Mycobacterium tuberculosis causes tuberculosis, an infectious disease; this acid-fast bacillus has various functions that enable it to survive within the host. Importantly, the type VII secretion system plays a vital role in host immune evasion. However, the early secretory antigenic target secretion system (ESX) component is crucial for mycobacteria survival, plays a significant role in bypassing the host immune response, and is linked to the prognosis of the disease. The review aims to analyze the ESX-associated genes’ functions in defence mechanisms against host immune response. There are five types of ESX, with the ESX-1 effectors consisting of the heterodimers EsxA/ESAT-6 and EsxB/CFP-10. The precise membranolytic role of EsxA remains unclear; however, mycobacterial mutants deficient in EsxA show reduced membrane lytic activity and lack the ability to perforate phagosomes. ESX-5 substrates, such as glycine-rich and repetitive PE_PGRS proteins, are associated with immune evasion and pathogenicity. ESX-5 releases a substantial amount of PE and PPE proteins, along with various other immune-modulating substrates. In addition, ESX-3 facilitates iron acquisition through mycobactin and regulates metal homeostasis. ESX 4 has been studied in two fast-growing mycobacterial species: M. abscessus and M. smegmatis. Notably, conjugal DNA transfer in the recipient strain of M. smegmatis requires ESX-4. Therefore, the type VII secretion system of ESX-associated genes plays a crucial role in bacterial survival and action against autophagosome-lysosome fusion. Thus, studying this system will explore the effects of specific antigenic structures and their relationships with autophagy and mycobacterial self-defense mechanisms.

Epigenetic regulators alter chromatin to control transcription in response to pathogens. Histone acetylation influences DNA accessibility and gene expression, impacting latent and active tuberculosis (TB). Mycobacterium tuberculosis (MTB) requires specific components to harm the host immune system. The review aims to analyze MTB epigenetic processes and the impact of host immune system genes. This review analyzed histone deacetylases, DNA methyltransferases, epigenetic linkages to non-coding RNAs, and enhanced epigenetic detection. Also, it described mycobacteria’s evasion of the host immune system through lipid metabolism, autophagy, oxidative stress, and epigenetic efflux pump inhibitors. The MTB DNA methyltransferase (DNMT) Rv2966c (I6XFS7) modifies histones H3 and H4, impacting host transcription. The MTB acetyltransferase EIS (Rv2416c, P9WFK7) enhances human IL-10 synthesis and acetylates the H3 gene promoter. MTB infection activates an epigenetic repressor complex with HDAC1 and ZBTB25, which restricts IL-12B production in macrophages. MTB inhibits HDAC1 and ZBTB25, enhances autophagic clearance, reduces bacterial viability, and increases IL-12B. ADP-ribosyl polymerase Rv1899c interacts with HDAC1 and may inhibit immune activation. Rv1899c interacts with HDAC1 and ZBTB25 to silence inflammatory promoters and maintain immune suppression without effector release. NLRP3 activation is influenced by DNA methylation. DNMT inhibitor DAC increased transcriptional activity in vitro, while DNA methylase Sss I decreased NLRP3 promoter activity. In small RNAs, links to epigenetics, the miR-15/16 family’s miR-15a-5p, regulate apoptosis, the cell cycle, and inflammatory cytokines. MiR-15a-5p affects inflammation by targeting genes in the BCL2, IKKα, and NF-κB pathways. Thus, epigenetic studies on MTB are vital to identify host immune evasion and host-directed therapy.

Pyrazinamide (PZA) is a key first-line antituberculosis drug that plays an important role in eradicating persister Mycobacterium tuberculosis (TB) bacilli and shortening the duration of tuberculosis treatment. However, PZA-resistance is on the rise, particularly among persons with multidrug-resistant (MDR) tuberculosis. This nationwide study was conducted to explore the prevalence of mutations conferring PZA resistance, catalogue mutation diversity, investigate the associations of PZA resistance with specific lineages, examine co-resistance to 13 first- and second-line drugs, and evaluate the diagnostic accuracy of sequencing pncA and panD genes for predicting PZA resistance. Whole genome sequencing was performed on 2,207 M. tuberculosis isolates from 25 States and 4 Union Territories of India. The majority of phenotypically PZA-resistant isolates (77%) harbored 171 distinct mutations in pncA; however, a small number of mutations in panD, rpsA and clpC1 were also observed. A set of novel mutations associated PZA resistance was uncovered, along with an additional 143 PZA resistance-conferring mutations in pncA based on application of WHO-endorsed grading rules. PZA resistance was predominately observed in Lineage 2 and eight lineage-specific resistance markers were identified. Mutations distributed across pncA correlate to 94% of PZA resistance and were the predominant drivers of phenotypic resistance; evidence generated herein substantiates sequencing the entire gene and promoter for comprehensive genotypic-based prediction of PZA resistance. This work provides key insights into the scope of PZA-resistance in India, a high drug-resistant TB burden country, and can support the effectiveness of TB prevention and control efforts.

Mycobacterium cell wall and membrane proteins, which play a central role in tuberculosis pathogenesis, were successfully separated using preparative Isoelectric Focusing (IEF) and preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Followed by gel elution, overcoming limitations in conventional methods for the separation of hydrophobic proteins. In this procedure, M. tuberculosis colonies were transferred from Lowenstein-Jensen slants into 2 mL of 7H9 broth, dispersed with glass beads, and incubated at 37 °C for 2 weeks. Then, the culture was scaled up to 200 mL and grown in a shaker for 4 weeks. It was further upscaled to 1 L with 500 mL of 7H9 broth and grown for an additional 4 weeks. Grown Mycobacteria were pelleted by centrifugation at 1741 × g for 30 min. For each 2 g pellet, 1 mL of breaking buffer was added, and the sample was sonicated. The lysate was centrifuged at 3436 × g for 15 min to remove unbroken cells, and the supernatant was concentrated. This supernatant (whole cell lysate) was centrifuged at 13751 × g for 30 min to pellet cell wall proteins. The remaining supernatant was ultra-centrifuged at 100,000 × g for 4 h to separate the cell membrane and cytosol. The isolated cell wall and membrane proteins were loaded onto a liquid preparative IEF system at 4 °C and separated at 12 W until the voltage stabilized at 1400 V, which separates 20 fractions. These IEF fractions were further separated by preparative SDS-PAGE, and proteins were eluted using a whole gel eluter at 250 mA, resulting in 30 fractions. Through this protocol, we were able to identify novel M. tuberculosis cell walls and membrane-specific biomarkers, and it also shows potential for characterizing similar proteins in other pathogens.

The emergence of multidrug-resistant tuberculosis (MDR-TB) necessitates rapid and accurate drug susceptibility testing (DST) methods to guide effective treatment. This study introduces a methodology combining the resazurin microtiter assay (REMA) and checkerboard assay to determine minimum inhibitory concentration (MIC) and evaluate drug-drug interactions of anti-tuberculosis drugs against Mycobacterium tuberculosis. The REMA, adapted to a 96-well format, leverages the reduction of resazurin dye by metabolically active M. tuberculosis as a visual indicator of drug susceptibility. Varying concentrations of anti-TB drugs are tested against M. tuberculosis isolates, and color changes are observed to determine the MIC. Subsequently, a checkerboard assay is employed to assess potential synergistic, additive, or antagonistic effects between drug combinations. This simple and inexpensive method yields results within seven days, offering a significant advantage over traditional DST methods. This method provides valuable insights into the DST of M. tuberculosis isolates and facilitates the identification of promising drug combinations for improved treatment outcomes against MDR-TB.

Secreted proteins of Mycobacterium tuberculosis (M. tuberculosis) play a crucial role in tuberculosis pathogenesis, immune modulation, and disease progression. Understanding their composition and function is essential for identifying novel biomarkers that can aid in tuberculosis diagnosis, vaccine development, and therapeutic interventions. This study focuses on the systematic isolation, fractionation, and characterization of culture filtrate proteins (CFPs) to enable comprehensive immunological and proteomic analyses. CFPs were obtained from M. tuberculosis H37Rv cultures grown in chemically defined conditions to ensure controlled protein expression. The culture supernatant was purified through filtration and concentrated using a hollow fiber system to retain proteins above 10 kDa. Fractionation was achieved through liquid-phase isoelectric focusing, separating proteins based on their isoelectric points into 20 distinct fractions. A further resolution was performed using preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), followed by electroelution, yielding 30 protein fractions. The fractionated proteins obtained through this approach provide a valuable resource for immunological profiling and mass spectrometry-based proteomic analyses. By systematically isolating and characterizing secreted proteins, this study contributes to the identification of tuberculosis-specific protein biomarkers, which could improve diagnostic accuracy and advance our understanding of M. tuberculosis pathogenesis.

Infection with Mycobacterium tuberculosis (Mtb) triggers an autoimmune-like response in the host leading to further complications. One of the major concerns in eliminating Tuberculosis (TB) is identifying individuals with Latent Tuberculosis Infection (LTBI) who serve as major reservoirs of Mtb making them the important target group for TB eradication. Since no gold standard tests are available for detecting LTBI, the global burden of LTBI cannot be precisely determined. Since LTBI poses several challenges to worldwide healthcare, managing LTBI must be the key priority to achieve a TB-free status. The inflammatory mediators play a major role in determining the outcome of the Mtb infection and also their levels seem to change according to the disease severity. Identification of inflammatory mediators and utilizing them as diagnostic biomarkers for detecting the various stages of TB disease might help identify the reservoirs of Mtb infection even before they become symptomatic so that preventative treatment can be started early. In summary, this review primarily focuses on exploring different inflammatory markers along the course of the Mtb infection. Identifying LTBI-specific biomarkers helps to identify individuals who are at higher risk of developing TB and preparing them to adhere to preventive therapy thus minimizing the global burden of TB.

Cyp27b1 polymorphisms are stated to be associated with different diseases including tuberculosis (TB). Since the gene variants located in the promoter region may have a significant influence on gene transcription/translation and Cyp27b1 enzyme is involved in critical steps in vitamin D metabolism, we aim to study whether Cyp27b1 gene promoter variants namely -1077 (C/G), -1260 (C/A) and the region immediately 5' to the promoter -1918 (C/T) have any linkage with pulmonary tuberculosis risk/defence and to determine their influence on vitamin D level in normal healthy controls (HCs) and pulmonary tuberculosis (PTB) patients of the South Indian population. The polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method were used to genotype the genomic DNA after it was extracted using the salting-out approach. The Enzyme-Linked Immunosorbent Assay (ELISA) was used to measure the amount of vitamin D. In the co-dominant model, a significant association was detected with TB liability in the -1077 "GG" genotype [Odds ratio (OR): 2.10(1.18-3.73); p = 0.015]. In addition, a noteworthy linkage was detected with TB protection in the dominant model [GG vs CG + CC, OR: 0.40(0.21-0.75); p = 0.0035]. In the -1918 (C/T) variant, a substantial linkage was detected in the heterozygous -1918 "CT" genotype with TB risk [OR: 1.90 (1.05-3.44); p = 0.046] in co-dominant model, whereas a protective linkage was detected in less recurrent "TT" genotype [OR: 0.42 (0.19-0.94); p = 0.049] with TB. Furthermore, those risky genotypes are substantially linked with more TB risk in males than females. Strong links between -1077 and -1260 variations were revealed by haplotype analysis, and its haplotypes "GC" (-1077G, -1260C) were found to be significantly associated with increased TB risk. Vitamin D deficiency (<20 ng/ml) was detected at a higher frequency in PTB patients than HCs in -1077 "GG", -1260 "CA" and -1918 "CT" risky genotypes. This needs to be confirmed by bigger sample sizes in future research.

Multisystem Inflammatory Syndrome in Children (MIS-C) is a rare manifestation of Severe Acute Respiratory Syndrome-CoronaVirus-2 (SARS-CoV-2) infection that can result in increased morbidity and mortality. Mounting evidence describes sex disparities in the clinical outcomes of coronavirus disease 2019 (COVID-19). However, there is a lack of information on sex-specific differences in immune responses in MIS-C. This study is an observational and cross-sectional study and we wanted to examine immune parameters such as cytokines, chemokines, acute phase proteins (APPs), growth factors, microbial translocation markers (MTMs), complement components and matrix metalloproteinases (MMPs) in MIS-C children, based on sex. Male children were associated with heightened levels of pro-inflammatory cytokines—IFNγ, IL-2, TNFα, IL-1α, IL-1β, IL-6, IL-12, G-CSF and GM-CSF, chemokines-CCL2, CCL11, CXCL1, CXCL8 and CXCL10, acute phase proteins-α-2M, CRP, growth factors VEGF and TGFα, microbial translocation markers- iFABP, LBP, EndoCAb, complement components—C1q, MBL and C3 and matrix metalloproteinases MMP-8 and MMP-9 compared to female children with MIS-C. These results indicate that the heightened immune response in males is a characteristic feature of MIS-C. These findings might explain the differential disease pathogenesis in males compared to females with MIS-C and facilitate a deeper understanding of this disease.

A natural infection or a vaccination can initially prime the immune system to form immunological memory. The immunity engendered by vaccination against COVID-19 versus natural infection with SARS-CoV-2 has not been well studied in the Indian population. In this study, we compared the immunity conferred by COVID-19 vaccines to naturally acquired immunity to SARS-CoV-2 in a South Indian population. We examined binding and neutralizing antibody (NAb) levels against the ancestral and variant lineages and assessed the ex vivo cellular parameters of memory T cells, memory B cells, and monocytes and finally measured the circulating cytokine response. COVID-19 vaccination stimulates heightened levels of IgG antibodies against the original strain of SARS-CoV-2, as well as increased binding to the spike protein and neutralizing antibody levels. This enhanced response extends to variant lineages such as B.1.617.2 (Delta, India), B.1.1.529 (Omicron, India), B.1.351 (Beta, South Africa), and B.1.1.7 (Alpha, UK). COVID-19 vaccination differs from SARS-CoV-2 infection by having increased frequencies of classical memory B cells, activated memory B and plasma cells, CD4/CD8 T cells of effector memory, effector cells, stem cell-like memory T cells, and classical and intermediate monocytes and diminished frequencies of CD4/CD8 T cells of central memory and non-classical monocytes in vaccinated individuals in comparison to those with natural infection. Thus, COVID-19 vaccination is characterized by enhanced humoral responses and robust activation of innate and memory T cell responses in comparison to natural infection in a South Indian population.

BACKGROUND:Tuberculosis (TB) ranks as the second leading cause of death globally among all infectious diseases. This problem is likely due to the lack of biomarkers to differentiate the heterogeneous spectrum of infection. Therefore, the first step in solving this problem is to identify biomarkers to distinguish the different disease states of an individual and treat them accordingly. Circulating microRNA (miRNA) biomarkers are promising candidates for various diseases. In fact, we are yet to conceptualize how miRNA expression influences and predicts TB disease outcomes. Thus, this systematic review and meta-analysis aimed to assess the diagnostic efficacy of circulating miRNAs in Latent TB (LTB) and Active Pulmonary TB (PTB).METHODS:Literature published between 2012 and 2021 was retrieved from PubMed, Web of Science, Cochrane, Scopus, Embase, and Google Scholar. Articles were screened based on inclusion and exclusion criteria, and their quality was assessed using the QUADAS-2 tool. Funnel plots and forest plots were generated to assess the likelihood of study bias and heterogeneity, respectively.RESULTS:After the screening process, seven articles were selected for qualitative analysis. The study groups, which consisted of Healthy Control (HC) vs. TB and LTB vs. TB, exhibited an overall sensitivity of 81.9% (95% CI: 74.2, 87.7) and specificity of 68.3% (95% CI: 57.8, 77.2), respectively. However, our meta-analysis results highlighted two potentially valuable miRNA candidates, miR-197 and miR-144, for discriminating TB from HC. The miRNA signature model (miR197-3p, miR-let-7e-5p, and miR-223-3p) has also been shown to diagnose DR-TB with a sensitivity of 100%, but with a compromised specificity of only 75%.CONCLUSION:miRNA biomarkers show a promising future for TB diagnostics. Further multicentre studies without biases are required to identify clinically valid biomarkers for different states of the TB disease spectrum.SYSTEMATIC REVIEW REGISTRATION:PROSPERO (CRD42022302729).

Salmonella ranks among the prominent etiological agents responsible for foodborne illnesses on a global scale. Within the scope of this investigation, a bacteriophage capable of eliminating Salmonella enteritidis was isolated using the double-layer agar overlay technique. The phage's morphological characteristics were elucidated through the application of Transmission Electron Microscopy. The genomic DNA of the phage underwent complete sequencing utilizing the MiSeq platform, with library preparation executed through the NexteraXT library prep kit method accompanied by the NexteraXT index kit. Paired-end sequencing was performed over 2 × 251 cycles read length, employing a Miseq V3 kit within the Illumina MiSeq system. Notably, the phage manifested conspicuous plaques upon S. enteritidis when subjected to the double agar overlay technique. NINP13076 displayed a 22-min latency period with a calculated average burst size of 53 PFU/cell. Phages exhibited resilience to the diverse pH conditions, manifesting no discernible impact on their viability over a storage duration of up to one week. storage at temperatures of 4 °C, 26 °C, and 37 °C demonstrated minimal effects on the phage population, with no statistically significant alterations observed. Genome assembly yielded a draft genome encompassing 161,329 base pairs with a GC content of 44.4 % and achieved coverage at a depth of 104x. Phylogenetic tree analysis unveiled a highly proximate relationship with the Salmonella Phage SSE-121 genome, demonstrating a distance score of 0.1 and signifying its classification as a novel member within the SSE121 virus group.

BACKGROUND AND OBJECTIVES:Genetic factors are reported to be connected with tuberculosis (TB) infection. Studies have shown that genetic variations in genes involved in the vitamin D pathway influence the levels of vitamin D found in the bloodstream (serum). Cyp27b1 (1α-hydroxylase) is an enzyme that activates the synthesis of bioactive vitamin D3 by hydroxylation of 25(OH)D3.The in vitro studies reported rare gene variants of Cyp27b1 such as rs118204011 and rs118204012, associated with loss of Cyp27b1 function and lower serum vitamin D levels. Globally, a critical gap exists in understanding the link between these gene variants with TB and vitamin D levels. Hence, the study objective is to comprehend the association of Cyp27b1 rs118204009 (G/A), rs118204011 (C/T), and rs118204012 (A/G) with tuberculosis susceptibility/protection and to assess the influence of gene variants on vitamin D levels in both healthy controls (HCs) and those with pulmonary tuberculosis (PTB) in South India. METHODS:Genomic DNA extraction was performed by salting-out procedure and subsequently genotyped through polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method. Vitamin D level was measured by Enzyme-Linked Immunosorbent Assay (ELISA). RESULTS:In rs118204012 (A/G), a substantial association was found with PTB susceptibility in allele 'A' [Odds Ratio (OR): 1.52 (1.02-2.26); p = 0.044] and 'AA' genotype [OR: 1.69 (1.02-2.81); p = 0.040] through the dominant model. Allele 'G' [OR: 0.66 (0.44-0.98); p = 0.044) was found to be associated with protection against TB. Males were associated with increased susceptibility towards TB compared to females in the rs118204011 "CC" [OR: 3.94 (1.94-7.98); p = 0.002] and rs118204012 'AA' [OR: 4.57 (2.13-9.79); p = 0.0001] genotypes. Vitamin D insufficiency (<30 ng/ml) was more prevalent in PTB patients (66.67 %) with the rs118201012 'AA' genotype compared with healthy controls (57.14 %). This genotype was associated with disease susceptible odds ratio of 1.5. CONCLUSION:Cyp27b1 rs118204012 'AA' genotype was found to have association with vitamin D insufficiency and TB susceptibility. In terms of gender, our findings suggest that male individuals are correlated with a higher TB risk. This suggest that the gene variants may be involved in the downstream processing of serum Vitamin D levels and its association with the disease.

Tuberculosis (TB) elimination is possible with the discovery of accurate biomarkers that define the stages of infection. Drug-resistant TB impair the current treatment strategies and worsen the unfavourable outcomes. The knowledge on host immune responses between drug-sensitive and drug-resistant infection is inadequate to understand the pathophysiological differences and disease severity. The secreted proteins, cytokines display versatile behaviour upon infection with Mycobacterium tuberculosis (MTB) and their imbalances often tend to assist disease pathology than protection. Therefore, studying these soluble proteins across TB infection spectrum (drug-resistant TB, drug-sensitive TB, and latent TB) may unveil the disease mediated responses and unique stage specific cytokine signatures. Thus, we sought to determine the plasma cytokine levels from healthy, latently infected, drug-sensitive, and drug-resistant TB individuals. Our study revealed top 8 cytokines (IL-17, IL-1α, IL-2, IL-10, IL-5, IFN-γ, TNF-α and IL-6) and their biomarker abilities to discriminate different stages of infection.

Background : Multisystem inflammatory syndrome (MIS) in children is considered to be a post-infectious complication of COVID-19. T-cell responses in children with this condition have not been well-studied.Methods: We aimed to study the immune responses in children with MIS in comparison to children with acute COVID-19 and children with other infections. Whole blood was stimulated with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-specific antigens and flow cytometry was performed to examine CD4+ and CD8+ T-cell responses.Results : Children with MIS had higher frequencies of CD4+ and CD8+ T cells expressing cytokines at baseline and upon SARS-CoV-2 antigen-specific stimulation in comparison to children with COVID-19 and/or other infections. Children with COVID-19 also exhibited higher frequencies of CD4+ and CD8+ T cells expressing cytokines at baseline and upon SARS-CoV-2 antigen-specific stimulation in comparison to children with other infections. At 6-9 months following treatment and recovery, this enhanced response against SARS-CoV-2 antigens was down modulated in children with MIS.Conclusion: Our study, therefore, provides evidence of enhanced activation of CD4+ and CD8+ T-cell responses in children with MIS and reversal following recovery.

Background:Monocyte miRNAs govern both protective and pathological responses during tuberculosis (TB) through their differential expression and emerged as potent targets for biomarker discovery and host-directed therapeutics. Thus, this study examined the miRNA profile of sorted monocytes across the TB disease spectrum [drug-resistant TB (DR-TB), drug-sensitive TB (DS-TB), and latent TB] and in healthy individuals (HC) to understand the underlying pathophysiology and their regulatory mechanism.Methods:We sorted total monocytes including three subsets (HLA-DR+CD14+, HLA-DR+CD14+CD16+, and HLA-DR+CD16+cells) from peripheral blood mononuclear cells (PBMCs) of healthy and TB-infected individuals through flow cytometry and subjected them to NanoString-based miRNA profiling.Results:The outcome was the differential expression of 107 miRNAs particularly the downregulation of miRNAs in the active TB groups (both drug-resistant and drug-sensitive). The miRNA profile revealed differential expression signatures: i) decline of miR-548m in DR-TB alone, ii) decline of miR-486-3p in active TB but significant elevation only in LTB iii) elevation of miR-132-3p only in active TB (DR-TB and DS-TB) and iv) elevation of miR-150-5p in DR-TB alone. The directionality of functions mediated by monocyte miRNAs from Gene Set Enrichment Analysis (GSEA) facilitated two phenomenal findings: i) a bidirectional response between active disease (activation profile in DR-TB and DS-TB compared to LTB and HC) and latent infection (suppression profile in LTB vs HC) and ii) hyper immune activation in the DR-TB group compared to DS-TB.Conclusion:Thus, monocyte miRNA signatures provide pathological clues for altered monocyte function, drug resistance, and disease severity. Further studies on monocyte miRNAs may shed light on the immune regulatory mechanism for tuberculosis.

Tuberculosis (TB) diagnosis still remains to be a challenge with the currently used immune based diagnostic methods particularly Interferon Gamma Release Assay due to the sensitivity issues and their inability in differentiating stages of TB infection. Immune markers are valuable sources for understanding disease biology and are easily accessible. Chemokines, the stimulant, and the shaper of host immune responses are the vital hub for disease mediated dysregulation and their varied levels in TB disease are considered as an important marker to define the disease status. Hence, we wanted to examine the levels of chemokines among the individuals with drug-resistant, drug-sensitive, and latent TB compared to healthy individuals. Our results demonstrated that the differential levels of chemokines between the study groups and revealed that CXCL10 and CXCL9 as potential markers of drug-resistant and drug-sensitive TB with better stage discriminating abilities.

Current knowledge on resistance-conferring determinants in Mycobacterium tuberculosis is biased toward globally dominant lineages 2 and 4. In contrast, lineages 1 and 3 are predominant in India.

Nested in 3 tuberculosis (TB) cohorts with and without diabetes mellitus (DM) in India, whole genome sequencing revealed considerable intrahost Mycobacterium tuberculosismutation rates among TB-DM patients at recurrence in India. Exogenous reinfection was identified in one-fourth of patients with DM. Background Evidence describing the impact of diabetes mellitus (DM) on the recurrence and mutation rate of Mycobacterium tuberculosis (Mtb) is limited. Methods This study was nested in 3 cohort studies of tuberculosis (TB) patients with and without DM in India. Paired Mtb isolates recovered at baseline and treatment failure/recurrence underwent whole genome sequencing. We compared acquisition of single-nucleotide polymorphisms (SNPs), TB drug resistance mutations, and type of recurrence (endogenous reactivation [<8 SNPs] or exogenous reinfection [>= 8 SNPs]) by DM status. Results Of 1633 enrolled in the 3 parent cohorts, 236 (14.5%) had microbiologically confirmed TB treatment failure/recurrence; 76 Mtb isolate pairs were available for sequencing (22 in TB-DM and 54 in TB-only). The SNP acquisition rate was overall was 0.43 (95% confidence interval [CI], .25-.64) per 1 person-year (PY); 0.77 (95% CI, .40-1.35) per 1 PY, and 0.44 (95% CI, .19-.86) per 1 PY at treatment failure and recurrence, respectively. Significant difference in SNP rates by DM status was seen at recurrence (0.21 [95% CI, .04-.61]) per 1 PY for TB-only vs 1.28 (95% CI, .41-2.98) per 1 PY for TB-DM; P = .02). No significant difference in SNP rates by DM status was observed at treatment failure. Acquired TB drug resistance was seen in 4 of 18 (22%) in TB-DM vs 4 of 45 (9%) in TB-only (P = .21). Thirteen (17%) participants had exogenous reinfection; the reinfection rate at recurrence was 25% (3/12) for TB-DM vs 17% (4/24) in TB-only (P = .66). Conclusions Considerable intrahost Mtb mutation rates were present at recurrence among patients with DM in India. One-fourth of patients with DM had exogenous reinfection at recurrence.

Background Covaxin/BBV152 is one of the most widely used vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and one of the few vaccines used extensively in low- and middle-income countries (LMIC). Methods We investigated the effect of Covaxin on the SARS-CoV-2 specific IgG and IgA and neutralizing antibody (NAb) levels at baseline (M0) and at Months 1 (M1), 2 (M2), 3 (M3), 4 (M4), 6 (M6) and 12 (M12) following vaccination in healthcare workers. In addition, we also examined the NAb levels against variant lineages of B.1.617.2 (Delta, India), B.1.617.2.1 (Delta Plus, India), B.1.351 (Beta, SA), B.1.1.7 (Alpha, UK) and B.1.1.529 (Omicron). Results Covaxin induces enhanced SARS-CoV-2 binding antibodies of IgG and IgA responses against both spike (S) and nucleocapsid (N) antigens at M1, M2, M3, M4, M6 and M12 in comparison with M0. Our data also reveal that NAb levels against the ancestral strain (Wuhan, wild type) are elevated and sustained at M1, M2, M3, M4, M6 and M12 in comparison with M0 and against variant lineages of B.1.617.2 (Delta, India), B.1.617.2.1 (Delta Plus, India), B.1.351 (Beta, SA) and B.1.1.7 (Alpha, UK) are elevated at M3, M6 and M12 in comparison with M0. However, NAb levels against B.1.1.529 (Omicron) was consistently below the limit of detection except at M12. Conclusion Thus, Covaxin induces an enhanced humoral immune response, with persistence till at least 12 months post-vaccination against most SARS-CoV-2 variants.