Field-based evidence for copper contamination induced changes of antibiotic resistance in agricultural soils

Abstract

Bacterial resistance to antibiotics and heavy metals are frequently linked, suggesting that exposure to heavy metals might select for bacterial assemblages conferring resistance to antibiotics. However, there is a lack of clear evidence for the heavy metal-induced changes of antibiotic resistance in a long-term basis. Here, we used high-capacity quantitative PCR array to investigate the responses of a broad spectrum of antibiotic resistance genes (ARGs) to 4-5 year copper contamination (0-800 mg kg-1 ) in two contrasting agricultural soils. In total, 157 and 149 unique ARGs were detected in the red and fluvo-aquic soil, respectively, with multidrug and β-lactam as the most dominant ARG types..