Chromoblastomycosis due to Fonsecaea pedrosoi and F. monophora in Cuba

Chromoblastomycosis Caused by Fonsecaea monophora Mimicking Lichen Planus

Chromoblastomycosis is a rare fungal infection acquired by traumatic inoculation of pigmented fungi from an environmental source. The polymorphic presentation of chromoblastomycosis may mimic other dermatologic conditions, leading to delays in diagnosis. Thus, histopathology is critical in identifying the presence of fungi and confirming the diagnosis. We present a case of chromoblastomycosis caused by the organism Fonsecaea monophora mimicking a lesion of lichen planus to highlight the importance of histopathology in the diagnosis of this condition.

Fungal Infections in the Caribbean: A Review of the Literature to Date

The most common fungal infections reported from the Caribbean include dermatophytosis, candidiasis, pneumocystis, aspergillosis, histoplasmosis, and cryptococcosis. The Caribbean is hyperendemic for histoplasmosis, with high population exposures. Fungal infections are a significant public health problem in the Caribbean, with rates varying depending on the specific country or region. In Trinidad and Tobago, the fungal burden accounts for 3.3% of the 1.4 million population, while in Jamaica, with a population of 2.9 million, over 57,600 people suffer from fungal infections each year. A study in the Dominican Republic estimated that approximately 221,027 (2%) of over 10 million people have a serious fungal infection. Fungal infections accounts for 21.9% of all skin infections in Haiti. The diagnosis of fungal infections in the Caribbean can be challenging, as access to laboratory testing and specialized medical services is limited in many areas. Access to antifungal medications can also be a challenge in some areas, and antifungal resistance has been reported.

Repurposing Benzimidazoles against Causative Agents of Chromoblastomycosis: Albendazole Has Superior In Vitro Activity Than Mebendazole and Thiabendazole

Chromoblastomycosis (CBM) is a neglected human implantation mycosis caused by several dematiaceous fungal species. Currently available therapy is usually associated with physical methods, especially surgery, and with high refractoriness. Therefore, drug discovery for CBM is essential. Drug repositioning is a strategy used to facilitate the discovery of new treatments for several diseases. The aim of this study was to discover substances with antifungal activity against CBM agents from a collection of drugs previously approved for use in human diseases. A screening was performed with the NIH Clinical Collection against Fonsecaea pedrosoi. Ten substances, with clinical applicability in CBM, inhibited fungal growth by at least 60%. The minimum inhibitory concentration (MIC) of these substances was determined against other CBM agents, and the benzimidazoles albendazole, mebendazole and thiabendazole presented the lowest MIC values. The selectivity index, based on MIC and cytotoxicity of these substances, revealed albendazole to be more selective. To investigate a possible synergism of this benzimidazole with itraconazole and terbinafine, the chequerboard method was used. All interactions were classified as indifferent. Our current results suggest that benzimidazoles have repositioning potential against CBM agents. Albendazole seems to be the most promising, since it presented the highest selectivity against all dematiaceous fungi tested.

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 β-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.

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-1β, 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.

Chromoblastomycosis in Latin America and the Caribbean: epidemiology over the past 50 years

Chromoblastomycosis is a chronic disease caused by melanized fungi that mainly affect individuals performing soil-related labour. The objective of this study was to analyse the epidemiological and clinical characteristics of chromoblastomycosis in Latin America and the Caribbean by an extensive literature review. An integrative review was performed of English, French, Portuguese, and Spanish publications in LILACS, SciELO, PubMed, SCOPUS and Web of Science databases covering the period 1969-2019. A total of 1,211 articles were identified, of which 132 were included in the review, covering 2,081 patients, 80.3% were male, the mean age was 56.1 years. The mean duration of the disease was 10.8 years. The lesions were mainly described in the lower limbs (60%). The most frequent clinical forms were verrucous (46.4%) and tumorous (21.7%). Major disease symptoms and signs consisted of itching and pain. Bacterial infection and functional limitation were important complications. Immunosuppression post-kidney transplantation was the most frequent comorbidity while leprosy was the main concomitant infectious disease. Fonsecaea pedrosoi and Cladophialophora carrionii were the predominant etiological agents. Majority of the cured cases were treated with itraconazole as monotherapy or in combination with other antifungals, surgery or cryosurgery. Chromoblastomycosis affects hundreds of rural workers in Latin America and the Caribbean, causing disability and personal, family and economic losses. It is important to prioritize epidemiological surveillance and early diagnosis of this disease in order to reveal its real prevalence and direct resources to preventive actions, diagnosis and early treatment.

LAY SUMMARY

Chromoblastomycosis is a slowly progressing chronic disease caused by melanized fungi. We collected data from South America and the Caribbean covering 1969-2019, the 132 articles included 2 081 patients, mean disease duration was 10.8 years. Fonsecaea pedrosoi and Cladophialophora carrionii predominated.

Chromoblastomycosis caused by Fonsecaea monophora in Mexico

Chromoblastomycosis is a chronic subcutaneous fungal infection caused by melanized fungi. It is usually an occupational mycosis affecting people in rural areas in tropical and subtropical regions. We present two cases of chromoblastomycosis in Mexican farmers, characterized by skin verrucous plaques. Direct examination with KOH 10% showed the presence of muriform cells. The fungal isolation was carried out in Sabouraud dextrose agar and molecular identification was achieved by 18S-ITS1-5.8S-ITS2-28S rRNA gene amplification and sequencing. Fonsecaeamonophora was identified in both cases. A therapy with itraconazole and terbinafine was used with a partial favorable response. However, patients did not return for medical examination after 4 months. The current status of the patients is unknown. We reported the first two cases of chromoblastomycosis caused by F. monophora in Mexico.

[Chromoblastomycosis]

The paper describes a case of chromoblastomycosis, a rare implantation mycosis in the Russian Federation. It gives data on the prevalence, etiology, and clinical presentations of the disease, and the diagnostic possibilities. Emphasis is laid on the leading role of a pathomorphological study in the diagnosis of chromoblastomycosis in non-endemic countries, including Russia. The clinical and pathomorphological presentations are described in detail. Histological examination detected 5-12-µm spherical or polygonal pigmented cells that are fungal elements, which allows chromoblastomycosis to be diagnosed in the cytoplasm of macrophages and extracellularly. A refusal to conduct a pathomorphological study leads to diagnostic errors and an irrational treatment policy.

Subcutaneous Mycoses in Travelers

Purpose of Review

The increase in international travel in recent decades has contributed to the risk of acquiring diseases considered endemic to a region or country and the change in the epidemiology of these diseases. Endemic mycoses that may be acquired by travelers in the short or long term are endemic subcutaneous mycoses such as sporotrichosis and lobomycosis, while endemic systemic mycoses are a group of serious diseases including histoplasmosis and coccidioidomycosis. Herein, we review the current knowledge and highlight the most important aspects of these fungal infections in travelers.

Recent Findings

The most relevant advances in the study of these mycoses involve the epidemiological distribution; human mycoses can be fatal and there are few antifungal drugs available, increasing drug resistance, and a risk of emerging fungal diseases associated with climate change, as well as the increasing virulence, and the diagnostic strategies that may be limited in many countries.

Summary

Although endemic mycoses are relatively rare, they should be considered as potentially travel-related illnesses. A recent or late trip to an endemic country may guide the clinical suspicion, an early diagnosis, and the institution of effective therapy.

Cinnamyl Schiff bases: synthesis, cytotoxic effects and antifungal activity of clinical interest

The aim of this study was to synthesize and investigate the in vitro antifungal properties of 23 cinnamyl Schiff bases. In addition, cytotoxic effects of such cinnamyl Schiff bases against human lung, kidney or red blood cells were also checked. The compounds were synthesized in a single-step, 2 min of reaction under microwave irradiation produced up to 97% yield. Six of the 23 cinnamyl Schiff bases possessed antifungal activities against strains of Candida, Aspergillus, Fonsecaea and, particularly, Cryptococcus species. Indeed, cinnamyl Schiff bases 1 and 23 exhibited minimum inhibitory concentration (MIC) values more than twofold lower than fluconazole (FCZ) against all the Cryptococcus neoformans strains (MIC = 1·33, 1·4 and 5·2 µg ml^-1 , respectively) and Cryptococcus gattii strains (MIC = 5·3, 2·8 and 9·2 µg ml^-1 , respectively) (12 strains of each species) while cinnamyl Schiff base 11 was as potent as FCZ against all strains from both Cryptococcus species. No significant cytotoxic effects were observed for Schiff bases against human lung, kidney or red blood cells, all presenting selective indexes higher than 10. In conclusion, this study revealed cinnamyl Schiff bases, especially 1 and 23, as new lead anticryptococcal agents for the discovery of novel antifungal drugs. SIGNIFICANCE AND IMPACT OF THE STUDY: The occurrence and severity of fungal infections have increased in recent decades due to resistance to available antifungal drugs and the appearance of new emerging pathogens. Thus, the search for new antifungal agents is mandatory. From a series of 23 cinnamyl Schiff bases, two compounds (1 and 23) were interrogated as new anticryptococcal agents without significant cytotoxicity against human lung, kidney or red blood cells. In turns, these new Schiff bases are lead compounds for the discovery of novel antifungal drugs.

In vitro susceptibility of chromoblastomycosis agents to antifungal drugs: A systematic review

Chromoblastomycosis (CBM) is a chronic granulomatous mycosis caused by dematiaceous fungi that affects cutaneous and subcutaneous tissues. The standard antifungal drug for treatment is itraconazole, followed by terbinafine. However, cure rates vary from 15% to 80% when these drugs are used as monotherapy. A systematic review of the in vitro susceptibility of CBM agents to antifungal drugs, alone and in combination, was conducted using the Cochrane methodology. Forty-seven search terms were included in the PICOS method of searching electronic databases. The search resulted in 35 studies, of which 8 evaluated antifungal drugs in combination. Based on minimum inhibitory concentrations (MICs), posaconazole, terbinafine, itraconazole and voriconazole were, in descending order, the most effective antifungal drugs against CBM agents in vitro. In drug combination studies, only terbinafine-voriconazole and itraconazole-caspofungin showed 100% synergy for Fonsecaea pedrosoi, Exophiala jeanselmei and Phialophora verrucosa. However, none of the combinations studied showed antagonism.

Molecular identification and antifungal susceptibility profiles of clinical strains of Fonsecaea spp. isolated from patients with chromoblastomycosis in Rio de Janeiro, Brazil

BACKGROUND

Chromoblastomycosis (CBM) is a difficult-to-treat chronic subcutaneous mycosis. In Brazil, the main agent of this disease is Fonsecaea pedrosoi, which is phenotypically very similar to other Fonsecaea species, differing only genetically. The correct species identification is relevant since different species may differ in their epidemiologic aspects, clinical presentation, and treatment response.

METHODOLOGY/PRINCIPAL FINDINGS

Partial sequencing of the internal transcribed spacer (ITS) was used to identify twenty clinical isolates of Fonsecaea spp. Their in vitro antifungal susceptibility was determined using the broth microdilution method, according to the M38-A2 protocol. Amphotericin B (AMB), flucytosine (5FC), terbinafine (TRB), fluconazole (FLC), itraconazole (ITC), ketoconazole (KTC), posaconazole (POS), voriconazole (VRC), ravuconazole (RVC), caspofungin (CAS), and micafungin (MFG) were tested. The association between ITC/TRB, AMB/5FC, and ITC/CAS was studied by the checkerboard method to check synergism. The available patients' data were correlated with the obtained laboratory results. Fonsecaea monophora (n = 10), F. pedrosoi (n = 5), and F. nubica (n = 5) were identified as CBM' agents in the study. TRB and VRC were the drugs with the best in vitro activity with minimal inhibitory concentrations (MIC) lower than 0.25 mg/L. On the other hand, FLC, 5FC, AMB, and MFG showed high MICs. The AMB/5FC combination was synergistic for three F. monophora strains while the others were indifferent. Patients had moderate or severe CBM, and ITC therapy was not sufficient for complete cure in most of the cases, requiring adjuvant surgical approaches.

CONCLUSIONS/SIGNIFICANCE

F. monophora, the second most frequent Fonsecaea species in South America, predominated in patients raised and born in Rio de Janeiro, Brazil, without cerebral involvement in these cases. TRB, VRC, and the AMB/5FC combination should be further investigated as a treatment option for CBM.

Differential distribution patterns of Fonsecaea agents of chromoblastomycosis, exemplified by the first case due to F. monophora from Argentina

Chromoblastomycosis is a mutilating infection of the skin and subcutaneous tissues caused by melanized fungi belonging to the order Chaetothyriales. Proven cases of the main agent, Fonsecaea pedrosoi are mainly limited to (sub)tropical, humid climates of Latin and Central America and the Caribbean. Fonsecaea monophora has a global distribution along the equator. Cases outside the (sub)tropics have thus far mostly been considered to have been imported, but here we report the first endemic case by F. monophora from Argentina. Patient was a 82-year-old rural female worker from Corrientes, a province with a dry continental climate.

Successful treatment of chromoblastomycosis of 10-year duration due to Fonsecaea nubica

We report a case of chromoblastomycosis due to the presence of large plaque and verrucous hyperplasia lesions on the left upper limb, with elbow abnormal activities, in a 56-year-old male. The diagnosis of chromoblastomycosis was based on gross and microscopic morphologies, histopathological examination and clinical manifestation. Molecular tools were applied to identifying the causative agent Fonsecaea nubica, which is rarely reported to be associated with chromoblastomycosis. The patient was initially treated orally with terbinafine (250 mg/day) and itraconazole (200 mg/day), subsequently patient received thermotherapy (45-50°C, 3 h/day) for 1 month. The patient was successfully cured. A literature review was performed to assess general features, treatment and outcome of chromoblastomycosis due to F.  nubica. All the 5 reviewed patients were male, over 30 years old and their lesions occurred after traumatic inoculation.

Chromoblastomycosis

Chromoblastomycosis (CBM), also known as chromomycosis, is one of the most prevalent implantation fungal infections, being the most common of the gamut of mycoses caused by melanized or brown-pigmented fungi. CBM is mainly a tropical or subtropical disease that may affect individuals with certain risk factors around the world. The following characteristics are associated with this disease: (i) traumatic inoculation by implantation from an environmental source, leading to an initial cutaneous lesion at the inoculation site; (ii) chronic and progressive cutaneous and subcutaneous tissular involvement associated with fibrotic and granulomatous reactions associated with microabscesses and often with tissue proliferation; (iii) a nonprotective T helper type 2 (Th2) immune response with ineffective humoral involvement; and (iv) the presence of muriform (sclerotic) cells embedded in the affected tissue. CBM lesions are clinically polymorphic and are commonly misdiagnosed as various other infectious and noninfectious diseases. In its more severe clinical forms, CBM may cause an incapacity for labor due to fibrotic sequelae and also due to a series of clinical complications, and if not recognized at an early stage, this disease can be refractory to antifungal therapy.

Burden of serious fungal infections in Trinidad and Tobago

The information on the prevalence of fungal infections in the Caribbean region including Trinidad and Tobago (population 1,339,000 million) is scanty. Tinea capitis is common in children, being predominant in those of African descent, with no definitive estimate. Asthma is also common affecting 77,000-139,000 adults with an estimated 1927-3491 affected by allergic bronchopulmonary aspergillosis (ABPA) and 2544-4608 with severe asthma and fungal sensitisation (SAFS). An estimated 23,763 women have ≥4 attacks of vaginal candidiasis annually. Among the estimated 14,000 HIV-infected patients, 750 cases of oesophageal candidiasis, 400 cases of Pneumocystis pneumonia (PCP) and 50 cases of cryptococcal meningitis are anticipated. Histoplasma capsulatum is endemic in the islands with a 49% skin positivity rate in those <60 years old. Three cases of cutaneous histoplasmosis in AIDS patients have been reported. Three cases of pulmonary histoplasmosis were reported among German biologists following exposure to bats in a cave in Trinidad. Using a low mean international incidence figure for candidaemia of 5/100,000, 67 cases of candidaemia are estimated. The burden of fungal infections in Trinidad and Tobago is considerable and requires appropriate diagnostic and clinical expertise.

Spectral Manifestation of Melanized Fungal Infections in Kidney Transplant Recipients: Report of Six Cases

Chromoblastomycosis and phaeohyphomycosis are melanized fungal infections, which affect skin and subcutaneous tissues in immunocompetent and immunosuppressed patients, as solid-organ transplant recipients, respectively. In this present study, we report six cases of melanized fungal infection in kidney transplant recipients. In five cases, culture of tissue specimens identified two cases of Exophiala spp. and three cases of Fonsecaea spp. Molecular identification was performed in three cases based on sequencing of rDNA (ITS region) that revealed the following agents: Exophiala xenobiotica, Exophiala bergeri and Fonsecaea monophora. Clinically, they presented verrucous lesion, erythematous-squamous plaque, nodules and lymphangitic distribution. Histopathological aspect was tuberculous granuloma, with concomitant presence of muriform bodies and hyphae. Some patients presented fungal transepithelial elimination. One patient received only terbinafine. Three patients underwent surgery, and two of them received itraconazole. In these four cases, the infection did not relapse. The other two patients were treated only with itraconazole, one of them is still under treatment and the other one was lost to follow-up. These patients presented clinical and histopathological characteristics ranging from resistant to nonresistant forms.

Chromoblastomycosis caused by Rhinocladiella aquaspersa

A case of chromoblastomycosis of the hand caused by Rhinocladiella aquaspersa is described. The case was acquired locally in tropical Venezuela and was successfully treated with oral itraconazole.