产超广谱β-内酰胺酶细菌中I类整合子的研究进展

Advances in class I integron in extended-spectrum beta-lactamase producing bacteria

产超广谱β-内酰胺酶(Extended-spectrum beta-lactamase,ESBLs)细菌的多重耐药性是临床用药的一大难题,近年研究发现其耐药性的产生与整合子密切相关,其中临床最常见、研究最深入的是I类整合子。整合子是一种可移动基因元件,在整合酶的作用下捕捉外源基因盒并使之表达,是具有基因整合和切除功能的天然克隆和表达系统。研究表明I类整合子可连续捕捉和整合多种耐药基因,以质粒或转座子为载体在细菌之间传播耐药性,使ESBLs细菌多重耐药趋势十分严峻。本文就I类整合子的结构特征、I类整合子对耐药基因盒的整合作用及其与ESBLs细菌耐药性的关系等方面进行综述。

The multidrug resistance of ESBL-producing bacteria poses a serious problem in the clinical therapy. In recent years, some studies indicate that integrons are closely linked to the antibiotic resistance in bacterial pathogens. Class I integron is the most ubiquitous among clinical microbes and remains the focus of numerous investigations. Integrons are specialized genetic elements capable of capturing exogenous gene cassettes and ensuring their expression under the action of integrases. Integrons are natural cloning and expression systems in the function of integration and excision. It has been demonstrated that integrons can continuously capture and integrate multiple genes that confer resistance to antibiotics. The conjugative plasmids and transposons associated can serve as vehicles for the transmission of drug-resistance genes, leading to the serious trend of multidrug resistance. This paper reviews the structure of class I integron, the integration of gene cassettes by class I integron and the relationship between class I integron and multidrug resistance in ESBL-producing bacteria.