PCR法快速鉴定小儿咳喘灵颗粒中大肠埃希菌

Rapid Identification of Escherichia Coli in Xiaoer Kechuanling Granules by PCR Method

目的建立快速鉴定药品中大肠埃希氏菌的聚合酶链反应(PCR)法。方法以小儿咳喘灵颗粒为试验样本,选择22种(共24株)实验室常见菌株,提取样品增菌液中菌株DNA,采用PCR法对目标基因uidA、ipaH、invE进行检测,分析方法的可行性和可靠性,并通过与传统生化鉴定方法比较以考察其特异性。结果PCR法通过3种基因检测结果的不同组合,能快速准确筛查出供试液中大肠埃希菌,特别是可有效区分大肠埃希菌及与其同源性较高的志贺菌。结论与传统微生物鉴定方法相比,PCR法在特异性和鉴定效率方面均有较大优势,可应用于采用直接接种法的药品微生物限度大肠埃希菌的快速鉴定。且单一基因检测无法区分时,可加入多种基因,一次检测即可获得满意效果。

Objective To establish a polymerase chain reaction(PCR)method for rapid identification of Escherichia coli in drugs.Methods With Xiaoer Kechuanling Granules as the test samples,22 common laboratory strains(24 strains in total)were selected to extract DNA in the enrichment medium.The target genes uidA,ipaH and invE were tested by the PCR method,the feasibility and reliability of the method was analyzed,and its specificity was investigated by comparison with that of traditional biochemical identification method.Results Based on different combinations of testing results of the three genes,the PCR method could quickly and accurately screen for Escherichia coli in the test solution,especially distinguishing Escherichia coli and its highly homologous Shigella species effectively.Conclusion Compared with traditional microbial identification method,the PCR method is specific and efficient,which can be used to the rapid identification of Escherichia coli in the microbial limit test of drugs by direct inoculation.When a single gene testing cannot be distinguished,we can add multiple genes and obtain satisfactory results by a single testing.