A new rapid and sensitive detection method for cereulide-producing Bacillus cereus using a cycleave real-time PCR.

摘要

A rapid and sensitive detection method was developed for cereulide-producing Bacillus cereus using a real-time PCR based on the sequence of the cereulide synthesis gene. A total of 56 cereulide-producing B. cereus and 15 cereulide-negative strains were tested. Specific primers and probes were designed for the detection of cereulide-producing B. cereus. The new cycleave real-time PCR assay gave positive detections for all of 56 cereulide-producing B. cereus strains, whereas all other strains including 10 systemic infectious disease strains were negative. No cross-reaction was observed and the internal control was positive for all samples. Performance of the assay was highly reproducible and specific for cereulide-producing B. cereus. Positive detection was obtained within only 2 h and the detection limit was 104 cfu/g food sample. The assay also confirmed that strains from systemic infectious cases were cereulide-negative. It is suggested that this assay is applicable to contaminated foods as well as specimens from infectious disease cases; it is recommended for routine examination of suspected B. cereus food poisonings.