a novel dimorphic species resemblingin a clinical sample: questions on ecological strategy.

in mBio by Na Li, Jennifer Bowling, Sybren de Hoog, Chioma I Aneke, Jung-Ho Youn, Sherin Shahegh, Jennifer Cuellar-Rodriguez, Christopher G Kanakry, Maria Rodriguez Pena, Sarah A Ahmed, Abdullah M S Al-Hatmi, Ali Tolooe, Grit Walther, Kyung J Kwon-Chung, Yingqian Kang, Hyang Burm Lee, Amir Seyedmousavi

TLDR

  • The study describes a fungus that can change its shape depending on the temperature. This fungus was found in a patient with a rare type of cancer and ongoing reactions from a transplant. The study shows that the fungus can turn from a long, branching shape to a round, single-celled shape. This shape change can happen at body temperature and is common in many fungi. The study suggests that this shape change can be useful for diagnosing infections caused by this fungus in patients.

Abstract

Dimorphism is known among the etiologic agents of endemic mycoses as well as in filamentous. 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 assp. nov. Laboratory studies were performed to simulate temperature-dependent dimorphism, with two environmental strainsandas controls. Both strains could be induced to form multinucleate arthrospores and subsequent yeast-like cells. Multilateral yeast cells emerge in all threeat 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. The ecological role of yeast forms inis 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 foror. We demonstrate that the dimorphic transition is common inspecies 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.

Overview

  • The study focuses on a dimorphic mucoralean fungus obtained from the sputum of a patient with Burkitt lymphoma and ongoing graft-versus-host reactions. The fungus is described assp. nov. The methodology used for the experiment includes laboratory studies to simulate temperature-dependent dimorphism, with two environmental strains and controls. The primary objective of the study is to investigate the morphological transformation of the fungus and its ecological role in mucormycosis.

Comparative Analysis & Findings

  • The study compares the outcomes observed under different experimental conditions or interventions, specifically the dimorphic transition of the fungus. The results show that both strains could be induced to form multinucleate arthrospores and subsequent yeast-like cells. The yeast-like cells emerge in all three at elevated temperatures. The study identifies the dimorphic transition as a common occurrence in species and suggests that it can be driven by many factors. The key findings of the study are that the multi-nucleate yeast-like cells provide an effective parameter to distinguish mucoralean infections from similar yeast-like species in clinical samples.

Implications and Future Directions

  • The study's findings have significant implications for the field of research and clinical practice, as accurate diagnosis of mucormycosis is crucial for timely clinical management. The study suggests that some species may produce yeast-like cells, potentially being mistaken for other yeast-like species in clinical samples. The study identifies the dimorphic transition as a common occurrence in species and suggests that it can be driven by many factors. Future research directions could explore the mechanisms underlying the dimorphic transition and its role in mucormycosis, as well as the development of new diagnostic tools to distinguish mucoralean infections from similar yeast-like species.
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