SakA对马尔尼菲篮状菌药物应激及致病力的影响

摘要

目的 探讨SakA对马尔尼菲篮状菌(Talaromyces marneffei,TM)致病力及药物应激的影响.方法 构建SakA敲除株(△sakA),观察孢子与巨噬细胞共培养;比较野生株及△sakA在药物压力下的生长状况;比较野生株和△sakA分别感染小鼠的死亡率、菌载量.结果 被巨噬细胞吞噬24 h后,野生株在胞内可见腊肠样酵母细胞,而△sakA以孢子形态存在.△sakA共培养裂解物形成的菌落数少于野生株.与野生株比较,△sakA对棘白霉素类药物更敏感.△sakA感染小鼠死亡率、菌载量较野生株明显降低.结论 SakA与TM酵母相对棘白霉素不敏感相关,在其致病过程中发挥重要作用.%Objective Environmental stress signals are transmitted by evolutionarily conserved MAPKs in most fungi,such as Hog1 in the budding yeast Saccharomyces cerevisiae,Spcl in the fission yeast Schizosaccharomyces pombe and SakA in the Aspergillus nidulans.It has been shown that in Talaromyces marneffei,a pathogenic dimorphic fungus,the SakA (HOG1) gene is involved,not only in tolerance against oxidative and heat stresses,but also in playing a role in growth,morphology,asexual development and the integrity of the cell wall.In this study,the role of the TM SakA gene on the drug Stress and virulence were investigated.Methods We constructed a SakA knockout strain (AsakA) of TM to observe the coculture of spores with macrophages and compare the growth status of wild plants and △sakA at drug pressures.In addition,we infected mice with wild and knockout strains,respectively,and the mortality and fungi loading were compared between these two groups.Results After being phagocytosed by macrophages for 24 h,the sausage-like yeast cells were observed in the wild-type strain while the △sakA was still in the form of spores and could not be transformed into yeast cells.The number of colonies formed by △sakA co-cultivation was less than that of the wild-type strain.Compared with the wild strain,△sakA is more sensitive to echinodermycin drugs.In the infected mouse model,the mortality and fungi loading of △sakA-infected mice were significantly lower than those of wild strains.Conclusion SakA gene plays an important role in the pathogenesis of TM and is associated with why the wild strains of TM is not sensitive to echinodermycin.