Derick Singleton M.S. Defense

Map of AMR Gene Expression by Impact Class Across Continental United StatesDerick Singleton

Master's Degree Candidate

Miller Lab

CU Denver Department of Integrative Biology

When: Friday, April 18th, 2025, 9:30am - 10:30am
Where: Science Building Room 4127 (Conference Room)

Inference and Characterization of Antimicrobial Resistance Genes in Freshwater River Microbial Communities Across the United States 

Antimicrobial resistance genes (ARGs) in aquatic environments are of growing concern due to their potential for environmental persistence and horizontal gene transfer. In this study, I analyzed 2,093 microbial metagenome-assembled genomes (MAGs) recovered from river systems across the continental United States.  I assessed the distribution and expression of ARGs, their co-occurrence with biosynthetic gene clusters (some of which code for antimicrobial production), and association with environmental variables such as site-level anthropogenic impact and wastewater treatment plant density.  Importantly, several ARGs—particularly glycopeptide resistance genes—were detected and expressed within MAGs assigned to novel genera, including those from samples collected from "pristine" environments. I highlight the complex relationship between impacted and pristine environments, potential antimicrobial production, and antimicrobial resistance gene expression, emphasizing the need to monitor emerging resistance in both anthropogenically impacted and more "pristine” ecosystems.