We aim to assess intra- and interspecies differences in the virulence of Candida spp. strains causing candidemia using the invertebrate Galleria mellonella model. We studied 739 Candida spp. isolates (C. albicans [n = 373], C. parapsilosis [n = 203], C. glabrata [n = 92], C. tropicalis [n = 53], and C. krusei [n = 18]) collected from patients with candidemia admitted to Gregorio Marañon Hospital (Madrid, Spain). Species-specific infecting inocula (yeast cells/larva) were adjusted (5 × 105 [C. albicans, and C. tropicalis], 2 × 106-5 × 106 [C. parapsilosis, C. glabrata, and C. krusei]) and used to infect 10 larvae per isolate; percentage of survival and median survival per isolate were calculated. According to the interquartile range of the median survival, isolates with a median survival under P25 were classified as of high-virulence and isolates with a median survival over P75 as of low virulence. The median survival of larvae infected with different species was variable: C. albicans (n = 2 days, IQR <1-3 days), C. tropicalis (n = 2 days, IQR 1.5-4 days), C. parapsilosis (n = 2 days, IQR 2-3.5 days), C. glabrata (n = 3 days, IQR 2-3 days), and C. krusei (n = 7 days, 6.5->8 days) (P < .001). Differences in virulence among species were validated by histological examination (day +1 post-infection) in the larvae infected by the isolates of each virulence category and species. Virulence-related gene expression in C. albicans isolates did not reach statistical significance. We report species-specific virulence patterns of Candida spp. and show that isolates within a given species have different degrees of virulence in the animal model.

中文翻译：

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导致念珠菌血症的念珠菌分离株在梅勒埃勒菌园中显示出不同程度的毒力。

我们的目的是评估种内和种间假丝酵母菌毒力的差异。无脊椎动物Galleria mellonella模型导致念珠菌血症的菌株。我们研究了739个念珠菌。分离株（白色念珠菌[n = 373]，副念珠菌[n = 203]，光滑念珠菌[n = 92]，热带念珠菌[n = 53]和克鲁氏梭菌[n = 18]）格雷戈里奥·马拉尼翁医院（西班牙马德里）的念珠菌血症患者。调整了特定物种的感染接种菌（酵母细胞/幼虫）（5×105 [白色念珠菌和热带念珠菌]，2×106-5×106 [副寄生虫，光滑念珠菌和克鲁氏梭菌]）每个隔离株可感染10个幼虫；计算每个分离株的存活百分比和中位存活率。根据中位生存的四分位数范围，在P25下具有中值生存期的分离株被分类为高毒力，在P75之上具有中值生存期的分离株被分类为低毒力。感染了不同物种的幼虫的中位生存期是可变的：白色念珠菌（n = 2天，IQR <1-3天），热带念珠菌（n = 2天，IQR 1.5-4天），副鸡念珠菌（n = 2天，IQR 2-3.5天），光滑念珠菌（n = 3天，IQR 2-3天）和克鲁氏梭菌（n = 7天，6.5-> 8天）（P <.001）。通过组织学检查（感染后第+1天）验证了每种毒力类别和物种的分离株感染的幼虫的物种间毒力差异。白色念珠菌分离株的毒力相关基因表达未达到统计学意义。我们报告了念珠菌属物种的特定毒力模式。