临床常见产AmpC β-内酰胺酶菌株中染色质ampC共同序列的研究

目的分析临床常见AmpC β-内酰胺酶（简称AmpC酶）产酶菌株中染色质ampC的基因序列,从而为AmpC酶的分子生物学检测以及其调控机制研究提供理论依据。方法 57株临床常见AmpC酶产酶菌株分离自医院感染患者样本,抽提细菌染色质DNA,聚合酶链反应（PCR）扩增ampC基因并连接入pMD19-T载体,双链测序后比对同种细菌之间和不同种细菌之间染色质ampC基因的同源性和共同序列。根据共同序列设计引物,进一步利用该引物检测染色质ampC。结果 57株细菌的基因组中,使用PCR扩增出染色质ampC基因41株,并成功测定了其ampC基因的序列。比对后发现大肠埃希菌、阴沟肠杆菌、鲍曼不动杆菌和产气肠杆菌的染色质ampC菌种内有很高的同源性,但细菌之间的同源性较低。根据共同序列设计出菌种特异性PCR引物,能够有效的鉴定出染色质ampC基因。结论大肠埃希菌、阴沟肠杆菌、鲍曼不动杆菌和产气肠杆菌各自染色质ampC具有高度同源性,其菌种特异性的ampC引物可用来检测其染色质ampC的存在。

Exploration of the consensus sequence among the genomic ampC from the clinical isolates producing AmpC beta-lactamase

Objective To analyze the consensus sequence among the genomic ampC from the clinical isolates producing AmpC beta-lactamase and provide the theoretical basis for new molecular biological way to determine AmpC beta-lactamase and the regulatory mechanism of AmpC beta-lactamase.Methods 57 AmpC beta-lactamase strains were isolated from clinical samples,and the genomic DNA was extracted.Genomic ampC was amplified by polymerase chain reaction（PCR） and ligated into pMD19-T vector.The homology and consensus sequences were analyzed by comparison.Related primer was designed according to the consensus sequence and was used to detect the genomic ampC.Results 41 out of the 57 clinical isolates were identified to contain genomic ampC,and their sequences were successfully obtained.The consensus sequences of the genomic ampC from Escherichia coli,Enterobacter cloacae,Acinetobacter baumannii and Enterobacter aerogenes had high species homology respectively,but the homology between the different species was rather low.The designed primers according to the species consensus sequences could detect the genomic ampC.Conclusions The consensus sequences of the genomic ampC from Escherichia coli,Enterobacter cloacae,Acinetobacter baumannii and Enterobacter aerogenes have high species homology respectively.The species primers from the consensus sequences can be used to identify the genomic ampC.