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

Area of Science:

• Microbiology
• Food Safety
• Molecular Diagnostics

Background:

• Bacillus cereus can produce cereulide, a toxin causing food poisoning.
• Existing detection methods for cereulide-producing B. cereus can be slow or lack specificity.

Purpose of the Study:

• To develop a rapid and sensitive real-time PCR assay for detecting cereulide-producing Bacillus cereus.
• To utilize the cereulide synthesis gene sequence for specific pathogen identification.

Main Methods:

• Design of specific primers and probes targeting the cereulide synthesis gene.
• Validation of the real-time PCR assay using 56 cereulide-producing B. cereus strains and 15 non-producing strains.
• Testing for cross-reactivity with other bacterial strains, including those from systemic infections.

Main Results:

• The developed real-time PCR assay successfully identified all 56 cereulide-producing B. cereus strains.
• No cross-reactivity was observed with other tested strains, including 10 from systemic infections.
• The assay demonstrated high specificity and reproducibility.

Conclusions:

• The real-time PCR assay provides a rapid (within 2 hours) and specific method for detecting cereulide-producing B. cereus.
• The assay has a detection limit of 10(4) CFU/g in food samples.
• This method is suitable for routine examination of foodborne B. cereus poisoning and clinical specimens from infectious disease cases.