Prevalence of antibiotic resistance genes in antibiotic-resistant Escherichia coli isolates in surface water of Taihu Lake Basin, China

Abstract

The rapid development of antibiotic-resistant bacteria (ARB) has been of concern worldwide. In this study, antibiotic resistance genes (ARGs) were investigated in antibiotic-resistant Escherichia coli isolated from surface water samples (rivers, n = 17; Taihu Lake, n = 16) and from human, chicken, swine, and Egretta garzetta sources in the Taihu Basin. E. coli showing resistance to at least five drugs occurred in 31, 67, 58, 27, and 18% of the isolates from surface water (n = 665), chicken (n = 27), swine (n = 29), human (n = 45), and E. garzetta (n = 15) sources, respectively. The mean multi-antibiotic resistance (MAR) index of surface water samples (0.44) was lower than that of chicken (0.64) and swine (0.57) sources but higher than that of human (0.30) and E. garzetta sources (0.15). Ten tetracycline, four sulfonamide, four quinolone, five β-lactamase, and two streptomycin resistance genes were detected in the corresponding antibiotic-resistant isolates. Most antibiotic-resistant E. coli harbored at least two similar functional ARGs. Int-I was detected in at least 57% of MAR E. coli isolates. The results of multiple correspondence analysis and Spearman correlation analysis suggest that antibiotic-resistant E. coli in water samples were mainly originated from swine, chicken, and/or human sources. Most of the ARGs detected in E. garzetta sources were prevalent in other sources. These data indicated that human activities may have contributed to the spread of ARB in the aquatic environment.

Antibiotic resistance and virulence genes in coliform water isolates

“…This could be due to the fact that these antibiotics are most commonly produced and prescribed in human and veterinary medicine in Germany (GERMAP, and sulfamethoxazole/trimethoprim is not surprising in coliform bacteria isolated from surface water and the findings are consistent with published literature (Laroche et al, 2009;Ibekwe et al, 2011;Su et al, 2012;Koczura et al, 2012;Rosas et al, 2015;Kotlarska et al, 2015;Zhang et al, 2015). The assessment of antibiotic resistance in only water phase may lead to an underestimation of the health risk, as higher number of resistant E. coli have been reported in the sediment (Rosas et al, 2015).…”

“…isolates from rivers and Tai Lake (Zhang et al, 2015). Similarly, Su et al, 2012 reported presence of class 1 and 2 integrons in 83.2 % of 3456 E. coli strains isolated from the Dongjiang River catchment whereas, the occurrence of class 2 integrons in this study was very low (2 %).…”

“…However, widespread application of antibiotics in human and veterinary medicine has led to the emergence, selection, and dissemination of antibiotic resistant bacteria and genes encoding for antibiotic resistance in different environmental compartments such as surface water (Zhang et al, 2015;Stoll et al, 2012), groundwater (Li et al, 2014), drinking water (Schwartz et al, 2003;Guo et al, 2014) and sediments (Rosas et al, 2015) throughout the world. Antibiotic resistance genes (ARGs) and virulence genes (VGs) are emerging environmental contaminants (Pruden et al, 2006;Haack et al, 2009).…”

Presence of Antibiotics in Shallow Groundwater in the Northern and Southwestern Regions of China

“…In 2013, the total usage for 36 common antibiotics in China was 92,700 tons—it was estimated that 54,000 tons of these antibiotics was excreted by human and animals and 53,800 tons entered the environment with the help of discharged streams from numerous wastewater treatment facilities (Zhang et al ; Liu et al ). In China, antibiotics are widely detected in surface water (Wei et al ; Chen et al ; Tang et al ; Xiong et al ; Zhang et al ; Cheng et al ; Li et al ), soil, and sediments (Li et al ; Xie et al ; Wang et al ; An et al ; Gao et al ; Li et al ; Dong et al ; Xiang et al ; Zhao et al ). Until recently, very limited data on antibiotics in groundwater are available in China with only a few studies on groundwater samples from monitoring wells at Jianghan plain (central China [Yao et al , ] and 15 cities [Ma et al ] being reported).…”

Since 2015 the SinoGerman research project SIGN supports water quality improvement in the Taihu region, China

“…Furthermore, a large number of organo chemicals from different sources can be detected such as pesticides from agriculture [10], pharmaceuticals from the surrounding cities [11] and perfluorinated compounds from industrial production and use [12]. Another water quality issue is the occurrence of unwanted microbes such as bacteria carrying antibiotic resistance genes [13, 14]. …”