Exploring the correlations between antibiotics and antibiotic resistance genes in the wastewater treatment plants of hospitals in Xinjiang, China

Various antibiotics have been extensively used to treating infectious diseases in hospitals. In this study, the abundance and diversity of antibiotics and antibiotic resistance genes (ARGs) were observed in the wastewater samples from five hospitals in Xinjiang, China. The total concentrations of tetracyclines, sulphonamides, and quinolones in hospital influents ranged from 363.4 to 753.3 ng/L, 285.5 to 634.9 ng/L, and 1355.8 to 1922.4 ng/L, respectively. However, the removal efficiency of tetracyclines, sulphonamides, and quinolones in wastewater treatment processes ranged from 72.4 to 79.3 %, 36.0 to 52.2 %, and 45.1 to 55.4 %, respectively. The contamination levels of the selected ARGs varied in all wastewater samples. The highest relative concentrations of sul1 , sul2 , tetQ , and qnrS were significantly higher than those of other ARGs in this study. Significant positive correlations between the relative abundance of partial ARGs and concentrations of certain antibiotics were observed in hospital wastewaters. Results show that integrons played an important role in disseminating and distributing ARGs in microorganism systems. Furthermore, strong correlations were observed between tetQ , sulphonamide resistance genes (except sulA ) and intI1 . This study aimed to determine the contamination levels of antibiotics and ARGs and analyze the relationships among ARGs, and antibiotics and integron genes in hospital wastewaters.