噬菌体结构简单，基因数目少，其宿主细胞（细菌）易于培养，噬菌体有蝌蚪形、球形和细杆状3种形态，是基因工程和分子生物学研究的重要工具。
如由噬菌体介导的细菌毒力基因的转移、细菌耐药基因的传递等导致了病原菌基因表型的多态性，这在医学与遗传学中是一个日益严峻的重要问题。
For example, transfer of virulence gene and transmission of drug-resistant gene mediated by a phage results in gene polymorphism of bacteria, which is an important problem in medicine and genetics.
借用电子显微镜，对分离得到的8株苏云金芽孢杆菌噬菌体进行了形态学研究。
Morphology of 8 strains of phages of Bacillus thuringiensis was examined with electronic microscopy.
目的：开展对伤寒病原学和耐药性监测以及伤寒噬菌体的分型研究，摸清伤寒流行规律，为制定防治措施提供依据。
Objective: In order to recognize the epidemic characteristics of Salmonella typhi and to provide scientific basis for formulating prevention and treatment measures.
应用推荐