Dimorphism in Histoplasma capsulatum and Blastomyces dermatitidis.
Dimorphism in Histoplasma capsulatum and Blastomyces dermatitidis.
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荚膜组织胞浆菌和皮炎芽生菌的二态性。
DOI：
10.1159/000060346
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Kobayashi,GS
中科院分区：
文献类型：
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作者：
Maresca,B;Kobayashi,GS
几种真菌病原体的一个重要形态学特征是它们在感染宿主组织时从多细胞丝状形式变为单细胞形态的固有能力。这是真菌如荚膜组织胞浆菌、皮炎芽生菌、巴西副球孢子菌、申克孢子丝菌、马尔尼菲青霉菌和粗球孢子菌的固有遗传特性[1]。致病性似乎与这种转化密切相关，因为H. capsulatum，B.不能经历形态转变的皮内阿米巴和巴西变形杆菌是无毒的[2]。这些真菌呈现不同形状的能力被称为二型性。因此，二型性与这些真菌在哺乳动物宿主中定殖、侵入和存活的能力密切相关，并且与特定基因产物的诱导密切相关[3]。然而，形态转换是不必要的，以延续物种，因为这些真菌是土壤saprobes和有能力复制菌丝体。只有当它们偶然感染易感宿主时，才会发生形态学上的变化。在H. capsulatum和B.在皮肤炎中，两个重要特征表征了这种转化：它们响应温度可逆地改变形态的能力，以及酵母形式在宿主内侵入和繁殖的能力。因此，这些细胞特性取决于这些真菌所具有的适应各种环境条件（例如不同的温度制度）的固有能力，并且在巨噬细胞和其他宿主组织中存在的极其恶劣的条件下存活和繁殖。细胞适应是一个复杂的现象，可能是所有二型病原真菌最基本的生物学特性。解开-
An important morphological feature of several fungal pathogens is their inherent ability to change from a multicellular filamentous form to a unicellular morphology when they infect host tissues. This is an intrinsic genetic property of fungi such as Histoplasma capsulatum, Blastomyces dermatitidis, Paracoccidioides brasiliensis, Sporothrix schenkii, Penicillium marneffei and Coccidioides immitis [1]. Pathogenicity appears to be intimately linked to this transformation since strains of H. capsulatum, B. dermatitidis and P. brasiliensis that are unable to undergo the morphologic transition are not virulent [2]. The ability of these fungi to assume different shapes is referred to as dimorphism. Therefore, dimorphism is intimately associated with the ability of these fungi to colonize, invade and survive in mammalian hosts and is critically linked to the induction of specific gene products [3]. However, the morphological switch is not necessary in order to perpetuate the species since these fungi are soil saprobes and have the ability to replicate as mycelia. It is only when they accidently infect a susceptible host that the change in morphology occurs. In the case of H. capsulatum and B. dermatitidis, two important features characterize this transformation: their competence to reversibly change morphology in response to temperature, and the ability of the yeast forms to invade and multiply within the host. Thus, these cellular properties depend on the inherent ability these fungi possess to adapt to various environmental conditions, such as different temperature regimes and survive and multiply under the extremely hostile conditions present in macrophages and other host tissues. Cellular adaptation is a complex phenomenon, probably the most fundamental biological property of all dimorphic pathogenic fungi. Unravel-