摘要
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 The underlying mechanism for the resistance of Yersiniapestisto phages is still unclear.The aims of this study were to cultivate a mutant strain,0614 F,of Y.pestis that was resistant to the phage Yep-phi and to preliminarily assess its stability in order to provide basic data for further research into the interaction between Y.pestis and its phage. Methods The wild strain 0614 Fof Y.pestis was infected with successive generations of the phage Yepphi at different concentrations.The stability of the mutant strain was assessed by culturing intermediate generations（the13th,25 th,and 43 rd generations）of the mutant strain with the parent strain of Y.pestis serving as a control.The characteristics of colonies of the mutant strain were ascertained and the strain＇s resistance to bacteriophages and lysis by bacteriophages were determined. Results Bacteriophage-resistant mutants of Y.pestis were obtained by means of repeated infection with phage,and the 43 rd generation of the mutant strain tolerated phages at a titer of 10-9.The strain＇s resistance to bacteriophages and lysis by bacteriophages indicated that the mutant was genetically stable and displayed no atavism. Conclusion Infection with bacteriophages was used to screen and cultivate resistant mutants of Y.pestis.Genetic mutations and changes in extracellular receptors seem to be responsible for the phenotypic change that allowed the wild strain of Y.pestis to resist phages.
出处
《中国病原生物学杂志》
CSCD
北大核心
2015年第7期582-586,共5页
Journal of Pathogen Biology
基金
国家自然科学基金项目(No.31360034)
关键词
鼠疫耶尔森氏菌
噬菌体耐受
选育
Yersinia pestis
bacteriophage resistance
cultivate
