马铃薯葡萄糖琼脂与孟加拉红琼脂培养基检测霉菌的效果比较

Comparison of the mold counting effects between potato dextrose agar and rose Bengal agar culture medium

中文关键词:  霉菌  孟加拉红琼脂  马铃薯葡萄糖琼脂  计数检测

英文关键词:mold  rose Bengal agar culture medium  potato dextrose agar culture medium  counting detection

中文摘要:

      目的 比较马铃薯葡萄糖琼脂与孟加拉红琼脂两种计数培养基的霉菌计数效果。方法 分别使用马铃薯葡萄糖琼脂培养基与孟加拉红琼脂培养基对20株霉菌标准菌株、15株常见食源性致病菌标准菌株进行生长率、特异性及选择性比较, 并应用两种培养基对36件实际食品样品和174件食品接触环境冰箱涂抹样品进行计数效果对比。结果 测试的20种霉菌标准菌株在马铃薯葡萄糖琼脂与孟加拉红琼脂两种培养基的生长率PR值均大于0.7、选择性G值均小于1, 但在马铃薯葡萄糖琼脂培养基上霉菌具有更为典型的菌落形态, 其特异性优于孟加拉红琼脂培养基。在实际样品检测中马铃薯葡萄糖琼脂培养基检出率较高, 与孟加拉红培养基相比差异性显著(χ2=13.551, P=0.001), 特别是在低污染的样品检测中具有较高的检出率(χ2=9.929, P=0.001), 但是对于高污染样品, 使用孟加拉红琼脂培养基更便于计数。结论 使用单一培养基会影响计数结果, 建议在食品样品进行霉菌计数时, 同时应用两种培养基或根据污染程度选择适当的计数培养基。

英文摘要:

      Objective To compare the mold counting effects of potato dextrose agar and rose Bengal agar as 2 types of counting culture medium. Methods Growth rate, specificity, and selectivity were compared between potato dextrose agar and rose Bengal agar culture medium using 20 kinds of standard mold strains and 15 kinds of common foodborne pathogen strains. Additionally, the counting effects of both culture medium were assessed using 36 actual food samples and 174 swab samples from food contact environments in refrigerators. Results The growth rate (PR value) of the 20 kinds of mold strains on both potato dextrose agar and rose Bengal agar culture medium was greater than 0.7, and the selectivity (G value) was less than 1. However, molds on potato dextrose agar culture medium exhibited more typical colony morphology, indicating better specificity than rose Bengal agar culture medium. In the detection of actual samples, the detection rate of potato dextrose agar culture medium was relatively high, showing a significant difference compared to rose Bengal agar culture medium (χ2=13.551, P=0.001). It exhibited a particularly higher detection rate in samples with low contamination (χ2=9.929, P=0.001). However, for highly contaminated samples, rose Bengal agar culture medium was more convenient for counting. Conclusion Using a single culture medium can affect counting results. It is recommended to apply 2 types of culture medium or select an appropriate counting medium based on the contamination level when conducting mold counting tests on food samples.