本研究旨在探讨机械通气患者分离的金黄色葡萄球菌的分子流行病学以及毒力因子参与呼吸机相关性肺炎（VAP）的发展。我们进行了一项前瞻性队列研究，对机械通气患者定期进行气管吸出物和临床数据的收集。分析了金黄色葡萄球菌分离株的耐药谱、毒力、蛋白A和α-毒素的表达情况，采用Western blot，PFGE分子生物学技术分析其克隆谱、MLST序列类型，并对酚可溶性调解素进行了特征和定量分析。在本研究的270名患者中，共从47名患者中分离出51株金黄色葡萄球菌。金黄色葡萄球菌和MRSA VAP的发病密度分别为2.35/1000和1.96/1000呼吸机日，其中45%（n = 5）对氧化苏必利的耐药，100%（n = 5）携带SCCmec II和IV型。经测试的毒力因子中，icaA、hla和hld最常见。克隆谱显示以社区来源的序列类型为主导。VAP的风险因素包括存在实体肿瘤和carl-AB基因。综上所述，与患者相关的风险因素以及微生物学因素共同参与了金黄色葡萄球菌VAP的发展，该疾病由患者自身菌株引起。

This study aimed to explore the molecular epidemiology of Staphylococcus aureus isolated from patients on mechanical ventilation and the participation of virulence factors in the development of ventilator-associated pneumonia (VAP). A prospective cohort study was conducted on patients under mechanical ventilation, with periodic visits for the collection of tracheal aspirates and clinical data. The S. aureus isolates were analyzed regarding resistance profile, virulence, expression of protein A and alpha-toxin using Western blot, clonal profile using PFGE, sequence type using MLST, and characterization and quantification of phenol-soluble modulins. Among the 270 patients in the study, 51 S. aureus strains were isolated from 47 patients. The incidence density of S. aureus and MRSA VAP was 2.35/1000 and 1.96/1000 ventilator days, respectively; of these, 45% (n = 5) were resistant to oxacillin, with 100% (n = 5) harboring SCCmec types II and IV. The most frequent among the tested virulence factors were icaA, hla, and hld. The clonal profile showed a predominance of sequence types originating from the community. Risk factors for VAP were the presence of solid tumors and the sea gene. In conclusion, patient-related risk factors, together with microbiological factors, are involved in the development of S. aureus VAP, which is caused by the patient's own strains.