Bacillus cereus strains containing voitoxin cereulide are pathogenic bacteria. The cereulide is produced by B. cereus strains containing plasmid pCER270. To establish a specific loop‐mediated isothermal amplification (LAMP) method detecting pathogenic B. cereus, LAMP primer sets were designed based on 16SrDNA and pCER270 plasmid cesA sequence. The LAMP reaction was carried out under optimal conditions with 2 mM of Mg2+ at 65C for 1 h. Specificity of LAMP primers were validated by assaying 19 B. cereus strains with and without pCER270 plasmid and 42 non‐B. cereus species. Detection limits of the LAMP assay were 1 cfu/mL of B. cereus without pCER270 plasmid and 11 cfu/mL of pathogenic B. cereus with pCER270 plasmid. Furthermore, liquid milk samples were detected by the LAMP method. The results showed that LAMP method is a reliable method used for rapid detection of B. cereus and its pathogenic strains of milk and other food stuff. PRACTICAL APPLICATIONS Loop‐mediated isothermal amplification (LAMP) is a novel nucleic acid amplification method. In this study LAMP method was specific and sensitive for detection of B. cereus which grown in liquid medium or on solid medium, or from liquid milk samples as well. In addition, the pathogenic strains expressed voitoxin cereulide could be readily identified after amplification using specific LAMP primer sets. The whole procedure is simple and rapid, the reaction carried out in tens of minutes at a constant temperature. LAMP could be routinely used for B. cereus especially pathogenic strains in food.

ABSTRACT. Using rapid amplification of cDNA ends, a full-length cDNA sequence of a GDP-L-galactose phosphorylase-like gene was isolated from leaves infected by Erysiphe necator in the Chinese wild (Vitis pseudoreticulata) clone, 'Baihe-35-1', an E. necator-resistant genotype. The full-length cDNA, designated as VpVTC, comprised 1943 bp and putatively encodes a 453-amino acid polypeptide containing an HIT motif. The deduced amino acid sequence showed high similarity with that of VTC genes from other plants. The expression of VpVTC, determined by reverse transcriptase-polymerase chain reaction, was induced by E. necator and defense signaling molecules, including salicylic acid, methyl jasmonate, and ethephon, in 'Baihe-35-1', the V. quinquangularis genotype 'Shang-24', and the E. necator-susceptible A GGP-like gene from a Chinese wild Vitis species V. pseudoreticulata genotype, 'Hunan-1'. Transcript levels of VpVTC correlated well with the degree of disease resistance in the 3 genotypes. Maximum induction of VpVTC by E. necator (>7-fold at 96 h postinoculation) occurred in 'Baihe-35-1', which also showed the fastest response to signaling molecules. Upregulating the expression of VpVTC in 'Baihe-35-1' resulted in a gradual increase in the ascorbic acid concentration of leaves inoculated with E. necator. Furthermore, VpVTC was expressed in leaves, stems, inflorescence, tendrils, and fruit at all developmental stages, with the highest level occurring in fruit 35 days after flowering.