Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620-7115, United States.
J Microbiol Methods. 2011 Dec;87(3):338-42. doi: 10.1016/j.mimet.2011.09.010. Epub 2011 Oct 1.
The purpose of this study was to develop a detection method for viable E. coli O157:H7 in fresh produce and recreational water. The method was evaluated using eight samples of produce wash and recreational water with or without spiked E. coli O157:H7 at ≤10(2) CFU·ml(-1) and concentrated using dead-end ultrafiltration (DEUF) to produce primary and secondary retentates. Fifty-four matrix replicates of undiluted secondary retentates or dilutions (1:2 or 1:10 in buffer) were evaluated using an IMS/ATP bioluminescence assay (IMS/ATP). Combining primary and secondary DEUF yielded a 2-4 log(10) increase in E. coli O157:H7 concentrations in spiked samples and resulted in signal-to-noise ratios 2-219 fold higher than controls, depending on the sample type. DEUF increased the concentration of E. coli O157:H7 to within the detectable limits of IMS/ATP. The combined assay provided detection of viable E. coli O157:H7 in produce and recreational water. Accurate detection of microbial pathogens using DEUF and IMS/ATP could reduce disease outbreaks from contaminated water sources and food products.
本研究旨在开发一种用于检测新鲜农产品和娱乐水中存活的大肠杆菌 O157:H7 的方法。该方法使用 8 份带有或不带有浓度为 ≤10(2) CFU·ml(-1)的大肠杆菌 O157:H7 污染的农产品清洗液和娱乐用水样本进行评估，并使用死端超滤（DEUF）浓缩以产生初级和次级截留物。使用 IMS/ATP 生物发光检测法（IMS/ATP）对未经稀释的次级截留物或稀释物（在缓冲液中 1:2 或 1:10）的 54 个基质重复样本进行评估。初级和次级 DEUF 的结合使污染样本中大肠杆菌 O157:H7 的浓度增加了 2-4 个对数（10），并且取决于样品类型，信号与噪声的比值比对照高 2-219 倍。DEUF 将大肠杆菌 O157:H7 的浓度提高到 IMS/ATP 的检测限内。联合检测法可用于检测农产品和娱乐水中的存活大肠杆菌 O157:H7。使用 DEUF 和 IMS/ATP 准确检测微生物病原体可以减少由污染水源和食品引起的疾病爆发。
