Key role of cyromazine in the distribution of antibiotic resistance genes and bacterial community variation in aerobic composting

The risks that have not been noted so far have come from the use of non-antibiotics. In this study, non-antibiotic drug (cyromazine) was used in composting to investigate its possible effects on the distribution of ARGs and changes of bacterial community. Results showed that cyromazine increased the abundances of highly-risky ARGs (bla(CTX-M) and bla(VIM)), and heavy metal resistance genes (MRGs). Low and high concentrations of cyromazine increased the abundance of Tn916/1545 by 18.27% and 64.26%, respectively, compared with the control treatment. Mobile genetic elements (MGEs) and MRGs were not the major cause of the dynamic changes in ARGs, but instead the bacterial community succession changed according to the moisture content, pH, and bio-Cu. Network analysis showed that Proteobacteria and Actinobacteria were the major hosts for ARGs, and there was a significant correlation between tcrB, sul1 and Tn916/1545.