PCR-DGGE를 이용한 유기농 채소의 유해 미생물 신속 검지

In this study the polymerase chain reaction (PCR) combined with denaturing gradient gel electrophoresis (DGGE) was evaluated as a method permitting the rapid detection of pathogens in fresh originally grown vegetables. A universal primer (341GCf/534r) was selected for its ability to amplify the V3 region of 16S-rRNA genes in their target pathogens (Salmonella typhimurium, Pseudomonas fluorescens, Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, E. coli). The 194 bp fragments in PCR were successfully duplicated as expected. The amplified fragments of the same size from six different pathogens also showed good separation upon DGGE. The detection limit of PCR-DGGE for six pathogens in fresh-cut lettuces were over 105 CFU/g when sampled by stomaching. However, when the sampling method was changed from stomaching to shaking, the detection limit of six pathogens in organic vegetables was shown to increase by over 10¹ CFU/g, but only those of B. cereus were over 10³ CFU/g. Therefore, PCR-DGGE was shown to be a reliable method for the detection of pathogens in fresh-cut vegetables.