Exploring virulence and immunogenicity in the emerging pathogen Sporothrix brasiliensis

Exploring virulence and immunogenicity in the emerging pathogen Sporothrix brasiliensis

Author Della Terra, Paula Portella Autor UNIFESP Google Scholar
Rodrigues, Anderson Messias Autor UNIFESP Google Scholar
Fernandes, Geisa Ferreira Autor UNIFESP Google Scholar
Nishikaku, Angela Satie Autor UNIFESP Google Scholar
Burger, Eva Google Scholar
de Camargo, Zoilo Pires Autor UNIFESP Google Scholar
Abstract Sporotrichosis is a polymorphic chronic infection of humans and animals classically acquired after traumatic inoculation with soil and plant material contaminated with Sporothrix spp. propagules. An alternative and successful route of transmission is bites and scratches from diseased cats, through which Sporothrix yeasts are inoculated into mammalian tissue. The development of a murine model of subcutaneous sporotrichosis mimicking the alternative route of transmission is essential to understanding disease pathogenesis and the development of novel therapeutic strategies. To explore the impact of horizontal transmission in animals (e.g., cat-cat) and zoonotic transmission on Sporothrix fitness, the left hind footpads of BALB/c mice were inoculated with 5x10(6) yeasts (n = 11 S. brasiliensis, n = 2 S. schenckii, or n = 1 S. globosa). Twenty days post-infection, our model reproduced both the pathophysiology and symptomology of sporotrichosis with suppurating subcutaneous nodules that progressed proximally along lymphatic channels. Across the main pathogenic members of the S. schenckii clade, S. brasiliensis was usually more virulent than S. schenckii and S. globosa. However, the virulence in S. brasiliensis was strain-dependent, and we demonstrated that highly virulent isolates disseminate from the left hind footpad to the liver, spleen, kidneys, lungs, heart, and brain of infected animals, inducing significant and chronic weight loss (losing up to 15% of their body weight). The weight loss correlated with host death between 2 and 16 weeks post-infection. Histopathological features included necrosis, suppurative inflammation, and polymorphonuclear and mononuclear inflammatory infiltrates. Immunoblot using specific antisera and homologous exoantigen investigated the humoral response. Antigenic profiles were isolate-specific, supporting the hypothesis that different Sporothrix species can elicit a heterogeneous humoral response over time, but cross reaction was observed between S. brasiliensis and S. schenckii proteomes. Despite great diversity in the immunoblot profiles, antibodies were mainly derived against 3-carboxy-muconate cyclase, a glycoprotein oscillating between 60 and 70 kDa (gp60-gp70) and a 100-kDa molecule in nearly 100% of the assays. Thus, our data broaden the current view of virulence and immunogenicity in the Sporothrix-sporotrichosis system, substantially expanding the possibilities for comparative genomic with isolates bearing divergent virulence traits and helping uncover the molecular mechanisms and evolutionary pressures underpinning the emergence of Sporothrix virulence.
Language English
Sponsor Sao Paulo Research Foundation (FAPESP)
National Council for Scientific and Technological Development
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
National Council for Scientific and Technological Development (CNPq)
Grant number FAPESP: 2009/54024-2
FAPESP: 2015/19746-8
[CNPq: 150605/2015-3
Date 2017
Published in Plos Neglected Tropical Diseases. San Francisco, v. 11, n. 8, p. -, 2017.
ISSN 1935-2735 (Sherpa/Romeo, impact factor)
Publisher Public Library Science
Extent -
Origin http://dx.doi.org/10.1371/journal.pntd.0005903
Access rights Open access Open Access
Type Article
Web of Science ID WOS:000411068800061
URI http://repositorio.unifesp.br/handle/11600/51420

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