Rapid Detection of Bacillus Cereus in Food by Real-Time Fluorescence PCR

Bacillus cereus gyrB gene was used as the target gene, and the specific primers were designed. The reaction procedure was as follows: predenaturation at 95℃ for 5 min, denaturation at 95 ℃ for 15 s, refolding at 50 ℃ for 30 s, extension at 72 ℃ for 30 s, 45 cycles of reaction. Bacillus cereus DNA was used as the template, and a rapid method for detection of Bacillus cereus in food was proposed by fluorescence quantitative polymerase chain reaction (PCR). Tests for specificity of the method, sensitivity of Bacillus cereus DNA and detection limit of live bacteria were carried out. As shown by the results, the primer could achieve rapid detection of Bacillus cereus in segmented amplification, and had good repeatability. 3 non-Bacillus cereus and Bacillus cereus were used for specificity test, and no amplification curve was found for non-Bacillus cereus, but the specific curve was found for Bacillus cereus. Sensitivity detection was performed for Bacillus cereus DNA in 10-fold serial dilutions, giving the result of 0.01 mg·L^-1, and detection limit of live bacteria was 8.9×10²CFU·mL^-1.