Search

Background: Auranofin is an approved anti-rheumatic drug that has a broad-range inhibitory action against several microorganisms, including human pathogenic fungi. The auranofin activity against Histoplasma capsulatum, the dimorphic fungus that causes histoplasmosis, has not been properly addressed. Since there are few therapeutic options for this life-threatening systemic mycosis, this study evaluated the effects of auranofin on H. capsulatum growth and expression of virulence factors. Methodology/principal findings: Minimal inhibitory and fungicidal concentrations (MIC and MFC, respectively) of auranofin against 15 H. capsulatum strains with distinct genetic backgrounds were determined using the yeast form of the fungus and a microdilution protocol. Auranofin activity was also assessed on a macrophage model of infection and on a Tenebrio molitor invertebrate animal model. Expression of virulence-related genes was compared between auranofin treated and untreated H. capsulatum yeast cells using a quantitative PCR assay. Auranofin affected the growth of different strains of H. capsulatum, with MIC and MFC values ranging from 1.25 to 5.0 μM and from 2.5 to >10 μM, respectively. Auranofin was able to kill intracellular H. capsulatum yeast cells and conferred protection against the fungus in the experimental animal model of infection. Moreover, the expression of catalase A, HSP70, superoxide dismutase, thioredoxin reductase, serine proteinase, cytochrome C peroxidase, histone 2B, formamidase, metallopeptidase, Y20 and YPS3 proteins were reduced after six hours of auranofin treatment. CONCLUSIONS/SIGNIFICANCE: Auranofin is fungicidal against H. capsulatum and reduces the expression of several virulence-related genes, which makes this anti-rheumatic drug a good candidate for new medicines against histoplasmosis. Author summary: Histoplasmosis is a serious disease caused by the fungus Histoplasma capsulatum, which can be life-threatening and has limited treatment options. In this study, we investigated the potential of auranofin, a drug originally approved for treating rheumatoid arthritis, to combat H. capsulatum. We tested auranofin against different strains of the fungus and found that it effectively inhibited fungal growth. This drug was also effective in killing the fungus within cells from the immune system and provided protection in an experimental animal model. Furthermore, auranofin reduced the expression of several genes associated with the fungus's ability to cause disease. These genes are involved in critical functions such as detoxifying harmful substances and maintaining cellular structures. By suppressing these genes, auranofin hampers the fungus's ability to survive and cause infection. These findings suggest that auranofin could be repurposed as a treatment for histoplasmosis, offering a new avenue for therapy against this challenging infection. This research is significant because it highlights the potential of existing drugs to treat other diseases, broadening our arsenal of available treatments and contributing to better healthcare solutions. [ABSTRACT FROM AUTHOR]

Over the past two decades, zoonotic sporotrichosis transmitted by naturally infected cats has become hyperendemic in Rio de Janeiro, Brazil. Sporothrix brasiliensis is the main agent involved. However, there are other forms of transmission of sporotrichosis. The aim of this study was to evaluate and associate the epidemiological, clinical and therapeutic data and the susceptibility of Sporothrix spp. to antifungal drugs in 43 non-zoonotic sporotrichosis cases. Forty-three clinical strains of Sporothrix were identified by partial sequencing of the calmodulin gene. An antifungal susceptibility test of amphotericin B, terbinafine, itraconazole, posaconazole and isavuconazole was performed according to the broth microdilution method. Most patients were male (55.8%). Regarding the source of infection, 21 patients (48.8%) reported trauma involving plants and/or contact with soil. Sporothrix brasiliensis was the predominant species (n = 39), followed by S. globosa (n = 3) and S. schenckii (n = 1). Sporothrix brasiliensis was associated with all the sources of infection, reinforcing previous data showing the presence of this species in environmental sources, as well as with all the clinical forms, including severe cases. One clinical strain of Sporothrix brasiliensis was classified as a non-wild-type strain for amphotericin B and another for itraconazole. S. schenckii was classified as non-WT for all the antifungals tested. In this context, it is important to emphasize that non-zoonotic sporotrichosis still occurs in the state of Rio de Janeiro, with S. brasiliensis as the main etiological agent, primarily associated with infections acquired after traumatic inoculation with plants and/or soil contact, followed by S. globosa and S. schenckii. In addition, non-WT strains were found, indicating the need to monitor the antifungal susceptibility profile of these species. It is crucial to investigate other natural sources of S. brasiliensis to better understand this fungal pathogen and its environment and host cycle. [ABSTRACT FROM AUTHOR]

Sporotrichosis is the most frequent subcutaneous or implantation mycosis in Latin America, and its transmission occurs as a result of traumatic inoculation into the skin by organic matter containing the thermodimorphic fungi of the genus Sporothrix. Although cutaneous forms are more common, another important site is the osteoarticular system, whose hematogenous involvement is commonly associated with disseminated forms, especially in people who have an immunosuppressive condition, such as HIV/AIDS, chronic steroid use, and alcohol abuse. We present two cases of osteoarticular sporotrichosis of the knee caused by Sporothrix brasiliensis and followed up at our institution, with different outcomes. In the cases presented here, aging, anatomical sites, comorbidities, subtherapeutic serum levels, low adherence to treatment, and late diagnosis for different reasons may explain the observed outcomes. Early diagnosis of Sporothrix infection is critical in preventing complications, including death. We also highlight the importance of multidisciplinary follow-up and adherence to treatment for a favorable outcome. [ABSTRACT FROM AUTHOR]

Feline sporotrichosis has emerged as an important public health issue in some countries, especially Brazil. Currently, zoonotic transmission of Sporothrix brasiliensis by domestic cats is the major sporotrichosis spread form throughout this country. Sporotrichosis in Brazil is a good model for the One Health concept application, which connects the environment, human and animal health. Under this thinking, the aim of this study was to investigate the seroprevalence of sporotrichosis in cats from Rolim de Moura, Rondônia, Brazil, using antibody detection by an ELISA test previously validated for human diagnosis. For the standardization of this test, 30 serum samples from cats with proven sporotrichosis and 11 sera from healthy cats were used. The assay showed 87% sensitivity and 100% specificity for the diagnosis of feline sporotrichosis. After the standardization, 202 serum samples from distinct cats from Rolim de Moura were evaluated. The test was positive in 63 (31.19%) cats from the studied area. A multivariate analysis revealed that living far from forest or agricultural areas as well as pure breed animals had higher odds ratios (3.157 and 2.281, respectively) for the presence of detectable levels of anti-Sporothrix antibodies. These results show the applicability of this assay in the detection of anti-Sporothrix antibodies in feline serum samples and point to a putative new occurrence area of urban sporotrichosis dispersing to the North region of Brazil. [ABSTRACT FROM AUTHOR]

The zoonotic transmission of sporotrichosis due to Sporothrix brasiliensis occurs largely in Rio de Janeiro state, Brazil since the 1990´s. Most patients infected with S. brasiliensis respond well to itraconazole or terbinafine. However, a few patients have a slow response or do not respond to the treatment and develop a chronic infection. The aim of this study was to analyze strains of S. brasiliensis against five different drugs to determine minimal inhibitory concentration distributions, to identify non-wild type strains to any drug evaluated and the clinical aspects of infections caused by them. This study evaluated 100 Sporothrix spp. strains obtained from 1999 to 2018 from the Evandro Chagas National Institute of Infectious Diseases, Fiocruz, which were identified through a polymerase chain reaction using specific primers for species identification. Two-fold serial dilutions of stock solutions of amphotericin B, itraconazole, posaconazole, ketoconazole and terbinafine prepared in dimethyl sulfoxide were performed to obtain working concentrations of antifungal drugs ranging from 0.015 to 8.0 mg/L. The broth microdilution reference method was performed according the M38-A2 CLSI guideline. All strains were identified as S. brasiliensis and thirteen were classified as non-wild type, two of them against different drugs. Non-wild type strains were identified throughout the entire study period. Patients infected by non-wild type strains presented prolonged treatment times, needed increased antifungal doses than those described in the literature and one of them presented a permanent sequel. In addition, three of them, with immunosuppression, died from sporotrichosis. Despite the broad use of antifungal drugs in hyperendemic areas of sporotrichosis, an emergence of non-wild type strains did not occur. The results of in vitro antifungal susceptibility tests should guide sporotrichosis therapy, especially in immunosuppressed patients. [ABSTRACT FROM AUTHOR]

Conventional systemic and topical treatments have proven ineffective for the treatment of onychomycosis caused by Neoscytalidium dimidiatum. Our aimwas to evaluate the effectiveness and safety of laser monotherapy for the treatment of onychomycosis caused by this pathogen. Patients with clinical onychomycosis of the toenails and positive results both on direct mycological examination and N. dimidiatum culture underwent four 1064 nm Nd:YAG laser sessions with 6-week intervals between sessions. Participants were monitored by clinical examination supported by dermoscopy, measurement of diseased nail and the onychomycosis severity index (OSI), and by mycological examination for 12 months after completion of treatment. Treatment outcome was based on clinical and laboratory criteria and was divided in complete or partial cure, clinical improvement, treatment failure and relapse. No patient had complete or partial cure at any time during the study. Clinical improvement was observed in 40.6% of the patients at the end of the laser sessions; however, it did not persist during the follow-up. Treatment failure was observed in 64.7% of the patients at the end of 12 month follow-up period. Direct microscopy and culture results remained positive in most patients. Adverse events, in addition to treatment-related pain, were observed and considered severe in one case. The 1064 nm Nd:YAG laser was not able to cure onychomycosis caused by N. dimidiatum but temporarily improved the clinical appearance of the nail; however, adverse events may occur. [ABSTRACT FROM AUTHOR]

Conventional systemic and topical treatments have proven ineffective for the treatment of onychomycosis caused by Neoscytalidium dimidiatum. Our aimwas to evaluate the effectiveness and safety of laser monotherapy for the treatment of onychomycosis caused by this pathogen. Patients with clinical onychomycosis of the toenails and positive results both on direct mycological examination and N. dimidiatum culture underwent four 1064 nm Nd:YAG laser sessions with 6-week intervals between sessions. Participants were monitored by clinical examination supported by dermoscopy, measurement of diseased nail and the onychomycosis severity index (OSI), and by mycological examination for 12 months after completion of treatment. Treatment outcome was based on clinical and laboratory criteria and was divided in complete or partial cure, clinical improvement, treatment failure and relapse. No patient had complete or partial cure at any time during the study. Clinical improvement was observed in 40.6% of the patients at the end of the laser sessions; however, it did not persist during the follow-up. Treatment failure was observed in 64.7% of the patients at the end of 12 month follow-up period. Direct microscopy and culture results remained positive in most patients. Adverse events, in addition to treatment-related pain, were observed and considered severe in one case. The 1064 nm Nd:YAG laser was not able to cure onychomycosis caused by N. dimidiatum but temporarily improved the clinical appearance of the nail; however, adverse events may occur. [ABSTRACT FROM AUTHOR]

The gold standard for the diagnosis of sporotrichosis consists of the isolation and identification of the fungus from clinical exudates and/or biopsy specimens. However, new technologies offer several advantages over the traditional methods because they are noninvasive and more sensitive in the differential diagnosis of infectious diseases. In the present study, we performed a validation, impact evaluation, and analysis of the applicability of an enzyme-linked immunosorbent assay (ELISA) for the diagnosis of sporotrichosis in different groups of patients in comparison with the reference protocols for the evaluation of diagnostic tests for infectious diseases. We used 177 serum samples that were collected between 1998 and 2008 from patients in a geographic area related to the Rio de Janeiro outbreak of sporotrichosis. The ELISA had a low rate of cross-reactivity based on the reference values for diagnostic tests, and the analysis of the receiver operating characteristic curve revealed an area under the curve of 0.9154. Furthermore, higher accuracy was observed in the serodiagnosis of infections in special groups of patients such as pediatric and human immunodeficiency virus–positive patients. We concluded that this ELISA had a good clinical serological correlation and, therefore, can be considered a new diagnostic tool applicable to all clinical presentations of sporotrichosis. [ABSTRACT FROM PUBLISHER]