Effective removal of antibiotic resistance genes from wastewater using marine waste-derived novel nanocomposites

Abstract

Wastewater (WW) has been identified as a major hotspot of microbial emerging contaminants (MECs), such as antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). Currently used WW treatment methods cannot efficiently eliminate these pollutants, resulting in passive contamination of adjacent environments receiving undertreated discharge. More effective WW treatment strategies are therefore urgently required. In this study, newly developed and well-characterised semi-interpenetrating polymer network (semi-IPN) hydrogels derived from the valorisation of marine wastes (e.g., shrimp shells) were investigated for their ARG removal potential. The results indicated that multiple ARGs prevalent in WW, such as ermB, qrnS, sul1 and tetO, were removed by up to 100% after being treated by novel hydrogels. In terms of horizontal gene transfer-associated genetic elements, such as integron-1 intl1, transposons tnpA1 (IS4 group) and tnpA2 (IS6 group), substantial reduction approaching 99.9% was also achieved. Moreover, up to 97% of efflux pump-associated qacEΔ1 conferring multidrug resistance (MR) was successfully attenuated. To conclude, the semi-INP hydrogels developed exhibited great potential for ARG mitigation towards strengthening WW decontamination, which provides a viable, cost-effective and environmentally friendly novel treatment approach.