Samrat Ghosh

Mr. Samrat Ghosh

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Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 October 2019 in Microorganisms
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Journal Article
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SGSamrat Ghosh
Samrat Ghosh
ASAditya Narayan Sarangi
Aditya Narayan Sarangi
MMMayuri Mukherjee
Mayuri Mukherjee
SBSwati Bhowmick
Swati Bhowmick
STSucheta Tripathy
Sucheta Tripathy
Lactobacillus paracasei are diverse Gram-positive bacteria that are very closely related to Lactobacillus casei, belonging to the Lactobacillus casei group. Due to extreme genome similarities between L. casei and L. paracasei, many strains have been cross placed in the other group. We had earlier sequenced and analyzed the genome of Lactobacillus paracasei Lbs2, but mistakenly identified it as L. casei. We re-analyzed Lbs2 reads into a 2.5 MB genome that is 91.28% complete with 0.8% contamination, which is now suitably placed under L. paracasei based on Average Nucleotide Identity and Average Amino Acid Identity. We took 74 sequenced genomes of L. paracasei from GenBank with assembly sizes ranging from 2.3 to 3.3 MB and genome completeness between 88% and 100% for comparison. The pan-genome of 75 L. paracasei strains hold 15,945 gene families (21,5232 genes), while the core genome contained about 8.4% of the total genes (243 gene families with 18,225 genes) of pan-genome. Phylogenomic analysis based on core gene families revealed that the Lbs2 strain has a closer relationship with L. paracasei subsp. tolerans DSM20258. Finally, the in-silico analysis of the L. paracasei Lbs2 genome revealed an important pathway that could underpin the production of thiamin, which may contribute to the host energy metabolism.

30 September 2013 in Journal of Pharmacopuncture
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Journal Article
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SSSourav Sikdar
Sourav Sikdar
AMAvinaba Mukherjee
Avinaba Mukherjee
Kausik BishayeeKausik Bishayee
Kausik Bishayee
APAvijit Paul
Avijit Paul
SSSantu Saha
Santu Saha
AKAnisur Rahman Khuda-Bukhsh
Anisur Rahman Khuda-Bukhsh
The present investigation aimed at examining if post-cancer treatment with a potentized homeopathic drug, Condurango 30C, which is generally used to treat oesophageal cancer, could also show an ameliorating effect through apoptosis induction on lung cancer induced by benzo[a]pyrene (BaP) in white rats (Rattus norvegicus). Lung cancer was induced after four months by chronic feeding of BaP to rats through gavage at a dose of 50 mg/kg body weight for one month. After four months, the lung-cancer-bearing rats were treated with Condurango 30C for the next one (5(th)), two (5(th)-6(th)) and three (5(th)-7(th)) months, respectively, and were sacrificed at the corresponding time- points. The ameliorating effect, if any, after Condurango 30C treatment for the various periods was evaluated by using protocols such as histology, scanning electron microscopy (SEM), annexinV-FITC/PI assay, flow cytometry of the apoptosis marker, DNA fragmentation, reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry, and western blot analyses of lung tissue samples. Striking recovery of lung tissue to a near normal status was noticed after post-cancerous drug treatment, as evidenced by SEM and histology, especially after one and two months of drug treatment. Data from the annexinV-FITC/PI and DNA fragmentation assays revealed that Condurango 30C could induce apoptosis in cancer cells after post-cancer treatment. A critical analysis of signalling cascade, evidenced through a RT-PCR study, demonstrated up-regulation and down-regulation of different pro- and anti-apoptotic genes, respectively, related to a caspase-3-mediated apoptotic pathway, which was especially discernible after one-month and two- month drug treatments. Correspondingly, Western blot and immunohistochemistry studies confirmed the ameliorative potential of Condurango 30C by its ability to down-regulate the elevated epidermal growth factor receptor (EGFR) expression, a hallmark of lung cancer. The overall result validated a positive effect of Condurango 30C in ameliorating lung cancer through caspase-3-mediated apoptosis induction and EGFR down-regulation.

15 December 2012 in Journal of Chinese Integrative Medicine
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Journal Article
Closed access
AMAvinaba Mukherjee
Avinaba Mukherjee
SSSourav Sikdar
Sourav Sikdar
Kausik BishayeeKausik Bishayee
Kausik Bishayee
APAvijit Paul
Avijit Paul
SGSamrat Ghosh
Samrat Ghosh
AKAnisur Rahman Khuda-Bukhsh
Anisur Rahman Khuda-Bukhsh
To study the possible anticancer and antiproliferative activities of ethanolic leaf extract of Thuja occidentalis (TO) on A549 non-small lung carcinoma cells in vitro. Cell viability was ascertained through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay after deployment of TO in different doses. The half maximal inhibitory concentration (IC50) dose (282 μg/mL) was determined, and two other doses for dose-dependence study, one below the IC50 dose (IC35=188 μg/mL) and one above the IC50 dose (IC65=376 μg/mL) were selected. Bromodeoxyuridine (BrdU) incorporation assay and migration studies were performed to elucidate antiproliferative activity of the drug, if any. Fluorescence-activated cell sorting analysis after annexin V-fluorescein isothiocyanate and propidium iodide (annexin V-FITC-PI) dual staining method was done to ascertain early stage of apoptosis, if any. DNA fragmentation assay was done through Hoechst 33258 and acridine orange-ethidium bromide staining. DNA damage was quantified through comet assay. Bax-Bcl2 regulation and expression studies were performed through indirect enzyme-linked immunosorbent assay (ELISA). Caspase 3 activity was measured at gene level through reverse transcription-polymerase chain reaction (RT-PCR) analysis. Its activation at protein level was analyzed through indirect ELISA and Western blot analysis. TO demonstrated a dose-dependent decrease in viability of A549 cells after 24 h of exposure. Cell proliferation was reduced in a time-dependent manner of drug exposure as revealed from BrdU incorporation and migration studies. Annexin-V-FITC positivity of cells up to 11.72% as compared to the untreated control revealed early state of TO-induced apoptosis. Occurrence of comet tail and increased fluorescence of Hoechst after 24 h of drug exposure revealed significant DNA nick generation and chromatin condensation. Bax up-regulation and Bcl-2 down-regulation suitably altered ratio of Bax/Bcl-2 in favor of apoptosis. From RT-PCR, indirect ELISA and Western blot studies, caspase 3 activity was also found to be significantly increased along with cleaved poly ADP-ribose polymerase expression. Ethanolic leaf extract of TO demonstrated apoptotic and antiproliferative potentials against A549 cell line.

26 July 2022 in Biology
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Journal Article
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Sumit MukherjeeSumit Mukherjee
Sumit Mukherjee
ZKZhuoran Kuang
Zhuoran Kuang
SGSamrat Ghosh
Samrat Ghosh
RDRajesh Detroja
Rajesh Detroja
GCGon Carmi
Gon Carmi
KLKexin Li
Kexin Li
Soil bacteria respond rapidly to changes in new environmental conditions. For adaptation to the new environment, they could mutate their genome, which impacts the alternation of the functional and regulatory landscape. Sometimes, these genetic and ecological changes may drive the bacterial evolution and sympatric speciation. Although sympatric speciation has been controversial since Darwin suggested it in 1859, there are several strong theoretical or empirical evidences to support it. Sympatric speciation associated with soil bacteria remains largely unexplored. Here, we provide potential evidence of sympatric speciation of soil bacteria by comparison of metagenomics from two sharply contrasting abutting divergence rock and soil types (Senonian chalk and its rendzina soil, and abutting Pleistocene basalt rock and basalt soil). We identified several bacterial species with significant genetic differences in the same species between the two soil types and ecologies. We show that the bacterial community composition has significantly diverged between the two soils; correspondingly, their functions were differentiated in order to adapt to the local ecological stresses. The ecologies, such as water availability and pH value, shaped the adaptation and speciation of soil bacteria revealed by the clear-cut genetic divergence. Furthermore, by a novel analysis scheme of riboswitches, we highlight significant differences in structured non-coding RNAs between the soil bacteria from two divergence soil types, which could be an important driver for functional adaptation. Our study provides new insight into the evolutionary divergence and incipient sympatric speciation of soil bacteria under microclimatic ecological differences.

1 January 2021 in Bioinformatics and Biology Insights
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Journal Article
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SGSamrat Ghosh
Samrat Ghosh
ASAditya Narayan Sarangi
Aditya Narayan Sarangi
MMMayuri Mukherjee
Mayuri Mukherjee
DSDeeksha Singh
Deeksha Singh
MMMadduluri Madhavi
Madduluri Madhavi
STSucheta Tripathy
Sucheta Tripathy
Rabindra Sarovar lake is an artificial freshwater lake in the arsenic infested eastern region of India. In this study, using the genome resolved metagenomics approach; we have deciphered the taxonomic diversity as well as the functional insights of the gene pools specific to this region. Initially, a total of 113 Metagenome Assembled Genomes (MAGs) were recovered from the two predominant seasons, that is, rainy (n = 50) and winter (n = 63). After bin refinement and de-replication, 27 MAGs (18 from Winter season and 9 from Rainy season) were reconstructed. These MAGs were either of high-quality (n = 10) or of medium quality (n = 17) that was determined based on genome completeness and contamination. These 27 MAGs spanning across 6 bacterial phyla and the most predominant ones were Proteobacteria, Bacteroidetes, and Cyanobacteria regardless of the season. Functional annotation across the MAGs suggested the existence of all known types of arsenic resistance and metabolism genes. Besides, important secondary metabolites such as zoocin_A, prochlorosin, and microcin were also abundantly present in these genomes. The metagenomic study of this lake provides the first insights into the microbiome composition and functional classification of the gene pools in two predominant seasons. The presence of arsenic metabolism and resistance genes in the recovered genomes is a sign of adaptation of the microbes to the arsenic contamination in this region. The presence of secondary metabolite genes in the lake microbiome has several implications including the potential use of these for the pharmaceutical industry.