Occurrence and distribution characteristics of antibiotic resistance genes in sediments between urban and rural of the Liaohe River Basin, China.

Antibiotic resistance genes (ARGs) are considered to be emerging pollutants related to human activities. The rapid development of global urbanization has expanded human activities, thereby exacerbating the global human health risks caused by antibiotic resistance genes. The effects of urban and rural environments are multifarious, which makes the source and distribution of ARGs in the environment diversification. Understanding the distribution and spread of ARGs is essential for studying the environmental behavior of ARGs. In this study, the occurrence 296 genes were detected by the high-throughput qPCR technology, and FC value was used to analyze the diversity of ARGs and mobile genetic elements (MGEs) in sediments between urban and rural areas of the Liaohe River Basin, China. The co-occurrence of MGEs and ARGs was analyzed using network to decipher core genes. A total of 187 ARGs and 10 MGEs were detected in all sediment samples. The average number of genes detected in urban sites is 89 higher than that in rural sites. The high abundance and various types of ARGs and MGEs detected in urban river sediments indicate that the occurrence of urban ARGs is more complex. MGEs were detected high levels and were significantly correlated with the abundance and diversity of ARGs in river sediments providing evidence that MGEs were related to the occurrence and distribution of ARGs and tnpA (tnpA-07, tnpA-01, and tnpA-03) gene were at the key position of co-occurrence of various types of ARGs.