二态性是地方性真菌病和丝状毛霉目病原体中已知的。在适当的热条件下，单核酵母菌与多核菌丝交替形成。在这里，我们描述了从患有伯基特淋巴瘤和正在进行的移植物抗宿主反应的患者的痰中获得的二形性毛霉真菌。该真菌被描述为毛霉（Mucor germinans sp）。十一月进行实验室研究以模拟温度依赖性二态性，以两种环境菌株卷枝毛霉和昆良格里毛霉作为对照。两种菌株均可在体外被诱导形成多核节孢子和随后的酵母样细胞。在高温下，所有三种毛霉属物种中都会出现多边酵母细胞。这种形态转变似乎在体温下发生，因为在免疫功能低下患者的肺部观察到了酵母样细胞。临床样品中酵母样细胞的微观外观很容易与副球孢子菌的细胞相混淆。讨论了毛霉目中酵母形式的生态作用。重要性毛霉菌病是一种毁灭性的疾病，在易感患者中具有高发病率和死亡率。由于不同物种的抗真菌敏感性不同，因此需要准确诊断以进行及时的临床治疗。不规则的菌丝成分通常被认为是毛霉菌病的标志，但在这里，我们表明某些物种也可能产生酵母样细胞，可能被误认为是念珠菌或副球孢子菌。我们证明二态性转变在毛霉属物种中很常见，并且可以由许多因素驱动。多核酵母样细胞提供了区分临床样本中类似酵母菌感染和毛霉菌感染的有效参数。

Dimorphism is known among the etiologic agents of endemic mycoses as well as in filamentous Mucorales. Under appropriate thermal conditions, mononuclear yeast forms alternate with multi-nucleate hyphae. Here, we describe a dimorphic mucoralean fungus obtained from the sputum of a patient with Burkitt lymphoma and ongoing graft-versus-host reactions. The fungus is described as Mucor germinans sp. nov. Laboratory studies were performed to simulate temperature-dependent dimorphism, with two environmental strains Mucor circinelloides and Mucor kunryangriensis as controls. Both strains could be induced to form multinucleate arthrospores and subsequent yeast-like cells in vitro. Multilateral yeast cells emerge in all three Mucor species at elevated temperatures. This morphological transformation appears to occur at body temperature since the yeast-like cells were observed in the lungs of our immunocompromised patient. The microscopic appearance of the yeast-like cells in the clinical samples is easily confused with that of Paracoccidioides. The ecological role of yeast forms in Mucorales is discussed.IMPORTANCEMucormycosis is a devastating disease with high morbidity and mortality in susceptible patients. Accurate diagnosis is required for timely clinical management since antifungal susceptibility differs between species. Irregular hyphal elements are usually taken as the hallmark of mucormycosis, but here, we show that some species may also produce yeast-like cells, potentially being mistaken for Candida or Paracoccidioides. We demonstrate that the dimorphic transition is common in Mucor species and can be driven by many factors. The multi-nucleate yeast-like cells provide an effective parameter to distinguish mucoralean infections from similar yeast-like species in clinical samples.