Foodborne bacteria are typically present at very low concentrations in food. This study describes a quick and simple method for concentrating E. coli O157:H7 present in lettuce and cabbage, without microbial enrichment culture. This method involved reducing the extraction buffer and DNA elution volumes. The extraction buffer volume was adjusted to 225, 100, 50, 25, and 12.5 mL to isolate E. coli O157:H7 from 25 g of lettuce or cabbage. DNA was concentrated and compared using real-time PCR. When using 12.5 mL of buffer, < 4 CFU/g of E. coli O157:H7 could be detected within 2 h without enrichment. This result is 100-fold sensitive than pretreatment with of the conventional method using 225 mL. It is suggested that this method could contribute to the prevention of food poisoning accidents in institutional catering settings, such as schools or military facilities, by the rapid and sensitive detection of pathogens without special equipment prior to food consumption stages.

食源性细菌通常以非常低的浓度存在于食物中。这项研究描述了一种无需微生物富集培养即可浓缩生菜和卷心菜中存在的大肠杆菌O157：H7的快速简便方法。该方法涉及减少提取缓冲液和DNA洗脱量。将提取缓冲液的体积调整为225、100、50、25和12.5 mL，以从25 g的生菜或卷心菜中分离出O157：H7大肠杆菌。浓缩DNA并使用实时PCR进行比较。当使用12.5 mL缓冲液时，<4 CFU / g大肠杆菌在不富集的情况下，可以在2小时内检测到O157：H7。该结果比使用225 mL的常规方法预处理的灵敏度高100倍。有人建议，这种方法可以通过在食物消费阶段之前无需特殊设备对病原体进行快速而灵敏的检测，从而有助于预防诸如学校或军事设施等机构饮食环境中的食物中毒事故。