肠出血性大肠杆菌O157：H7噬菌体的分离纯化

分离纯化了抑制肠出血性大肠杆菌（Enterohemorrhagic E coli，EHEC）0157：H7的噬菌体，并对其进行效价测定。将宿主菌EHEC0157：H7培养制成悬液后与污水样品37℃共培养16h，将培养物离心、过滤除菌后得到该菌的噬菌体原液。噬菌体原液采用双层琼脂平板法进行5次纯化，得到直径相同的噬菌斑。纯化后噬菌体的效价达到12×10^pfu。电镜观察表明，该噬菌体呈蝌蚪状。根据ICTV对病毒的分类标准，该噬菌体属长尾噬菌体科，为烈性噬菌体。

Separation and Purification of Enterohemorrhagic E.coli O157:H7 Bacteriophage

The separation and purification of bacteriophage inhibiting Enterohemorrhagic E. coli O 157：H7 were studied and the titre of the isolated bacteriophage was evaluated. The host strain, EHEC O 157：H7, was cultured as a suspension and then cocultured with sewage at 37 ℃ for 16h, the cocultured sample was then centrifuged and filtered to eliminate bacteria and thus the bacteriophage superuatant was obtained. The bacteriophage superuatant was purified for 5 times using the two layer plates, and the bacteriophage plaques of uniform diameter were obtained. The titer of purified bac- tiriophage was 1.2 × 10^10pf u .The bacteriophage was tadpole-like bacteriophage as observed by electronmicroscope. According to ICIV（Interuational Committee for Taxonomy of Viruses）, it belongs to the Siphoviridae family and is a virulent phage.