Use of Bacteriophage in the Prevention, Diagnosis, and T

我们一直在研究噬菌体作为模型系统的研究等课题的基因调控，宿主-病毒相互作用和大分子组装。我们正在利用噬菌体遗传学和生理学信息基础来进行多重耐药细菌病原体的噬菌体治疗。 我们选择了万古霉素耐药屎肠球菌（VRE）和K抗原E。大肠杆菌病原体，目的是开发用于治疗的噬菌体。 1. E. coli-K噬菌体：我们分离了一种强毒双链DNA噬菌体，命名为FK 1 -5，并发现它能够感染E.具有K1或K5多糖荚膜的大肠杆菌菌株。电子显微镜照片显示，病毒粒子由一个小的二十面体头部与短尾刺，类似于短尾病毒科的成员。编码尾丝蛋白的区域的DNA序列分析显示两个开放阅读框编码先前表征的水解噬菌体尾丝蛋白。第一个是FK 5的K5裂解酶蛋白基因，其允许该噬菌体特异性感染K5 E。大肠杆菌菌株。第二个开放阅读框编码的蛋白质在氨基酸序列上与FK 1 E的N-乙酰神经氨酸酶（内唾液酸酶）蛋白几乎相同，这使得该噬菌体能够特异性感染大肠杆菌的K1菌株。杆菌我们证明，成熟的噬菌体颗粒包含两个尾纤维蛋白，和突变分析表明，每个蛋白质可以独立地失活。FK 5、FK 1 E和FK 1 -5的尾基因区的比较表明，这些基因以模块或盒构型排列，并表明该家族的Escherichia coli可以通过水平基因转移来扩大宿主范围。 2.沙门氏菌噬菌体：裂解性沙门氏菌噬菌体SP 6编码一种尾部蛋白，该蛋白与生物学上不相关的溶原性沙门氏菌噬菌体P22的尾部蛋白具有高度序列相似性。SP 6尾基因的侧翼是含有启动子的上游区域和含有推定的Rho非依赖性转录终止子的下游区域，使其具有与大肠杆菌K1 E、K5和K1-5的尾基因的结构几乎相同的盒或模块结构。现在看来，SP 6，K1-5，K5和K1 E非常密切相关，但具有不同的尾纤维蛋白，使它们具有不同的宿主特异性。

We have been studying bacteriophages as model systems for the study of such topics as gene regulation, host-virus interaction and macromolecular assembly. We are taking advantage of the base of information of phage genetics and physiology for the purpose of bacteriophage therapy of multi-drug resistant-bacterial pathogens. We chose to work on infections with vancomycin-resistant Enterococcus faecium (VRE) and with K-antigenic E. coli pathogen with the purpose of developing phage for therapy. 1. E. coli-K phage: We isolated a virulent double-stranded DNA bacteriophage, named FK1-5, and found it to be capable of infecting E. coli strains that possess either the K1 or the K5 polysaccharide capsule. Electron micrographs show that the virion consists of a small icosohedral head with short tail spikes, similar to members of the Podoviridae family. DNA sequence analysis of the region encoding the tail fiber protein showed two open reading frames encoding previously characterized hydrolytic phage tail fiber proteins. The first is the K5 lyase protein gene of FK5, which allows this phage to specifically infect K5 E. coli strains. A second open reading frame encodes a protein almost identical in amino acid sequence to the N-acetylneuraminidase (endosialidase) protein of FK1E, which allows this phage to specifically infect K1 strains of E. coli. We demonstrated that mature phage particles contain both tail fiber proteins, and mutational analysis indicates that each protein can be independently inactivated. A comparison of the tail gene regions of FK5, FK1E, and FK1-5 showed that the genes are arranged in a modular or cassette configuration and suggested that this family of phages can broaden host range by horizontal gene transfer. 2. Salmonella phage: The lytic Salmonella phage SP6 encodes a tail protein with a high degree of sequence similarity to the tail protein of the biologically unrelated lysogenic Salmonella phage P22. The SP6 tail gene is flanked by an upstream region that contains a promoter and a downstream region that contains a putative Rho-independent transcription terminator, giving it a cassette or modular structure almost identical to the structure of the tail genes of coli-phages, K1E, K5, and K1-5. It now appears that SP6, K1-5, K5, and K1E are very closely related but have different tail fiber proteins, giving them different host specificities.