Ahmed R, Sankar-Mistry P, Jackson S, Ackermann H W, Kasatiya S S
Ontario Public Health Laboratory, Ottawa, Canada.
J Clin Microbiol. 1995 Mar;33(3):636-40. doi: 10.1128/jcm.33.3.636-640.1995.
Bacillus cereus is responsible for an increasing number of food poisoning cases. By using 12 bacteriophages isolated from sewage, a typing scheme for B. cereus isolates from outbreaks or sporadic cases of food poisoning was developed. The phages belonged to three morphotypes. Ten phages with contractile tails and icosahedral heads were members of the Myoviridae family, and two phages with noncontractile tails belonged to the Siphoviridae family. Phage 11 represented a new species. It had an isometric head and a very long contractile tail with long wavy tail fibers and was one of the largest viruses known. The vast majority of 166 B. cereus strains (161, or 97%) isolated from food poisoning cases were typeable. Of 146 strains isolated from 18 outbreaks, 142 (97%) could be divided into 17 phage types. A good correlation, on the order of 80 to 100%, between phage types of strains isolated from suspected foods and those of strains isolated from stools of symptomatic patients was observed. Most Bacillus thuringiensis strains were also typeable, providing further evidence of the close relatedness of B. cereus and B. thuringiensis. This phage typing scheme can be a valuable epidemiological tool in tracing the origins of food poisoning caused by B. cereus.
蜡样芽孢杆菌导致的食物中毒病例数量日益增加。通过使用从污水中分离出的12种噬菌体，开发了一种针对食物中毒暴发或散发病例中分离出的蜡样芽孢杆菌菌株的分型方案。这些噬菌体属于三种形态类型。十种具有收缩尾和二十面体头部的噬菌体属于肌尾噬菌体科，两种具有非收缩尾的噬菌体属于长尾噬菌体科。噬菌体11代表一个新物种。它有一个等轴面体头部和一条非常长的收缩尾，尾纤维长且呈波浪状，是已知最大的病毒之一。从食物中毒病例中分离出的166株蜡样芽孢杆菌菌株中的绝大多数（161株，即97%）可进行分型。从18起暴发中分离出的146株菌株中，142株（97%）可分为17种噬菌体类型。观察到从疑似食品中分离出的菌株与从有症状患者粪便中分离出的菌株的噬菌体类型之间存在80%至100%的良好相关性。大多数苏云金芽孢杆菌菌株也可进行分型，这进一步证明了蜡样芽孢杆菌和苏云金芽孢杆菌的密切相关性。这种噬菌体分型方案在追踪蜡样芽孢杆菌引起的食物中毒来源方面可能是一种有价值的流行病学工具。
