目的：了解某地区耐甲氧西林金黄色葡萄球菌（MRSA）中α型-酚溶调制蛋白（PSM-α）基因携带情况及对人外周血中性粒细胞的影响，为指导临床治疗及明确该地区 MRSA 致病机制提供理论依据。方法收集临床标本中分离并经SCCmec分型的MRSA 90株，采用聚合酶链反应（PCR）方法扩增PSM-α基因，并通过细胞形态学方法研究PSM-α对人外周血中性粒细胞的影响。结果86株医院获得性 MRSA（HA-MRSA）中，PSM-α基因阳性者78株，PSM-α阳性率为90．70％；4株社区获得性 MRSA（CA-MRSA）中，2株为PSM-α基因阳性，阳性率为50．00％；PSM-α阳性组中性粒细胞死亡率与生理盐水组、PSM-α阴性组和ATCC 25923组间比较，差异有统计学意义。PSM-α阳性组死亡率高于其他3组，而PSM-α阴性组和ATCC 25923组差异无统计学意义。结论该地区 HA-MRSA携带PSM-α基因，且PSM-α基因阳性的 MRSA菌株分泌的PSM-α具有促进中性粒细胞溶解的活性。%Objective To investigate the carriage of phenol soluble modulin-α(PSM-α)in methicillin-resistant Staphylococcus aureus(MRSA)and influence in human peripheral blood neutrophils,so as to provide theoretical ba-sis for guiding clinical treatment and identifying pathogenesis of MRSA. Methods Ninety MRSA isolates which were isolated from clinical specimens and performed SCCmec genotyping were collected,PSM-αgene was amplified by polymerase chain reaction(PCR),and the effects of PSM-αgene on hunman peripheral blood neutrophils was studied by cell morphology analysis.Results Of 86 hospital-acquired MRSA(HA-MRSA)isolates,78 were positive for PSM-αgene,the positive gene was 90.70% ;Of 4 community-acquired MRSA(CA-MRSA),2 were positive for PSM-αgene,the positive rate was 50.00% ;neutrophil death rate in PSM-αpositive group was significantly higher than normal saline group,PSM-αnegative group and ATCC 25923 group,but there was no significant difference between PSM-αnegative group and ATCC 25923 group. Conclusion HA-MRSA detected in this region carry PSM-αgene,and PSM-αsecreted by PSM-αpositive MRSA has the activity of promoting the lysis of neutrophils.
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