Determination of antimicrobial resistance and plasmid content of escheri̇chia coli strains isolated i̇n agri̇cultural water resources

This study aims to investigate the presence of Escherichia coli in four different water sources used for agricultural irrigation in Muş (province) and to determine the antimicrobial resistance and plasmid content of the strains. For this purpose, according to the "Su Kirliliği Kontrolü Yönetmeliği Numune Alma ve Analizi Metodları Tebliği", a total of 54 water samples were taken from the Murat River (M), Karasu Creek (K), Pond Yurt (GY) and Pond Fish (GB) water sources used as agricultural irrigation sources. Each water sample was filtered through a membrane filter with a pore diameter of 0.45 µm in a sterile membrane filtration device, filter paper was taken with sterile forceps and placed on Chromogenic Coliform Agar (CCA). The petri dishes were incubated at 37 oC for 24 hours. At the end of incubation, dark blue-purple colonies were transferred to Eosine Methylene Blue Agar (EMB) medium by streak culture method and incubated at 35 oC for 24 hours. Primers UAL-1939 (5'-TATGGAATTTCGCCGATTTTT-3') and UAR-2105 (5'-TGTTTGCCTCCTGCTGCTGCGG-3') designed specifically for the uidA gene region were used to confirm by PCR method that the pure colonies obtained were E. coli. To determine antibiotic resistance, the isolated E. coli strains were performed according to the disc diffusion method specified by the Clinical and Laboratory Standards Institute (CLSI). In our study, Ampicillin (AM, 10 µg), Gentamicin (CN, 10 µg), Chloramphenicol (C, 30 µg), Ciprofloxacin (CIP, 5 µg), Erythromycin (E, 15 µg), Kanamycin (K, 30 µg), Rifampicin (RA, 5 µg), Sulfamethoxazole (SMZ, 300 µg), Tetracycline (TE, 30 µg) and Vancomycin (VA, 30 µg) antibiotic discs were used. The plasmid contents of the isolated E. coli strains were determined. In addition, the DNAs belonging to the isolated E. coli strains were analyzed for relationships by using 27 RAPD primers. Optimal results were obtained with the use of OPA8 (5'-CCTGGGTGGA-3'), OPA29 (5'-AGGGCGTAAG-3'), OPA30 (5'-AAAACCGGGC-3') and OPA1247 (5'-AAGAGCCCGT-3') RAPD primers from the RAPD primers used. 34 E. coli strains isolated from 54 water samples were confirmed by the methods used. It was determined that these strains were resistant to erythromycin and rifampicin. As a result of RAPD analysis and plasmid content analysis, it was determined that the strains isolated from the same region showed high similarity. The presence of E. coli in waters poses a serious danger to public health. For this reason, it is of great importance to determine the antibiotic resistance profiles of E. coli strains in aquatic ecosystems.