A new rapid and sensitive detection method for cereulide-producing Bacillus cereus using a cycleave real-time PCR.
OBJECTIVE
To develop a rapid and sensitive detection method for cereulide-producing Bacillus cereus using a real-time PCR based on the sequence of the cereulide synthesis gene.


RESULTS
A total of 56 cereulide-producing B. cereus and 15 cereulide-negative strains were tested. We designed specific primers and probes 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 showed positive for all samples.


CONCLUSIONS
The performance of the assay was highly reproducible and specific for cereulide-producing B. cereus. The positive detection was obtained within only 2 h for cereulide-producing strains. The detection limit of this assay was evaluated as 10(4) CFU g(-1) food sample. The assay also confirmed that strains from systemic infectious cases were cereulide-negative.


CONCLUSIONS
This assay is applicable for contaminated foods as well as specimens from infectious disease cases. We recommend this assay for routine examination of suspected B. cereus food poisonings.
Nagoya City Public Health Research Institute, Nagoya, Japan.
M
M
Yabutani
N
N
Agata
M
M
Ohta
D001409:Bacillus cereus / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D047630:Depsipeptides / Q000378:metabolism*; D005506:Food Contamination / Q000032:analysis; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity
D001426:Bacterial Proteins; D047630:Depsipeptides; C089294:cereulide