Distribution Characteristics of Antibiotic Resistance Bacteria and Related Genes in Urban Recreational Lakes Replenished by Different Supplementary Water Source
Abstract The objective of this study was to investigate the distribution characteristics of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in urban recreational water with different water supply sources, 2 lakes as XQ and FQ which represented as surface water and reclaimed water were selected for the study. Water samples were collected from April to November in 2018 to investigate aspects including 8 physical and chemical indexes of waters, resistance degree of 5 different kinds of antibiotics, antimicrobial resistance heterotrophic bacteria content, resistance phenotype, antibiotic resistance gene types and antibiotic resistance strains of species distribution. The results showed that the changes of antibiotic resistance rate of heterotrophic bacteria in 2 lakes to 5 kinds of antibiotics were synchronous with time, and it would reach its maximum in autumn. The detection of 10 ARGs and intⅠ gene in 80 strains screened out from 125 strains of heterotrophic bacteria showed that the detection rate of tetG and tetA genes was relatively high, especially intI, with the rate as high as 90%. In the detection of resistance spectrum, 51.25% of the resistance bacteria were double-resistance to AMP-CTX. The 80 isolate strains were of 9 genera and 19 species, among which Bacillus cereus, Escherichia coli, Aeromonas veronii, Aeromonas caviae and Raoultella ornithinolytica were the common ARB species in FQ and XQ. There was no relatively large differences in the content of ARB, detection rate, and identification of ARGs in 2 lakes. Correlation analysis was used to evaluate the association between the change of water quality indexes and the content of antibiotic resistance bacteria in 2 lakes, and it was found that the water temperature was significantly correlated with the content of ARB in Sulfamethoxazole and Cefotaxime (p<0.05), while there were no other correlations between the changes of other water quality indexes and the content of ARB (p>0.05).