Among these,S

Among these,S. indicate that besides the immunological background of the host, other factors associated with the pathogen can impair the clinical manifestations of this disease, such as virulence factors (i.e., adhesins) and antigenic molecules. Some of these factors ofS. schenckiiwill be briefly discussed in this review article, focusing on the fungus surface. Another important feature that should be highlighted is the recent description of several genotypes indicating thatS. schenckiiis a complex of cryptic species, denominated theS. schenckiicomplex (Marimon et al.,2006,2007). Within this complex, at least five species are considered of interest due to their pathogenic potential (Arrillaga-Moncrieff et al.,2009). Among these,S. globosahave Carebastine already been associated with human cases (Oliveira Carebastine et al.,2010) andS. brasiliensiswith feline sporotrichosis (Lopes-Bezerra L. M., unpublished results) in Brazil. The genome project of two pathogenic species,S. schenckiiandS. brasiliensis, are currently under development (Felipe M. S. and Lopes-Bezerra L. M., personal communication) and will bring new insights regarding virulence factors and other relevant biological aspects of these two pathogenic species, which can be further associated with noteworthy clinical and epidemiological aspects of sporotrichosis. Subcutaneous ER81 fungal infections are usually chronic conditions. They often begin after the skin has been pierced following an injury of some kind, since this allows infectious fungi to penetrate the skin and establish themselves inside the host. Eventually, a subcutaneous contamination like sporotrichosis can evolve to severe systemic or disseminated forms. In this rather complicated puzzle, the first step for a pathogen to succeed is its capacity to adhere to and colonize host tissues. The binding of pathogen-associated molecular patterns (PAMPs) as cell wall sugar polymers and proteins, to pattern recognition receptors (PRRs) on innate immune cells triggers the activation of the immune system (Bourgeois et al.,2010; Latg,2010). Additionally, adhesion molecules expressed around the fungus cell surface can mediate their interaction with host cells and extracellular matrix components (Tronchin et al.,2008). One of the well known cell wall components ofS. schenckiiis the peptidorhamnomannan. This glycopeptide or glycoconjugate is a complex of molecules with a wide range of molecular weights that are hard to purify as individual components (Lima and Lopes-Bezerra,1997). This cell wall peptidorhamnomannan fraction (CWPR) can be recognized by IgG antibodies present in patient sera (Lloyd and Bitoon,1971; Penha and Lopes-Bezerra,2000) and by host cell receptors and matricial proteins (Lima et al.,2001; Figueiredo et al.,2004). Another interesting cell wall component, also present in the fungus culture filtrate, is a 70-kDa antigen (Lima and Lopes-Bezerra,1997; Nascimento and Almeida,2005). Furthermore, several groups have reported evidence of the role of gp70 as an important adhesin that can mediate fungus adhesion to host tissues and to matricial proteins of the basal lamina (Lpez-Romero et al.,2011). == Cell Wall Glycoconjugates == Sporothrix schenckiihas two morphological phases: a mycelial saprophytic form and a parasitic yeast-like form. Alkali-soluble and -insoluble glucans were detected in both morphological phases of this fungus. Alkali-soluble glucans of the yeast form ofS. schenckiiare linked by (1,3), (1,6), and (1,4) bonds at 44, 28, and 28%, respectively. Insoluble glucans contain 66, 29, and 5%, respectively, of (1,3), (1,6), and (1,4) bonds. No variations in Carebastine -glucan composition were correlated with the fungus morphological transition (Previato et al.,1979). Furthermore, there is no evidence in the literature concerning the presence of an -glucan around the fungus surface, similar to that described for other dimorphic fungi. The cell wall peptidorhamnomannan is composed of 33.5% rhamnose, 57% mannose, and 14.2% protein and was characterized in the yeast-phase ofS. schenckii(Lloyd and Bitoon,1971). In addition to rhamnose and mannose, polysaccharides containing galactose have also been identified on the surface of this fungus. A similar component containing rhamnose and mannose was detected in a fraction isolated from the culture filtrate ofS. schenckii(Ishizaki,1970). This culture filtrate glycopeptide was also shown to be antigenic and its antigenicity varied according to the rhamnose:mannose molar ratio, which is influenced by the culture conditions (Takata and Ishizaki,1983). Another intriguing obtaining was the observation thatS. schenckiipeptidorhamnomannans reacted with the carbohydrate-binding protein Concanavalin A (lectin ConA), but the rhamnomannans extracted by warm alkali treatment was non-reactive (Travassos et al.,1977). These findings did not confirm the preliminary structural evidence indicating the presence of mannose.