沙门氏菌能力验证样品制备

Preparation of Salmonella samples for proficiency testing

中文关键词:  沙门氏菌  能力验证  分离  鉴定

英文关键词:Salmonella  proficiency test  isolation  identification

中文摘要:

      目的 研究制备适用于沙门氏菌(Salmonella)能力验证(PT)检测项目的冷冻干燥样品, 通过能力验证确定实验室或检查机构的校准、检测能力。方法 对目标菌与干扰菌进行10倍梯度稀释, 对不同稀释度的菌液进行菌落计数并计算菌浓度, 确定沙门氏菌与干扰菌的添加量, 以冻干的绿豆粉为基质, 脱脂奶粉为冻干保护剂, 将细菌混合物与冻干保护剂混合均匀, 采用真空冷冻干燥方式分别制备沙门氏菌能力验证阳性样品与阴性样品, 采用西林瓶真空包装、4 ℃冷藏贮存; 通过随机抽样和鉴定以评估样品的均匀性, 通过观察样品在90 d内不同温度下目标菌的测试结果以评估样品的稳定性。结果 每个样品最终添加10~100 CFU目标菌, 添加104 CFU干扰菌; 抽检的样品均能有效鉴定, 显示PT样品具有较好的均匀性; 通过保存温度和时间的稳定性检验显示测试结果符合预期效果, PT样品具有较好的稳定性。结论 建立了有效的沙门氏菌能力验证样品制备的方法与评价程序。

英文摘要:

      Objective The preparation of lyophilization samples were applied in Salmonella proficiency testing, to assess the calibration and testing capability of participating laboratories. Methods A suitable proportion and concentration of Salmonella and interference were selected through 10 times dilution and colony counts, selecting freeze-dried mung bean powder as matrix and skimmed milk powder as lyoprotectant, and mixing them well. Salmonella proficiency testing positive samples and negative samples were made by vacuum freeze drying method, by schering bottles vacuum packaging, 4 ℃ refrigerated storage. The uniformity of the PT samples was evaluated through random sampling, and evaluates the stability of PT samples kept for 90 d. Results Adding 10~100 CFU salmonella and 104 CFU interference to every PT sample. The batch of samples could be identified and in a preferable accordance ratio, and could keep stable for at least 90 d while storing at different temperatures. Conclusion Suitable Salmonella PT samples and effective sample preparation and evaluation process were established.