycloserine before and after the CRRT were measured. The peak concentration of cycloserine was 39.93 mg/L with a trough concentration of 7.90 mg/L, and the AUC0-12h was 294.36 mg•h/L. These findings firstly suggested that the pharmacokinetics of cycloserine may be influenced by sepsis and CRRT therapy, and cycloserine doses may need to be increased during CRRT therapy in patients with sepsis.

Malnutrition and unsuccessful tuberculosis treatment among people with multi-drug resistant tuberculosis in Uganda: A retrospective analysis

RationaleMulti-drug-resistant tuberculosis (MDR-TB) poses a significant public health challenge to the control and successful eradication of TB globally. Suboptimal treatment outcomes are common among persons with MDR-TB necessitating a need to understand the contextual factors. ObjectiveWe determined the factors associated with unsuccessful TB treatment among persons with MDR-TB at a large TB Unit in Central Uganda. MethodsWe retrospectively reviewed medical records for all persons with MDR-TB at Mubende Regional Referral Hospital MDR-TB Clinic in Central Uganda. The patients were treated with either second-line, modified second-line, or individualized anti-TB regimens and completed treatment between January 2012 and October 2023. The primary outcome was unsuccessful TB treatment defined as death, treatment failure, or loss to follow-up and measured as a binary outcome. We used a multivariable binary logistic regression analysis to determine the factors independently associated with unsuccessful TB treatment at a 5 % statistical significance level. We reported the adjusted odds ratio (aOR) and the 95 % confidence interval (CI). Measurements and resultsWe analyzed data from 98 persons with MDR-TB who were aged 15–78 years (mean 36.4 ± 15.4 years). Of these, 40 (40.8 %) were cured, 25 (25.5 %) completed TB treatment, 1 (1.0 %) had treatment failure, 13 (13.3 %) died, and 19 (19.4 %) were lost to follow-up. Overall, 33 (33.7 %) participants had unsuccessful TB treatment which was associated with older age for a 1-year increase in age (aOR 1.05, 95 % CI 1.01–1.09), malnutrition—mid-upper arm circumference of <12.5 cm (aOR 2.99, 95 % CI 1.16–7.98), and previous TB treatment (aOR 0.28, 95 % CI 0.10–0.77). ConclusionUnsuccessful TB treatment is high among persons with MDR-TB at this TB Unit. It is more likely as age advances and when persons with MDR-TB have malnutrition, but less likely when they have been previously treated for TB. Therefore, interventions to improve treatment outcomes may be beneficial for persons with MDR-TB who are older, malnourished, and those newly diagnosed with the disease. For example, routine nutritional assessment and counseling, including nutritional support for malnourished persons with MDR-TB may be needed to optimize their TB treatment success.

Assessment of treatment outcomes of daily fixed-dose combination therapy among drug-sensitive pulmonary tuberculosis patients: A prospective study from Bengaluru, India.

The annual incidence cases report depicts India as having the highest tuberculosis (TB) burden globally. Following a programmatic change, the daily fixed-dose combination (FDC) anti-TB treatment regimens were introduced by the Indian government's National Tuberculosis Elimination Program (NTEP). The aim of the study was to assess the treatment outcomes among drug-sensitive pulmonary TB patients receiving daily FDC drugs and the associated factors influencing the treatment outcomes. A prospective study was conducted among 300 drug-sensitive pulmonary TB cases in the Bruhat Bengaluru Mahanagara Palike (BBMP) area. The TB units and designated microscopic centers (DMCs) were selected by multistage random sampling. Data were collected through a pre-tested and semi-structured questionnaire. Patients were followed up until treatment completion. Data were compiled and analyzed using IBM Statistical Package for Social Sciences (SPSS) statistics version 20.0. Descriptive statistics and the Chi-square test were used for interpretation. A P-value less than 0.05 was considered statistically significant. Around 86.33% of patients were cured, 4% had completed treatment, and 1% had treatment failure. Older age, human immunodeficiency virus (HIV) reactive status, alcohol intake, tobacco use, and migrants were associated with poor outcomes. The daily FDC regimen had better outcomes than intermittent regimens. Smokers, alcoholics, migrants, and patients with co-morbidity need to be given priority in management as they are prone to poorer outcomes.

Medication nonadherence and associated factors in patients with tuberculosis in Wau, South Sudan: a cross- sectional study using the world health organization multidimensional adherence model

BackgroundTuberculosis medication nonadherence is a multi-dimensional public health problem with serious consequences worldwide. There is little information available for medication nonadherence in South Sudan. This study assessed the proportion, reasons, and associated factors for nonadherence among patients with TB in Wau Municipality, South Sudan.MethodsA health facility based cross-sectional study was conducted among 234 tuberculosis (TB) patients receiving first line anti-TB regimen in Wau Municipality. Urine isoniazid metabolite testing (IsoScreen®) was used to determine nonadherence (visualized by negative test results) and a questionnaire was used to describe the reasons for nonadherence. Modified poisson regression with robust standard errors was performed since the proportion of nonadherence was < 10%, to identify nonadherence associated factors using the WHO Multidimensional adherence model.ResultsOut of 234 participants, 24.8% (95% CI, 19.2 − 30.3) were nonadherent to the TB treatment regimen. At multivariate analysis, nonadherence was significantly associated with: relief of symptoms (APR 1.93, 95% CI 1.12 − 3.34, p = 0.018), alcohol use (APR 2.12, 95% CI 1.33 − 3.96, p = 0.019) and waiting time to receive drugs (APR 1.77, 95% CI 1.11 − 2.83, p = 0.017).ConclusionTuberculosis medication nonadherence was high, and it’s associated with patients’ relived of symptoms, alcohol use, and prolonged waiting time at health facility. Hence, addressing these barriers and the use of multifaceted interventions e.g. counseling, health education and improve appointments are crucial to reduce nonadherence among patients with TB in South Sudan.

Fecal microbiota transplantation: A potential novel treatment strategy for extensively drug-resistant tuberculosis

Tuberculosis (TB) is one of the infectious diseases with the highest mortality and morbidity. The evolution of drug-resistant TB, particularly extensively drug-resistant TB (XDR-TB) is a global concern. The current anti-TB treatment regimens for XDR-TB are long and associated with adverse events, low patient adherence, and low success rates. Fecal microbiota transplantation (FMT) was approved for the treatment of recurrent or refractory Clostridium difficile infection in 2019 and has been shown to be a safe and well-tolerated treatment strategy. Given the bidirectional movement and interaction of metabolites, hormones, and cytokines between the gut and the lungs, FMT may be able to enhance overall XDR-TB treatment by facilitating immune cell activation. Here, we hypothesize that FMT, in conjunction with standard TB treatment, may improve TB treatment outcomes for those with XDR-TB. We discuss the efficacy, safety, and ethical issues associated with the use of FMT.

Efficacy of dolutegravir + lamivudine q.d. with food in people with TB/HIV using a rifampicin-based regimen: A retrospective observational case series.

Dolutegravir + lamivudine (DTG + 3TC) is a first-line regimen for people with HIV. However, there are still concerns about its efficacy in people with tuberculosis (TB)/HIV due to the lack of available evidence and drug-drug interaction with rifampicin. A single-centre retrospective observational case series was conducted in Guangxi Zhuang Autonomous Region, China. We included all people with TB/HIV on combined use of once-daily (q.d.) dosing DTG + 3TC and rifampicin (RIF)-containing anti-TB regimens between 2020 and 2022. HIV-RNA, CD4 cell counts were collected and analysed. In all, 21 people with HIV (PWH) were included in this study. All the PWH were treatment-naïve and told to take DTG + 3TC q.d. with food. The median age was 53 years, and 71.43% were male. A total of 71.43% PWH had baseline viral load (VL) > 100 000 copies/mL, and 33.33% had baseline VL greater than 500 000 copies/mL. Only one PWH had CD4 cell count greater than 200 cells/μL, and the median CD4 count was 20 cells/μL. A total of 16 PWH started DTG + 3TC after initiation of the RIF-based anti-TB regimen, and the other five PWH initiated DTG + 3TC before the treatment of TB. All the PWH had at least 24 weeks of follow-up visits and all of the TB treatments were successful. A total of 20 PWH (95.24%) achieved viral suppression (VL <50 copies/mL). All detected viral loads between weeks 24 and 48 were less than 200 copies/mL. Among the PWH who started DTG + 3TC after the initiation of RIF-based anti-TB regimen, all achieved viral suppression by week 24 except the non-suppressed PWH. CD4 counts were greatly improved after antiretroviral treatment: the median CD4 counts were raised from 20 to 171 cells/μL at week 48. No serious adverse events were reported. This case series preliminarily validates the efficacy of DTG + 3TC q.d. with food when combined with RIF-based anti-TB regimens in people with TB/HIV.

Acquired rifamycin resistance among patients with tuberculosis and HIV in new York City, 2001–2023

IntroductionAcquired rifamycin resistance (ARR) in tuberculosis (TB) has been associated with HIV infection and can necessitate complicated TB treatment regimens, particularly in people living with HIV (PLWH). This work examines clinical characteristics and treatment outcomes of PLWH who developed ARR from 2001 to 2023 in New York City (NYC) to inform best practices for treating these patients. MethodsPLWH who developed ARR 2001–2023 were identified from the NYC TB registry. ResultsSixteen PLWH developed ARR; 15 were diagnosed 2001–2009 and the 16th was diagnosed in 2017. Median CD4 count was 48/mm3. On initial presentation, 14 had positive sputum cultures; of these, 12 culture-converted prior to developing ARR. Ten patients completed a course of TB treatment but subsequently relapsed; in six of these cases, ARR was discovered upon relapse, triggering treatment with a non-rifamycin-containing regimen, while in the other four, ARR was discovered during a second round of rifamycin-containing treatment. Three patients were lost to follow-up during their initial course of TB treatment and later returned to care; after being restarted on a rifamycin-containing regimen, ARR was discovered. Finally, three patients culture-converted during their first course of treatment but subsequently had cultures that grew rifamycin-resistant Mycobacterium tuberculosis prior to treatment completion, leading to changes in their treatment regimens. Among the 16 patients, eight died before being cured of TB, seven successfully completed treatment, and one was lost to follow-up. ConclusionsPLWH should be monitored closely for the development of ARR during treatment for TB, and sputum culture conversion should be interpreted cautiously in this group. Collecting a final sputum sample may be especially important for PLWH, as treatment failure and relapse were common in this population. The decrease in the number of cases of ARR among PLWH during the study period may reflect the decrease in the total number of PLWH diagnosed with TB in NYC in recent years, improved immune status of PLWH due to increased uptake of antiretroviral drugs, and improvements in the way anti-TB regimens are designed for PLWH (such as recommending daily rather than intermittent rifamycin dosing).

The prevalence, clinical reasoning and impact of non-standard anti-tuberculosis regimens at the initial prescription

Regarding clinically-concerning non-standard initial anti-tuberculous (TB) regimens, few studies have examined their prevalence, risk factors and impacts. We recruited patients with drug susceptible TB and non-standard initial anti-TB regimens (NSTB group) and matched them with patients with standard initial regimens (STB group) in a 1:1 ratio. The risk factors and outcomes were analyzed. During the 11-year study period, we analyzed 50 (3.7%) patients with NSTB from a total set of 1337 patients with drug-susceptible TB. Pyrazinamide (60%) was the drug most commonly not prescribed in the NSTB group, followed by ethambutol (34%). Multivariable logistic regression identified independent risk factors as underlying eye disease (adjusted odds ratio [aOR]: 8.869; 95% CI 2.542–30.949; p = 0.001), gout/hyperuricemia (aOR: 4.012 [1.196–13.425]; p = 0.024), and liver disease (aOR: 12.790 [3.981–41.089]; p < 0.001). The NSTB group had longer treatment durations (281 ± 121 vs. 223 ± 63 days; p = 0.003) and more occurrences of treatment interruption (26% vs. 8%; p = 0.021) than the STB group. In conclusion, NSTB occurs in around 3.7% of patients and is associated with longer treatment and more treatment interruption. The risk factors might include underlying liver and eye diseases, and gout. Further studies to improve non-standard initial regimens and prevent negative outcomes are warranted.

Managing Hepatotoxicity Caused by Anti-tuberculosis Drugs: A Comparative Study of Approaches.

Tuberculosis (TB) is one of the oldest and most well-known diseases that has been associated with humans for many years and remains a global health challenge today. Timely diagnosis and proper treatment are crucial for controlling and preventing the spread of the disease. While anti-TB drugs offer many benefits, inadequate monitoring can lead to a range of side effects, including hepatotoxicity, which is a major concern and can cause treatment discontinuation. The aim of this study was to determine the approach to the hepatotoxicity of anti-TB drugs and to investigate potential relationships between demographic factors, underlying medical conditions, and successful retreatment outcomes for hepatotoxicity induced by anti-TB drugs. For this study, we reviewed the medical records of patients who experienced hepatotoxicity due to anti-TB treatment and were admitted to the infectious ward of Imam Khomeini Hospital between April 2015 and February 2019. The data were collected using a questionnaire. The findings indicated that the female gender, weight loss at the beginning of hospitalization, hepatitis C virus, hepatitis B virus (HBV), heart disease, and high levels of aspartate aminotransferase (AST) and alanine transaminase (ALT) at the beginning of hepatotoxicity are risk factors for failure to the retreatment of hepatotoxicity. There were two different approaches to the anti-TB retreatment regimen. The first approach involved gradually starting the drugs in full dose, while the second approach encompassed starting the drugs in the minimum dose and then increasing to the maximum dose. The results demonstrated no significant difference between the two approaches to managing hepatotoxicity induced by anti-TB drugs. Drug-induced hepatotoxicity is a common occurrence that often results in treatment discontinuation. Understanding the prevalence of this complication and identifying appropriate methods of rechallenge treatment is crucial to reducing complications and mortality rates.

Changes of Mycobacterium tuberculosis specific antigen-stimulated CD27−CD38+IFN-γ+CD4+ T cells before and after anti-tuberculosis treatment

BackgroundThe aim of the study was to investigate whether the expression of CD27−CD38+ in interferon (IFN)-γ+CD4+ T cells stimulated by the specific antigen early secreted antigenic target-6 (ESAT-6)/culture filter protein-10 (CFP-10) could be a potential new therapeutic evaluation indicator for anti-tuberculosis (TB) treatment.MethodsNewly diagnosed active pulmonary TB patients, latent TB infection (LTBI) and healthy controls were enrolled from January 2021 to December 2021. PTB patients were treated by standard anti-TB regimen 2HREZ/4HR (2 months of isoniazid (H), rifampin (R), ethambutol (E), and pyrazinamide (Z) followed by 4 months of isoniazid (H) and rifampin (R)). The difference of CD27−CD38+ expression in IFN-γ+CD4+ T cells before treatment, 2 months after treatment, and 6 months after treatment were compared.ResultsTotal 45 PTB patients, 38 LTBI cases and 43 healthy controls were enrolled. The expression of CD27−CD38+ decreased significantly after anti-TB treatment and was comparable with that in LTBI and healthy controls when the 6-month anti-TB treatment course was completed. The decline rate of CD27−CD38+ between 6 months after treatment and baseline was positively correlated with erythrocyte sedimentation rate (r = 0.766, P < 0.0001), C-reactive protein (r = 0.560, P = 0.003) and chest computerized tomography severity score (r = 0.632, P = 0.0005). The area under receiver operator characteristic curve of CD27−CD38+ in distinguish pulmonary TB patients before and after treatment was 0.779.ConclusionThe expression of CD27−CD38+ in ESAT-6/CFP-10 stimulated IFN-γ+CD4+T cells can well reflect the changes of the disease before and after anti-TB treatment, which is expected to be a potential new therapeutic evaluation index.Clinical Registry number chiCTR1800019966.

Compliance with new drug use and the effect of discrepant drug susceptibility testing on MDR/RR-TB treatment.

BACKGROUND: Following the WHO???s announcement in 2018, the use of new drugs was recommended for all patients with multidrug-resistant TB (MDR-TB) in Korea. This study aimed to evaluate adherence to new anti-TB drug regimens and implementation of molecular drug susceptibility testing (mDST) in Korea.METHODS: Nationwide, 560 patients were reported as having MDR-TB in 2021. The implementation of mDST and new anti-TB drug use were analysed. The discrepancy between mDST and phenotypic DST (pDST) results and their implications on the use of new anti-TB drugs were also analysed. The use of novel anti-TB drugs has been approved by the National TB Expert Committee.RESULTS: The non-adherence rate in MDR-TB patients was 14.3%. The mDST implementation rate was 96.1%. Of the 459 patients who underwent both mDST and pDST, the discordance rate for rifampicin (RIF) resistance was 22.6% (n = 104), of which 72.1% (n = 75) were resistant on mDST but susceptible on pDST. The discrepancy in mDST and pDST results related to RIF resistance was found to be the main cause of non-adherence to new drug regimen.CONCLUSION: Comprehensive training on how to interpret conflicting results between mDST and pDST could enhance the utilisation of new drugs in the treatment of MDR/RIF-resistant TB.

Metabolic Rewiring of Mycobacterium tuberculosis upon Drug Treatment and Antibiotics Resistance.

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a significant global health challenge, further compounded by the issue of antimicrobial resistance (AMR). AMR is a result of several system-level molecular rearrangements enabling bacteria to evolve with better survival capacities: metabolic rewiring is one of them. In this review, we present a detailed analysis of the metabolic rewiring of Mtb in response to anti-TB drugs and elucidate the dynamic mechanisms of bacterial metabolism contributing to drug efficacy and resistance. We have discussed the current state of AMR, its role in the prevalence of the disease, and the limitations of current anti-TB drug regimens. Further, the concept of metabolic rewiring is defined, underscoring its relevance in understanding drug resistance and the biotransformation of drugs by Mtb. The review proceeds to discuss the metabolic adaptations of Mtb to drug treatment, and the pleiotropic effects of anti-TB drugs on Mtb metabolism. Next, the association between metabolic changes and antimycobacterial resistance, including intrinsic and acquired drug resistance, is discussed. The review concludes by summarizing the challenges of anti-TB treatment from a metabolic viewpoint, justifying the need for this discussion in the context of novel drug discovery, repositioning, and repurposing to control AMR in TB.

Rv0495c regulates redox homeostasis in Mycobacterium tuberculosis

Mycobacterium tuberculosis (Mtb) has evolved sophisticated surveillance mechanisms to neutralize the ROS-induces toxicity which otherwise would degrade a variety of biological molecules including proteins, nucleic acids and lipids. In the present study, we find that Mtb lacking the Rv0495c gene (ΔRv0495c) is presented with a highly oxidized cytosolic environment. The superoxide-induced lipid peroxidation resulted in altered colony morphology and loss of membrane integrity in ΔRv0495c. As a consequence, ΔRv0495c demonstrated enhanced susceptibility when exposed to various host-induced stress conditions. Further, as expected, we observed a mutant-specific increase in the abundance of transcripts that encode proteins involved in antioxidant defence. Surprisingly, despite showing a growth defect phenotype in macrophages, the absence of the Rv0495c enhanced the pathogenicity and augmented the ability of the Mtb to grow inside the host. Additionally, our study revealed that Rv0495c-mediated immunomodulation by the pathogen helps create a favorable niche for long-term survival of Mtb inside the host. In summary, the current study underscores the fact that the truce in the war between the host and the pathogen favours long-term disease persistence in tuberculosis. We believe targeting Rv0495c could potentially be explored as a strategy to potentiate the current anti-TB regimen.

Clinical Significance of Preoperative Pyrazinamide-Containing Therapy in Tuberculous Constrictive Pericarditis.

Tuberculous constrictive pericarditis (TCP) is recommended to be treated with anti-tuberculosis (TB) therapy before pericardiectomy. Whether different preoperative anti-TB regimens may lead to different outcomes is unclear. We retrospectively collected patients diagnosed as TCP and received pericardiectomy from April 2016 to June 2023. The study patients were assigned into the active TCP (A-TCP) group and the inactive TCP (IA-TCP) group according to the results of Mycobacterium tuberculosis (MTB) culture and MTB RNA assay. Baseline characteristics including anti-TB regimens and surgical outcomes were compared between the two groups. Logistic regression analysis and subgroup analysis were conducted to identify the protective factors of A-TCP. Of the 102 study patients, 24 was in the A-TCP group and 78 was in the IA-TCP group. The rate of preoperative anti-TB regimen containing pyrazinamide was 37.5% in the A-TCP group, as compared with 74.4% in the IA-TCP group (P = 0.001). Multivariate analysis showed that preoperative use of pyrazinamide was the protective factor of A-TCP (OR 0.194, 95% CI 0.053-0.703, P = 0.013). Subgroup analysis based on age also showed consistent findings. In the analyses of surgical outcomes, A-TCP was the independent risk factor of postoperative cardiac complications (OR 4.231, 95% CI 1.317-13.593, P = 0.015) and associated with longer hospital stay (P = 0.004) and higher hospitalization cost (P = 0.001). A strategy involving anti-TB regimen containing pyrazinamide before pericardiectomy was superior to that without pyrazinamide in the patients with TCP. The strategy was associated with lower risk of A-TCP and might lead to better postoperative recovery and cost-effectiveness.

Cytochrome bd oxidase: an emerging anti-tubercular drug target.

Cytochrome bd (cyt-bd) oxidase, one of the two terminal oxidases in the Mycobacterium tuberculosis (Mtb) oxidative phosphorylation pathway, plays an indispensable role in maintaining the functionality of the metabolic pathway under stressful conditions. However, the absence of this oxidase in eukaryotic cells allows researchers to select it as a potential drug target for the synthesis of anti-tubercular (anti-TB) molecules. Cyt-bd inhibitors have often been combined with cytochrome bcc/aa3 super-complex inhibitors in anti-TB drug regimens to achieve a desired bactericidal response. The functional redundancy between both the terminal oxidases is responsible for this. The cryo-EM structure of cyt-bd oxidase from Mtb (PDB ID: 7NKZ) further accelerated the research to identify its inhibitor. Herein, we have summarized the reported anti-TB cyt-bd inhibitors, insight into the rationale behind targeting cyt-bd oxidase, and an outline of the architecture of Mtb cyt-bd oxidase.

Influence of Rifamycin on Survival in Patients with Concomitant Lung Cancer and Pulmonary Tuberculosis.

The coexistence of lung cancer and tuberculosis is not rare. Rifamycin plays a pivotal role in anti-tuberculosis therapy. However, its potential impact on the liver metabolism of oncology drugs raises concerns. We performed this study to explore whether Rifamycin affects the survival of patients with tuberculosis and lung cancer. Drawing from the Taiwan National Health Insurance Research Database, we identified patients diagnosed with concurrent lung cancer and tuberculosis between 2000 and 2014. Patients were categorized based on whether they underwent rifamycin-inclusive or rifamycin-exempt anti-tuberculosis therapy. Subsequently, we paired them at a 1:1 ratio and evaluated the mortality risk over a two-year span. Out of the study participants, 1558 (81.4%) received rifamycin-based anti-tuberculosis therapy, while 356 (18.6%) underwent a rifamycin-free regimen. Analysis revealed no marked variance in the biennial mortality rate between the groups (adjusted hazard ratio: 1.33, 95% confidence interval 0.93-1.90, p = 0.1238). When focusing on the matched sets comprising 127 individuals in each group, the data did not indicate a significant link between rifamycin and a heightened two-year mortality risk (adjusted hazard ratio: 1.00, 95% confidence interval 0.86-1.18, p = 0.9538). For individuals with concomitant lung cancer and tuberculosis, rifamycin's administration did not adversely influence two-year survival. Thus, rifamycin-containing anti-TB regimens should be prescribed for the indicated patients.