An Unusual Case of Actinomucor elegans: A Challenging Diagnosis

Abstract

BACKGROUND Actinomucor elegans is an unusual cause of mucormycosis and can be difficult to identify by conventional methods. Mucormycosis has a very high mortality rate, especially among immunocompromised individuals. Due to the morbid and progressive nature of opportunistic fungal infections, early diagnosis is paramount for effective disease management. Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI) and Sanger sequencing are useful methods for rapid diagnosis of unusual fungal pathogens. CASE REPORT We report a fatal case of mucormycosis caused by A. elegans in an immunocompromised man. The pathogen was isolated from a large nasal septal black eschar that developed rapidly during tooth extraction in a patient with myelodysplastic syndrome and diabetes mellitus. After unsuccessful identification by conventional methods, A. elegans was identified using MALDI and Sanger sequencing. CONCLUSIONS Diagnosing fungal organisms poses many difficulties, but amidst the technological evolution in pathogen identification, there are useful methods for rapid identification, including MALDI and sequencing. With these powerful tools, earlier diagnosis will give health professionals an advantage against potentially fatal fungal infections.

Figure 1.

Clinical imaging: (A) black eschar on the hard palate shortly after tooth extraction; (B) magnetic resonance imaging of the head showing rhino-orbital sinus masses consistent with mucormycosis (white arrows) and mycotic embolus in the brain (black arrow).

Figure 2.

Characteristic morphologies of A. elegans with Lactophenol cotton blue staining: (A) multiple branches of the sporangiophore; (B) sac surrounding sporangium, columella with no collaret, and smooth, round sporangiospores from ruptured sporangium; (C) an extensive rhizoid system; (D) and no apophysis.