运用显色培养基从食品微生物中鉴别蜡样芽孢杆菌

Identifying Bacillus cereus from other food microorganisms by chromogenic media

目的评价本实验室为克服甘露醇卵黄多黏菌素B琼脂(MYP)选择性差及接合生长很难计数的缺点而研制的蜡样芽孢杆菌显色培养基(HK)的检测效果。方法通过纯培养物和混合菌对本实验室研制的蜡样芽孢杆菌显色培养基(HK)和4种商品化的选择性计数培养基进行选择性、特异性和灵敏度测试。结果在选择性方面,HK和CHROMagar培养基选择性抑菌能力最好,MYP最差;在特异性方面,HK、CHROMagar和厂家Ⅰ显色培养基相当,优于厂家Ⅱ和MYP;在生长率方面,HK和CHROMagar显色培养基与MYP接近,明显优于厂家Ⅰ和厂家Ⅱ;在灵敏度方面,HK、CHROMagar和MYP 3种培养基灵敏度远优于厂家Ⅰ和厂家Ⅱ。在有杂菌干扰的情况下,HK和CHROMagar的分离效果较好,而厂家Ⅰ、厂家Ⅱ和MYP分离效果较差,容易造成漏检。结论本实验室研制的HK和CHROMagar蜡样芽孢杆菌显色培养基综合检测效果良好,可以作为MYP培养基的有效替代和补充。

Objective To evaluate the performance of the Bacillus cereus chromogenic medium（ HK） that made by our lab in order to overcome the disadvantages of Mannitol Yolk Polymyxin Agar（ MYP）,including poor selectivity and colony coalescing.Methods Using pure cultures and mixture strains to detect the selectivity,specificity and sensitivity of HK,as well as 4 kinds of commercialized selective counting medium. Results In terms of selectivity,HK and CHROMagar had the best ability in inhibit other bacteria. MYP was the worst. HK,CHROMagar and Ⅰ were equivalent in specificity. They were significantly better than Ⅱand MYP. The growth rates of HK and CHROMagar were close to MYP. They were better than Ⅰand Ⅱ. The sensitivity of HK,HROMagar and MYP were much better than Ⅰand Ⅱ. In the case of bacteria interference,HK and CHROMagar had good separation results. Ⅰ,Ⅱ and MYP had poor performance in test. This could easily cause leakage detection. Conclusion Bacillus cereus chromogenic medium HK and CHROMagar can be used as alternative and complementary products for the good performance in selection and identification test.