Effects of compost containing antibiotic resistant genes on soil characteristics

Abstract

© SGEM2019. Manure and manure-based composts may contain antibiotics and antibiotic–resistant genes (ARGs). Application of composts on agricultural soils can be a potential risk of the spread of antibiotic resistance. The effect of compost containing ARGs was assessed in a 35–day pot experiment on the following soil characteristics: The level of respiratory activity and microbial biomass, the bacteria–fungi ratio, the content of tetracycline–resistant genes tet(M) and tet(X), and the content of OmpF gene encoding horizontal transfer. The following mixtures were analyzed: Control soil, soil with “clean” compost, and soil with compost contaminated by ARGs. Respiratory activity, microbial biomass and the bacteria–fungi ratio in the soil treated with both types of compost was equally high as compared with the control soil. Tetracycline-resistant tet(M) and tet(X) genes in the soil with “clean” compost were detected between the 7th-14th days. ARGs were found in the soil with compost from the 1st day. The OmpF gene encoding horizontal transfer was present in samples with compost from the 1st to the 35th days. In the control soil there were no tet-genes and the content of the OmpF gene was lower and not at all time points.