不同pH值的赫氏干燥培养基对鼠疫菌生长影响观察

摘要:目的　观察不同pH值的赫氏干燥培养基对鼠疫菌生长的影响，从中筛选鼠疫菌生长的最适pH值。方法　同一批号的赫氏干燥培养基分别加入到pH值为6.2、6.6、7.0、7.4、7.8、8.2的蒸馏水溶液中，121℃30 min高压灭菌后倾注平皿。通过进行鼠疫菌强毒141标准株和鼠疫菌弱毒EV 76巴黎株菌落计数实验，观察不同pH值的赫氏干燥培养基对鼠疫菌生长的差异。结果　不同pH值的赫氏干燥培养基对鼠疫菌的生长均有影响且其差异有统计学意义（EV76χ2＝190.804，P＜0.05；141χ2＝151.742，P＜0.05）。EV76株鼠疫菌和141株鼠疫菌在pH值7.0的赫氏干燥培养基中活菌数值最大。结论　赫氏干燥培养基对鼠疫菌生长的最适pH值为7.0。

Effect of pH in Hershey medium on growth of Yersinia pestis

Abstract: Objective This work aimed to observe the effect of different pH on the growth of Yersinia pestis in Hershey medium and screen for the optimal pH value. Methods Hershey medium was added to the distilled water and the pH was adjusted to be 6.2, 6.6, 7.0, 7.4, 7.8, 8.2, respectively. The medium was then autoclaved in 121 ℃ for 30 min before being poured into plates. Viable cell count experiment was conducted to observe the growth of two Y. pestis strains, the reference strain 141 and strain Paris EV76, in medium with different pH. Results The growth of Y. pestis behaved significantly different in Hershey medium with different pH (EV76 χ2=190.804, P<0.05; 141 χ2=151.742, P<0.05). Conclusion In Hershey medium the optimal pH for the growth of Y. pestis was 7.0.