【作者】 顾兵；

【导师】 童明庆；

【作者基本信息】 南京医科大学 ， 临床检验诊断学， 2006， 硕士

【摘要】 背景 抗菌药的大量及不合理使用促进了细菌耐药的迅速发展。目前，细菌耐药已逐渐成为一个全球性的问题，其严重后果是影响抗菌药的临床治疗效果，增加患者治疗成本，缩短新药应用周期，直接威胁人体健康。传统观念认为，细菌耐药是由基因突变引起。然而，这种基因突变引起的细菌耐药性并不能传播。近年来，整合子作为一种新的可移动的基因捕获和表达的元件被提出，整合子由5’保守区、3’保守区和两者之间的可变区组成。在整合酶的作用下，整合子可捕获外源耐药基因，在位于整合子上游的启动子作用下表达，使携带整合子的菌株具有耐药及多重耐药性，并可将自身可变区的基因切除成为游离的环状分子，介导细菌耐药性的传播。整合子是细菌，尤其是革兰阴性菌耐药性迅速发展的重要原因。但目前关于整合子的流行现状、基因盒的特性及功能尚未见大样本的地区性研究报道。 目的 本研究旨在调查南京地区肠杆菌科细菌、铜绿假单胞菌和鲍曼不动杆菌中整合子的种类及分布，分析整合子与这些菌耐药和多重耐药的关系，并进一步探讨整合子参与这些菌耐药和多重耐药的分子机制。更多还原

【Abstract】 BackgroundsThe serious abuse of antibiotics has promoted the rapid development of bacteria resistance. At present, bacteria resistance has gradually become a severe and universal problem, leading to the ineffective clinical treatment of antimicrobial agents. It has been associated with the higher cost of clinical treatment and shorter period of new drugs application, and threatenes the health of human directly. In traditional concepts, bacteria resistance is caused by gene mutation, however, it has no transmissibility. In recent years, integrons which consists of 5’ conserved segment, 3’ conserved segment and a variable region between the two conserved segments, have been found to be a novel mobilizable element concerned with gene capture and expression. By integrase, integron can capture external drug-resistance genes which are expressed by the promoter located upstream of integron, so that bacteria containing integron have resistance and multidrug resistance. Integron can excise the genes in its variable region as free circle molecules, and mediate the transmissibility of bacteria resistance. It has been an important reason for the rapid spread of resistance in bacteria, especially in gram negative bacteia. However, the frequency, characteristics, and roles of integrons and gene cassettes have not yet been investigated in a large-scale population of bacteria.更多还原