ACCUMULATION OF ANTIBIOTICS AND TET RESISTANCE GENES FROM SWINE WASTEWATER IN WETLAND SOILS

The accumulated characteristics of typical veterinary antibiotics (tetracyclines, sulfonamides, quinolones and macrolides) and tetracycline resistance (tet) genes in the different wetland soils (Krasnozem and Chernozem), and the effects from Phragmites australis were evaluated in this study. Results indicated that the concentrations of targeted antibiotics and tet genes in soils with swine treatment would increase as time progressed. The tet genes and targeted antibiotics (except sulphonamides) at different depth profiles showed a similar change tendency, namely the concentrations of those remained at a consistently higher level in the surface layer of the soils system (P < 0.05). The targeted tetracyclines showed the highest concentration in the soils (61.73-998.9 mu g/kg) compared with the others antibiotics, and tet M (5.8x10(-1)-9.31x10(-2) for the relative abundance range) was the predominant tet gene in the all soil samples. However, due to the different physicochemical properties of the two kinds of soils, the behaviours of antibiotics and tet genes in the different soils also exhibited obvious difference. The presence of P. australis could play a role in reduction of sulfonamides in the soils (P < 0.05), while the accumulated concentrations of tetracyclines, quinolones and macrolides in the soil systems with plant were similar to those in their unplanted equivalent (P > 0.05). Furthermore, there was not a significant influence of plant growth on the relative abundance of tet M, tet W and tet O in the soils (P > 0.05).