尉文霞 邓自新 孟媛

摘  要：比较评价三种配方的伊红美蓝琼脂培养基（EMB），筛选出一种培养效果优，成本低的纯化学合成培养基，消除现市售伊红美蓝培养基中因蛋白胨营养成分不明确对菌落生长带来的干扰，提高结果准确率。以20种氨基酸为氮源，3个浓度（8.08g、10.0g、20.0g）代替现市售伊红美蓝琼脂培养基中的动植物源性蛋白胨成分，制成纯化学合成伊红美蓝琼脂培养基，比较多种菌株在此培养基上的颜色、菌落形态及生长率。结果表明大肠埃希菌在EMB-1、EMB-2、EMB-3和市售EMB上生长良好，菌落呈黑色，有或无金属光泽，生长率均大于0.7;金黄色葡萄球菌均受到抑制，生长微弱或不生长;沙门氏菌的生长率在自配EMB与市售EMB上相差不大，均为无色菌落。使用全自动生化鉴定仪分析EMB-1和市售EMB上的大肠埃希菌，结果63项生化试验完全一致。综合菌落形态特征、生长率、生化反应、原料成本等因素，选择第1种配方（10.0g）的纯化学合成伊红美蓝琼脂培养基，为纯化学参考物质体系的建立提供一定的数据及实物支撑。

關键词：纯化学伊红美蓝琼脂培养基;大肠埃希菌;动植物源性蛋白胨

中图分类号：Q93           文献标志码：A      文章编号：2095-2945（2020）15-0001-06

Abstract： By comparing and evaluating the three formulations of eosin methylene blue （EMB） agar medium， a pure chemical synthesis medium with excellent culture effect and low cost was selected to eliminate the interference to colony growth caused by unclear nutritional composition of peptone in eosin methylene blue agar medium sold in the market， and improve the accuracy of the results. The pure chemical synthetic eosin methylene blue agar medium was prepared using 20 kinds of amino acids as nitrogen source and 3 concentrations （8.08g， 10.0g， 20.0g） instead of animal and plant-derived peptone in eosin methylene blue Agar. The color， colony morphology and growth rate of many strains on this medium were compared. The results showed that Escherichia coli grew well on EMB-1， EMB-2， EMB-3 and commercial EMB， the colony was black， with or without metallic luster， the growth rate was more than 0.7; Staphylococcus aureus was inhibited， the growth rate of salmonella was weak or non-growing， and the growth rate of salmonella was almost the same in self-made EMB and commercial EMB， all were colorless colonies. Using automatic biochemical analyzer to analyze Escherichia coli on EMB-1 and commercial EMB， the results of 63 biochemical tests were consistent. Considering the colony morphological characteristics， growth rate， biochemical reaction， raw material cost and other factors， the first formula （10.0g） pure chemical synthetic eosin methylene bluec agar medium was selected to provide some data and physical support for the establishment of pure chemical reference material system.

Keywords： pure chemical eosin-methylene blue （EMB） agar medium; Escherichia coli; animal or plant peptone

大肠埃希菌（E. coli）即大肠杆菌，是医院最常见的革兰氏阴性致病菌[1]。原料加工过程、外包装污染、生产环节或灭菌不够彻底等原因都会导致大肠埃希菌超标，国内外通常将其作为食品药品等卫生状况的指示菌。有研究报导革兰氏阴性菌如大肠埃希菌等对多种药物耐受[2]，因此提高检验结果的准确性非常必要。……