标题：Rapid and Specific Detection of Escherichia coli O157:H7 in Ground Beef Using Immunomagnetic Separation Combined with Loop-Mediated Isothermal Amplification
期刊名称：Polish Journal of Food and Nutrition Sciences
印刷版ISSN：1230-0322
电子版ISSN：2083-6007
出版年度：2018
卷号：68
期号：2
页码：115-123
DOI：10.1515/pjfns-2017-0014
语种：English
出版社：Walter de Gruyter GmbH
摘要：Escherichia coli O157:H7 is well known for many foodborne outbreaks that lead to fatal infections in human being worldwide. The objective of this study was to develop a rapid and sensitive method for detection of EHEC O157:H7 from ground beef using a method that combined immunomagnetic separation (IMS) with loop-mediated isothermal amplification (LAMP). The EHEC O157:H7 cells were separated with Dynabeads coated with anti- EHEC O157:H7 after a short enrichment for 4 h. Then, EHEC O157:H7 was identified by LAMP assay for amplifying and detecting the rfbE gene, which is highly conserved in all EHEC O157:H7 strains and exhibits strain-specifi c gene expression. The LAMP method results analyzed with real time turbidity measurements showed a high specificity and sensitivity, with a positive detection rate of amplifi cation of EHEC O157:H7 DNA diluted to a minimum equivalent concentration of 1.8 × 101 CFU/mL, which was 10 times more sensitive than the conventional PCR assay. The IMS followed with LAMP could capture and detect a bacterial concentration as low as 3×101 CFU/mL from the meat samples, which was close to the sensitivity of LAMP assay with pure culture. IMS combined with realistic LAMP method is a simple, rapid, highly specific gene amplifi cation technology that is suitable for implementing as a screening assay in basic laboratory and field test for detecting food contamination.
