Elusive treatment for human rhinosporidiosis

Abstract

Objectives: The aim of this study was to clarify the contentious taxonomic classification of Rhinosporidium seeberi, the cause of human rhinosporidiosis, which may have treatment implications. Methods: PCR was used to amplify the internal transcribed spacer (ITS)-2 region from the genomic DNA of the aetiological agent obtained from a sample of human rhinosporidiosis lesions. The amplicon was sequenced and the organism identified using the Basic Local Alignment Search Tools (BLAST). Results: Phylogenetic analysis revealed that the aetiological agent clustered along with the R. seeberi isolated from humans and also with Amphibiocystidium ranae from frogs. This organism is a member of the order Dermocystida in the class Mesomycetozoea. A patient with disseminated rhinosporidiosis did not respond to conventional therapy with dapsone and surgical excision, and treatment with amphotericin B also proved futile. Conclusion: An effective treatment for R. seeberi—a eukaryote belonging to the class Mesomycetozoea—is still elusive.

Keywords

• Rhinosporidium seeberi
• Rhinosporidiosis
• Mesomycetozoea
• Amphotericin B