Publications by authors named "Shakti Kumar"

Pesticide contamination in water bodies is an emerging driver of antimicrobial resistance (AMR), posing severe environmental and public health risks. Due to excessive agricultural use, pesticides routinely end up in water bodies due to leaching, improper disposal, and agricultural runoff. Pesticides act as selective pressures, promoting resistant microbial strains by providing evolutionary pressure for the strains to thrive.

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Gut microbiota-derived metabolites play a crucial role in modulating the inflammatory response in inflammatory bowel disease (IBD). In this study, we identify gut microbiota-derived succinate as a driver of inflammation in ulcerative colitis (UC) by activating succinate-responsive, colitogenic helper T (Th) cells that secrete interleukin (IL)-9. We demonstrate that colitis is associated with an increase in succinate-producing gut bacteria and decrease in succinate-metabolizing gut bacteria.

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Gallbladder stones alone do not explain the risk of gallbladder cancer (GBC) as the sole etiological factor. Chronic microbial infection, particularly Salmonella, has been implicated in GB carcinogenesis, but its causative role and the underlying mechanisms are largely unknown. We studied gut and gallbladder tissue microbiome through targeted metagenomics to identify pathogenic bacteria in GBC.

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Article Synopsis
  • In India, 13% of newborns are preterm, contributing to a significant portion (23.4%) of global preterm births.
  • A study was conducted analyzing 600 high vaginal swab samples from pregnant women across all trimesters to compare microbiome differences between those who delivered at term and those with preterm births.
  • The research identified specific microbial signatures linked to term and preterm births and developed a simple dipstick assay for quick identification of preterm-associated bacteria in low-resource settings.
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Delta and Omicron variants of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) are remarkably contagious, and have been recognized as variants of concern (VOC). The acquisition of spontaneous substitutions or insertion-deletion mutations (indels) in the spike protein-encoding gene substantially increases the binding affinity of the receptor binding domain (RBD)-hACE2 complex and upsurges the transmission of both variants. In this study, we analyzed thousands of genome sequences from 30 distinct SARS-CoV-2 variants, focusing on the unique nucleic acid signatures in the spike gene specific to the Delta and Omicron variants.

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Dendritic cell (DC) dysfunction is known to exacerbate intestinal pathologies, but the mechanisms compromising DC-mediated immune regulation in this context remain unclear. Here, we show that intestinal dendritic cells from a mouse model of experimental colitis exhibit significant levels of noncanonical NF-κB signaling, which activates the RelB:p52 heterodimer. Genetic inactivation of this pathway in DCs alleviates intestinal pathologies in mice suffering from colitis.

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Article Synopsis
  • - This study aimed to investigate the relationship between SARS-CoV-2 variants and the severity of COVID-19 across India, using a nationwide platform for molecular epidemiology analysis.
  • - Conducted from September 2021 to December 2022, the cohort included nearly 5,000 participants, with successful sequencing of 2,723 samples, revealing key insights about different virus variants and their impacts on health outcomes.
  • - Findings demonstrated that the Delta variant significantly raised the risk of severe disease, while Omicron presented a milder illness, with age, comorbidities, and lack of vaccination identified as major risk factors for mortality.
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Non-alcoholic fatty liver disease (NAFLD) is an emerging global health problem and a potential risk factor for metabolic diseases. The bidirectional interactions between liver and gut made dysbiotic gut microbiome one of the key risk factors for NAFLD. In this study, we reported an increased abundance of in the gut of obese and NASH patients living in India.

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Objective: One or more inexcitable motor (IM) nerves are common during electrodiagnostic (EDx) study in Guillain-Barré syndrome (GBS). This study assessed the dose-effect relationship of IM nerves on outcome in patients with acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor and/or sensory axonal neuropathy (AMAN and AMSAN).

Materials And Methods: Eighty-eight GBS patients admitted during May 2018-June 2023 underwent detailed clinical evaluation and EDx study.

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Solid lubricant coatings play a critical role in enhancing the tribological properties of engineering materials, particularly in aerospace and biomedical applications. Ti6Al4V is widely used in aerospace and defense industries due to its excellent mechanical properties and high strength-to-weight ratio. In this regard, a solid lubricant metal matrix composite (MMC) clad was successfully fabricated over Ti6Al4V.

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We report complete genome sequence of BBC32B, which was isolated from human feces sample and submitted to Microbial-Type Culture Collection (MTCC), India with deposition number MTCC 25432. The bacteria from Lactobacillaceae family contained 3,411,152 bp; 3,425 protein coding genes, sharing 69.67% average nucleotide identity with closest species of ATCC367.

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Microbes evolve rapidly by modifying their genomes through mutations or through the horizontal acquisition of mobile genetic elements (MGEs) linked with fitness traits such as antimicrobial resistance (AMR), virulence, and metabolic functions. We conducted a multicentric study in India and collected different clinical samples for decoding the genome sequences of bacterial pathogens associated with sepsis, urinary tract infections, and respiratory infections to understand the functional potency associated with AMR and its dynamics. Genomic analysis identified several acquired AMR genes (ARGs) that have a pathogen-specific signature.

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SARS-CoV-2 infection is known for causing broncho-alveolar inflammation. Interleukin 9 (IL-9) induces airway inflammation and bronchial hyper responsiveness in respiratory viral illnesses and allergic inflammation, however, IL-9 has not been assigned a pathologic role in COVID-19. Here we show, in a K18-hACE2 transgenic (ACE2.

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Article Synopsis
  • The study focused on a patient with diarrhea linked to extensively drug-resistant bacteria, using disk diffusion to test for antimicrobial susceptibility.
  • The genome sequencing revealed 76 genes related to antibiotic resistance and potential virulence factors, indicating a broad resistance profile.
  • The findings suggest that the patient's diarrhea was likely due to antibiotic-associated dysbiosis, exacerbated by the pathogen's toxicity, potentially linked to its type three secretion system (T3SS).
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  • Helicobacter pylori (H. pylori) is a common bacterium linked to chronic gastritis, peptic ulcers, and gastric cancer, with varying virulence and resistance factors, especially in India.
  • A study analyzed the genomes of 143 H. pylori strains from eastern and southern India, revealing distinct regional differences in antibiotic resistance and virulence genes.
  • Findings indicate lower resistance to amoxicillin and furazolidone in eastern strains, while resistance to metronidazole and clarithromycin is more prevalent; this suggests careful antibiotic use in eastern India and highlights the need for understanding local strain characteristics.
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Microbes evolve rapidly by modifying their genome through mutations or acquisition of genetic elements. Antimicrobial resistance in Helicobacter pylori is increasingly prevalent in India. However, limited information is available about the genome of resistant H.

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Background: The composition of the human milk microbiome is highly variable and multifactorial. Milk microbiota from various countries show striking differences. There is a paucity of data from healthy lactating Indian mothers.

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High-salt diet (HSD) modulates effector and regulatory T cell functions and promotes tissue inflammation in autoimmune diseases. However, effects of HSD and its association with gut microbiota in tumor immunity remain undefined. Here, we report that HSD induces natural killer (NK) cell–mediated tumor immunity by inhibiting PD-1 expression while enhancing IFNγ and serum hippurate.

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Transcriptome profiling of Vrindavani and Tharparkar cattle (n = 5 each) revealed that more numbers of genes were dysregulated in Vrindavani than in Tharparkar. A contrast in gene expression was observed with 18.9 % of upregulated genes in Vrindavani downregulated in Tharparkar and 17.

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One major obstacle in designing a successful therapeutic regimen to combat COVID-19 pandemic is the frequent occurrence of mutations in the SARS-CoV-2 resulting in patient to patient variations. Out of the four structural proteins of SARS-CoV-2 namely, spike, envelope, nucleocapsid and membrane, envelope protein governs the virus pathogenicity and induction of acute-respiratory-distress-syndrome which is the major cause of death in COVID-19 patients. These effects are facilitated by the viroporin (ion-channel) like activities of the envelope protein.

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Background: The incidence of preterm birth (PTB) in India is around 13%. Specific bacterial communities or individual taxon living in the vaginal milieu of pregnant women is a potential risk factor for PTB and may play an important role in its pathophysiology. Besides, bacterial taxa associated with PTB vary across populations.

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Sphingobium fuliginis ATCC 27551, previously classified as Flavobacterium sp. ATCC 27551, degrades neurotoxic organophosphate insecticides and nerve agents through the activity of a membrane-associated organophosphate hydrolase. This study was designed to determine the complete genome sequence of S.

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On screening of endolithic actinobacteria from a granite rock sample of Meghalaya for antibacterial compound, a novel antibacterial compound CCp1 was isolated from the fermentation broth of Actinomadura sp. AL2. On purification of the compound based on chromatographic techniques followed by characterization with FT-IR, UV-visible, H NMR, C NMR and mass spectrometry, the molecular formula of the compound was generated as CHNO, a furopyrimidine derivative.

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