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目的选育能够耐受鼠疫噬菌体Yep-phi的鼠疫耶尔森氏菌0614F突变株,并观察其稳定性,为鼠疫菌对噬菌体的耐受机制研究提供实验基础。方法用不同浓度的噬菌体Yep-phi逐代对鼠疫菌0614F进行侵染诱变。分别选取鼠疫菌0614F野生株和由鼠疫噬菌体侵染诱变后的中间代第13代、第25代和第43代突变株进行培养,通过菌落特征描述,噬菌体耐受能力测定和噬菌体裂解试验评价噬菌体耐受株的稳定性。结果获得的鼠疫菌0614F第43代突变株能够耐受效价为10-9的Yep-phi噬菌体原液。噬菌体耐受能力测定和噬菌体裂解试验显示突变株遗传表型稳定性良好,无返祖现象。结论利用鼠疫噬菌体Yep-phi可诱导产生鼠疫菌抗Yep-phi突变株。其抗性的产生可能是由于鼠疫菌细胞外受体或菌株基因组结构发生改变引起的。
Objective To breed the Yersinia pestis 0614F mutant that can tolerate the Yep-phi plague phage and observe the stability of Yep-phi 0614F. It provides the experimental basis for the research on the mechanism of phage tolerance of Y. pestis. Methods Different concentrations of phage Yep-phi were used to mutagenize Yersinia pestis 0614F. The 13th generation, the 25th generation and the 43rd generation mutants of Yersinia pestis 0614F wild strain and the intermediate strain mutated by the plague phage were selected respectively and cultured. The colony characterization, phage tolerance test and phage lysis test Phage resistant Strain stability. As a result, the 43rd generation mutant of Y. pestis 0614F was able to tolerate Yep-phi phage stock with a titer of 10-9. Phage tolerance assay and phage lysis test showed that the mutant phenotype stability is good, no ancestor phenomenon. Conclusion Yep-phi YP-phi mutant can be induced by Yep-phi. The resistance may be caused by the change of the genome structure of Y. pestis extracellular receptors or strains.