Profiling of Antibiotic Resistome and Mobilome in Drinking Water Sources Across Rural Communities in Nasarawa State Using Shotgun Metagenomics

Drinking water contamination with antibiotic-resistant bacteria and resistance genes is a significant public health concern in rural communities where water treatment infrastructure is inadequate. The resistome (totality of ARGs) and mobilome (mobile genetic elements) of drinking water sources directly reflect environmental antibiotic resistance burden. This study profiled the antibiotic resistome and mobilome in drinking water from boreholes, hand-dug wells, and surface water sources across three rural local government areas in Nasarawa State, North Central Nigeria, using shotgun metagenomics. Forty-eight water samples were collected in sterile containers, filtered to concentrate microbial biomass, and DNA extracted by bead-beating. Sequencing was performed on the Illumina NextSeq 550 platform. Reads were processed through KneadData, and ARGs were annotated using DeepARG against the CARD database. Integrons and transposons were characterized with IntegronFinder and ISfinder tools. Borehole sources had significantly lower ARG abundance compared to hand-dug wells and surface water. Beta-lactam, tetracycline, and sulfonamide resistance genes dominated all source types. Mobile integrase genes (intI1) were co-detected with ARGs in 74% of samples, indicating high horizontal gene transfer potential. Community composition analysis revealed fecal indicator bacterial genera (Escherichia, Enterococcus) as dominant ARG hosts. These findings underscore the need for water quality management interventions that explicitly address ARG contamination in rural Nasarawa State water supply systems. Keywords: resistome, mobilome, drinking water, metagenomics, Nasarawa State.