The virulence of two strains of Sporothrix schenckii isolated from patients with lymphocutaneous or disseminated sporotrichosis were examined in BALB/c mice (Group 1 and 2, respectively). The mice were inoculated subcutaneously into the left hind footpad with 4×10⁶S. schenckii yeast cells in order to evaluate (i) the development of cutaneous lesions, (ii) signs of inactivity, (iii) weight loss, (iv) survival rates, (v) number of viable yeast cells in the lungs and spleen, (vi) splenic index, (vii) extent of organ lesions, and (viii) immunological responses. Comparison of the two groups showed more severe disease in Group 2 mice that developed significant weight and hair loss associated with inactivity and left hind footpad lesions that extended close to the testicular area. The histopathology and large number of viable microorganisms isolated from the spleen confirmed the higher invasive ability of this strain. Moreover, a decrease of an in vitro specific lymphoproliferative response and IFN-gamma production were observed over time in Group 2 mice. As a result, at the end of the experiment, the S. schenckii-antigen (Ss-Ag) response was considered negative with a stimulation index (SI)=2. In contrast, Group 1 mice presented a positive response to Ss-Ag (SI=14.1). These results confirm the existence of different virulence profiles in S. schenckii strains. In addition, the use of subcutaneous inoculation as a suitable route for verification of the pathogenicity of this fungus in the murine model was confirmed.

Paecilomyces spp. and Byssochlamys spp. are heat-resistant fungi important to industry because they can cause food and beverage spoilage, incurring economic loss. The consequences of food or beverage fungal colonization is the loss of nutritional value, structure and taste, and the possibility of producing toxic secondary metabolites that may result in medical problems. Furthermore, these fungi can infect animals and humans and it is unknown if contaminated foods may be fomites. P. variotii is the principal agent of food spoilage or contamination and it is most frequently associated with human hyalohyphomycosis with clinical manifestations including peritonitis, cutaneous and disseminated infections, among others. Byssochlamys spp. had not been identified as a cause of systemic infection until the case of a dog with a fungal infection, after immunosuppressive therapy. P. variotii has clinical importance because it causes severe infection in immunosuppressed patients and also because the number of immunocompetent infected patients is increasing. This review draws attention to the ability of these species to grow at high temperatures, to colonize food products, and to cause human disease.

Purpureocillium lilacinum is a filamentous, hyaline fungus considered an emerging pathogen in humans. The aim of our study was to evaluate the outcome of hyalohyphomycosis in C57BL/6 murine models inoculated with two clinical P. lilacinum isolates (S1 and S2). Each isolate was inoculated in mice randomly distributed in immunocompetent (CPT) and immunosuppressed (SPS) groups. Mice were evaluated at day 7, 21 and 45 after inoculation for histopathological analysis, recovery of fungal cells and immunological studies. Histological analysis showed scarce conidia-like structures in lung tissue from CPT mice and a lot of fungal cells in SPS mice inoculated with S2 compared to mice inoculated with S1. The maximum recovery of fungal cells was seen in CPT mice inoculated with both isolates at day 7th, but with mean significantly higher in those inoculated with S2 isolate. Phenotypical characterization of T cells showed TCD8+ lymphocytes predominance over TCD4+ in immunosuppressed mice infected and control groups. We also observed higher percentages of the central and effector memory/effector phenotype in CPT mice infected with S2 strain, especially in TCD8+ in the initial period of infection. Regulatory T cells showed higher percentages in immunosuppressed, predominantly after the acute phase. Our results showed that the P. lilacinum is a fungus capable to cause damages in competent and immunosuppressed experimental hosts. Furthermore, S2 isolate seems to cause more damage to the experimental host and it was possible to identify different cellular subsets involved in the mice immune response.

Twenty Coccidioides immitis strains were evaluated. Only 5 of the 20 strains kept under mineral oil maintained their viability while all 5 subcultures preserved in water remained viable and none of the 13 subcultures kept in soil were viable. A 519 bp PCR product from the csa gene confirmed the identity of the strains.