Efficacy of Compact Dry EC for Coliform Detection in Seafood

摘要

The Compact Dry EC (CD-EC) plate is ready-to-use test method for the enumeration of Escherichia coli and coliform bacteria in food. The plates are pre-sterilized and contained culture medium with a cold water-soluble gelling agent. The medium is re-hydrated with1ml of diluted sample inoculated onto the center of the self-diffusible medium; allowing the solution to diffuse by capillary action. The plate can be incubated at 35。C for 20—24hr and the colonies counted without any further working steps.The CD-EC plate method was compared with the violet red bile agar (VRBA) and MPN of the FDA-BAM methods. The correlation coefficients were 0.96 between the CD-EC plate and VRBA methods, and 0.85 between the CD-EC plate and MPN methods. Of the142 red/pink-colony-forming isolates from the CD-EC plate method,116 isolates were identified as Enterobacteriaceae. Blue/blue purple-colonies on the CD-EC plate method were found in 8 samples. E. coli was detected in 5 samples, however the isolates from 3 samples were identified as Escherichia vulneris. These results suggest that the CD-EC plate method is useful for screening test on the spot for E. coli and coliform bacteria in seafood.