@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 {117,
	title = {Occurrence and source apportionment of sulfonamides and their metabolites in Liaodong Bay and the adjacent Liao River basin, North China.},
	journal = {Environ Toxicol Chem},
	volume = {30},
	year = {2011},
	month = {2011 Jun},
	pages = {1252-60},
	abstract = {<p>The presence of antibiotics in the environment is of great concern because of their potential for resistance selection among pathogens. In the present study we investigated the occurrence of 19 sulfonamides, five N-acetylated sulfonamide metabolites, and trimethoprim in the Liao River basin and adjacent Liaodong Bay, China, as well as 10 human/agricultural source samples. Within the 35 river samples, 12 sulfonamides, four acetylated sulfonamides, and trimethoprim were detected, with the dominant being sulfamethoxazole (66.6 ng/L), N-acetylsulfamethoxazole (63.1 ng/L), trimethoprim (29.0 ng/L), sulfadiazine (14.0 ng/L), and sulfamonomethoxine (8.4 ng/L); within the 36 marine samples, 10 chemicals were detected, with the main contributions from sulfamethoxazole (25.2 ng/L) and N-acetylsulfamethoxazole (28.6 ng/L). Sulfamethoxazole (25.9\%), N-acetylsulfamethoxazole (46.6\%), trimethoprim (22.9\%), and sulfapyridine (1.4\%) were the main chemicals from human sources, while sulfamonomethoxine, sulfamethazine, sulfaquinoxaline, sulfaguanidine, sulfadiazine, sulfanilamide, and sulfamethoxypyridazine were dominant in the animal husbandry sources, specifically, swine and poultry farms, and sulfamethoxazole (91\%) was dominant in the mariculture source. A principal component analysis with multiple linear regression was performed to evaluate the source apportionment of total sulfonamides in Liaodong Bay. It was found that animal husbandry contributed 15.2\% of total sulfonamides, while human sources contributed 28.5\%, and combined human and mariculture sources contributed 56.3\%. In addition, the mariculture contribution was 24.1\% of total sulfonamides into the sea based on mass flux estimation. The present study is the first report that the environmental levels of sulfonamide metabolites were comparable to the corresponding parents; therefore, we should pay attention to their environmental occurrence. Source apportionment showed human discharge (60.7\%) significantly contributed to these antibiotics in Liaodong Bay, which provides important information for environmental management.</p>},
	keywords = {Agriculture, Anti-Bacterial Agents, Aquaculture, China, Environmental Monitoring, Humans, Linear Models, Principal Component Analysis, Rivers, Seawater, Spectrometry, Mass, Electrospray Ionization, Sulfamethazine, Sulfamethoxazole, Sulfamethoxypyridazine, Sulfamonomethoxine, Sulfapyridine, Sulfaquinoxaline, Sulfonamides, Tandem Mass Spectrometry, Trimethoprim, Water Pollutants, Chemical, Water Pollution, Chemical},
	issn = {1552-8618},
	doi = {10.1002/etc.508},
	author = {Jia, Ai and Hu, Jianying and Wu, Xiaoqin and Peng, Hui and Wu, Shimin and Dong, Zhaomin}
}
