Factors influencing the transfer and abundance of antibiotic resistance genes in livestock environments in China

Antibiotic resistance genes (ARGs) have become a global concern for causing serious ecological environmental problems and public health risks. Livestock systems have drawn increasing attention in recent years for a massive consumption of antibiotics and heavy metals (HMs) and become one of main pollution sources of ARGs to aquatic and terrestrial environments. Generally, the generation, evolution and dissemination of ARGs are primarily influenced by biological (bacterial community, mobile genetic elements (MGEs)) and non-biological (antibiotics and/or HMs) factors. However, the separate and comprehensive influence of these factors on the ARGs behavior in livestock environments is still indistinct. Herein, we analyzed single or complex effects of antibiotics, heavy metals, bacterial community and MGEs to the distribution and spread of ARGs in such environments of China based on part meta-analysis of previous work. Besides, some enhanced control strategies of ARGs in livestock waste were briefly introduced. The future research fields are also highlighted. This would provide basic but meaningful information to understand the complexity behind ARGs transfer and spread, underline the significance of ARGs removal from pollution sources and develop efficient elimination protocols for heavy pollution areas.