Longitudinal Dynamics of Antimicrobial Resistance Gene Transfer Between Livestock, Environment, and Human Populations in Kano State

The longitudinal dynamics of antimicrobial resistance gene transfer across the livestock-environment-human continuum represent a complex, understudied phenomenon in sub-Saharan Africa. This study investigated the temporal dynamics and ecological pathways of antimicrobial resistance gene dissemination between livestock, farm environments, and adjacent human communities in Kano State, North West Nigeria over a 24-month period. A longitudinal cohort design enrolled five commercial poultry and pig farms, their adjacent water bodies, and human households within 500 meters. Fecal, water, and soil samples were collected every three months. Metagenomic whole-genome sequencing was applied to characterize total resistome profiles. Human participants provided fecal swabs, and clinical E. coli isolates were also analyzed. Temporal resistome analysis showed increasing diversity and abundance of mobile genetic elements over the study period, with integrons and transposons showing seasonal amplification correlated with antibiotic use cycles. Conjugative plasmid-mediated transfer of extended-spectrum beta-lactamase genes was traced from livestock E. coli to environmental water to human isolates using network phylogenomics. Resistance gene flow was bidirectional and accelerated after rainfall events. The study is the first longitudinal metagenomic analysis of the livestock-environment-human resistome in northern Nigeria and contributes original data on temporal resistance dynamics and ecological connectivity. Ecosystem-level antimicrobial resistance management strategies targeting the water-soil-animal interface are proposed as the logical public health response. Keywords: antimicrobial resistance genes, resistome, longitudinal dynamics, metagenomics, Kano State