Abstract
Pharmaceuticals and personal care products (PPCPs) such as antibiotics are widely used daily in hospitals and in the home, and are mainly excreted in urine. Treatments of PPCPs are not always sufficient and this may result in the occurrence of drag-tolerant microorganisms in the environment. In this study, the concentrations of the antibiotics levofloxacin (LVFX) and clarithromycin (CAM), total coliform count, fecal coliform count, dissolved DNA concentration, and TEM gene load in river water and discharges in Yodo River basin were analyzed and calculated. The concentrations of LVFX and CAM in the river, water samples and discharges were lower than the MICs, and E.coli JM109 grew on the LB agar plate with 100 ng · l-1 antibiotics. The dissolved DNA in the discharges was found to be approx. 3.4 times higher than that in the river water samples. Although the TEM gene load decreased, the loads of LVFX and CAM remained at least 40% of their cumulative values. Microorganisms were isolated in the presence of 60 μg · ml-1 ABPC, LVFX, CP, CM and VCM. 90% of the isolates from LVFX formed colonies in 60 μg · ml-1 of ABPC, CP, CM and VCM.
