针对不同来源金黄色葡萄球菌分离菌株的agr Ⅰ-Ⅳ分型初探

目的:金黄色葡萄球菌附属基因调节子(agr)位点是一个全面的群集感应系统并且控制着毒力因子的产生,本研究旨在针对不同来源的金黄色葡萄球菌分离菌株进行agr Ⅰ-Ⅳ基因分型研究.方法:根据金黄色葡萄球菌agrⅠ-Ⅳ基因组别类型的引物,对五种不同来源的169株金黄色葡萄球菌DNA模板进行多重PCR扩增,获得目的基因,以判断agr基因型.结果:169株分离菌株中,agrⅡ型的检出率为19%(32/169),agrⅢ型检出率为12%(20/169),agrⅣ型检出率为8%(14/169),五种不同来源的金黄色葡萄球菌均有检出agrⅡ型,均未检出agrⅠ型,并且都含有未能分型的agr阴性菌株.研究结果表明不同来源金黄色葡萄球菌分离菌株中agr Ⅰ-Ⅳ基因型的流行情况.该方法对于金黄色葡萄球菌菌株分子分型有一定的借鉴意义,也为金黄色葡萄球菌菌株分子流行病学调查奠定一定的基础.

Investigation of the agr I-IV groups in Staphylococcus aureus isolates from five different sources

Objective： The accessory gene regulator （agr） locus in Staphylococcus aureus is a global regulator of quorum sensing and controls the production of many virulence factors. This study was carried out to investigate the agr I-IV groups in Staphylococcus aureus isolates from five different sources. Methods： According to agr allele types （I - IV） specific primers, multiplex PCR was used to amplify the extracted DNA of 169 S. aureus isolates and to determine the agr groups. Results： The agr groups＇ distribution in 169 S. aureus isolates was as follows： 19%（32/169） belonged to agrlI, 12%（20/169） belonged to agr Ill and 8%（14/169） belonged to agrIV, agr I was not detected in all the isolates. For 109 isolates, the agr group was not detected. This study shows that different agr I-IV groups prevail over our area and agr typing has some significance to investigate the genotypic information of the S. aureus isolated strains.