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Abstract Bacillus cereus is one of the important food pathogenes
which may cause food poisoning. To investigate the relationship
between B. cereus group cells and their toxigenicities and to
develop rapid methods for the detection of B. cereus group cells
and their hemolysin BL and/or B. cereus BceT enterotoxin is
important. Based on the gene sequences coding for phospholipase
C and sphingomyelinase, 16S rRNA, hblA of hemolysin BL B
component and bceT, we have developed some novel PCR primers for
the specific detection of B. cereus group cells and their genes
coding for hemolysin BL and/or BceT toxins. The molecular
weights generated from these PCR primers are 558 and 433 bp for
B. cereus cells and 691 as well as 297 bp for hemolysin BL and
BceT toxin, respectively. All the B. cereus group cells, such as
B. cereus, B. thuringiensis, B. mycoides and B. anthracis would
generate the expected PCR products with molecular weights equal
to 558 or 433 bp, depending on the primers used. Of the 54 B.
cereus strains tested, 18 were found to be hemolysin BL
producing strains and 22 were bceT gene containing strains. In
addition, for the 18 B. cereus strains containing hblA gene of
hemolysin BL B component, further confirmation of their
toxigenicity using blood agar hemolysis method and BCET-RPLA kit
were performed. Results indicate that the PCR method might be
used for the reliable detection of hemolysin BL productivity.
Also, none of the bacterial strains other than B. cereus group
cells would generate the false positive reaction. Thus,
specificities of these PCR primers were assured. For food
samples, such as whole milk, cooked pork, egg and cooked rice,
which were inoculated with B. cereus cells, if a 8 hr preculture
step was performed for target cells prior to the PCR, as low as
N×100 cells per gram of the food sample could be detected.
Also, the hemolysin BL and BceT toxin genes were detectable too.
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