Fátima Conceição-Silva

Cat-Transmitted Sporotrichosis Epidemic in Rio de Janeiro, Brazil: Description of a Series of Cases

Sporotrichosis is the most common subcutaneous mycosis in South America. Classic infection is associated with traumatic inoculation of soil, vegetables, and organic matter contaminated with Sporothrix schenckii. Zoonotic transmission has been described in isolated cases or in small outbreaks. Since 1998, we have been observing an increasing number of cases of sporotrichosis in persons from the city of Rio de Janeiro, Brazil, and surroundings. From 1998 to 2001, 178 cases of culture-proven sporotrichosis had been diagnosed. Female patients predominated, and the median age was 39 years. The most frequent clinical presentation was lymphocutaneous disease. Of the 178 patients, 156 reported domiciliary or professional contact with cats with sporotrichosis, and 97 of these patients had a history of receipt of cat scratch or bite. The patients received itraconazole as first-line treatment. This study suggests that feline transmission of sporotrichosis was associated with a large and long-lasting outbreak of the disease in Rio de Janeiro.

Leishmania (Viannia) braziliensis genotypes identified in lesions of patients with atypical or typical manifestations of tegumentary leishmaniasis: evaluation by two molecular markers.

Analyses of MLEE, RAPD and LSSP-PCR were used to compare the panel of american tegumentary leishmaniasis (ATL) isolates obtained from lesions of patients with rare clinical manifestations of the disease and typical lesions. All of the 34 samples analyzed by MLEE demonstrated similar electromorphic profiles with Leishmania (Viannia) braziliensis reference strain. Through the RAPD analysis, nine genetic profiles (genotypes) were identified. LSSP-PCR corroborates the initial screening and phenetic analysis has grouped the isolates into two major clusters comprising the nine different genotypes. Prevalent genotype defined as LbmtDNAgen1 was detected in the largest number of isolates. There was no association between genotypes and clinical symptoms. However, two different genotypes could be identified in the initial (LbmtDNAGen9) and reactivated lesion (LbmtDNAGen3) of the same patient. Our results support the idea of a less pronounced genotypic diversity among L. (V.) braziliensis circulating in the State of Rio de Janeiro and demonstrate the useful application of these molecular markers in genetics variability studies.

Comparison of virulence of different Sporothrix schenckii clinical isolates using experimental murine model

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 x 10(6) S. 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.

Feline sporotrichosis: Histopathological profile of cutaneous lesions and their correlation with clinical presentation

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.

Differential Interferon-γ Production Characterizes the Cytokine Responses to Leishmania and Mycobacterium leprae Antigens in Concomitant Mucocutaneous Leishmaniasis and Lepromatous Leprosy

BACKGROUND Tegumentary leishmaniasis and leprosy display similar spectra of disease phenotypes, which are dependent on cell-mediated immunity to specific antigens. Diffuse cutaneous leishmaniasis and lepromatous leprosy represent the anergic end of the spectrum, whereas mucocutaneous leishmaniasis and tuberculoid leprosy are associated with marked antigen-specific cellular immune response. METHODS We characterized and compared the cell-mediated response to Leishmania and Mycobacterium leprae antigens in a patient with an intriguing association of mucocutaneous leishmaniasis with lepromatous leprosy, which are at opposite ends of the immunopathological spectra of these diseases. This was done by performance of skin tests and by assessment of the cell proliferation and cytokine production of peripheral blood mononuclear cells (PBMCs). RESULTS Strong skin-test reactions and PBMC proliferation were observed in response to Leishmania antigens but not to M. leprae antigens. The stimulation of PBMCs with Leishmania and M. leprae antigens induced comparable levels of tumor necrosis factor- alpha , interleukin-5, and interleukin-10. However, the interferon- gamma response to Leishmania antigens was remarkably high, and that to M. leprae antigens was almost nil. CONCLUSIONS We found that concomitant leprosy and tegumentary leishmaniasis can produce opposite polar forms associated, respectively, with absent or exaggerated cell-mediated immune responses to each pathogen. This suggests that independent mechanisms influence the clinical outcome of each infection. Moreover, interferon- gamma appears to play a major role in the clinical expression of these intracellular infections.

Histoplasmose cutânea primária: relato de caso em paciente imunocompetente e revisão de literatura

This report describes a case of primary cutaneous histoplasmosis in a 45-year-old male. The presentation consisted of an erythematous nodule on the back of the right hand, accompanied by nontender regional lymphadenomegaly that developed following local trauma that occurred during military training in a tunnel inhabited by bats. Histological examination of a biopsy specimen from the skin lesion showed granulomatous infiltrate, but did not show fungal elements. Culturing of this material, incubated in Sabouraud agar, showed growth of Histoplasma capsulatum. No evidence of systemic involvement or immunosuppression was found. Treatment with 400 mg/day of itraconazole orally for six months resulted in complete remission of the lesion, which was maintained one year after the end of the treatment.

Are Neutrophil Extracellular Traps Playing a Role in the Parasite Control in Active American Tegumentary Leishmaniasis Lesions

Neutrophil extracellular traps (NETs) have been described as a network of extracellular fibers composed by DNA, histones and various proteins/enzymes. Studies have demonstrated that NETs could be responsible for the trapping and elimination of a variety of infectious agents. In order to verify the presence of NETs in American tegumentary leishmaniasis (ATL) and their relationship with the presence of amastigotes we evaluated active cutaneous lesions of 35 patients before treatment by the detection of parasites, neutrophils (neutrophil elastase) and histones through immunohistochemistry and confocal immunofluorescence. Intact neutrophils could be detected in all ATL lesions. NETs were present in 27 patients (median 1.1; range from 0.1 to 23.5/mm2) with lesion duration ranging from one to seven months. NETs were in close proximity with neutrophils (r = 0.586; p = 0.0001) and amastigotes (r = 0.710; p = 0.0001). Two patterns of NET formation were detected: small homogeneously distributed networks observed in all lesions; and large structures that could be visualized at a lower magnification in lesions presenting at least 20% of neutrophils. Lesions presenting the larger NET formation showed high parasite detection. A correlation between NET size and the number of intact amastigotes was observed (p=0.02). As we detected an association between NET and amastigotes, our results suggest that neutrophil migration and NET formation could be stimulated and maintained by stimuli derived from the parasite burden/parasite antigen in the extracellular environment. The observation of areas containing only antigens not intermingled with NETs (elastase and histone) suggests that the involvement of these structures in the control of parasite burden is a dynamic process in which the formation of NETs is exhausted with the destruction of the parasites. Since NETs were also associated with granulomas, this trapping would favor the activity of macrophages in order to control the parasite burden.

Endemic tegumentary leishmaniasis in Brazil: correlation between level of endemicity and number of cases of mucosal disease.

The purpose of this study was to establish a correlation between the endemic level of tegumentary leishmaniasis in different regions of Brazil during 2002-2009 and the number of cases of mucosal or mucocutaneous leishmaniasis. The proportion of mucosal leishmaniasis was inversely correlated with prevalence of infection. In areas with a lower infection prevalence, the proportion of mucosal leishmaniasis increased (P < 0.05). The hypothesis of an Amazonian origin and dissemination through human migration is considered. Our results show that in regions with lower prevalence and endemically younger, the proportion of cases that evolve to the mucosal form is higher than in regions with higher prevalence and endemically older.

Signs of an in situ inflammatory reaction in scars of human American tegumentary leishmaniasis

Skin inflammation plays an important role during the healing of American tegumentary leishmaniasis (ATL), the distribution of cells in active lesions may vary according to disease outcome and parasite antigens in ATL scars have already been shown. We evaluated by immunohistochemistry, 18 patients with 1‐ or 3‐year‐old scars and the corresponding active lesions and compared them with healthy skin. Small cell clusters in scars organized as in the active lesions spreaded over the fibrotic tissue were detected, as well as close to vessels and cutaneous glands, despite a reduction in the inflammatory process. Analysis of 1‐year‐old scar tissue showed reduction of NOS2, E‐selectin, Ki67, Bcl‐2 and Fas expression. However, similar percentages of lymphocytes and macrophages were detected when compared to active lesions. Only 3‐year‐old scars showed reduction of CD3+, CD4+ and CD8+T cells, in addition to reduced expression of NOS2, E‐selectin, Ki67 and BCl‐2. These results suggest that the pattern of cellularity of the inflammatory reaction observed in active lesions changes slowly even after clinical healing. Analysis of 3‐year‐old scars showed reduction of the inflammatory reaction as demonstrated by decrease in inflammatory cells and in the expression of cell‐activity markers, suggesting that the host–parasite balance was only established after that period.

American Tegumentary Leishmaniasis in Older Adults: 44 Cases Treated with an Intermittent Low‐Dose Antimonial Schedule in Rio de Janeiro, Brazil

American tegumentary leishmaniasis (ATL) is a disease affecting the skin and mucosae caused by protozoans of the genus Leishmania transmitted by the bite of female sandflies. Cutaneous leishmaniasis (CL) presents mainly as skin ulcers at exposed body sites. Mucosal leishmaniasis (ML) manifests as chronic and destructive lesions of the nasal, oral, pharyngeal, and laryngeal tissues.1 Pentavalent antimonials are the first-line treatment for ATL. Reports of pentavalent antimonial toxicity include renal tubular dysfunction; cardiac, hepatic, pancreatic, and hematological alterations; and even death.2–6 Adverse effects (AEs) are frequent, and interruption is sometimes needed in patients aged 60 and older, even those receiving low-dose treatment. Observing that lesions continued to heal during withdrawal, it was decided to evaluate the safety and efficacy of an intermittent low-dose meglumine antimonate (MA) regimen for ATL in the elderly.....