Effective removal of antibiotic resistance genes by high-frequency electromagnetic field combined with chlorine disinfection

The presence of antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) in the environment is of great concern to human health. This study developed a new combination of high-frequency electromagnetic field (HEMF) and low-dosage chlorine disinfection to reduce the abundance of extracellular ARG (eARG) sul2 and intracellular ARG (iARG) adeF. The removal efficiencies of sul2 and adeF from sulfamethoxazole- and multidrugresistant Acinetobacter junii were measured by quantitative PCR (qPCR). Compared to chlorine disinfection alone, the combination of HEMF treatment exhibited significantly improved ARG removal efficiency. The highest removal efficiencies of sul2 and adeF under the combination were 75.7% and 91.4%, respectively. Treatment time and the dosage of chlorine played pivotal roles in the removal efficiency of ARGs via HEMF treatment and chlorine disinfection, respectively. Importantly, a combination of low-dose chlorine with HEMF treatment could serve as a viable alternative to high-dose chlorine disinfection. This work offers essential process parameters for optimizing the elimination of iARGs and eARGs and presents a viable solution for addressing the issue of ARG contamination.