Comparison of the antifungal activity of the pyrimidine analogs flucytosine and carmofur against human-pathogenic dematiaceous fungi.

Chromoblastomycosis (CBM) and pheohyphomycosis (PHM) are the most common implantation mycoses caused by dematiaceous fungi. In the past, flucytosine (5-FC) has been used to treat CBM, but development of resistance is common. Carmofur belongs to the same class as 5-FC and has in vitro inhibitory activity against the main agents of CBM and PHM. The aim of this study was to compare the action of these two pyrimidine analog drugs against CBM and PHM agents. The minimum inhibitory concentration (MIC) and the selectivity index based on cytotoxicity tests of these two drugs against some agents of these mycoses were determined, with carmofur presenting a higher selectivity index than 5-FC. Carmofur demonstrated here synergistic interactions with itraconazole and amphotericin B against Exophiala heteromorpha, Fonsecaea pedrosoi, Fonsecaea monophora, and Fonsecaea nubica strains. Additionally, carmofur plus itraconazole demonstrated here synergism against a Phialophora verrucosa strain. To evaluate the development of carmofur resistance, passages in culture medium containing subinhibitory concentrations of this pyrimidine analog were carried out, followed by in vitro susceptibility tests. Exophiala dermatitidis quickly developed resistance, whereas F. pedrosoi took seven passages in carmofur-supplemented medium to develop resistance. Moreover, resistance was permanent in E. dermatitidis but transient in F. pedrosoi. Hence, carmofur has exhibited certain advantages, albeit accompanied by limitations such as the development of resistance, which was expected as with 5-FC. This underscores its therapeutic potential in combination with other drugs, emphasizing the need for a meticulous evaluation of its application in the fight against dematiaceous fungi.

Nodular lesions of the buttock for 20 years: the challenge of chromoblastomycosis in non-endemic settings.

Chromoblastomycosis is an implantation mycosis of the skin caused by certain species of melanised fungi. A man in his 50s, born in Kerala but living in England for 14 years, presented with a nodular lesion on his left buttock, which had been present for 20 years. Biopsy revealed muriform cells and fungal culture isolated Fonsecaea spp, consistent with a diagnosis of chromoblastomycosis. Treatment with oral terbinafine was initiated and changed to itraconazole based on results of antifungal susceptibility. Drug intolerance and low drug levels of itraconazole necessitated change to voriconazole and topical terbinafine. Despite long-term combined therapy, the lesions worsened, and the patient opted for surgical excision abroad. Recurrence was evident at surgical sites and combined therapy continues. Chromoblastomycosis is an insidious and burdensome neglected tropical disease. Within non-endemic countries, diagnosis remains challenging. A travel history and appropriate fungal investigations are vital.

An Experimental Model of Chromoblastomycosis Caused by Fonsecaea sp. Species.

The experimental rodent models for the fungal disease are a handy tool for understanding host-fungus interactions. To Fonsecaea sp., one of the causative agents of chromoblastomycosis, there is an extra challenge because the animals preferably used show a spontaneous cure; so until now, there is no model to reproduce the long-term disease similar to human chronic disease. In this chapter, we described an experimental model using rats and mice with a subcutaneous route, with the checkpoints of acute-like and chronic-like lesion analysis comparable with human lesions, the fungal burden, and the lymphocytes investigation.

New methylene blue-mediated photodynamic inactivation of multidrug-resistant Fonsecaea nubica infected chromoblastomycosis in vitro.

Chromoblastomycosis is a fungal disease presented with local warty papule, plaque, and verrucous nodules. In addition, the incidence and drug resistance of chromoblastomycosis are increasing each year worldwide. Photodynamic therapy is a promising method to treat mycoses. The purpose of this study was to evaluate the effect of new methylene blue (NMB)-induced PDT on multidrug-resistant chromoblastomycosis in vitro. We isolated one wild-type strain pathogen from one clinical patient diagnosed with chromoblastomycosis for over 27 years. The pathogen was identified by histopathology, the morphology of fungal culture, and genetic testing. Drug susceptibility testing was performed on the isolate. It was cultured with logarithmic growth phase spore in vitro and incubated with different concentrations of NMB for 30 min, and received illumination by red light-emitted diode with different light doses. After photodynamic treatment, the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were conducted. The pathogen was Fonsecaea nubica, and it was resistant to itraconazole, terbinafine, amphotericin B, voriconazole andcaspofungin. At the same NMB concentration, the sterilization efficiency of NMB-photodynamic therapy (PDT) on F. nubica increased with increasing light intensity; F. nubica was completely killed at 25 µmol/L NMB with a light dose of 40 J/cm2 or 50 µmol/L NMB and light doses of ≥ 30 J/cm2. SEM and TEM observed ultrastructural changes after PDT. NMB-PDT inactivates the survival of multidrug-resistant F. nubica in vitro; it therefore has the potential to become an alternative or adjuvant treatment for refractory chromoblastomycosis.

Draft Genome Sequence of the Rhinocladiella similis Clinical Isolate CBS 149759.

Rhinocladiella similis is a melanized fungi involved in chromoblastomycosis. R. similis genome has never been sequenced, therefore we propose the first draft genome of R. similis.

Chromoblastomycosis: A Rare Presentation With Polymorphic Cutaneous Lesions And Bone Involvement, Caused By Exophiala Janselmei.

Chromoblastomycosis, a chronic fungal infection of skin and subcutaneous tissue arises as a result of traumatic inoculation of exposed areas of the body. We present a unique case of chromoblastomycosis caused by Exophiala janselmei in a female farmer who presented with multiple smooth non-tender nodules on trunk and limbs for 5 years and pigmented indurated plaques on her face for 2 years along with deformities of her hands. Imaging investigations revealed multiple lytic lesions in the bones of the upper and lower limbs. Histopathological findings showed characteristic sclerotic bodies, consistent with the diagnosis of chromoblastomycosis. She was started on a combination of oral antifungals with a good response. This case highlights the importance of high suspicion and early diagnosis of deep fungal infections in order to avoid disfigurement and comorbidities.

Treatment responses in patients with chromoblastomycosis to itraconazole in Madagascar.

INTRODUCTION: Chromoblastomycosis (CBM) is a chronic fungal infection of the skin and subcutaneous tissue caused by several pigmented fungi. It is frequently found in tropical and subtropical areas like Madagascar. This study primarily discusses the effects of antifungal therapy while also describing the epidemiological, clinical, and pathological features of CBM in our patients. METHODS: From March 2013 to January 2019, a descriptive prospective study on CBM patients was undertaken. The study included patients with CBM who had received antifungal treatment for at least 3 months. Itraconazole 200 mg was given to patients every day for ˃3 months. Results were assessed at the 6th and 12th months and classified as major responses, minor responses to treatment, or failure. RESULTS: A total of 29 cases of CBM were included. The mean age of patients was 42.02 years. They primarily worked in rural areas. Infected men were more prevalent. At the end of the 12th month of itraconazole therapy, 3 patients presented major responses, 14 patients had minor responses to treatment, and 12 had been lost to follow-up. The clinical response of CBM to treatment was correlated to the severity and the long course of CBM. When compared with CBM caused by Cladophialophora, CBM caused by Fonsecaea showed a greater clinical response. CONCLUSION: These findings demonstrated that CBM lesions are recalcitrant and difficult to treat.

Chromoblastomycosis (CBM) is a chronic fungal infection of the skin and subcutaneous tissue commonly seen in tropical and subtropical areas. This study mainly discusses the therapeutic while also describing the epidemiological, clinical, and pathological features of CBM in Madagascar.

Chromoblastomycosis: A case series from Eastern China.

Chromoblastomycosis (CBM) is a chronic fungal infection of the cutaneous and subcutaneous tissues caused by brown pigmented fungi. Fonsecaea monophora is one of the most common pathogens of CBM in China. Most formal cases have been reported from Southern China, however, the infection is not uncommon in Eastern China where very few case series are available. To describe the clinical aspects of CBM, we report a series of 11 cases between 2018 and 2021 at a single medical center in Eastern China. The patients were predominately male (n = 9) and the disease duration ranged from 3 months to 20 years. Plaque type lesions were the most common clinical manifestations. There were 7 cases of mild forms and 3 cases of severe forms. Among the 3 severe cases, one case gave up treatment due to economic poverty; one case did not respond to a 1-year systemic treatmen; one case was cured by combination therapy of 10 months. Other cases were cured by treatment with antifungal agents. All cases of direct mycological examination were positive. All isolates were identified by morphology and sequencing of the the ITS regions of ribosomal DNA, Ten were F. monophora and 1 was Cladophialophora carrionii. All cases had been evaluated at other clinics, where 8 cases were misdiagnosed as other diseases. As a neglected tropical disease (NTD), CBM is still a major challenge in the field of dermatology, especially in its severe clinical forms. As an effective and simple diagnostic method of CBM, direct microscopic examination should be further promoted in rural hospitals.

[Chromoblastomycosis. First allochthonous case treated in Chile]. / Cromoblastomicosis. Primer caso alóctono tratado en Chile.

Chromoblastomycosis is a fungal infection of the skin and subcutaneous tissue, of chronic evolution, caused by dematiaceous fungi. The disease occurs worldwide, mainly in tropical and subtropical regions, but in regions like Chile there is only one report of a human case more than 30 years ago. We present the case of a 46-year-old Haitian man, resident in Chile, with verrucous plaques in the right anterior tibial area of one year of evolution. The diagnosis of chromoblastomycosis was confirmed when muriform cells and dematiaceous colonies were observed in the histopathological analysis and the direct microscopy, respectively. After six months of treatment with systemic antimycotics and cryotherapy, complete remission of the lesions was achieved.

New possibilities for chromoblastomycosis and phaeohyphomycosis treatment: identification of two compounds from the MMV Pathogen Box® that present synergism with itraconazole.

BACKGROUND: Black fungi of the Herpotrichiellaceae family are agents of chromoblastomycosis and phaeohyphomycosis. There are few therapeutic options for these infections and it is common to associate antifungal drugs in their treatment. OBJECTIVES: To investigate the Medicines for Malaria Venture (MMV) Pathogen Box® for possible compounds presenting synergism with antifungal drugs used to treat black fungal infections. METHODS: An initial screening of the Pathogen Box® compounds was performed in combination with itraconazole or terbinafine at sub-inhibitory concentrations against Fonsecaea pedrosoi. Hits were further tested against eight Herpotrichiellaceae using the checkerboard method. FINDINGS: No synergism was observed with terbinafine. MMV687273 (SQ109) and MMV688415 showed synergism with itraconazole against F. pedrosoi. Synergism of these compounds was confirmed with some black fungi by the checkerboard method. SQ109 and itraconazole presented synergism for Exophiala dermatitidis, F. pedrosoi, F. monophora and F. nubica, with fungicidal activity for F. pedrosoi and F. monophora. MMV688415 presented synergism with itraconazole only for F. pedrosoi, with fungicidal activity. The synergic compounds had high selectivity index values when combined with itraconazole. MAIN CONCLUSIONS: These compounds in combination, particularly SQ109, are promising candidates to treat Fonsecaea spp. and E. dermatitidis infections, which account for most cases of chromoblastomycosis and phaeohyphomycosis.

Molecular epidemiology and clinical-laboratory aspects of chromoblastomycosis in Mato Grosso, Brazil.

INTRODUCTION: Chromoblastomycosis is a disease caused by melanized fungi, primarily belonging to the genera Fonsecaea and Cladophialophora, mainly affecting individuals who are occupationally exposed to soil and plant products. This research aimed to determine the clinical, epidemiological and laboratory characteristics of chromoblastomycosis in the state of Mato Grosso, Brazil. MATERIALS AND METHODS: Patients diagnosed with chromoblastomycosis treated at the Júlio Müller University Hospital, Cuiabá, Brazil, from January 2015 to December 2020, whose isolates were preserved in the Research Laboratory of the Faculty of Medicine of the Federal University of Mato Grosso. Isolates were identified by partly sequencing the Internal Transcribed Spacer (ITS) and ß-tubulin (BT2) loci. AFLP fingerprinting was used to explore the genetic diversity. Susceptibility to itraconazole, voriconazole, 5-fluorocytosine, terbinafine and amphotericin B was determined by the broth microdilution technique. RESULTS: Ten patients were included, nine were male (mean age = 64.1 years). Mean disease duration was 8.6 years. Lesions were mainly observed in the lower limbs. Predominant clinical forms were verrucous and scarring. Systemic arterial hypertension and type II diabetes mellitus were the predominant comorbidities. Leprosy was the main concomitant infectious disease. Fonsecaea pedrosoi was the unique aetiological agent identified with moderate genetic diversity (H = 0.3934-0.4527; PIC = 0.3160-0.3502). Antifungal agents with the highest activity were terbinafine, voriconazole and itraconazole. CONCLUSION: Chromoblastomycosis is affecting the poor population in rural and urban areas, mainly related to agricultural activities, with F. pedrosoi being the dominant aetiologic agent. All isolates had low MICs for itraconazole, voriconazole and terbinafine, confirming their importance as therapeutic alternatives for chromoblastomycosis.

Tuberculosis verrucous cutis mimicking chromoblastomycosis: A case report and diagnostic challenges.

Tuberculosis verrucous cutis (TBVc) is a skin infection caused by M. tuberculosis, characterized by the presence of a solitaire verrucous plaque but may present as a varies of different clinical morphologies on the finger and or feet. The diagnosis is often late because of its mimicking other diseases with different etiology. Bacterial culture examination is negative because there are few pathogens in the lesion. Meanwhile, other diagnostic methods provide lower sensitivity and specificity which add further diagnostic challenges. We presented one case report of TBVc mimicking chromoblastomycosis. A 26-year-old man complain a multiple papule-plaque verrucose on the dorsum of the right foot and extending to all of fingers for 2 years ago. The first lesion appears as a small papule verrucous then progressively to form plaque with curst yellow-red and central healing. Examination of bacterial culture with Ziehl-Neelsen stain and GeneXpert did not find M. tuberculosis but could not rule out the diagnosis of TBVc. The diagnosis was established based on the correlation of clinical manifestations and dermoscopy with histopathological examination. To date, there is no gold standard for TBVc testing. Correlation analysis of clinical manifestations, dermoscopy, and histopathology can be considered to establish the diagnosis of TBVc, especially if the culture is negative and the limitations of polymerase chain reaction tools.

Pathogenicity and Growth Conditions Modulate Fonsecaea Extracellular Vesicles' Ability to Interact With Macrophages.

Chromoblastomycosis (CBM) is a chronic cutaneous and subcutaneous mycosis caused by black, dimorphic, and filamentous fungi of the Herpothrichiellaceae family, such as species of the genus Fonsecaea. These fungi can switch between the saprophytic forms (conidia and hyphae) and the pathogenic form, the muriform cells (MCs), which is considered an essential mechanism for fungal virulence. Nearly all types of cells can produce membranous structures formed by a lipid bilayer that communicate extracellularly with other cells, known as "extracellular vesicles" (EVs), which may act as virulence factors, as observed for several species of pathogenic fungi. Our findings demonstrated for the first time that F. pedrosoi, F. nubica, and F. erecta produce EVs in response to nutritional conditions. The EVs varied in sterol and protein contents, size, and morphology. Moreover, the EVs induced different cytokine and nitric oxide release patterns by bone marrow-derived macrophages (BMDMs). The EVs activated IL-1ß production, possibly acting as the first signal in inflammasome activation. Unlike the pathogenic species, the EVs isolated from F. erecta did not significantly stimulate TNF and IL-10 production in general. Overall, these results demonstrated that different species of Fonsecaea produce EVs capable of modulating pro- and anti-inflammatory cytokine and nitric oxide production by BMDMs and that growth conditions affected the immunomodulatory capacities of the EVs as well as their size, content, and morphology.

Cromoblastomicosis: primer caso alóctono tratado en Chile / Chromoblastomycosis: first allochthonous case treated in Chile

Resumen La cromoblastomicosis es una infección fúngica de la piel y del tejido subcutáneo, de evolución crónica, causada por hongos dematiáceos que se caracterizan por presentar melanina en su pared celular. La enfermedad se presenta en todo el mundo, principalmente en regiones tropicales y subtropicales. En Chile, solo hay un reporte de caso humano hace más de 30 años. Se presenta el caso de un varón de 46 años, haitiano, residente en Chile, con placas verrucosas en la zona tibial anterior de un año de evolución. El diagnóstico de cromoblastomicosis se confirmó al observar células muriformes en la histopatología y colonias dematiáceas en el cultivo micológico; además, en la miscroscopía directa se observaron conidias compatibles con Fonsecaea spp. Luego de seis meses de tratamiento con antimicóticos sistémicos y crioterapia, se logró la remisión completa de las lesiones.

Abstract Chromoblastomycosis is a fungal infection of the skin and subcutaneous tissue, of chronic evolution, caused by dematiaceous fungi. The disease occurs worldwide, mainly in tropical and subtropical regions, but in regions like Chile there is only one report of a human case more than 30 years ago. We present the case of a 46-year-old Haitian man, resident in Chile, with verrucous plaques in the right anterior tibial area of one year of evolution. The diagnosis of chromoblastomycosis was confirmed when muriform cells and dematiaceous colonies were observed in the histopathological analysis and the direct microscopy, respectively. After six months of treatment with systemic antimycotics and cryotherapy, complete remission of the lesions was achieved.

Identifying novel drugs with new modes of action for neglected tropical fungal skin diseases (fungal skinNTDs) using an Open Source Drug discovery approach.

INTRODUCTION: The three fungal skin neglected tropical diseases (NTD) - mycetoma, chromoblastomycosis and sporotrichosis - currently lack prioritization and support to establish drug discovery programs in search for novel treatment options. This has made the efforts to identify novel drugs for these fragmented skinNTDs. AREAS COVERED: To help escalate the discovery of novel drugs to treat these fungal skinNTDs, the authors have prepared an overview of the compounds with activity against fungal skinNTDs by analyzing data from individual drug discovery studies, including those performed on the Medicines for Malaria Venture (MMV) open access boxes. EXPERT OPINION: The authors were unable to identify studies in which causative agents of all three skinNTDs were included, indicating that an integrated approach is currently lacking. From current available data, the azoles and iodoquinol were the only compounds with activity against causative agents from the three different fungal skinNTDs. Fungal melanin inhibition enhanced the activity of antifungal agents. For mycetoma, the fenarimols, aminothiazoles and benzimidazole carbamates are currently being investigated in the MycetOS initiative. To come to a more integrated approach to identify drugs active against all three fungal skinNTDs, compounds made in the MycetOS initiative could also be explored for chromoblastomycosis and sporotrichosis.

Molecular Characteristics of Regional Chromoblastomycosis in Guangdong, China: Epidemiological, Clinical, Antifungal Susceptibility, and Serum Cytokine Profiles of 45 Cases.

Chromoblastomycosis (CBM) is a chronic disease caused by several species of dematiaceous fungi. In this study, a regional collection of 45 CBM cases was conducted in Guangdong, China, a hyper-endemic area of CBM. Epidemiology findings indicated that the mean age of cases was 61.38 ± 11.20 years, long duration ranged from 3 months to 30 years, and the gender ratio of male to female was 4.6:1. Thirteen cases (29%) declared underlying diseases. Verrucous form was the most common clinical manifestation (n = 19, 42%). Forty-five corresponding clinical strains were isolated, and 28 of them (62%) were identified as F. monophora; the remaining 17 (38%) were identified as F. nubica through ITS rDNA sequence analysis. Antifungal susceptibility tests in vitro showed low MICs in azoles (PCZ 0.015-0.25 µg/ml, VCZ 0.015-0.5 µg/ml, and ITZ 0.03-0.5 µg/ml) and TRB (0.015-1 µg/ml). Itraconazole combined with terbinafine was the main therapeutic strategy used for 31 of 45 cases, and 68% (n = 21) of them improved or were cured. Cytokine profile assays indicated upregulation of IL-4, IL-7, IL-15, IL-11, and IL-17, while downregulation of IL-1RA, MIP-1ß, IL-8, and IL-16 compared to healthy donors (p < 0.05). The abnormal cytokine profiles indicated impaired immune response to eliminate fungus in CBM cases, which probably contributed to the chronic duration of this disease. In conclusion, we investigated the molecular epidemiological, clinical, and laboratory characteristics of CBM in Guangdong, China, which may assist further clinical therapy, as well as fundamental pathogenesis studies of CBM.