Urban parks as potential hotspots for pathogenic determinants: A One Health perspective on environmental-human transmission risks

Abstract

Urban parks are vital public spaces, yet their role as potential reservoirs and transmission pathways for pathogenic bacteria under the “One Health” framework remains poorly understood. We gathered paired soil, water, and human fecal samples from nine parks in Lanzhou, China. Metagenomic and 16S rRNA sequencing revealed abundant pathogenic bacteria, virulence factor (VF) genes, and pathogen-host interaction (PHI) genes. Pathogenic bacteria were significantly more abundant in water than in soil, and their presence was positively correlated with key environmental nutrients (TC, TN, TP, TS). Immune modulation and motility genes dominated the VF repertoire, while PHI genes primarily mediated virulence attenuation, maintenance, or enhancement. Crucially, the profile of these virulence genes was significantly shaped by the native bacterial community and mobile genetic elements (MGEs). Metagenomic binning provided direct genomic evidence that MGEs frequently co-localize with VF and PHI genes, demonstrating a high potential for horizontal gene transfer from park environments to humans. Our findings highlight urban parks as significant environmental reservoirs for pathogenic determinants and delineate the ecological and genetic drivers of their dissemination, providing a critical basis for targeted environmental management and public health protection.