Richards A B, Renshaw H W, Sneed L W
Am J Vet Res. 1985 May;46(5):1215-20.
Pasteurella haemolytica (biotype A, serotype 1) isolates (n = 15) from the upper respiratory tract of clinically normal cattle, as well as from lung lesions from cases of fatal bovine pasteurellosis, were examined for the presence of bacteriophage after irradiation with UV light. Treatment of all P haemolytica isolates with UV irradiation resulted in lysis of bacteria due to the induction of vegetative development of bacteriophages. The extent of growth inhibition and bacterial lysis in irradiated cultures was UV dose-dependent. Bacterial cultures exposed to UV light for 20 s reached peak culture density between 60 and 70 minutes after irradiation; thereafter, culture density declined rapidly, so that by 120 minutes, it was approximately 60% of the original value. When examined ultrastructurally, lytic cultures from each isolate revealed bacteriophages with an overall length of approximately 200 nm and that appeared to have a head with icosahedral symmetry and a contractile tail. Cell-free filtrate from each noninduced bacterial isolate was inoculated onto the other bacterial isolates in a cross-culture sensitivity assay for the presence of phages lytic for the host bacterial isolates. Zones of lysis (plaques) did not develop when bacterial lawns grown from the different isolates were inoculated with filtrates from the heterologous isolates.
对从临床健康牛的上呼吸道以及致命性牛巴氏杆菌病病例的肺部病变中分离出的15株溶血巴斯德菌（生物型A，血清型1）进行紫外线照射后，检测其中噬菌体的存在情况。用紫外线照射所有溶血巴斯德菌分离株后，由于噬菌体的营养发育诱导，导致细菌裂解。照射培养物中生长抑制和细菌裂解的程度与紫外线剂量相关。暴露于紫外线20秒的细菌培养物在照射后60至70分钟达到培养物密度峰值；此后，培养物密度迅速下降，以至于到120分钟时，约为原始值的60%。超微结构检查时，每个分离株的裂解培养物显示噬菌体全长约200 nm，头部呈二十面体对称且有一个收缩尾。在交叉培养敏感性试验中，将每个未诱导细菌分离株的无细胞滤液接种到其他细菌分离株上，检测对宿主细菌分离株有裂解作用的噬菌体。当用来自异源分离株的滤液接种从不同分离株生长的细菌菌苔时，未出现裂解区（噬菌斑）。
