Relationships among genotypes, virulence and clinical forms of Sporothrix schenckii infection

Abstract

This study explored the relationships among genotypes, virulence and clinical forms of Sporothrix schenckii. Genomic DNA from isolates of S. schenckii, collected from different clinical forms of sporotrichosis, was amplified by randomly amplified polymorphic DNA (RAPD). Suspensions of different isolates of S. schenckii were inoculated into healthy BALB/c mice to compare their virulence, and the numbers and distribution of spores were determined by histological analysis. RAPD analysis indicated that the isolates from different clinical forms of sporotrichosis belonged to different genotypes. The mice inoculated with isolates from disseminated sporotrichosis showed an earlier onset of illness and more severe lesions than those inoculated with isolates from lymphocutaneous sporotrichosis, which, in turn, showed an earlier onset of illness and more severe lesions than those inoculated with isolates from fixed cutaneous sporotrichosis. Healthy BALB/c mice injected with isolates from disseminated sporotrichosis died within 10 days, whereas isolates from lymphocutaneous sporotrichosis and fixed cutaneous sporotrichosis failed to cause death. Histologically, mice inoculated with isolates from disseminated sporotrichosis had more spores than those inoculated with isolates from lymphocutaneous sporotrichosis and fixed cutaneous sporotrichosis. Thus, different genotypes may be associated closely with the virulence of different clinical forms of S. schenckii infection.

Characterization of virulence profile, protein secretion and immunogenicity of differentSporothrix schenckii sensu strictoisolates compared withS. globosaandS. brasiliensisspecies

“…35 Some comparative studies were conducted correlating the route of experimental infection 32 or clinical manifestation in humans with the virulence degree of different isolates. 33,34 Recently, Arrillaga-Moncrieff et al 2,3 showed different degrees of virulence among S. schenckii s. str., S. brasiliensis and S. globosa species.…”

“…30 On the other hand, other studies showed the differences in Sporothrix virulence and the clinical presentation of the disease, geographic origin, genotype and thermotolerance. [31][32][33][34] The time of cultivation of yeast and mycelial cells of S. schenckii induces changes in cell wall composition, causing a decrease of pathogenic power. 35 Some comparative studies were conducted correlating the route of experimental infection 32 or clinical manifestation in humans with the virulence degree of different isolates.…”

Cell surface expression of adhesins for fibronectin correlates with virulence in Sporothrix schenckii

“…The variety of clinical presentations of the disease could be due at least in part to variations in the expression of virulence factors/regulators between S. schenckii isolates. Some S. schenckii genotypes seem to be associated with particular clinical manifestations (Maia et al, 2006;Kong et al, 2006). However, the intrinsic virulence factors of this pathogen remain unclear.…”

“…Kong et al (2006) reported that isolates recovered from a disseminated form of sporotrichosis were more virulent in mice than those from lymphocutaneous and fixed cutaneous sporotrichosis. Our present results indicate that all S. schenckii isolates have an intrinsic pathogenicity, but distinct dissemination patterns were observed from one isolate to another.…”

“…However, other studies report that variations in clinical presentations may also be explained by factors intrinsic to the pathogen, such as strain variations in thermotolerance or pathogenicity (Tachibana et al, 1998(Tachibana et al, , 2001. Kong et al (2006) suggested that some genotypes may be closely associated with S. schenckii virulence and infection outcome.…”