title: Occurrence of chloramphenicol-resistance genes as environmental pollutants from swine feedlots.
abstract: Chloramphenicol-resistance genes could be propagated to the surrounding environment via agricultural application of swine waste. This study investigated the potential risks of chloramphenicol-resistance genes from swine feedlots and their surrounding environment. We applied a culture-independent method to investigate levels of chloramphenicol-resistance genes in the wastewater from swine feedlots and the correspondingly impacted agricultural fields in Beijing. The cmlA, floR, fexA, cfr, and fexB genes were present in all samples, with the highest absolute concentrations of 1.50 × 10(6) copies/g in soil and 6.69 × 10(6) copies/mL in wastewater. The concentration of chloramphenicol residue was determined by ultra performance liquid chromatography-electrospray tandem mass spectrometry (UPLC-MS/MS), with the highest concentrations of 0.83 ng/g in soil and 11.5 ng/mL in wastewater. Significant correlations were found between chloramphenicol-resistance genes and chloramphenicol residues (r = 0.79, p = 0.0008) as well as between chloramphenicol-resistance genes in swine feedlots and corresponding agricultural soils (r = 0.84, p = 0.02). Consequently, swine feedlot wastewater could become a source of chloramphenicol-resistance genes, which could then lead to the spread of antibiotic resistance and eventually pose a risk to public health. To our knowledge, this is the first study to examine the occurrence of floR, fexA, cfr, and fexB genes in the environment using a culture-independent method.
authors: Key Laboratory of Development and Evaluation of Chemical and Herbal Drugs for Animal Use, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors: Juan
authors: J
authors: Li
authors: Bing
authors: B
authors: Shao
authors: Jianzhong
authors: J
authors: Shen
authors: Shaochen
authors: S
authors: Wang
authors: Yongning
authors: Y
authors: Wu
mesh_terms: D000821:Animal Feed / Q000032:analysis / Q000382:microbiology*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001419:Bacteria / Q000235:genetics*; D002701:Chloramphenicol / Q000494:pharmacology; D002702:Chloramphenicol Resistance; D004785:Environmental Pollutants / Q000378:metabolism*; D005798:Genes, Bacterial; D012988:Soil Microbiology; D013552:Swine; D062065:Wastewater / Q000032:analysis / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D002701:Chloramphenicol; D004785:Environmental Pollutants; D062065:Wastewater