Trends of drug resistance in M. tuberculosis in a reference laboratory in Central India: Forging ahead towards TB elimination.

PURPOSE: The National Tuberculosis Elimination Programme (NTEP) of the Government of India has strived to control tuberculosis (TB) in the country through various interventions. Understanding the trends of resistance patterns may provide insights into the effectiveness of TB control activities in the country. METHODS: A total of 31,144 clinical samples were received from 2013 to 2022 from presumptive drug-resistant TB patients. All the specimens were decontaminated and subjected to the line probe assay for detection of resistance to rifampicin and isoniazid. Mycobacterium tuberculosis (MTB) was detected in 28,814 samples. Autoregressive integrated moving average model (ARIMA) was fitted to assess the trend over time. RESULTS: A decreasing trend in multi-drug resistant TB from 19 % in 2013 to 4 % in 2022 was seen. A decreasing trend in rifampicin monoresistance from 11.2 % in 2013 to 1.5 % in 2022 was seen, though there was an increase in resistance in 2017. No significant decreasing trends were seen in the proportion of isoniazid monoresistance from 8.3 % in 2013 to 7 % in 2022. CONCLUSION: The findings are encouraging, and to a considerable extent, affirm that India is well on track with regard to the goal of TB elimination.

Heteroresistance to rifampicin & isoniazid in clinical samples of patients with presumptive drug-resistant tuberculosis in Central India.

Background & objectives: A combination of resistant and susceptible Mycobacterium tuberculosis (MTB) isolated from clinical specimens is referred to as heteroresistance. Heteroresistance leads to difficulties in drug resistance testing and may adversely affect treatment outcomes. The present study estimated the proportion of heteroresistance among MTB in clinical samples of presumptive drug-resistant tuberculosis (TB) patients in Central India. Methods: A retrospective analysis of data generated from line probe assay (LPA) at a tertiary care hospital in Central India between January 2013 and December 2018 was carried out. A heteroresistant MTB in a sample was indicated by the presence of both wild-type and mutant-type patterns on an LPA strip. Results: Data analysis was carried out on interpretable 11,788 LPA results. Heteroresistance in MTB was detected in 637 (5.4%) samples. Of these, heteroresistance in MTB was detected in 413 (64.8%), 163 (25.5%) and 61 (9.5%) samples with respect to rpoB, katG and inhA genes, respectively. Interpretation & conclusions: Heteroresistance is considered a preliminary step in the development of drug resistance. Delayed or suboptimal anti-tubercular therapy in patients with heteroresistance of MTB may elicit full clinical resistance and negatively impact the National TB Elimination Programme. Further studies are, however, needed to determine the impact of heteroresistance on treatment outcomes in individual patients.

Burden of baseline resistance of Mycobacterium tuberculosis to fluoroquinolones and second-line injectables in central India.

BACKGROUND: Drug-resistant TB is a serious public health problem in India. Pre-existing resistance to fluoroquinolones (FQs) and second-line injectable drugs (SLIDs) in strains of Mycobacterium tuberculosis (MTB) resistant to rifampicin (RIF) and/or isoniazid (INH) contributes to treatment failures and consequent transmission of drug-resistant TB. A baseline assessment of resistance of MTB to FQs and SLIDs may help guide policies to further improve management of drug-resistant TB in India. This study aims to determine the prevalence of resistance to FQs and SLIDs among MTB strains having RIF and/or INH resistance in central India. METHOD: A total of 1032 smear positive sputum samples were subjected to line probe assay (GenoType MTBDRsl version 2) to test for resistance to FQs and SLIDs, according to the integrated diagnostic algorithm of the revised national TB control programme. RESULTS: Of 1032 samples, 92 (8.91%) were not interpretable and hence excluded, 295 (31.38%) were resistant to FQs alone, 13 (1.38%) were resistant to SLIDs alone, 15 (1.59%) were resistant to both FQs as well as SLIDs and 617 (65.63%) were sensitive to both FQs and SLIDs. The most common mutations in gyrA and gyrB genes were observed at codons D94G and E540V, respectively. Mutations at codon A1401G in rrs genes and in the C-14 T region of eis genes were most frequently observed. CONCLUSION: High levels of FQ resistance points towards indiscriminate use of this class of drugs. Regulation for judicial use of FQs is an urgent requirement.

Occult hepatitis B virus infection with low viremia induces DNA damage, apoptosis and oxidative stress in peripheral blood lymphocytes.

Occult HBV infections (OHBI) are often associated with poor therapeutic response and increased risk of developing hepatocellular carcinoma. Despite a decade of research, OHBI still remains an intricate issue and much is yet to be defined about their possible immune implications. As HBV is known to infect peripheral blood lymphocytes, the present study aimed to explore the molecular mechanisms underlying DNA damage response triggered due to OHBI in host cells. The study was divided into three groups i.e. group A (OHBI patients n=30, viral load

Status of inflammatory biomarkers in the population that survived the Bhopal gas tragedy: a study after two decades.

Bhopal gas tragedy is considered as one of the world's worst industrial disaster. Approximately, 3,000-6,000 people died and 200,000 injured due to the leak of 40 tons of methyl isocyanate (MIC) gas from a pesticide plant. We aimed to decipher any persistent and subtle immunotoxic effects of MIC in the survivors of the tragedy. The study was divided into 3 groups i.e. group I (n=40); Age and gender matched non-exposed healthy controls recruited from places within the geographical region of Bhopal but from unaffected zones, group II (n=40); Age and gender matched non-exposed healthy controls recruited from places well outside geographical region of Bhopal and group III (n=40); Age and gender matched MIC exposed subjects from affected zones inside geographical region of Bhopal and the status of inflammatory biomarkers (IL-8, IL-1beta, IL-6, TNF, IL-10, IL-12p70 cytokines and C-reactive protein) were analysed. The results displayed a significant increase in the levels of all circulating inflammatory biomarkers in the MIC exposed group in comparison to non-exposed cohorts. A toxin induced genetic and/or epigenetic alteration seems to be the likely underlying cause. However, further studies are essential for both mechanistic understanding and clinical implications of these patterns.