结晶紫中性红胆盐琼脂配制中煮沸与高压灭菌效果比较

Comparison of sterilization effect of boiling and autoclaving method in preparation of crystal violet neutral red bile salt agar

目的探讨结晶紫中性红胆盐琼脂(violet red bile agar,VRBA)配制时,用高压灭菌法代替煮沸法的可行性。方法将大肠菌群的5种标准菌株用煮沸3次、121℃高压灭菌15min和115℃高压灭菌15min后,在VRBA分别培养,观察菌株成长的差异性;同时做目标菌生长率定量测试和非目标菌的定性测试。结果两种温度高压灭菌后,VRBA培养基和煮沸法处理的VRBA培养基培养的菌株成长、目标菌生长率P_R差异均无统计学意义(P值均>0.05)。肺炎克雷伯菌的生长率P_R<0.70,其余菌株的生长率P_R均>0.70。非目标菌的生长指数G均为0。结论 121℃、15min灭菌处理VRBA更方便实验室批量配制培养基和简化实验操作,提高工作效率。推荐配制VRBA时使用高压灭菌法代替煮沸法。VRBA不适用于分离肺炎克雷伯菌。

Objective To study the feasibility of replacing boiling method with autoclaving in preparation of violet red bile salt agar（VRBA）. Methods After 5 standard E.coli strains were boiled for 3 times, or autoclaved at 121 ℃ for 15 min or autoclaved at 115 ℃ for 15 min,respectively, the samples were cultured on VRBA to study the growth difference ; the growth rate of the target bacteria was quantitatively analyzed and the growth rate of non target bacteria was qualitative analyzed. Results After autoclaving at 2 temperatures, no significant difference was observed for the growth conditions and the growth rates of the target bacteria （ P R ） cultured on VRBA comparing to boiling method（all P 〉0.05）. The growth rate of Klebsiella pneumoniae was 〈0.7, while the growth rates of other strains were all〉0.70. The growth index G of non target bacteria was 0. Conclusion Autoclaving VRBA at 121 ℃ for 15 min is relatively convenient for laboratory preparation,which simplifies the operation and improves work efficiency. Autoclaving is recommended to replace boiling method for VRBA preparation while VRBA is not suitable for isolation of Klebsiella pneumonia .