Wong H C, Chang M H, Fan J Y
Department of Microbiology, Soochow University, Taipei, Taiwan, Republic of China.
Appl Environ Microbiol. 1988 Mar;54(3):699-702. doi: 10.1128/aem.54.3.699-702.1988.
A total of 293 dairy products purchased from local markets were examined to determine the incidence of and characterize Bacillus cereus. Isolations were made on mannitol-egg yolk-polymyxin B agar medium and confirmed by several staining and biochemical tests. B. cereus occurred in 17% of fermented milks, 52% of ice creams, 35% of soft ice creams, 2% of pasteurized milks and pasteurized fruit- or nut-flavored reconstituted milks, and 29% of milk powders, mostly in fruit- or nut-flavored milk mixes. The average population of B. cereus in these dairy products was 15 to 280 CFU/ml or CFU/g (range, 5 to 800). The characteristics of these B. cereus isolates in terms of heat resistance, biochemical reactions, and antibiotic susceptibility were similar to previously reported data except for a higher utilization of sucrose. Some isolates were especially resistant to carbenicillin, nalidixic acid, streptomycin, and tetracycline. The MICs for the isolates were also determined. All of the tested isolates lysed rabbit erythrocytes; 98% showed verotoxicity, 68% showed cytotonic toxicity for CHO cells, and 3 of 11 selected isolates that showed strong hemolysin activity killed adult mice.
对从当地市场购买的293种乳制品进行了检测，以确定蜡样芽孢杆菌的发生率并对其进行特征描述。在甘露醇-蛋黄-多粘菌素B琼脂培养基上进行分离，并通过多种染色和生化试验进行确认。蜡样芽孢杆菌存在于17%的发酵乳、52%的冰淇淋、35%的软冰淇淋、2%的巴氏杀菌乳以及巴氏杀菌水果或坚果风味复原乳和29%的奶粉中，主要存在于水果或坚果风味的混合乳中。这些乳制品中蜡样芽孢杆菌的平均菌数为15至280 CFU/ml或CFU/g（范围为5至800）。这些蜡样芽孢杆菌分离株在耐热性、生化反应和抗生素敏感性方面的特征与先前报道的数据相似，但蔗糖利用率较高。一些分离株对羧苄青霉素、萘啶酸、链霉素和四环素具有特别的抗性。还测定了分离株的最低抑菌浓度。所有测试分离株均能裂解兔红细胞；98%表现出细胞毒素活性，68%对CHO细胞表现出细胞紧张性毒性，11株表现出强溶血素活性的选定分离株中有3株可致成年小鼠死亡。
