一种快速准确测定A群脑膜炎奈瑟菌活菌率的方法

A rapid and accurate method in detection of survival rate for group A Neisseria meningitidis

目的研究"美蓝-(碱性)藏红O"双染色法用于快速准确测定A群脑膜炎奈瑟菌(group A Neisseria meningitidis,以下简称A群脑膜炎球菌)活菌率的可行性。方法制备A群脑膜炎球菌悬液,取菌悬液双染色法染色,用光学显微镜观察,计算活菌率。将菌悬液进行10倍系列稀释,各菌液分别用平板涂布法接种至10%羊血普通琼脂平皿,于CO2环境下、35~37℃培养12~20 h,计算菌悬液活菌率。比较两种方法测定8批A群脑膜炎球菌所测得的活菌率,并进行相关性和线性回归分析。结果 "美蓝-(碱性)藏红O"双染色法与平板涂布法所测得的活菌率结果差异无统计学意义(P>0.05);两种方法所测得的活菌率具有显著的直线回归关系(P<0.01,n=8),相关系数r=0.984,其回归方程为y=0.919x+1.661(R2=0.967)。结论 "美蓝-(碱性)藏红O"双染色法检测时间短、判定结果直观、操作简单、计数结果准确,可用于A群脑膜炎球菌活菌率的快速测定。

Objective To investigate the feasibility of ＂methylene blue-safranine O＂double staining method in measuring the survival rate of group A Neisseria meningitides in a rapid and accurate mode.Methods To prepare of group A Neisseria meningitides suspension,and to calculate the survival rates in observation under optical microscope by the double staining method.The spread plate method was conducted as the verification test,and the bacterial suspension was serial diluted by 10 folds which were inoculated onto the 10% sheep blood agars and cultured for 12-20 h at 35-37 ℃ in a CO_2 environment,respectively,the survival rate for each sample was calculated.For eight batches of group A Neisseria meningitides,the survival rates were analyzed in corresponding analysis and linear regression by the double staining method in comparison with the spread plate method.Results There was no a statistical difference between the data of survival rates obtained from two methods（P〉0.05）,but a very significant linear regression relation between them（P〈0.01,n=8）,with a correlation coefficient r=0.984,the regression equation as y=0.919x＋1.661（R2=0.967）.Conclusion The ＂methylene blue-safranine O＂ double staining method can be applied in detection of the survival rates for group A Neisseria meningitides,which has advantages including in a short detection time,easy in operation,judgement results by intuition,and with an accurate counting.