Mucormycosis caused by Syncephalastrum spp.: Clinical profile, molecular characterization, antifungal susceptibility and review of literature

Abstract

Objectives: The clinical profile, molecular characteristics and antifungal susceptibility patterns of the Mucoraceous mould, Syncephalastrum spp are poorly characterized. The present study provides a comprehensive overview of these aspects of this rare fungus. Methods: We characterized 8 clinical isolates of Syncephalestrum spp by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF), 28S rDNA sequencing, Amplified Fragment Length Polymorphism (AFLP, n = 7) and in-vitro antifungal susceptibility testing. Clinical details of these eight cases were reviewed with all cases of Syncephalestrum infections reported in the literature till August 2020. Results: S. racemosum (n = 4) and S. monosporum (n = 4) were identified by MALDI-TOF, sequencing and AFLP also clearly differentiated the two. All isolates were uniformly susceptible to amphotericin B and terbinafine. Analysis of clinical details in our eight patients with 43 more cases reported in the literature revealed that most of the reports were (78.4%) from India and cutaneous mucormycosis was the most common (37.3%) presentation followed by rhino-orbito-cerebral (23.5%) and pulmonary(17.6%) infection. Association of trauma with skin infection (p:0.042); immunosuppression/steroid use (p:0.005) and neutropenia (p:0.000) with pulmonary infection was seen. Conclusion: S. racemosum, S. monosporum give rise to human infections. The improved database of MALDI-TOF could distinguish the two species. Such rare and emerging infections merit careful consideration and clinical attention.

Keywords

• Syncephalastrum racemosum
• Syncephalastrum monosporum
• MALDI -TOF MS
• Molecular
• Clinical infections
• Antifungal susceptibility