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Biology subjects

Ahmed, A. N.

Publications and source records attributed to Ahmed, A. N..

3 recordsLinked to original sources

Structure-Guided Design and Dynamic Evaluation of VP4-Targeting siRNAs Against Rotavirus A

Rotavirus is a major cause of severe diarrheal disease in children under the age of five, with reduced vaccine effectiveness in low-resource settings causing substantial morbidity and mortality. In the absence of approved antiviral therapeutics, treatment is largely supportive, urging the need for targeted and precision-based interventions. VP4 protein plays an essential role in viral attachment, entry, and infectivity, making it a suitable target for targeted therapy. In this context, RNA interference is a specific method for inhibiting viral gene expression with its efficacy depending on sequence conservation, target accessibility, and compatibility with the RISC-loading machinery. In the present study, an integrative in silico approach was employed to design and evaluate siRNAs targeting conserved regions of the VP4 gene across six geographically diverse countries. Candidate siRNAs were screened using established design rules and regression-based scoring with off-target filtering. Three optimized siRNAs were further assessed through structural modeling, molecular docking, and molecular dynamics simulations to examine interactions with human Dicer, TRBP, and Argonaute-2. Comparative dynamic analyses identified one siRNA with enhanced structural compatibility, reduced conformational fluctuations, and stable interactions with RISC-loading proteins. These findings provide a rational computational basis for VP4-targeted siRNA development, facilitating experimental validation.

bioinformatics↗

Linking Genomic Landscape to Disease Mechanism: Core Genetic Factors Underlying Pathogenesis and Antimicrobial Resistance in Diarrheal Pathogens

BackgroundDiarrheal diseases remain a major global health burden, as they severely affect children, particularly in Bangladesh. After decades of research, the molecular mechanisms of diarrheal pathogens for disease pathogenesis and antibiotic resistance are still unknown, notably in Gram-negative bacteria. This pilot study fills the gap by employing whole genome sequencing and pan-genome analysis to analyze Bangladeshi diarrheal pathogens to identify genetic variables that cause disease pathogenesis and antibiotic resistance. ResultsHence, we investigated the genetic diversity of bacterial isolates from 31 clinical stool samples by a combination of whole-genome sequencing (WGS) and pan-genomic analysis. A core group of 50 genes, conserved across a significant number of strains, was identified via pan-genomic analysis, with considerable variation in accessory genes. This signifies a significant degree of genetic flexibility. Gene ontology analysis yielded substantial insights into prospective therapeutic targets by emphasizing the critical function of these core genes in bacterial survival and pathogenicity. Furthermore, the findings of the antimicrobial susceptibility test (AST) revealed concerning resistance trends, particularly to fluoroquinolones and beta-lactams, underscoring the necessity for enhanced surveillance and alternative therapeutic approaches. ConclusionThis study provides a comprehensive genetic framework to improve understanding of the complexity of diarrheal infections and the mechanisms underlying their resistance, fostering opportunities for potential therapeutic advancements.

microbiology↗

Gastrointestinal colonization as a source of Staphylococcus aureus in atopic dermatitis

Atopic dermatitis (AD) is a prevalent inflammatory skin disease with complex pathogenesis. Both skin and gut microbiota influence AD, with Staphylococcus aureus, in particular, exacerbating the disease. However, the relationship between S. aureus colonization in the gut and skin, and whether it affects AD, remains unclear. Using a combination of culture-based methods, microbiome analysis, and genome sequencing of S. aureus from multiple body sites of children with and without AD, we found that the gut represents a major reservoir of genetically diverse S. aureus that is transmitted to the skin, including mutants associated with worse disease. We validated this association between S. aureus gastrointestinal colonization and AD in an independent human cohort and demonstrated its direct effect on disease in an infantile AD mouse model, wherein S. aureus gastrointestinal colonization worsened skin inflammation. Overall, this study identifies a previously unrecognized S. aureus reservoir, with implications for microbiota-targeting therapies in AD.

microbiology↗