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), 28SrDNA 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.