CAJ | 학술논문

目的研究新的细胞壁锚定蛋白SasX对金黄色葡萄球菌黏附聚集和定植能力的影响.方法采用基因敲除及基因互补技术获得耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus,MRSA)ST-239 HS770 sasX基因突变株及基因互补株.显微镜下直接观察sasX 基因突变前后细菌自身的黏附聚集能力.通过黏附实验检测sasX基因突变前后对金黄色葡萄球菌黏附至人体鼻腔上皮细胞能力,并通过阻断实验检测表达纯化的SasX蛋白对金黄色葡萄球菌黏附至人体鼻腔上皮细胞的阻断能力,分析SasX蛋白对金黄色葡萄球菌定植能力的影响.结果与野生株相比,突变株HS770△sasX自身的聚集能力明显减弱,而互补表达株HS770 △sasX( pRBsasX)的自身聚集能力与野生株无明显差异.与野生株相比,突变株HS770△sasX黏附至人体鼻腔上皮细胞能力明显减弱(P＜0.01),互补表达株HS770△sasX(pRBsasX黏附能力明显增强(P＜0.01).表达纯化的GST融合蛋白SasX和人体鼻腔上皮细胞预培养对于野生株HS770黏附至人体鼻腔上皮细胞的能力具有明显的抑制作用.结论新的细胞壁锚定蛋白SasX影响金黄色葡萄球菌黏附聚集和定植能力,金黄色葡萄球菌通过获得sasX基因更加容易定植到宿主易感部位,进而引发感染.
목적 연구신적세포벽묘정단백SasX대금황색포도구균점부취집화정식능력적영향.방법 채용기인고제급기인호보기술획득내갑양서림금황색포도구균(methicillin-resistant Staphylococcus aureus,MRSA)ST-239 HS770 sasX기인돌변주급기인호보주.현미경하직접관찰sasX 기인돌변전후세균자신적점부취집능력.통과점부실험검측sasX기인돌변전후대금황색포도구균점부지인체비강상피세포능력,병통과조단실험검측표체순화적SasX단백대금황색포도구균점부지인체비강상피세포적조단능력,분석SasX단백대금황색포도구균정식능력적영향.결과 여야생주상비,돌변주HS770△sasX자신적취집능력명현감약,이호보표체주HS770 △sasX( pRBsasX)적자신취집능력여야생주무명현차이.여야생주상비,돌변주HS770△sasX점부지인체비강상피세포능력명현감약(P＜0.01),호보표체주HS770△sasX(pRBsasX점부능력명현증강(P＜0.01).표체순화적GST융합단백SasX화인체비강상피세포예배양대우야생주HS770점부지인체비강상피세포적능력구유명현적억제작용.결론 신적세포벽묘정단백SasX영향금황색포도구균점부취집화정식능력,금황색포도구균통과획득sasX기인경가용역정식도숙주역감부위,진이인발감염.
Objective To determine whether the novel surface-anchored protein SasX promotes aggregation of S.aureus and adherence of S.aureus to human nasal epithelial cells.Methods MRSA ST-239 HS770 sasX gene mutant ( HS770 △sasX) and complement [ HS770 △sasX (pRBsasX) ] were gotten by gene knock-out and complement methods.The aggregation ability of S.aureus was observed through microscope.By adherence assay which was used for detection of the adherence ability of wild type and mutant to human nasal epithelial cells and blocking experiments which detected the ability of the purified recombinant SasX protein in blocking the adherence of S.aureus to human nasal epithelial cells,we investigated the influence SasX on colonization of S.aureus.Results Compared to wild type,HS770△sasX showed a reduction in cell aggregation,while the complement had no difference with wild type in aggregation. HS770 △sasX showed a significant reduction of adherence to human nasal epithelial cells compared to wild type ( P＜0.01 ),and the complement showed a very clear increasement of adherence to human nasal epithelial cells compared to wild type(P＜0.01 ).Preincubation of nasal epithelial cells with the purified recombinant SasX protein inhibited S.aureus binding significantly.Conclusion SasX had an influence in aggregation of S.aureus and its adherence to human nasal epithelial cells.By acquiring sasX,S.aureus colonized more easily to the susceptible sites of the host,and thus caused infection.