Comparative Evaluation of Selective Media for the Detection of Bacillus cereus

Biocontrol Sci. 2019;24(4):221-227. doi: 10.4265/bio.24.221.

Abstract

The commercially available 3 types of selective media in Japan were compared for the detection of Bacillus cereus. When assessed inclusivity using 25 B. cereus strains, MYP agar, NGKG agar, and chromogenic X-BC agar demonstrated excellent inclusivity. For exclusivity study using 50 non-B. cereus strains, MYP, NGKG, and X-BC allowed to grow 11, 7, and 3 strains, respectively. Of the grown bacteria on each strains tested, only 2 strains of B. thuringiensis formed typical B. cereus colonies on all selective media tested. The NGKG and X-BC were compared with MYP as a reference using artificially contaminated food (fried rice, plain rice, fried noodle, and potato salad ), since MYP is recommended in ISO 7932: 2004. The both correlation coefficients between NGKG and MYP, and X-BC and MYP were 0.999. Therefore, we demonstrated that NGKG and X-BC can be adapted to ISO 7932: 2004 method for selected food as well as MYP.

Keywords: Bacillus cereus; Detection; ISO 7932: 2004; Selective medium.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Agar
  • Bacillus cereus / growth & development
  • Bacillus cereus / isolation & purification*
  • Bacillus thuringiensis / growth & development
  • Bacillus thuringiensis / isolation & purification
  • Bacterial Load
  • Culture Media* / chemistry
  • Food Contamination
  • Food Microbiology* / standards
  • Food Safety
  • Humans
  • Japan

Substances

  • Culture Media
  • Agar