风暴径流对佐治亚州南部新鲜农产品农场灌溉池中的沙门氏菌和大肠杆菌流行率的影响。
Impact of storm runoff on Salmonella and Escherichia coli prevalence in irrigation ponds of fresh produce farms in southern Georgia.
机构信息
Bureau of Water Resources, St. Johns River Water Management District, Palatka, FL, USA.
Department of Crop and Soil Sciences, University of Georgia, Tifton, GA, USA.
出版信息
J Appl Microbiol. 2018 Mar;124(3):910-921. doi: 10.1111/jam.13689. Epub 2018 Feb 8.
AIMS
To examine Salmonella and Escherichia coli in storm runoff and irrigation ponds used by fresh produce growers, and compare Salmonella serovars with those found in cases of human salmonellosis.
METHODS AND RESULTS
We collected water before and after rain events at two irrigation ponds on farms in southern Georgia, USA, and collected storm runoff/storm flow within the contributing watershed of each pond. Salmonella and E. coli concentrations were higher in ponds after rain events by an average of 0·46 (P < 0·01) and 0·61 (P < 0·05) log most probable number (MPN) per 100 ml respectively. Salmonella concentrations in storm runoff from fields and forests were not significantly higher than in ponds before rain events, but concentrations in storm flow from streams and ditches were higher by an average of 1·22 log MPN per 100 ml (P < 0·001). Eighteen Salmonella serovars were identified from 155 serotyped isolates, and eight serovars were shared between storm runoff/storm flow and ponds. Seven of the serovars, including five of the shared serovars, were present in cases of human illness in the study region in the same year. However, several serovars most commonly associated with human illness in the study region (e.g. Javiana, Enteritidis, and Montevideo) were not found in any water samples.
CONCLUSIONS
Salmonella and E. coli concentrations in irrigation ponds were higher, on average, after rain events, but concentrations of Salmonella were low, and the ponds met FDA water quality standards based on E. coli. Some similarities and notable differences were found between Salmonella serovars in water samples and in cases of human illness.
SIGNIFICANCE AND IMPACT OF THE STUDY
This study directly examined storm runoff/storm flow into irrigation ponds and quantified increases in Salmonella and E. coli following rain events, with potential implications for irrigation pond management as well as human health.
目的
检测新鲜农产品种植者使用的暴雨水和灌溉池塘中的沙门氏菌和大肠杆菌，并将沙门氏菌血清型与人类沙门氏菌病病例中的血清型进行比较。
方法和结果
我们在美国佐治亚州南部的两个农场的两个灌溉池塘在下雨前后采集水样，并采集每个池塘集水区内的暴雨水/暴流水。雨后池塘中沙门氏菌和大肠杆菌的浓度平均分别增加了 0.46（P<0.01）和 0.61（P<0.05）个对数最可能数（MPN）/100ml。来自田地和森林的暴雨水的沙门氏菌浓度并不明显高于雨前池塘中的浓度，但来自溪流和沟渠的暴流水的浓度平均增加了 1.22 个对数 MPN/100ml（P<0.001）。从 155 个定型分离物中鉴定出 18 种沙门氏菌血清型，8 种血清型在暴雨水/暴流水和池塘之间共享。在同年研究区域的人类疾病病例中发现了 7 种血清型，包括 5 种共享血清型。然而，在任何水样中均未发现与研究区域人类疾病最常见相关的几种血清型（例如 Javiana、Enteritidis 和 Montevideo）。
结论
雨后灌溉池塘中的沙门氏菌和大肠杆菌浓度平均升高，但沙门氏菌浓度较低，并且池塘符合 FDA 基于大肠杆菌的水质标准。水样和人类疾病病例中的沙门氏菌血清型之间存在一些相似之处和显著差异。
研究的意义和影响
本研究直接检测了暴雨水进入灌溉池塘，并量化了降雨事件后沙门氏菌和大肠杆菌的增加，这对灌溉池塘管理以及人类健康都有潜在影响。
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