Hirayama Tatsuro, Miyazaki Taiga, Sumiyoshi Makoto, Ashizawa Nobuyuki, Takazono Takahiro, Yamamoto Kazuko, Imamura Yoshifumi, Izumikawa Koichi, Yanagihara Katsunori, Kohno Shigeru, Mukae Hiroshi
Department of Respiratory Medicine, Nagasaki University Hospital, Nagasaki 852-8501, Japan.
Department of Infectious Diseases, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8501, Japan.
Pathogens. 2020 Dec 31;10(1):23. doi: 10.3390/pathogens10010023.
Gastrointestinal colonization by species is considered the main source of candidemia. The gene in encodes a sterol C5,6-desaturase, which is essential for ergosterol biosynthesis. Although inactivation shows reduced virulence in mouse models of disseminated candidiasis, the role of in intestinal infections is unknown. Here, we infected mice with the strains CAE3DU3 and CAF2-1, containing mutant and wild-type , respectively, and studied gut infection and colonization by these strains. We found that the CAE3DU3 strain showed reduced colonization, pathogenesis, damage to gut mucosa, and chemokine production in the mouse model of invasive candidiasis. Additionally, mice inoculated with CAE3DU3 showed lower mortality than mice inoculated with CAF2-1 ( < 0.0001). Chemokines were less induced in the gut inoculated with CAE3DU3 than in the gut inoculated with CAF2-1. Histopathologically, although the wild-type gene was associated with a higher pathogenicity and invasion of the gut mucosa and liver tissues causing remarkable tissue necrosis, the / mutant was associated with a higher accumulation of cells and lower damage to surrounding tissues than wild-type . These results establish that the ergosterol biosynthetic pathway may be associated with gut colonization and subsequent dissemination.
某物种的胃肠道定植被认为是念珠菌血症的主要来源。该物种中的某基因编码一种甾醇C5,6-去饱和酶,这对麦角固醇的生物合成至关重要。尽管该基因失活在播散性念珠菌病的小鼠模型中显示出毒力降低,但其在肠道感染中的作用尚不清楚。在此,我们用分别含有突变型和野生型该基因的菌株CAE3DU3和CAF2-1感染小鼠,并研究这些菌株在肠道的感染和定植情况。我们发现,在侵袭性念珠菌病的小鼠模型中,CAE3DU3菌株的定植、致病性、对肠道黏膜的损伤及趋化因子产生均有所降低。此外,接种CAE3DU3的小鼠死亡率低于接种CAF2-1的小鼠(P<0.0001)。与接种CAF2-1的肠道相比,接种CAE3DU3的肠道中趋化因子的诱导作用较小。组织病理学上,尽管野生型基因与更高的致病性以及肠道黏膜和肝组织的侵袭相关,导致明显的组织坏死,但该基因/突变体与细胞的更高积聚以及对周围组织的更低损伤有关,相比野生型而言。这些结果表明,麦角固醇生物合成途径可能与肠道定植及随后的播散有关。