ĐÁNH GIÁ TÌNH TRẠNG Ô NHIỄM KHÁNG SINH NHÓM QUINOLONE TRONG NƯỚC MẶT VÀ KIỂU HÌNH KHÁNG QUINOLONE CỦA Escherichia coli Ở MỘT SỐ KÊNH RẠCH TỈNH LONG AN

Abstract

Long An is a province with developing agriculture. However, improper agricultural wastewater treatment is polluting surface water in this area. One of the notable pollutants is Quinolone antibiotics which are widely used in animal husbandry. Residues of these antibiotics in the environment can increase the resistance and the antibiotic gene transmission of bacteria in surface water, especially E. coli. In this study, the culture method was used to quantify E. coli in the surface water samples collected in five places in Long An province (Lo Lu canal, Ong Sen sewer, Ap 2 canal, Cau Voi sewer, and Ba Lang canal). Next, the UPLC-MS/MS method was used to determine the residues of four Quinolone antibiotics (Levofloxacin, Ciprofloxacin, Norflocaxin, and Enrofloxacin) in the surface water samples mentioned above. Finally, the disk diffusion method was used to check the Quinolone antibiotic resistance types of the E. coli strains isolated from these areas. The results showed that E. coli was found in all 5 survey places, ranging from 2.4 x 10² to 9.3 x 10⁴ MPN/100 ml. In which 3/5 positions have the amount of E. coli exceeding the allowed threshold. In the Ap 2 canal, with Enrofloxacin values = 3.3 μL/L, Ciproflocaxin = 15.8 μL/L, Norflocaxin = 1.5 μL/L, Levofloxacin = 1.1 μL/L, we could conclude that this place was contaminated with antibiotics while four types of target antibiotics were not detected in the surface water samples collected from the remaining positions. Results also showed that E. coli is resistant to four target antibiotics at 4/5 (80%) surveyed locations except for the Ap 2 canal. This study provides some information and is an essential source of reference to propose timely and accurate water environment management solutions for Long An province in particular and other areas in general.