Effects of different wastewater treatment processes on occurrence and prevalence of antibiotic resistant bacteria and their resistance genes

This study aimed to explore the difference between hospital and municipal wastewater treatment processes regarding the reduction of antibiotic-resistant bacteria (ARB) and antibiotic resistant genes (ARGs). Samples were collected from raw and final effluent of four different wastewater treatment plants (WWTPs). ARB were evaluated by modified HPC method. Extraction and purification of DNA from the samples were conducted by Freeze-Thaw and DNA extraction kit. Real-time PCR (qPCR) was utilized to obtain the quantity of Sul1 and ErmB genes in the samples. For standard control in qPCR, was used plasmid containing each gene sequence. The average ARB concentration in the raw wastewater and effluent was 1.03�107-6.63�107 CFU/100mL. Quantitative range of the Sul1 and ErmB genes were obtained as 0-8.3�1010 Copies/100 mL and 9.29�105-9.64�109 Copies/100 mL, respectively. The results show that urban wastewaters play a more significant role than hospital wastewaters in the emission of sulfonamides and erythromycin-resistant bacteria and genes to the environment. Findings revealed that conventional wastewater treatment plants cannot be regarded as reliable barriers for the control of these agents. © 2020, Dorma Journals. All rights reserved