选择性增菌液对单核增生性李斯特氏菌检出效果的比较

为了了解食品中单核增生李斯特氏茵(Listeria monocytogenes)的污染状况,比较不同选择性增茵方法对单核增生李斯特氏茵的检出效果,并进一步比较不同增茵方法在不同类食品中检出单核增生李斯特氏茵的差异性,进而确定特定食品最合适的增茵方法,随机采集本市生鲜肉、水产品、果蔬及冷冻食品4类135份食品.采用国标LB二次增茵法、EB法、最新改良FDA法及Fraser肉汤增菌法进行增菌,采用PALCAM选择性平板进行分离,先用行标多重PCR法进行初步验证后再进行国标生化鉴定.4种方法共检出单核增生李斯特氏茵23株,其中LB二次增菌法检出5株、Fraser肉汤增菌法检出6株、EB法检出5株、最新改良FDA法检出7株.结论是4种方法总的检出率没有较大的差异性,但对于不同类食品的检出率有所不同.

Compare of Selectivity Enrichment Broth for Detectable Effect of Listeria monocytogenes

This paper investigated contamination situation of Listeria monocytogenes(Lm). To compare different selectivity enrichment broth for detectable effect of Lm and compare detectable effect in different samples by using different methods, furthermore, choose the best enrichment broth for specific food. One hundred and thirty five random samples from raw meat, aquatic product, fruit and vegetable, quick-frozen food in Baoding. Applied LB enrichment broth, EB enrichment broth, new modification FDA enrichment broth and Fraser enrichment broth before separated by PALCAM selective agar, then identified by international standard method after PCR. Results: Four methods showed that there were 23 Lm positive, detected 5 Lm by LB method, 6 Lm by Fraser method, 5 Lm by EB method and 7 Lm by new modification FDA method. The total detectable rate of four methods had no large specificity, but to specific kind of food was different.