铜绿假单胞菌对食品中沙门氏菌检测 干扰作用的评价

Evaluation on the interference of Pseudomonas aeruginosa to Salmonella detection in food samples

中文关键词:  沙门氏菌  铜绿假单胞菌  干扰作用

英文关键词:Salmonella  Pseudomonas aeruginosa  interference

中文摘要:

      目的 评价铜绿假单胞菌作为干扰菌对食品中沙门氏菌准确检出的影响。方法 在无菌奶粉样品中人工污染不同浓度的沙门氏菌(1~100 CFU/10 g)和铜绿假单胞菌(0~106 CFU/10 g), 参照GB4789.4-2010进行检测, 同时利用全自动酶联免疫检测系统(VIDAS30)和全自动病原微生物检测系统(BAX Q7 System)对样品进行快速筛查, 以此综合评价铜绿假单胞菌作为干扰菌对沙门氏菌检测过程的影响。结果 在不同浓度的铜绿假单胞菌干扰下, VIDAS和BAX系统均能够准确筛查出沙门氏菌阳性样品; 使用的3种选择性平板对沙门氏菌和铜绿假单胞菌的分离效果存在差异, XLD平板优于BS平板和科玛嘉CAS平板, 其中铜绿假单胞菌和沙门氏菌在科玛嘉CAS平板上具有相似的显色情况, 直接影响沙门氏菌的检测结果; BPW前增菌8 h沙门氏菌的平板分离效果优于前增菌18 h。结论 研究表明, 铜绿假单胞菌在选择性平板分离步骤时对沙门氏菌具有干扰作用。联合使用2种以上沙门氏菌选择培养基, 才能保证沙门氏菌的准确检出。VIDAS和BAX可作为沙门氏菌快速筛查的可靠技术手段。

英文摘要:

      Objective To evaluate the interference of Pseudomonas aeruginosa to Salmonella detection in food samples. Methods The sterile milk powder was artificially contaminated with different concentrations of Salmonella (1~100 CFU/10 g) and Pseudomonas aeruginosa (0~106 CFU/10 g). Then those samples were detected according to the GB 4789.4-2010. Meanwhile, VIDAS and BAX System were used to evaluate the interference of Pseudomonas aeruginosa to Salmonella detection. Results Under the interference of different concentrations of Pseudomonas aeruginosa, all Salmonella positive samples could be detected accurately by VIDAS and BAX System. Three kinds of selective culture plates had difference during the separation of Salmonella and Pseudomonas aeruginosa, XLD plate showed better separation ability than BS plate and CHROMagar CAS plate, and Salmonella and Pseudomonas aeruginosa showed similar colony morphology in CHROMagar CAS plate, which directly affected the detection result of salmonella. The separation ability of pre-enrichment 8 h in BPW was better than pre-enrichment 18 h for salmonella detection. Conclusion It indicated that Pseudomonas aeruginosa showed interference effect during the separation of Salmonella from selective culture plates, using more than 2 kinds of selective culture plates simultaneously could improve the detection efficiency and accuracy. VIDAS and BAX System could be used as the reliable reference of Salmonella detection in food samples.