Increase in virulence of Sporothrix brasiliensis over five years in a patient with chronic disseminated sporotrichosis

Abstract

The metropolitan region of Rio de Janeiro is hyperendemic for cat-associated sporotrichosis. This study aimed to assess the virulence of serial Sporothrix isolates from a 61-year-old male patient with chronic, destructive disseminated sporotrichosis. Five Sporothrix isolates were cultured from skin exudates and bone samples over a 5-year period, and all were molecularly identified as Sporothrix brasiliensis. The final isolate was significantly more virulent in Galleria mellonella larvae compared to earlier isolates. We conclude that S. brasiliensis has the capacity to increase in virulence in vivo. This finding is significant to clinicians caring for individuals with S. brasiliensis disease and it suggests that further studies are needed to identify the mechanisms underlying pathogenicity enhancement during chronic disease.

Keywords:

• Brazil
• chitin synthase
• disseminated
• Galleria mellonella
• reactive nitrogen intermediates
• Rio de Janeiro
• Sporothrix brasiliensis
• sporotrichosis
• T3B PCR
• Virulence

Acknowledgments

Thanks to David Alejandro Sanchez for the help with the virulence experiments, to Dr. Otávio Espíndola for the flow cytometry analysis and to Dr. Nelson Lima for the S. mexicana strain.

funding

DFSF received financial support from CNPq, CAPES and Fogarty International Center (NIH D43-TW007129). SSS received financial support from FAPESP/São Paulo, Brazil (grant proc. 2010/50439-0). RMZ-O was supported in part by CNPq 350338/2000-0 and FAPERJ E-26/103.157/2011. JDN is supported in part by NIH AI52733. Financial support provided by FAPERJ/Rio de Janeiro, Brazil (grant proc. E-26/110.619/2012) and PAPES VI – CNPq/Fiocruz (grant proc. 407693/2012-2).