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Sporothrix brasiliensis is a highly virulent member of the S. schenckii complex, which is responsible for the emergence of the epidemic sporotrichosis in southeastern Brazil over the last two decades. There are no in vivo studies on the sensitivity of S. brasiliensis to the therapeutic regimens used to treat sporotrichosis. Here, we evaluated the efficacy and safety of antifungal treatments against S. brasiliensis using a murine model of disseminated sporotrichosis. In vitro, S. brasiliensis yeasts were sensitive to low concentrations of amphotericin B-deoxycholate (AMB-d) and itraconazole (ITZ), the latter having greater selectivity toward the fungus. The following treatment regimens were tested in vivo: intravenous AMB-d for 7 days post-infection (p.i.), oral ITZ for up to 30 days p.i., and AMB-d followed by ITZ (AMB-d/ITZ). AMB-d and AMB-d/ITZ led to 100% survival of infected mice at the end of the 45-day experimental period. Although all treatments extended mice survival, only AMB-d and AMB-d/ITZ significantly reduced fungal load in all organs, but AMB-d/ITZ led to a more consistent decrease in overall fungal burden. No treatment increased the levels of serum toxicity biomarkers. Taken together, our results indicate that AMB-d/ITZ is the best therapeutic option for controlling disseminated sporotrichosis caused by S. brasiliensis., (© The Author 2014. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Sporotrichosis is a chronic infectious disease affecting both humans and animals. For many years, this subcutaneous mycosis had been attributed to a single etiological agent; however, it is now known that this taxon consists of a complex of at least four pathogenic species, including Sporothrix schenckii and Sporothrix brasiliensis. Gp70 was previously shown to be an important antigen and adhesin expressed on the fungal cell surface and may have a key role in immunomodulation and host response. The aim of this work was to study the virulence, morphometry, cell surface topology and gp70 expression of clinical isolates of S. brasiliensis compared with two reference strains of S. schenckii. Several clinical isolates related to severe human cases or associated with the Brazilian zoonotic outbreak of sporotrichosis were genotyped and clustered as S. brasiliensis. Interestingly, in a murine subcutaneous model of sporotrichosis, these isolates showed a higher virulence profile compared with S. schenckii. A single S. brasiliensis isolate from an HIV-positive patient not only showed lower virulence but also presented differences in cell morphometry, cell wall topography and abundant gp70 expression compared with the virulent isolates. In contrast, the highly virulent S. brasiliensis isolates showed reduced levels of cell wall gp70. These observations were confirmed by the topographical location of the gp70 antigen using immunoelectromicroscopy in both species. In addition, the gp70 molecule was sequenced and identified using mass spectrometry, and the sequenced peptides were aligned into predicted proteins using Blastp with the S. schenckii and S. brasiliensis genomes.

Cutaneous lesions of feline sporotrichosis show high fungal load and are associated with severe disease and elevated zoonotic potential. The present study describes the histopathology and fungal load of the lesions in different clinical presentations of feline sporotrichosis. Cats with sporotrichosis were separated into groups L1, L2 and L3 (lesions in one, two and three or more locations, respectively) and subjected to skin biopsies for histopathology. Eighty-six cats were included in the study. Lesions were suppurative granulomatous in 84 cases and poorly formed granulomas were predominant. The well-formed granulomas were associated with group L1. The high fungal load was predominant in group L3 and in poorly formed granuloma cases and did not occur in well-formed granulomas cases. The good general condition was associated with low fungal load. These findings suggest that the fungal load control in animals with more localized lesions and well-organized response is linked with the improvement in the outcome of infected cats., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Sporotrichosis is a subcutaneous fungal infection caused by Sporothrix schenckii and acquired by direct inoculation. Although the majority of cases consist of the classic lymphocutaneous presentation, the frequency of atypical and severe clinical forms of the disease has increased progressively. Systemic and disseminated cutaneous sporotrichosis constitute rare variants and such cases are generally associated with cellular immunodeficiency or debilitated states. The present paper describes the first published case of molluscum-like lesions in disseminated mucocutaneous sporotrichosis. Direct mycological examination and histopathology revealed numerous yeast cells.

The present study reports the histopathological findings of 86 skin lesions of dogs with sporotrichosis from Rio de Janeiro. Suppurative granulomatous inflammation was the predominant finding and was observed in 76 (88.37%) cases. Plasma cells surrounding the suppurative granulomas were detected in 68 (89.5%) cases and an inflammatory infiltrate at the periphery of these granulomatous lesions was observed in 63 (82.9%). Fungus-specific staining revealed yeast cells compatible with Sporothrix schenckii in 36 cases. These fungal elements were only detected in lesions characterized by suppurative granulomatous inflammation. Thus, specific staining of serial sections is recommended in the case of dogs with skin lesions whose histopathological presentation is consistent with sporotrichosis. However, due to the generally small number of yeast cells in lesions, the hypothesis of sporotrichosis should not be ruled out even if the result is negative, especially in epidemic areas where correlation with epidemiological data is particularly useful.

Twenty-three cats with respiratory signs who had domiciliary contact with cats with sporotrichosis were studied. Sneezing was the predominant extracutaneous sign. Twelve cats had no skin lesions and 11 had ulcerated skin lesions. Mycological culture of material obtained from the nasal cavity, oral cavity, bronchoalveolar lavage (BAL) and skin lesions, when present, was performed for all cats. In the case of autopsy, lung fragments were cultured. Sporothrix schenckii was isolated from four of the 12 cats without skin lesions: BAL (one cat) and oral and/or nasal cavity (three cats). The latter three animals developed nasal and distant skin lesions within the following 2-4 weeks. The cat with S. schenckii isolated from BAL did not develop skin lesions or lower respiratory tract symptoms during the 6 months of follow-up. S. schenckii was isolated from one or more biological samples of all 11 cats with skin lesions: oral cavity (five), nasal cavity (eight), BAL fluid (four), skin lesions (eight), and blood culture (one). No yeast-like structures were observed upon BAL cytology in any of the 23 cats. The results suggest that S. schenckii can cause infection of skin contiguous to the natural facial orifices through colonisation of the mucosal surfaces of the upper airways.

Seventy-four dogs from the State of Rio de Janeiro with ulcerated cutaneous lesions were submitted to clinical, dermatological, parasitological, mycological, histopathological and cytopathological exams, a leishmanin skin test, an indirect immunofluorescence (IIF) test for leishmaniosis, and nonspecific laboratory tests such as blood count and serum biochemistry. Sporothrix schenckii was isolated from 41 dogs and Leishmania (Viannia) braziliensis was isolated from 33 animals. Most dogs with sporotrichosis were from the municipality of Rio de Janeiro (53.7%) and presented ulcerated cutaneous lesions on the head (68.3%). Laboratory alterations in these animals included anemia (58.5%), hypoalbuminemia (83%) and hyperglobulinemia (75.6%). Histopathology revealed the predominance of a chronic granulomatous inflammatory infiltrate (70.7%), and yeast-like structures were detected in 17% of the histopathological exams and in 32% of the cytological exams. Three of 41 dogs with sporotrichosis were seropositive by IIF for leishmaniosis and 2 of 20 animals tested within this group had a positive leishmanin skin test. Similarly, most of the 33 dogs with leishmaniosis were from the municipality of Rio de Janeiro (69.7%) and had ulcerated cutaneous lesions on the head (84.8%). Laboratory alterations in these animals included anemia (66.7%), hypoalbuminemia (100%) and hyperglobulinemia (91%). Histopathology showed the predominance of a chronic granulomatous inflammatory infiltrate (63.6%) and amastigote forms were detected in 30.3% of the histopathological exams and in 31.8% of the 22 cytological exams performed. About 72.7% of the dogs were seropositive by IIF and five of seven animals had a positive skin test. Due to the clinical similarities, histopathological and nonspecific laboratory results similarities, the serological and skin tests for leishmaniosis positive in dogs with sporotrichosis, and the overlapping endemic areas in Rio de Janeiro, the differential diagnosis between the two diseases requires the demonstration of their respective etiological agents.

We studied 52 patients with sporotrichosis confirmed by isolation of Sporothrix schenckii and reactivity to the Montenegro skin test (MST) during an ongoing outbreak of this mycosis in Rio de Janeiro. The objective was to emphasize the importance of parasitological confirmation and the possibility of incorrect diagnosis based on the lesion's appearance, epidemiological information, and immunological tests. The antigen used for the MST was conserved in either thimerosal 1:10,000 (group 1) or 0.4% phenol (group 2). Nineteen patients (39%) in group 1 and seven (12%) in group 2 presented an induration>or=10 mm (p<0.001). Sera from three patients (6.7%) reacted to indirect immunofluorescence (IIF) for leishmaniasis, while sera from 10 patients (22.2%) reacted to enzyme-linked immunosorbent assay (ELISA). Fifteen patients (28.8%) presented up to two lesions, with a predominance of ulcers. Forty-four patients (84.6%) were treated with itraconazole. In the differential diagnosis between sporotrichosis and cutaneous leishmaniasis, the possibility of co-infection, allergy to the reagent diluent, and cross-reactions should be further investigated, especially in regions with limited laboratory facilities.