Mechanism of earthworm coelomic fluid inhibits multidrug-resistant bacteria and blocks resistance transmission.

Antibiotic resistance is a growing global health crisis, especially the spread of multi-drug resistance. In this study, the inhibitory effects of earthworm coelomic fluid (ECF) on multidrug-resistant bacteria (MRB) were investigated during employing vermicomposting to treat excess sludge generated from wastewater treatment. The results demonstrated that the ECF was able to inhibit, even completely decompose the MRB. Notably, when the ECF concentration reached 1.0 mg/mL, the intracellular reactive oxygen species (ROS) level increased by 46.7 %, while cell viability decreased by 55.2 % compared to the control, demonstrating that ECF exerts strong antibacterial activity by inducing oxidative stress and disrupting cellular homeostasis. Furthermore, ECF effectively degraded the DNA of MRB, with removal rates of aphA, KanR, and tetA reaching 51.8 %, 42.3 %, and 35.0 %, respectively, indicating its ability to eliminate resistance genes and hinder their potential transfer. Additionally, the upregulation of genes involved in signaling, DNA replication and repair, and energy metabolism pathways suggests a systemic stress response in MRB, further supporting the broad-spectrum inhibitory effects of ECF on bacterial viability and resistance maintenance. Taken together, these findings may open a door to naturally and ecologically combat antibiotic resistance in pollutants control in wastewater treatment.