Distribution of antibiotic resistant bacteria in different soil types following manure application

ARB was investigated in different soil types following manure application.CTC-manure induced more resistance of soil indigenous microbes in fluvo-aquic soil.Lactobacillus, Dyella, Ralstonia, and Bacillus were the key different genera.Manure control is an effective way to reduce the risk of soil ARB.Swine manure, commonly applied as organic compost in agricultural fields, is an important reservoir of antibiotic-resistant bacteria (ARB). Previous work indicated that manure application led to more antibiotic resistance genes in red soil compared with black soil and fluvo-aquic soil. Accordingly, the influencing mechanisms of soil types on the distribution of ARB was worthy of further exploration by a soil column experiment. The results showed that a higher shift in the operational taxonomic units and the community composition of chlortetracycline (CTC)-resistant bacteria (CRB) were observed in fluvo-aquic soil than in black and red soils. CTC induced antibiotic resistance development in soil indigenous microorganisms (Streptomyces, Pseudomonas, Bacillus, Rhodococcus, and Paenibacillus), and the induction was most obvious in fluvo-aquic soil. Streptomyces was significantly positively correlated with pH and organic matter. Additionally, LEfSe analysis indicated that the key different genera were Microbacteriaceae (black soil), Lactobacillus, unclassified_c__Bacilli and Paenibacillus (fluvo-aquic soil), and Dyella, Ralstonia and Bacillus (red soil). It was concluded that manure application led to higher CRB risk in fluvo-aquic soil compared with black and red soils. Overall, appropriate methods according to soil types are important ways to reduce the risk of soil resistant bacteria during manure return.