Quantitative detection of sulfonamides and tetracycline antibiotics and resistance genes in sewage farms

The emerging pollution of antibiotics and antibiotic resistance genes(ARGs) has gained great attention around the globe in recent years.In this study,high performance liquid chromatography-mass spectrometry(HPLC-MS) and real-time quantitative PCR(RT-PCR) were used for detecting occurrence of two tetracyclines [tetracycline(TC),oxtetracycline(OTC)],three sulfonamides [sulfamerazine(SDZ),sulfamethazine(SDMe),sulfamethoxazole(SMZ)],and 8 ARGs [sul(I),sul(II),sul(III),sul(A),tet(M),tet(O),tet(W),tet B(P)] in water samples collected from feedlot wastewater lagoons and irrigation ditch in Shanghai.The detection frequencies of the above 5 antibiotics were 100% in all samples.Antibiotics in feedlot wastewater lagoons are much higher than those in irrigation ditch.The total concentrations of sulfonamides and tetracyclines are 197.7~323.0μg﹒L-1 and 294.0~376.1μg﹒L-1 respectively.In the collected samples,both the absolute copies and the relative abundances of sulfonamide ARGs are higher than those of tetracycline ARGs.The highest relative abundance of sulfonamide ARGs is sul(A),and tet(W) is the highest among tetra-cycline ARGs,with the absolute copies 108.4108~1010.3728 and 106.18805~107.8874 respectively.All of the ARGs were detected in the two feedlot wastewater samples.7 ARGs,except for tet B(P),were detected in the irrigation ditch.In Pearson correlation analysis,almost no consistent positive correlations were found between ARGs and "their" antibiotics,except sul(Ⅲ) maintained a significant positive correlation with sulfonamide antibiotics.It indicated that the abundance of ARGs might be affected by other kinds of envi-ronmental factors besides antibiotics residues in aquatic environments.This study will help to know the pollution status of the antibi-otics and resistance genes in feedlot wastewater in Shanghai and provide valuable data for conducting further researches on pollution of antibiotic and ARGs in the Huangpu River.