A watershed study assessing effects of commercial hog operations on microbial water quality in North Carolina, USA
A watershed study assessing effects of commercial hog operations on microbial water quality in North Carolina, USA
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DOI：
10.1016/j.scitotenv.2022.156085
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发表时间：
2022-05-25
影响因子：
9.8
通讯作者：
Stewart, Jill
中科院分区：
文献类型：
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作者：
Christenson, Elizabeth;Wickersham, Lindsay;Stewart, Jill
商业养猪场（CHO）产生大量的粪便，这些粪便通常在泻湖中处理，并作为肥料喷洒到田间。与环境条件相比，这些系统对近端水质的影响尚未得到充分研究，对于了解粪便细菌的传播和抗菌素耐药性尤为重要。本研究采用纵向病例对照研究方法，研究了具有相似土壤、土地利用、人口和面积的流域中CHO对微生物水质的影响。我们比较了流域（n = 13）和（n = 9）CMO超过一年测量粪便指示细菌（FIB），微生物源跟踪（MST）粪便标记物，并在分离的大肠杆菌抗菌药物耐药性。E.与背景位点（687 CFU/100 mL，n = 74）相比，CHO下游位点（1284 CFU/100 mL，n = 103）的大肠杆菌浓度更高（p < 0.001）。在相似的低浓度下检测到人MST标志物HF 183（PR = 1.3（0.91，1.8），p = 0.30）。然而，在CMO下游的更多研究中心发现了猪MST标记物pig-2-bac（PR = 3.5（0.98，12），p = 0.035），并且与背景研究中心（0.76拷贝/mL）相比，CHO下游研究中心的平均浓度（283拷贝/mL）显著更高（p = 0.003）。任何抗菌药物耐药性的存在更经常观察到的E。大肠埃希菌在CHO下游的分离率（19%，n = 556）高于背景位点（6%，n = 356），四环素耐药率最高。来自CHO下游4个地点的9株分离株和来自背景地点的1株分离株被证实为产β-内酰胺酶的E.杆菌总的来说，这些结果表明，粪便微生物和来自CHO的抗菌素耐药性可能会转移到场外，但需要更多的研究来表征场外转移的时间和条件。缓解策略，如优化废物处理，缓冲区和抗生素管理，可以帮助减少微生物污染物对地表水的贡献。
Commercial Hog Operations (CHOs) produce large amounts of fecal waste, which is often treated in lagoons and sprayed onto fields as fertilizer. The effects of these systems on proximal water quality compared to ambient conditions have not been well-studied, and are particularly important for understanding the dissemination of fecal bacteria and antimicrobial resistance. A longitudinal, case-control watershed study was designed to study effects of CHOs on microbial water quality among watersheds with similar soil, land use, human population, and area. We compared water-sheds with (n = 13) and without (n = 9) CMOs over one year measuring fecal indicator bacteria (FIB), microbial source tracking (MST) fecal markers, and antimicrobial resistance in isolated Escherichia coli. E. coli concentrations were higher (p < 0.001) at sites downstream of CHOs (1284 CFU/100 mL, n = 103) compared to background sites (687 CFU/100 mL, n = 74). The human MST marker HF183 was detected at similarly low concentrations (PR = 1.3 (0.91, 1.8), p = 0.30). However, the swine MST marker pig-2-bac was found at more sites downstream of CMOs (PR = 3.5 (0.98, 12),p = 0.035) and at a significantly higher (p = 0.003) mean concentration at sites downstream of CHOs (283 copies/mL) compared to background sites (0.76 copies/mL). The presence of any antimicrobial resistance was observed more often for E. coli isolated downstream from CHOs (19%, n = 556) than background sites (6%, n = 356), with tetracycline resistance observed most often. Nine isolates from four sites downstream of CHOs and one isolate from a background site were confirmed beta-lactamase-producing E. coli. Overall, these results show that fecal microbes and antimicrobial resistance from CHOs may be transported off-site, however more research is needed to characterize timing and conditions of off-site transport. Mitigation strategies such as optimizeation of waste treatment, buffers, and antibiotic stewardship could help reduce the contributions of microbial contaminants to surface water.