Fungal necrotizing fasciitis, an emerging infectious disease caused by Apophysomyces (Mucorales)

Abstract

Background: The mucoralean fungi are emerging causative agents of primary cutaneous infections presenting in the form of necrotizing fasciitis.

Aims: The aim of this study was to investigate a series of suspected necrotizing fasciitis cases by Apophysomyces species over one-year period in a northern Indian hospital.

Methods: The clinical details of those patients suspected to suffer from fungal necrotizing fasciitis were recorded. Skin biopsies from local wounds were microscopically examined and fungal culturing was carried out on standard media. The histopathology was evaluated using conventional methods and special stains. Apophysomyces isolates were identified by their morphology and by molecular sequencing of the internal transcribed spacer (ITS) region of the ribosomal genes. Antifungal susceptibility testing was carried out following EUCAST guidelines and treatment progress was monitored.

Results: Seven patients were found to be suffering from necrotizing fasciitis caused by Apophysomyces spp. Six isolates were identified as Apophysomyces variabilis and one as Apophysomyces elegans. Five patients had previously received intramuscular injections in the affected area. Three patients recovered, two died and the other two left treatment against medical advice and are presumed to have died due to their terminal illnesses. Posaconazole and terbinafine were found to be the most active compounds against A. variabilis, while the isolate of A. elegans was resistant to all antifungals tested.

Conclusions: Apophysomyces is confirmed as an aggressive fungus able to cause fatal infections. All clinicians, microbiologists and pathologists need to be aware of these emerging mycoses as well as of the risks involved in medical practices, which may provoke serious fungal infections such as those produced by Apophysomyces.

Keywords: Apophysomyces; Emerging fungi; Fascitis necrotizante; Hongos emergentes; Mucorales; Mucormicosis; Mucormycosis; Necrotizing fasciitis.