Szabo Richard A, Speirs Joan I, Akhtar Mumtaz
Bureau of Microbial Hazards, Food Directorate, Health Protection Branch, Health and Welfare Canada, Tunney's Pasture, Ottawa, Ontario, Canada K1A 0L2.
J Food Prot. 1991 Apr;54(4):272-276. doi: 10.4315/0362-028X-54.4.272.
In rice, milk, and brain-heart-infusion cultures, 17 of 67 Bacillus cereus strains produced a heat-stable toxin causing morphological changes in cultures cells. All of the positive strains were associated with illness, eight with the emetic syndrome. Time-temperature studies indicated that toxin production was optimum at 25 to 30°C after 18 h in shaking culture, but low levels were produced at 15°C. Effects in cells included granulation, vacuole formation, cell rounding, acid production, and arrested cell multiplication. Of seven cell lines tested, Int 407, CHO, and HEp-2 were equally the most sensitive with the former being preferred for ease of interpreting results. The observed toxin had a molecular weight of about 14,000 and a pI of 5.9 as determined by Superose 12 chromatography and Mono P ion-exchange chromatofocusing, respectively.
在大米、牛奶以及脑心浸液培养基中，67株蜡样芽孢杆菌中有17株产生了一种热稳定毒素，该毒素可导致培养基中的细胞发生形态变化。所有阳性菌株都与疾病有关，其中8株与呕吐综合征有关。时间-温度研究表明，在振荡培养18小时后，毒素产生的最佳温度为25至30°C，但在15°C时产生的毒素水平较低。对细胞的影响包括颗粒化、液泡形成、细胞变圆、产酸以及细胞增殖停滞。在测试的7种细胞系中，Int 407、CHO和HEp-2同样是最敏感的，由于易于解释结果，前者更受青睐。通过Superose 12色谱法和Mono P离子交换色谱聚焦法分别测定，观察到的毒素分子量约为14,000，pI为5.9。
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