SS培养基实验室质量控制的探讨

摘要:目的　为了保证检验质量，使实验室能够提供准确的实验结果，对市售的商品化SS培养基，从质量性能测试及制成平皿后不同条件存放下肠道致病菌的生长情况两个方面对培养基进行实验观察。方法　依据国标GB4789.28-2013《食品微生物学检验 培养基和试剂的质量要求》。结果　4种SS干燥培养基，鼠伤寒沙门氏菌ATCC14028和福氏志贺氏菌［CMCC（B）51572］在1号和4号上的生长率为23.0%～26.8%，基本达到使用要求，2号和3号的生长率为3.3%～7.6%，存在着目标菌生长率过低的质量问题。4种培养基生长率越高，其选择因子G也呈现偏高的趋势。配置倾注的SS平皿，在密封条件下4℃～8℃冰箱内存放5 d内，其肠道菌的检出率仍可达96％以上，对肠道致病菌的检测效果无明显影响，而恒温保存的平皿检测效果逐日下降。结论　实验室对SS培养基的质量控制应从多方面综合考虑。

Discussion on the quality control of SS culture medium in laboratory

Abstract: Objective To observe the results of the quality performance testing and the growth of intestinal bacteria by using SS culture medium under different conditions. Methods The experiments were carried out according to the national standards GB4789.28-2013 "Food microbiology inspection The quality requirements of culture medium and reagent". Results The growth rates of Salmonella Typhimurium ATCC14208 and Shigella flexneri [CMCC (B) 51572] on the 1st and the 4th SS culture medium were from 23.0 to 26.8%, which suggested the two kinds of mediums basically reached the detecting requirements. But the growth rates on the 2nd and the 3rd SS culture mediums were only from 3.3 to 7.6%, which had low growth rates of target bacteria and suggested a quality problem on the two kinds of mediums. Moreover, higher growth rates correlated with higher concentrations of selective factor G in the mediums. The prepared SS culture medium was in refrigerator (4-8 ℃) within 5 days, and the detection rate of intestinal bacteria was still above 96%, which had no affected on the detection of intestinal bacteria. However, the detecting rates were falling day by day with the mediums kept in thermostat daily. Conclusion The quality control of SS culture medium in laboratory should be considered in many aspects.