Hutchison Scientific Ltd, Dundee, UK.
School of Veterinary Sciences, Food Microbiology, University of Bristol, Langford, UK.
J Appl Microbiol. 2017 Dec;123(6):1597-1606. doi: 10.1111/jam.13593. Epub 2017 Oct 22.
To determine the fate of Escherichia coli on vegetables that were processed through commercial wash treatments and stored under simulated retail conditions at 4°C or wholesale at fluctuating ambient temperatures (0-25°C, dependent on season).
Bovine slurry that was naturally contaminated with E. coli O145 was applied without dilution or diluted 1:10 using borehole water to growing potatoes, leeks or carrots. Manure was applied 1 week prior to harvest to simulate a near-harvest contamination event by manure deposition or an application of contaminated water to simulate a flooding event or irrigation from a contaminated water source. At harvest, crops were contaminated at up to 2 log cfu g . Washing transferred E. coli into the water of a flotation tank used for potato washing and did not completely remove all traces of contamination from the crop. Manure-contaminated potatoes were observed to contain 0·72 cfu E. coli O145 g after processing and retail storage. Manure-contaminated leeks harboured 0·73-1·55 cfu E. coli O145 g after washing and storage. There was no cross-contamination when leeks were spray washed. Washing in an abrasive drum resulted in less than perfect decontamination for manure-contaminated carrots. There were five post-distribution isolations from carrots irrigated with contaminated water 24 h prior to harvest.
Standard commercial washing and distribution conditions may be insufficient to reliably control human pathogenic E. coli on fresh produce.
Previous speculation that the cause of a UK foodborne disease outbreak was soil from imperfectly cleaned vegetables is plausible.
确定经过商业清洗处理并在 4°C 下模拟零售条件或在波动的环境温度（0-25°C，取决于季节）下批发储存的蔬菜上大肠杆菌的命运。
将自然污染有大肠杆菌 O145 的牛粪便不稀释或稀释 1:10 后，施用于生长中的土豆、韭菜或胡萝卜。粪便在收获前 1 周施用于模拟粪便沉积的接近收获的污染事件或应用污染水来模拟洪水事件或受污染水源的灌溉。在收获时，作物的污染程度高达 2 个对数 CFU g-1。清洗将大肠杆菌转移到用于土豆清洗的浮选槽的水中，但不能完全去除作物上的所有污染痕迹。处理和零售储存后，受粪便污染的土豆被观察到含有 0.72 CFU 大肠杆菌 O145 g-1。受粪便污染的韭菜在清洗和储存后含有 0.73-1.55 CFU 大肠杆菌 O145 g-1。当韭菜进行喷雾清洗时，没有交叉污染。在研磨桶中清洗导致受粪便污染的胡萝卜的去污效果不理想。在收获前 24 小时用污染水灌溉的胡萝卜中有五个分离株。
标准的商业清洗和分销条件可能不足以可靠地控制新鲜农产品上的人源致病性大肠杆菌。
之前推测英国食源性疾病爆发的原因是未完全清洗的蔬菜上的土壤，这是合理的。
