Although eye area cosmetics contain preservatives, contamination can still occur during or\nafter manufacture or through use. Understanding the likelihood of bacterial survival in eye creams\nbegins with sensitive and accurate methods for the detection of bacterial contamination; therefore,\nwe investigated optimal culture conditions, including neutralizers, dilution broths, and selective\nmedia for the detection of Bacillus in eye cream. Samples of three different brands of eye creams\nwere first mixed with Tween 80, Tween 20, or a blend of Tween 60 and Span 80, then neutralized and\nnon-neutralized samples were individually inoculated with B. cereus strains, B. mycoides, a mislabeled\nB. megaterium, B. subtilis or B. thuringiensis at a final concentration of 5 log CFU/g. The inoculated\nsamples, with and without neutralizers, were spiral-plated and incubated at 30 ââ??¦C for 24 h to\n48 h. Presumptive colonies of Bacillus were enumerated on U. S. Food and Drug Administration\nBacteriological Analytical Manual (FDA-BAM) referenced agars Bacillus cereus rapid agar (BACARA)\nand mannitol-egg yolk-polymixin agar (MYP). Our results show significant differences among the\nneutralizers, plates, and products. The combination of Tryptone- Azolectin-Tween and Tween 80\n(TAT and T80) produced higher levels of Bacillus, estimated at 4.18 log CFU/g compared to growth\non Modified letheen broth and Tween 80, which produced 3.97 log CFU/g (P < 0.05). Colony counts\nof B. cereus cells on MYP agar were significantly higher, than those on BACARA agar, showing\nan average of 4.25 log CFU/g versus 3.84 log CFU/g, respectively (P < 0.05). The growth of the\nstrain mislabeled B. megaterium ATCC 6458 on B. cereus selective agars BACARA and MYP agar\nled us to further investigations. We identified bi-pyramidal crystals among colonies of the strain,\nand subsequent PCR identified the cry 1 gene, indicating that strain was actually B. thuringiensis\nsubps. kurstaki.
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