USE OF BACTERIOPHAGE IN PREVENTION, DIAGNOSIS, AND TREATMENT OF HUMAN DISEASES

噬菌体如大肠杆菌噬菌体lambda已经被 作为研究的模型系统，进行了数十年的广泛研究 如基因调控和大分子组装等主题。我们有 利用有关Lambda和相关的信息库 噬菌体用于两个目的： (1)致突变物和致癌物的检测：我们开发了一种新的检测方法 用于检测小鼠体内含有的Lambda转基因的突变。 该检测只选择包含正向突变的噬菌体 Lambda CII基因，使用突变的(HFL)大肠杆菌宿主。此外 由于直接选择相对容易，这种分析的敏感性 无论是自发的还是化学诱导的突变都可以与 广泛使用的突变靶基因lacI，使CII检测成为一种 任何基于Lambda的突变噬菌体回收的有吸引力的替代方案 小鼠诱变试验系统。此外，我们的化验成本要低80倍 而不是使用Laci系统。我们的CII检测系统现已投入使用 全球范围内作为LACI系统的替代品。 (2)噬菌体疗法：多种药物的流行- 抗药性细菌病原体促使我们尝试增强 噬菌体的治疗效果。血凝素在临床上的应用 噬菌体作为抗菌剂被哺乳动物的能力所阻碍 宿主防御系统将噬菌体颗粒从循环中移除 系统。在我们关于细菌血症小鼠的研究中，为了减少噬菌体 被宿主防御系统淘汰，我们开发了一种连续通道 在小鼠中筛选能够在体内保留的噬菌体突变体的技术 更长时间的循环系统和孤立的长时间- 大肠杆菌噬菌体Lambda和沙门氏菌的循环突变株 鼠伤寒杆菌噬菌体P22。我们证明了长期循环的Lambda 突变体作为抗菌药物的能力也比 感染致死剂量马立克氏杆菌的动物的相应亲本菌株 细菌。亲本和突变型Lambda衣壳蛋白的比较 发现相关的突变改变了主要的噬菌体头部 蛋白E。 慢性感染的肠球菌种通常以 对药物万古霉素产生抗药性。我们已经分离并正在刻画 杀死这种抗药性菌株的噬菌体和细菌素。

Bacteriophages such as the Escherichia coli phage lambda have been studied extensively for several decades as model systems for the study of such topics as gene regulation and macromolecular assembly. We have taken advantage of the base of information about Lambda and related phages for two purposes: (1) Detection of mutagens and carcinogens: We developed a novel assay for the detection of mutations in a Lambda transgene contained in mice. The assay selects for phage containing forward mutations only in the Lambda cII gene, using a mutant (hfl) Escherichia coli host. In addition to the relative ease of direct selection, the sensitivity of this assay for both spontaneous and chemically induced mutation was comparable to the widely used mutational target gene lacI, making the cII assay an attractive alternative for mutant phage recovery for any Lambda-based mouse mutatgenesis assay system. Moreover, our assay costs 80 times less to use than the lacI system. Our cII assay system is now being used worldwide as a replacement for the lacI system. (2) Bacteriophage therapy: The increased prevalence of multidrug- resistant bacterial pathogens motivated us to attempt to enhance the therapeutic efficacy of bacteriophages. The therapeutic application of phages as antibacterial agents was impeded by the capacity of mammalian host defense systems to remove phage particles from the circulatory system. In our studies involving bacteremic mice, to reduce phage elimination by the host defense system, we developed a serial-passage technique in mice to select for phage mutants able to remain in the circulatory system for longer periods of time and isolated long- circulating mutants of E. coli phage Lambda and of Salmonella typhimurium phage P22. We demonstrated that the long-circulating Lambda mutants also have greater capability as antibaceterial agents than the corresponding parental strain in animals infected with lethal doses of bacteria. Comparison of the parental and mutant Lambda capsid proteins revealed that the relevant mutation altered the major phage head protein E. Chronically infective Enterococcus species are frequently found in forms resistant to the drug Vanomycin. We have isolated and are characterizing bacteriophages and bacteriocins that kill such drug resistant strains.