生菜表面肠炎沙门氏菌(ATCC13076)的吸附及其清除

Adsorption and Elimination of Salmonella enteritidis (ATCC13076) on the Lettuce

为了控制生鲜蔬菜上沙门氏菌的污染,本研究以肠炎沙门氏菌(ATCC13076)为研究对象,探索了其在生菜表面吸附的影响因素,同时比对了含氯消毒剂和裂解噬菌体对生菜上粘附沙门氏菌的清除效果。结果表明:随着温度的升高(4~32℃)和作用时间的延长(5~60 min),肠炎沙门氏菌在生菜表面的吸附量呈增加趋势(3.59~5.20 log cfu/cm^2)。用10 mg/mL次氯酸钠处理受污染的生菜,在作用2 h时达到最大清除量(3.83 log cfu/cm^2),随着作用时间的延长(0~48 h)清除量呈不断下降的趋势;而噬菌体随着感染复数MOI值的增加(0.1、1、10)与作用时间的延长(0~48 h),对肠炎沙门氏菌的清除量逐渐增加,在4℃和24℃时,对肠炎沙门氏菌的最高清除量分别为1.75 log cfu/cm^2和1.80 log cfu/cm^2。因此,肠炎沙门氏菌在生菜上的吸附量受到温度、作用时间和pH的影响,与含氯消毒剂相比,噬菌体可以安全有效的清除生菜上沙门氏菌。本研究可以为食源性病原微生物在生鲜蔬菜中的清除提供理论支撑与技术指导。

In order to control the Salmonella contamination on fresh vegetables, in this study, the influences of S. Enteritidis(ATCC13076) adsorption capacity on the lettuce surface under different culture conditions(temperature, pH, ionic concentration) were explored. And then, the effects of chlorine-containing disinfectant and phage on the decrease of S. Enteritidis adhering to the lettuce were compared. The results showed that with the increase of temperature(4~32 ℃) and incubation time(5~60 min), the adsorption of S. Enteritidis on the surface of lettuce increased(3.59~5.20 log cfu/cm^2). Then the contaminated lettuce was treated with 10 mg/mL sodium hypochlorite and phage suspension, respectively. The eliminating effect of sodium hypochlorite showed a decreasing trend with increase of incubation time, and the maximum eliminating effect was 3.83 log cfu/cm^2 within 2 h, while eliminating effect by phage was increased in different MOI, incubation time and temperature. At 4 ℃and 24 ℃, the highest eliminating effect of S. Enteritidis on lettuce were 1.75 log cfu/cm^2 and 1.80 log cfu/cm^2, respectively. Therefore, the adsorption of S. Enteritidis on the lettuce were effected by the temperature, time and pH. And compared with sodium hypochlorite, bacteriophage can decrease S. Enteritidis on the lettuce in a safe and effective manner. This study provided a theoretical foundation for further study on the elimination of food-borne bacteria on fresh vegetables.