Lozoya-Pérez Nancy E, Clavijo-Giraldo Diana M, Martínez-Duncker Iván, García-Carnero Laura C, López-Ramírez Luz A, Niño-Vega Gustavo A, Mora-Montes Héctor M
Departamento de Biología, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta s/n, col. Noria Alta, C.P., Guanajuato Gto. 36050, Mexico.
Laboratorio de Glicobiología Humana y Diagnóstico Molecular, Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca Mor. 62209, Mexico.
J Fungi (Basel). 2020 Nov 28;6(4):323. doi: 10.3390/jof6040323.
, , and are etiological agents of sporotrichosis, a human subcutaneous mycosis. Although the protocols to evaluate virulence in animal models are well described, the cell preparation before inoculation is not standardized, and several culturing media are used to grow yeast-like cells. Here, we found that carbon or nitrogen limitation during fungal cell preparation negatively impacted the ability of and to kill larvae, but not . The fungal growth conditions associated with the short median survival of animals were accompanied by increased hemocyte countings, phenoloxidase activity, and cytotoxicity. The fungal growth under carbon or nitrogen limitation also affected the cell wall composition of both and and showed increased exposure of β-1,3-glucan at the cell surface, while those growing conditions had a minimal impact on the wall, which had higher levels of this polysaccharide exposed on the wall regardless of the culture condition. This polysaccharide exposure was linked to the increased ability of insect hemocytes to uptake fungal cells, suggesting that this is one of the mechanisms behind the lower virulence of or cells from the other species grown in carbon or nitrogen limitation.
申克孢子丝菌、巴西孢子丝菌和球形孢子丝菌是孢子丝菌病的病原体，这是一种人类皮下真菌病。尽管在动物模型中评估这些真菌毒力的方案已有详细描述，但接种前的细胞制备并不标准化，并且使用了几种培养基来培养酵母样细胞。在此，我们发现真菌细胞制备过程中的碳或氮限制对申克孢子丝菌和巴西孢子丝菌杀死家蝇幼虫的能力有负面影响，但对球形孢子丝菌没有影响。与动物短中位生存期相关的真菌生长条件伴随着血细胞计数增加、酚氧化酶活性增强和细胞毒性增大。碳或氮限制条件下的真菌生长也影响了申克孢子丝菌和巴西孢子丝菌的细胞壁组成，并显示细胞表面β-1,3-葡聚糖的暴露增加，而这些生长条件对球形孢子丝菌的细胞壁影响最小，无论培养条件如何，其细胞壁上这种多糖的暴露水平都较高。这种多糖的暴露与昆虫血细胞摄取真菌细胞能力的增强有关，这表明这是碳或氮限制条件下生长的申克孢子丝菌或其他物种细胞毒力较低背后的机制之一。
