Department of Food Science and Human Nutrition, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611, USA.
J Food Prot. 2018 Jan;81(1):150-157. doi: 10.4315/0362-028X.JFP-17-226.
With the increased consumption of fresh produce, a proportional increase in numbers of produce-related foodborne illness has been observed. An estimate of foodborne illness during 1998 to 2008 attributed ∼46% of the incidences to produce. Any foodborne illness associated with produce can have devastating consequences to the industry. The most recent data from the Centers for Disease Control and Prevention implicate leafy vegetables, vine-stalk vegetables, root vegetables, and sprouts as the most common cause of produce-related foodborne outbreaks. Excess rainfall or flooding, mainly by altering levels of soil moisture and oxygen content, affects the microbial community in soil. The goal of this research was to determine the survivability of a three-serovar Escherichia coli and a five-serovar Salmonella enterica cocktail in microcosms prepared with Candler sand (CS) and Orangeburg sandy loam (OSL) soils. Microcosms were prepared with low, medium, and high volumetric water contents and were incubated at 20 and 30°C. Serotyping was used to determine which E. coli or Salmonella serovar(s) from each cocktail persisted. Microcosm inoculation levels were ∼7.0 log CFU/g. Sampling for CS and OSL microcosms incubated at 20°C ended on day 364 and 357, respectively. The reduction of Salmonella and E. coli to below the limit of detection (extinction) in CS microcosms (incubated at 30°C at all volumetric water content [VWC] levels) was reached on day 168 and 56, respectively. Extinction of Salmonella and E. coli in OSL microcosms (incubated at 30°C at all VWCs) was reached on day 168 and 224, respectively. Of the Salmonella and E. coli serovars analyzed, Salmonella Javiana persisted the longest in both soil types, whereas E. coli O104:H4 and E. coli O145 persisted the longest in CS and OSL microcosms, respectively. Results from the current study suggest that soil type and temperature influenced pathogen persistence in CS and OSL soils more than moisture level and pathogen type.
随着新鲜农产品消费的增加，与农产品相关的食源性疾病的数量也相应增加。据估计，1998 年至 2008 年间，约有 46%的食源性疾病与农产品有关。任何与农产品相关的食源性疾病都可能给该行业带来毁灭性的后果。美国疾病控制与预防中心（Centers for Disease Control and Prevention）的最新数据显示，叶菜类、茎菜类、根茎类和芽菜类是导致与农产品相关的食源性疾病爆发的最常见原因。过量降雨或洪水，主要通过改变土壤水分和氧气含量水平，影响土壤中的微生物群落。本研究的目的是确定三种血清型大肠杆菌和五种血清型沙门氏菌 Enterica 鸡尾酒在 Candler 砂（CS）和橙堡砂壤土（OSL）土壤中微宇宙中的生存能力。微宇宙用低、中、高体积含水量制备，并在 20 和 30°C 下孵育。血清分型用于确定每个鸡尾酒中哪些大肠杆菌或沙门氏菌血清型（s）存活下来。微宇宙接种水平约为 7.0 log CFU/g。在 20°C 下孵育的 CS 和 OSL 微宇宙的采样分别于第 364 天和第 357 天结束。沙门氏菌和大肠杆菌的数量减少到检测限以下（灭绝），CS 微宇宙（在所有体积含水量[VWC]水平下 30°C 孵育）分别在第 168 天和第 56 天达到，OSL 微宇宙（在所有 VWC 下 30°C 孵育）在第 168 天和第 224 天达到。在所分析的沙门氏菌和大肠杆菌血清型中，沙门氏菌 Javiana 在两种土壤类型中存活时间最长，而大肠杆菌 O104:H4 和大肠杆菌 O145 在 CS 和 OSL 微宇宙中存活时间最长。本研究结果表明，土壤类型和温度对病原体在 CS 和 OSL 土壤中的持久性影响大于水分水平和病原体类型。
