鼠疫活菌苗0614F株遗传稳定性研究

经多年研究选育出一株具有较好的免疫原性，又有一定残余毒力的可作为鼠疫活菌疫苗的菌株０６１４Ｆ株。为进一步了解该菌苗株的遗传稳定性，对其通过人工培养基、动物各传２０代后的菌株之生物学性状，对实验动物的毒力和免疫力观察其菌体形态、培养特性、生化、毒力因子、Ｆ１抗原含量、质粒分子量等都与原珠无差异。０６１４Ｆ原株及动物传２０代的菌株分别以２５０亿、３００亿菌皮下感染体重２５０～３００ｇ豚鼠，连续观察３０天无一死亡，说明经过动物传代毒力无增强。人工培养基传２０代菌免疫豚鼠后Ｆ１抗体水平与原代无差异；免疫２０天后用１４１毒菌１０亿活菌攻击，０６１４Ｆ组使９１．７％豚鼠得到保护，而同样条件的ＥＶ对照组只能保护５０％，说明经多次人工培养基传代免疫原性无改变，具有稳定的遗传特性。

Observation on the inheritance stability of a new plague live vaccine 0614F strain

After several years study a new plague live vaccine 0614F strain with certain residual virulence has been selected and cultured. To test its stability on the aspect of biological and inheritance features , the strain was cultured on the medium and inoculated in guinea pigs respectively for 20 passages. It was found that the strain's several specifications on the culture medium , biological characteristics , virulent factor , F1 antigen cotent and molecular weight of plasmid were all similar to the original strain's lt showed that there were no immunity decreasing from the culture medium and no virulence increasing in the animals after being inoculated for 20 passages , which was superior to that of EV live vaccine. The strain , therefore , as a new plague vaccine , has a stable feature on its inheritance.