Islam Mahbub, Morgan Jennie, Doyle Michael P, Jiang Xiuping
Center for Food Safety, University of Georgia, 1109 Experiment Street, Griffin, Georgia 30223-1797, USA.
J Food Prot. 2004 Mar;67(3):574-8. doi: 10.4315/0362-028x-67.3.574.
Studies were done to determine the fate of Escherichia coli O157:H7 in manure compost-amended soil and on carrots and green onions grown in an environmentally controlled growth chamber. Commercial dairy cattle manure compost was inoculated with a five-strain mixture of green fluorescent protein-labeled E. coli O157:H7 at 10(7) CFU g(-1) and mixed with unsterilized Tifton sandy loam soil at a ratio of 1:5. Baby carrot or green onion seedlings were planted into the manure compost-amended soil in pots, and soil samples surrounding the plant, edible carrot roots and onion bulb samples, and soil immediately beneath the roots were assayed for E. coli O157:H7 in triplicate at weekly intervals for the first 4 weeks, and every 2 weeks for the remainder of the plant growth cycle (up to 3 months). E. coli O157:H7 cell numbers decreased within 64 days by 3 log CFU/g in soil and soil beneath the roots of green onions and by more than 2 log CFU/g on onions. E. coli O157:H7 survived better during the production of carrots, with a 2.3-log CFU/g reduction in soil and a 1.7-log CFU/g reduction on carrots within 84 days. These results indicate that the type of plant grown is an important factor influencing the survival of E. coli O157:H7 both on the vegetable and in the soil in which the vegetable is grown.
开展了多项研究，以确定大肠杆菌O157:H7在添加了粪肥堆肥的土壤中，以及在环境控制生长室内种植的胡萝卜和大葱上的存活情况。用绿色荧光蛋白标记的大肠杆菌O157:H7的五菌株混合物，以10(7) CFU g(-1) 的浓度接种到商业奶牛粪肥堆肥中，并与未灭菌的蒂夫顿沙壤土以1:5的比例混合。将小胡萝卜或大葱幼苗种植到装有添加了粪肥堆肥土壤的花盆中，在最初4周内每周对植株周围的土壤样本、可食用的胡萝卜根和葱球样本以及根部正下方的土壤进行三次大肠杆菌O157:H7检测，在植株生长周期的剩余时间（长达3个月）每2周检测一次。在64天内，土壤和大葱根部下方土壤中的大肠杆菌O157:H7细胞数量减少了3 log CFU/g，大葱上的减少了2 log CFU/g以上。在胡萝卜生长期间，大肠杆菌O157:H7存活得更好，在84天内土壤中的数量减少了2.3 log CFU/g，胡萝卜上减少了1.7 log CFU/g。这些结果表明，种植的植物类型是影响大肠杆菌O157:H7在蔬菜及其生长土壤中存活的重要因素。
