Isolation of Bacillus cereus from rice flour and rice flour based food samples and identification using classical and molecular methods

Bacillus cereus, which is widely found in nature, is a pathogenic bacteria that causes food poisoning in humans with complaints such as food spoilage on the one hand and vomiting and diarrhea on the other. In this study, a total of 192 food samples including rice flour and rice flour-based food samples supplied from Adana market were examined for the presence of Bacillus cereus. Only 10 of the 32 isolates isolated from the examined samples by classical method were defined as Bacillus cereus. 14 of the isolates were determined as Bacillus subtilis, 4 as Escherichia coli, 2 as Pseudomonas aeruginosa and 2 as Proteus mirabilis. The isolation was performed from 18 of 74 infant formula samples (24.3% proportionally) and 11 of 50 packed rice flour samples (22% proportionally) 3 of 10 unpackaged rice flour samples (30% proportionally). Also, the strains defined as Bacillus cereus by the classical method were also defined molecularly using the PCR technique. The RAPD-PCR method was used to determine the genotypic affinity of Bacillus cereus and all strains were included in the study. When the genetic affinity between Bacillus cereus strains was examined, it was seen that it remained at 70%. As a result; have been shown that strains to be genetically different from each other and not originated from a single source.