The current culture-based bacterial detection technique is time-consuming and requires an extended sample preparation methodology. We propose the potential of surface-enhanced Raman spectroscopy (SERS) and surface plasmon-enhanced auto-fluorescence spectroscopy (SPEAS) for the label-free identification and quantification of bacterial pathogens at low concentrations collecting its unique auto-fluorescence and Raman signatures utilising highly anisotropic three-dimensional nanostructures of silver nano dendrites (Ag-NDs). The SERS data facilitates qualitative bacterial identification using the spectral features coming from the bacterial cell wall compound, and the SPEAS data was utilised to gain unique auto-fluorescence spectra present on the bacterial cell wall with enhanced quantification.
View Article and Find Full Text PDFThe genomic landscape associated with early adaptation to ciprofloxacin is poorly understood. Although the interplay between core metabolism and antimicrobial resistance is being increasingly recognized, mutations in metabolic genes and their biological role remain elusive. Here, we exposed Escherichia coli to increasing gradients of ciprofloxacin with intermittent transfer-bottlenecking and identified mutations in three non-canonical targets linked to metabolism including a deletion (tRNA-ArgΔ414-bp) and point mutations in the regulatory regions of argI (ARG box) and narU.
View Article and Find Full Text PDFNucleot(s)ide analogues, the current antiviral treatments against chronic hepatitis B (CHB) infection, are non-curative due to their inability to eliminate covalently closed circular DNA (cccDNA) from the infected hepatocytes. Preclinical studies have shown that coumarin derivatives can effectively reduce the HBV DNA replication. We evaluated the antiviral efficacy of thirty new coumarin derivatives in cell culture models for studying HBV.
View Article and Find Full Text PDFEmergence and spread of the hypervirulent pathotype of have significantly increased infection rates in community as well as healthcare settings. There is an increasing interest to identify discriminating features between classical (cKp) and hypervirulent (hvKp) to facilitate our understanding of the rapid emergence and dissemination of the hypervirulent pathotype. Here, we sought to identify unique epigenetic signatures of hvKp pathotype that differ from its classical counterpart using single-base resolution methylome analysis of native DNA sequencing on the Oxford Nanopore Technologies platform.
View Article and Find Full Text PDFAntimicrobial resistance (AMR) is a major health threat worldwide and the culture-based bacterial detection methods are slow. Surface-enhanced Raman spectroscopy (SERS) can be used to identify target analytes in real time with sensitivity down to the single-molecule level, providing a promising solution for the culture-free bacterial detection. We report the fabrication of SERS substrates having tightly packed silver (Ag) nanoparticles loaded onto long silicon nanowires (Si NWs) grown by the metal-assisted chemical etching (MACE) method for the detection of bacteria.
View Article and Find Full Text PDFWe investigate the role of Tachyplesin (Tpl), a marine antimicrobial cell-penetrating peptide, as an anti-HBV agent. Our findings, using confocal microscopy and flow cytometry, demonstrate the internalization of FITC-Tpl in both Huh7 and HepG2 cell lines. Further, our results show that Tpl inhibits the expression of HBV proteins, including hepatitis B surface antigen (HBsAg) and hepatitis B 'e' antigen (HBeAg) in cell supernatants of human liver cell lines transfected with 1.
View Article and Find Full Text PDFPhys Chem Chem Phys
February 2023
Upconversion materials have attracted considerable research interest for their application in bioimaging due to their unique optical properties. NaREF (RE = Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) based host lattice, which is widely used for upconversion, requires expensive rare-earth elements and tedious reaction conditions. Hence there is a need to develop environmentally friendly and cost effective materials for upconversion.
View Article and Find Full Text PDFHepatitis C virus (HCV) is a bloodborne pathogen that can cause chronic liver disease and hepatocellular carcinoma. The loss of CpGs from virus genomes allows escape from restriction by the host zinc-finger antiviral protein (ZAP). The evolution of HCV in the human host has not been explored in the context of CpG depletion.
View Article and Find Full Text PDFCurrently, there is no data on the molecular quantification of microbial indicators of recycled water quality in India. In this study, multiple microbial pathogens and indicators of water quality were evaluated at three wastewater treatment plants located in two Indian cities (New Delhi and Jaipur) to determine the treatment performance and suitability of recycled water for safe and sustainable reuse applications. Real-time polymerase chain reaction (PCR) was used for the rapid evaluation of six human pathogens and six microbial indicators of fecal contamination.
View Article and Find Full Text PDFCompared to the clinical sector, the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in the food sector is relatively low. However, their presence in seafood is a significant public health concern. In India, fish and fishery products are maximally manually handled compared to other food products.
View Article and Find Full Text PDFDelhi has been identified as one of the highly polluted cities in the world and recently associated with the highest population weighted PM concentration. However, the unavailability of the health risk estimations using long-term data for Indian cities has been pointed out as a hurdle in performing the correct assessment. The present work estimated deposition of particles in different regions of respiratory systems (head airway = 67% deposition for 2.
View Article and Find Full Text PDFClinical and studies have demonstrated a role for hepatitis B virus (HBV)-encoded HBsAg (hepatitis B surface antigen) in HBV-related hepatocellular carcinoma (HCC); however, the underlying mechanisms remain largely unknown. Here, we investigated the role of HBsAg in regulating long noncoding RNAs (lncRNAs) involved in HCC progression. Our analysis of microarray data sets identified LINC00665 as an HBsAg-regulated lncRNA.
View Article and Find Full Text PDFBackground: Currently approved oral antivirals for chronic HBV infection target the reverse transcriptase (RT) domain of the HBV polymerase. Emergence of drug resistance has been reported in a small proportion of chronic HBV patients on prolonged treatment with antivirals. We recently reported ZINC20451377, a small molecule targeting hepatitis B surface antigen (HBsAg) that effectively inhibits both WT HBV and tenofovir-resistant HBV.
View Article and Find Full Text PDFHerpesviruses are known to acquire several genes from their hosts during evolution. We found that a significant proportion of virus homologues encoded by HSV-1, HSV-2, EBV and KSHV and their human counterparts contain G-quadruplex motifs in their promoters. We sought to understand the role of G-quadruplexes in the regulatory regions of viral Bcl-2 homologues encoded by KSHV (KS-Bcl-2) and EBV (BHRF1).
View Article and Find Full Text PDFDepletion of CpG dinucleotides in severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) genomes has been linked to virus evolution, host-switching, virus replication, and innate immune responses. Temporal variations, if any, in the rate of CpG depletion during virus evolution in the host remain poorly understood. Here, we analyzed the CpG content of over 1.
View Article and Find Full Text PDFClinical and epidemiological studies support a role for vitamin D in suppressing hepatitis B virus (HBV). This antiviral role of vitamin D is widely attributed to vitamin D receptor (VDR)/retinoid X receptor-mediated regulation of host immunomodulatory genes through vitamin D response elements (VDREs) in their promoters. Here, we investigated the ability of calcitriol (1α,25-dihydroxyvitamin D3, metabolically activated vitamin D) to directly regulate HBV activity through this signaling pathway.
View Article and Find Full Text PDFMicroRNAs (miRNAs) are major post-transcriptional regulators of gene expression. They base pair with the complementary target mRNA at the 3'UTR and modulate cellular processes by repressing the mRNA translation or degrading the mRNA. There are well-documented mechanisms of biogenesis of miRNA; however, a sizeable number of miRNAs are also produced by non-canonical pathways.
View Article and Find Full Text PDFChronic hepatitis B virus (HBV) infection is a global problem. The loss of hepatitis B surface antigen (HBsAg) in serum is a therapeutic end point. Prolonged therapy with nucleoside/nucleotide analogues targeting the HBV-polymerase may lead to resistance and rarely results in the loss of HBsAg.
View Article and Find Full Text PDFA facile chemical route is reported for synthesizing red-emitting photoluminescent/MRI multi-functional KLa(0.95-x)GdxF4:Eu3+ (x = 0 to 0.4) bio-compatible nanomaterials for targeted in vitro tumor imaging.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2020
The biological applications of germylenes remain unrealised owing to their unstable nature. We report the isolation of air-, water-, and culture-medium-stable germylene DPMGeOH (3; DPM=dipyrromethene ligand) and its potential biological application. Compound 3 exhibits antiproliferative effects comparable to that of cisplatin in human cancer cells.
View Article and Find Full Text PDFThe fine particulate matter (PM) was collected at academic campus of Indian Institute of Technology, Delhi, India from January-December 2017. The PM samples were analysed for carcinogenic (Cd, Cr, As, Ni, and Pb) and non-carcinogenic (V, Cu, Zn, Fe) trace metals and their elicited effects on carcinoma epithelial cell line A549. Toxicological testing was done with ELISA kit.
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