肠道沙门氏菌双相亚利桑那亚种检验特征分析及检验方法比较研究

Comparative Study on Test Characteristics Analysis and Test Methods of Salmonella Enterica Subspecies Diarizonae

目的:通过参加中国食品药品检定研究院组织的能力验证,比对不同检验方法对巧克力样品中沙门氏菌的检出及鉴定效果,找出不同检验方法对样品中不典型沙门氏菌分离及鉴定的特性,有效提升实验室对不典型沙门氏菌检验能力及质量控制水平。方法:实验中样品前处理按照考核方案作业指导书进行,沙门氏菌的分离按照《食品安全国家标准食品微生物学检验沙门氏菌检验》(GB 4789.4—2016)要求进行操作,通过BAX®system Q7快速筛查可疑样品,MALDI-TOF-MS定位可疑菌株,VITEK 2 COMPACT全自动微生物分析系统确认阳性菌株,MLST技术对沙门氏菌阳性菌株进行分子生物学分型。结果:3个样品中两个样品检出沙门氏菌,样品CODE-0695检出鼠伤寒沙门氏菌,样品CODE-0050未检出沙门氏菌,样品CODE-0542检出肠道沙门菌双相亚利桑那亚种。结论:实验发现肠道沙门菌双相亚利桑那亚种在显色培养基上菌落形态及生化表征与常见沙门氏菌不一致,易漏检,实际工作中应加强对不典型沙门氏菌检验能力的建设。

Objective:By participating in the capability test organized by China food and drug testing and Research Institute,comparison of the detection and identification effects with different testing methods on Salmonella in chocolate samples,find out the characteristics of different testing methods on the isolation and identification of atypical Salmonella in samples,and effectively improve laboratory atypical Salmonella inspection capability and quality control level.Methods:The samples pre-treatment in this experiment were carried out in accordance with the assessment plan instructions.The isolation of Salmonella was carried out according to the requirements of GB 4789.4—2016 National food safety standard-Food microbiological testing-Salmonella testing.And the suspicious samples could be screened quickly through the BAX®system Q7.Suspicious strains were located by MALDI-TOF-MS.Using VITEK 2 COMPACT automatic microbial analysis system to confirm positive strains.Then performed the molecular biology typing for positive Salmonella by MLST.Results:Salmonella was detected in two of the three samples.Salmonella typhimurium was detected in sample CODE-0695,no Salmonella was detected in sample CODE-0050.Salmonella enterica subspecies diarizonae was detected in sample CODE-0542.Conclusions:The experiment found that the colony morphology and biochemical characteristics of Salmonella enterica subspecies diarizonae in the chromogenic medium were inconsistent with common Salmonella,which could be missed detection easily.The ability to test atypical Salmonella should be strengthened in practical work.