Coexistence and association between heavy metals, tetracycline and corresponding resistance genes in vermicomposts originating from different substrates

Abstract Coexistence of antibiotics/heavy metals and the overexpression of resistance genes in the vermicompost has become an emerging environmental issue. Little is known about the interaction and correlation between chemical pollutants and biological macromolecular compounds. In this study, three typical vermicompost samples were selected from the Yangtze River Delta region in China to investigate the antibiotic, heavy metal and corresponding antibiotic resistance genes (ARGs) and heavy metal resistance genes (HRGs). The results indicated the prevalence of tetracycline (TC), copper (Cu), zinc (Zn), cadmium (Cd), corresponding TC-resistance genes ( tet A, tet C, tet W, tet M, tet O, and tet S) and HRGs ( cop A, pco A, cus A, czc A, czc B, and czc R) in the three vermicompost samples. In addition, the ARG level was positively associated with the water-soluble TC fraction in the vermicompost, and it was same between the HRG abundance and exchangeable heavy metal content ( p