Scientific Publications by FDA Staff

J Microbiol Methods 2006 Jun;65(3):488-502

Microarray analysis of Bacillus cereus group virulence factors.

Sergeev N, Distler M, Vargas M, Chizhikov V, Herold KE, Rasooly A

Rasooly A, NCI, NIH, 6130 Execut Blvd,EPN,Room 6035A, Rockville, MD 20852 USA NCI, NIH, Rockville, MD 20852 USA US FDA, Ctr Devices & Radiol Hlth, Rockville, MD 20857 USA Univ Maryland, College Pk, MD 20742 USA US FDA, Ctr Biol Evaluat & Res, Rockville, MD 20857 USA

Bacillus cereus, B. thuringiensis and B. anthracis are closely related medically and economically important bacterial species that belong to the B. cereus group. Members of the B. cereus group carry genes encoding several important virulence factors, including enterotoxins, phospholipases and exotoxins. Since it is difficult to differentiate among B. cereus group members, and because Bacillus virulence factors are very important for pathogenesis, we explored the use of microarray-based detection of virulence factor genes as a tool for strain identification and for determining virulence. Our method requires an initial multiplex PCR amplification step, followed by identification of the PCR amplicons by hybridization to an oligonucleotide microarray containing genes for all three types of Bacillus virulence factors including B. anthracis virulence factors. The DNA chip described here contains 21 identical arrays used for analysis of seven samples in triplicates. Using the arrays, we found that virulence factors are present in several combinations in the strains analyzed. This work also demonstrates the potential of oligonucleotide microarrays for medical, food safety and biodefense analysis of microbial pathogens.