| Autor: |
Xi Xia, Zheng Wang, Yulin Fu, Xiang-dang Du, Binwen Gao, Yuqing Zhou, Junjia He, Yang Wang, Jianzhong Shen, Haiyang Jiang, Yongning Wu |
| Jazyk: |
angličtina |
| Rok vydání: |
2019 |
| Předmět: |
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| Zdroj: |
Environment International, Vol 127, Iss , Pp 361-370 (2019) |
| Druh dokumentu: |
article |
| ISSN: |
0160-4120 |
| DOI: |
10.1016/j.envint.2019.03.061 |
| Popis: |
Background: The extensive use of colistin in swine production may have contributed to the recent emergence of corresponding mobile resistance gene mcr-1. The use of colistin as a feed additive was banned in China in April 2017. Objectives: To examine the occurrence of colistin and dissemination of mcr-1 in swine feedlots before and after the colistin ban and effects of different manure treatments. Methods: Environmental samples were collected from swine feedlots before (December 2016) and after (December 2017) the colistin ban. Colistin concentrations were determined by ultra-high performance liquid chromatography coupled to tandem mass spectrometry. The prevalence of mcr-1 were determined by quantitative PCR analysis, while bacterial community composition was investigated by 16S rRNA sequencing. Results: In 2016, colistin was detected in feed and fresh manure samples at 67 mg/kg and 17 mg/kg, respectively, but was absent from all samples in 2017. In 2016, the relative abundance of mcr-1 in fresh manure was lower than that in solid samples after natural drying, while a higher relative abundance was detected in fresh manure samples compared with biogas slurry samples. A strong correlation between colistin concentration and relative abundance of mcr-1 was observed in fresh manure. The samples collected in 2017 showed a lower relative abundance of mcr-1 compared with those collected in 2016. Bacterial community analysis showed that the abundance of Enterobacteriaceae, which act as a vehicle and reservoir of mcr-1, increased with natural dying but decreased with anaerobic digestion. Conclusions: The presence of colistin exerts direct selection pressure for the accumulation of mcr-1 in manure, while the ban on colistin likely halted the dissemination of mcr-1 on pig farms. Anaerobic digestion is an effective waste treatment process for removing mcr-1, which might be mainly driven by the shift in bacterial community structure. Keywords: Colistin, mcr-1 gene, Wastewater treat process, Swine feedlot, Bacterial community |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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Full Text from ScienceDirect