Occurrence of antibiotic resistance genes and bacterial pathogens in water and sediment in urban recreational water

The emergence and prevalence of antibiotic resistance genes (ARGs) and pathogens in the environment are serious global health concern. However, information about the occurrence of ARGs and pathogens in recreational water is still limited. Accordingly, we investigated the occurrence of six ARGs and human pathogens in three recreational lakes, and the correlations between ARGs and one mobile genetic element (intI1) were analyzed. The quantitative PCR results showed that the concentration of ARGs ranged from 4.58 x 10(0) to 5.0 x 10(5) copies/mL in water and from 5.78 x 10(3) to 5.89 x 10(8) copies/g dry weight (dw) in sediment. Sul1 exhibited the highest level among the five quantifiable ARGs. The concentrations of sul1, bla(-TEM), and tetX exhibited significant positive correlations with intI1 (p < 0.05), indicating that intIl may be involved in their proliferation. The detection frequencies of ARGs ranged from 75%-100%, indicating the prevalence of these risks in this region. The concentration of Escherichia colt Aeromonas spp., Mycobacterium avium, Pseudomonas aeruginosa, and Salmonella enterica ranged from 10(3) to 10(5) copies/100 mL in water and 10(4)-10(5 )copies/g dw in sediment. In total, 25% of the samples harbored all pathogen genes, indicating the prevalence of these pathogens in recreational lakes. Furthermore, the next-generation sequencing results showed that 68 genera of pathogens were present, among which Aeromonas, Mycobacterium, and Pseudomonas were the dominant ones in this region, posing a considerable potential health risk to public health. Overall, the widespread distribution of ARGs and pathogens underscores the need to better monitor and mitigate their propagation in recreational lakes and the associated risks to human health. (C) 2018 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.