Search bioRxiv⌕ Search

Biology subjects

Doan, N. Q.

Publications and source records attributed to Doan, N. Q..

2 recordsLinked to original sources

AMR-GNN: A multi-representation graph neural network framework to enable genomic antimicrobial resistance prediction

Whole-genome sequencing (WGS) data are an invaluable resource for understanding antimicrobial resistance (AMR) mechanisms. However, WGS data are high-dimensional and the lack of standardized genomic representations is a key barrier to AMR prediction. To fully explore these high-resolution data, we propose AMR-GNN, a graph deep learning-based framework that integrates multiple genomic representations with graph neural networks (GNN) to enable AMR prediction from genomic sequence data. We tested AMR-GNN with Pseudomonas aeruginosa, a clinically relevant Gram-negative bacterial pathogen known for its complex AMR mechanisms. We demonstrate that AMR-GNN addresses several key problems in AMR prediction with data-driven machine learning (ML) approaches, including using multiple genomic representations to enhance performance, mitigate the influence of clonal relationships, and identify informative biomarkers to provide explainability and generate novel hypotheses. Follow-up validation on the largest publicly available dataset spanning both Gram-negative and Gram-positive pathogens highlights AMR-GNNs broad applicability in detecting AMR in diverse and clinically relevant pathogen-drug combinations.

genomics↗

A widespread hydrogenase drives fermentative growth of gut bacteria in healthy people

Molecular hydrogen (H2) is among the most central, but least understood, metabolites in the human gastrointestinal tract (gut). H2 gas is produced in large quantities during bacterial fermentation and consumed as an energy source by bacteria and archaea. Disruption of H2 cycling is linked to gastrointestinal disorders, infections, and cancers, with H2 used as an indicator of gut dysfunction through breath tests. Despite this, the microorganisms, pathways, and enzymes mediating H2 production remain unresolved. Here we show that a previously uncharacterised enzyme, the group B [FeFe]-hydrogenase, drives most fermentative H2 production in the human gut. Analysis of stool, biopsy, and isolate (meta)genomes and (meta)transcriptomes show this hydrogenase is encoded by most gut bacteria and is highly expressed. Through analysis of 19 taxonomically diverse gut isolates, the group B [FeFe]-hydrogenase produces large amounts of H2 gas and supports fermentative growth of both Bacteroidetes and Firmicutes. Bacteroides particularly dominate H2 production. Biochemical and spectroscopic characterisation shows purified group B [FeFe]-hydrogenases are catalytically active and bind a di-iron active site. These hydrogenases are highly enriched in the guts of healthy individuals, but significantly depleted in favour of other fermentative hydrogenases in Crohns disease. Furthermore, we show that metabolically flexible respiratory bacteria are the most abundant H2 oxidizers in the gut, not sulfate reducers, methanogens, and acetogens as previously thought. This combination of enzymatic, cellular, and ecosystem-level analysis provides the first detailed understanding of H2 cycling in the human gut and reveals new links between microbiota function and gastrointestinal health.

microbiology↗