副溶血性弧菌鉴定能力验证样品的制备

Preparation of Vibrio parahaemolyticus lyophilization materials for proficient test on bacteria identification

目的研制适用于副溶血性弧菌(Vibrio Parahaemolyticus,VP)能力验证(PT)项目的 VP菌及干扰菌的冷冻干燥样品,建立有效的样品制备与评估流程。方法通过不同比例混匀的VP和干扰菌拟态弧菌(Vibrio minicus,VM)经冻干后在鉴定培养基上菌落生长优势比,确定制备PT样品的混合菌VP和VM的浓度比例;通过系统抽样和鉴定以评估样品的均一性;通过观察样品在180 d保存期内菌量的变化情况以评估样品的稳定性;根据188间检测实验室反馈的鉴定结果以评估和计算样品的实际合格率。结果选择5 000∶1比例制备的VP和VM混合PT样品能在鉴定培养基有效分离两种菌落;抽检的40份样品均能有效鉴定,显示PT样品具有较好的一致性;通过保存温度和时间的稳定性实验显示,PT样品在36℃下能稳定保存5 d,冻干后PT样品于4℃保存180 d后VP菌仍能检出;188家参与实验室检测结果显示,PT样品合格率为97.3%。结论本研究制备的冻干PT样品及实验流程控制适用于副溶血性弧菌及类似的微生物鉴定能力验证项目。

Objective To establish and evaluate the procedure for preparation of lyophilized（freeze-dried）Vibrio parahaemolyticus（VP） composed with Vibrio minicus（VM） culture materials for Proficient Test（PT） on bacteria identification.Methods Selecting a suitable proportion and concentration of VP and VM for identifying the dominant ratio of VP to VM cultured in the identification medium after lyophilization.Assessing and identifying the homogenicity of random PT specimen and evaluating the stability of specimen kept for 180 days.The exact acceptability of PT specimen was calculated according to the results of participating laboratories.Results 5 000∶1（VP∶VM） was selected as a proper ratio for freeze-dried PT specimen.The batch of specimen was in a preferable accordance ratio and could keep stable for at least 180 days while storing at 4 ℃.Specimen can be stored at 36 ℃ for 5 days during transportation.The acceptability rate of samples was 97.3% calculated by the results of 188 participating laboratories.Conclusion Freeze-dried PT samples as well as preparation procedures were suitable for PT test of Vibrio Parahaemolyticus and can be used universally for analogical PT tests.