Abstract
This study was performed to increase the speed and sensitivity of the detection of E. coli O157: H7 in edible meats. We examined the efficiency and assay time of an improved enrichment culture procedure of the BAXTM screening system developed by Qua1icon Ltd. in the United States. The resu1ts are follows:
1) At 105 cfu/ml, the sensitivity of the PCR kit in detecting E. coli O157: H7 (VT2, VT 1, 2) in broth was less than that obtained by the culture method at 104 cfu/ml. On the other hand, the ability of the PCR kit to detect E. coli O157: H7 inoculated into edible beef, pork, chicken and calf/ox liver was greater than the culture method (1-40cfu/25g compared with 10-2, 100cfu/25g) except in the case of VT1, 2-producing strain in chicken.
2) An assay time of 40 hours was required with the culture method, but with the PCRkit, the assay time was only 25 hours. It is therefore possible to detect the presence of E. coli 0157: H7 in slightly over one day before a product is distributed.
3) Because the main reagents of the PCR kit were in tablet form, the whole PCR kit process was much simpler than that of the culture method. Consequently, the PCR kit is practical and useful.
4) Enrichment by shaking the culture shortened the time required for the PCR kit from 20 to 10 hours.
