The Presence of Stone Moroko (Pseudorasbora parva) Drives Divergent Sediment Resistome Profiles in Chinese Mitten Crab (Eriocheir sinensis) Polyculture Pond

The propagation of antibiotic resistance genes (ARGs) in aquatic environments poses a significant threat to global health. This study compared sediment resistome profiles in river crab (<i>Eriocheir sinensis</i>) polyculture systems with and without stone moroko (<i>Pseudorasbora parva</i>). The results showed that, compared to the control group (MC group), the sediment from the polyculture system containing stone moroko (PC group) exhibited significant reductions in the total abundances of ARGs, metal resistance genes (MRGs), biocide resistance genes (BRGs), and mobile genetic elements (MGEs). Crucially, the total abundance and composition of MGEs in pond sediment were substantially correlated with ARGs, MRGs, and BRGs, respectively. Co-occurrence network analysis revealed that there was only one edge between ARGs and MGEs in the PC group, whereas the MC group had eight edges. Additionally, the proportion of mobile ARGs in the PC group was significantly lower than that in the MC group. Alterations in resistome profiles were markedly associated with decreased levels of total carbon (TC) and phosphate in the sediment. All of the findings demonstrated that the introduction of stone moroko in the river crab polyculture system effectively mitigated the sediment resistome primarily by altering environmental factors and suppressing MGEs, thereby disrupting the horizontal transfer network of resistance genes. This study highlights the potential of leveraging aquatic biota as a novel biological strategy for the in situ management of environmental antimicrobial resistance.