@article {110,
	title = {Occurrences of three classes of antibiotics in a natural river basin: association with antibiotic-resistant Escherichia coli.},
	journal = {Environ Sci Technol},
	volume = {48},
	year = {2014},
	month = {2014 Dec 16},
	pages = {14317-25},
	abstract = {<p>To investigate the occurrence of antibiotics in urban rivers and their association with antibiotic-resistant Escherichia coli, 20 (fluoro)quinolone antibiotics (FQs), 16 tetracycline antibiotics (TCs) and their degradation products, and 25 sulfonamides (SAs) and some degradation products were determined in 45 river samples and 13 discharged wastewater samples collected from Wenyu River and its tributaries and 4 composite effluent samples from sewage treatment plants in Beijing, China. Fifteen FQs, eight TCs, including four degradation chemicals, and sixteen SAs, including four acetylated products, were detected in the river water. The SAs were the dominant antibiotic (total concentrations up to 3164.0 ng/L) in river water, followed by FQs (1430.3 ng/L) and TCs (296.6 ng/L). The sum concentrations for each class of detected antibiotic in the 13 discharge site samples were higher than those in river samples, up to 12326.7 ng/L for SAs, 6589.2 ng/L for FQs, and 730.1 ng/L for TCs, largely contributing to the high concentrations in the river basin. Log-linear regression analysis confirmed that the concentrations of FQs, TCs, and SAs in the Wenyu River basin were strongly correlated with the number of E. coli resistant to FQs (p \&lt; 0.05), TCs (p \&lt; 0.05), and SAs (p \&lt; 0.05), providing evidence for the environmental impacts of antibiotic usage.</p>},
	keywords = {Anti-Bacterial Agents, China, Drug Resistance, Bacterial, Environmental Monitoring, Escherichia coli, Fluoroquinolones, Rivers, Sulfonamides, Tetracyclines, Waste Water, Water Pollutants, Chemical},
	issn = {1520-5851},
	doi = {10.1021/es503700j},
	author = {Zhang, Qinqin and Jia, Ai and Wan, Yi and Liu, Hong and Wang, Kunping and Peng, Hui and Dong, Zhaomin and Hu, Jianying}
}
@article {121,
	title = {Molecular and physiological characterization of fluoroquinolone resistance in relation to uropathogenicity among Escherichia coli isolates isolated from Wenyu River, China.},
	journal = {Chemosphere},
	volume = {87},
	year = {2012},
	month = {2012 Mar},
	pages = {37-42},
	abstract = {<p>Increasing antibacterial resistance and pathogenicity in the environment is of growing concern due to its potential human risk. In the present study, 236 Escherichia coli isolates were collected from Wenyu River in China on drugless (48 isolates) and quinolone-containing plates (189 isolates). Their minimum inhibitory concentrations (MICs) were determined ranging from 0.125 μg mL(-1) to 128 μg mL(-1). Mutation points related to fluoroquinolone resistance were observed at S83 to L and D87 to N or Y in the GyrA subunit and S80 to R or I and E84 to G in the ParC subunit. Generally, MICs of LEV and GAT are dependent on the patterns of these mutation points. The profile with three mutation points was related to LEV-resistant E. coli isolates, and the (S83L, D87N+S80I) mutation profile was most prevalent (65.7\%) in LEV-resistant isolates, while a large proportion of isolates, even those with three mutation points, were susceptive to GAT. The incidence of virulence factors in LEV-resistant isolates (44.7\%, 59/132) was much higher than in nonresistant isolates (23.1\%, 24/104) (χ(2)=11.925, 1{\textdegree} of freedom, p\&lt;0.001) indicating that fluoroquinolone-resistant E. coli would pose a potential risk. A similar distribution was also found in isolates resistant to GAT (χ(2)=7.843, 1{\textdegree} of freedom, p=0.0079).</p>},
	keywords = {Anti-Bacterial Agents, China, Drug Resistance, Bacterial, Escherichia coli, Fluoroquinolones, Rivers, Water Pollutants, Chemical},
	issn = {1879-1298},
	doi = {10.1016/j.chemosphere.2011.11.050},
	author = {Sun, Jianxian and Hu, Jianying and Peng, Hui and Shi, Jiachen and Dong, Zhaomin}
}
