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

Novel amplified fragment length polymorphism (AFLP) markers for typing medically relevant Fusarium and allied fusarioid genera

Fusariosis is an emerging mycosis caused by diverse Fusarium and allied fusarioid genera that are characterized by spindle-shaped macroconidia. These fungi possess a broad ecological distribution, causing infections in a wide diversity of hosts, spanning the animal and plant kingdoms. The spectrum of human fusariosis encompasses superficial lesions like keratitis and onychomycosis to invasive fungal diseases. Notable genera within the medically relevant fusarioid group include Neocosmospora, Fusarium s. str., and Bisifusarium. While Neocosmospora species (formerly F. solani species complex) are primary causative agents of human fusariosis, instances involving Fusarium s. str. and Bisifusarium (formerly F. dimerum species complex) have been reported. There is an urgent need for DNA-based markers to explore the epidemiology of these emerging fusarioid pathogens using molecular methods. We took advantage of fusarioid genomes available in NCBI (n = 20) to optimize the development of novel amplified fragment length polymorphism (AFLP) markers by conducting in-depth in silico analyses to refine their applicability for studies on these pathogens' genetic epidemiology. In-silico screening highlighted eight primer pair combinations (C1-C8) to be tested in vitro. The AFLP protocol was used for genotyping 40 medically relevant fusarioid fungi. Based on the overall scored AFLP markers (77-93 fragments), the values of polymorphism information content (PIC = 0.3474-0.3725), marker index (MI = 0.0038-0.0056), effective multiplex ratio (E = 26.3750-40.4750), resolving power (Rp = 40.1500-54.6000), discriminating power (D = 0.7978-0.8857), expected heterozygosity (H = 0.4476-0.4949), and mean heterozygosity (H avp = 0.0001) demonstrated the utility of these primer combinations for discriminating Neocosmospora, Fusarium s. str., and Bisifusarium species. Of relevance, some AFLP panels were better than others at studying genetic trends in Neocosmospora (#2 EcoRI-AT/MseI-TA, #3 EcoRI-AA/MseI-TT, and #5 EcoRI-AT/MseI-AG) or Fusarium s. str. (mainly #2 EcoRI-AT/MseI-TA and #6 EcoRI-GA/MseI-TT) and Bisifusarium (#1 EcoRI-GA/MseI-AG and #6 EcoRI-GA/MseI-TT), and these combinations will better resolve disease transmission routes. Our DNA fingerprint assay has proven effective by exhibiting rapidity, reproducibility, and high discriminatory capabilities, which represents a valuable asset in the ongoing efforts to combat fusariosis and enhance our scientific understanding of medically relevant Fusarium and allied fusarioid genera. Citation: Monteiro RC, Yu CZ, Dolatabadi S, Hagen F, Sandoval-Denis M, Crous PW, Fisher MC, Gonçalves SS, de Camargo ZP, Hofling-Lima AL, Rodrigues AM (2025). Novel amplified fragment length polymorphism (AFLP) markers for typing medically relevant Fusarium and allied fusarioid genera. Fungal Systematics and Evolution 15: 79-96. doi: 10.3114/fuse.2025.15.03.

Chromoblastomycosis in Brazil: A review of 450 published cases

Chromoblastomycosis is a skin infection caused by melanized fungi that primarily affects rural workers. This study aimed to analyze the clinical and epidemiological manifestations of chromoblastomycosis in Brazil through an extensive literature review. A review of case reports or series of cases in English and Portuguese was conducted using the SciELO, LILACS, SCOPUS, PubMed, and Web of Science databases from 1963 to 2022. A total of 46 articles involving 450 patients were identified, among which, 83.1% were male rural workers with a mean age of 52.2 years. The clinical manifestations were most commonly observed in the lower extremities (78.7%). The most frequent clinical presentations of the disease were verrucous lesions and plaques. Fonsecaea and Rhinocladiella spp. were the most common agents responsible for chromoblastomycosis. Most cured cases were treated with itraconazole, either as monotherapy or in combination with other antifungals, surgery, or cryosurgery. Chromoblastomycosis affects hundreds of rural workers in Brazil, leading to financial disabilities as well as personal and family losses. It is essential to prioritize epidemiological surveillance and ensure the early diagnosis of this disease to reveal its true prevalence, guide resource allocation, improve diagnosis, ensure early treatment, and implement preventive measures.

Emerging Cases of Cat-Transmitted Sporotrichosis Driven by Sporothrix brasiliensis in Northeast Brazil

Cat-transmitted sporotrichosis is caused by the emerging fungal pathogen Sporothrix brasiliensis and constitutes a significant public health issue that affects people living in resource-poor urban centers in Brazil. The lack of knowledge about transmission dynamics makes it difficult to propose public health policies to contain the advance of sporotrichosis. We describe the recent emergence of 1,176 cases of sporotrichosis in cats (2016 to 2021) in the metropolitan region of Recife, Brazil, leading to significant zoonotic transmission and an overwhelming occurrence of S. brasiliensis as the etiological agent. Most cases were from cats in the cities of Olinda (408/1,176; 34.70%), Jaboatão dos Guararapes (332/1,176; 28.23%), and Recife (237/1,176; 20.15%). Molecular typing using amplified fragment length polymorphism (EcoRI-GA/MseI-AG) revealed low polymorphic information content (PIC = 0.2499) and heterozygosity (H = 0.2928), typical of an outbreak scenario. Dendrogram and multivariate cluster analysis revealed that isolates from Pernambuco are closely related to Rio de Janeiro isolates. We report a substantial occurrence of MAT1-2 idiomorphs in the metropolitan region of Recife (0:60 ratio; χ2 = 60.000, P < 0.0001). The limited population differentiation and genetic diversity of the isolates from Pernambuco suggest a recent introduction, possibly via a founder effect, from the parental population in Rio de Janeiro. Our findings emphasize the critical importance of molecular surveillance of S. brasiliensis for outbreak response. A comprehensive one-health strategy is mandatory to control the spread of cat-transmitted sporotrichosis driven by S. brasiliensis, encompassing sanitary barriers, quick diagnosis, and treatment.

From Child to Old Man: A Slowly Evolving Case of Chromoblastomycosis Caused by Cladosporium cladosporioides

Chromoblastomycosis is a chronic granulomatous mycosis of the skin and subcutaneous tissue caused by traumatic inoculation with dematiaceous fungi. This disease primarily affects agricultural workers, who are mostly men. We present a case of chromoblastomycosis in a 63-year-old male farmer patient with dermatosis over 50 years of evolution, with warty, erythematous, and scaly plaques that predominate on the left hemithorax. Direct examination with potassium hydroxide (KOH) revealed numerous fumagoid cells. Amplification and sequencing of the internal transcribed spacer (ITS) and translation elongation factor 1-alpha (TEF-1a) gene revealed that chromoblastomycosis was caused by Cladosporium cladosporioides. The chromoblastomycosis was treated with itraconazole and fluconazole without any improvement, and amphotericin B was administered with partial improvement.

Chromoblastomycosis: New Perspective on Adjuvant Treatment with Acitretin

Chromoblastomycosis (CBM) is a neglected human disease, caused by different species of pigmented dematiaceous fungi that cause granulomatous and suppurative dermatosis. This infection is difficult to treat and there are limited therapeutic options, including terbinafine, itraconazole, and tioconazole. Classic treatment is administered for a long period of time, but some patients do not respond properly, and therefore, such therapeutic approaches possess low cure rates. Therefore, it is vital to develop new strategies for the treatment of CBM. In this regard, it has been observed that the association of immunomodulatory molecules such as glucan with therapy carried out with antifungal drugs improves cutaneous lesions in comparison to treatment with antifungal drugs alone, suggesting that drug association may be an interesting and significant approach to incorporate into CBM therapy. Thus, the aim of this work was to associate classical antifungal therapy with the adjuvants imiquimod and acitretin. In the present case, we reported a patient with extensive CBM caused by Fonsaecae pedrosoi, that affected an extensive area of the right leg, that was left without treatment for 11 years. He was treated with a classical combination of itraconazole and terbinafine via the oral route plus topical imiquimod and oral acitretin, as an adjuvant therapy. After five months of treatment, a significant regression of verrucous plaques was observed, suggesting that the use of these adjuvants combined with the classical antifungal drugs, intraconazole plus terbinafine, can reduce treatment time and rapidly improve the patient's quality of life. This result confirms that the use of coadjuvant drugs may be effective in the treatment of this infectious disease.

High-Throughput Microsatellite Markers Development for Genetic Characterization of Emerging Sporothrix Species

Sporotrichosis is the main subcutaneous mycosis worldwide transmitted by animal or plant vectors and often escalates to outbreaks or epidemics. The current cat-transmitted sporotrichosis driven by Sporothrix brasiliensis has become a significant public health issue in South America. Transmission dynamics remain enigmatic due to the lack of development of polymorphic markers for molecular epidemiological analysis. This study used a high-throughput mining strategy to characterize simple sequence repeat (SSR) markers from Sporothrix genomes. A total of 118,140-143,912 SSR loci were identified (82,841-98,369 unique markers), with a 3651.55-3804.65 SSR/Mb density and a majority of dinucleotides motifs (GC/CG). We developed a panel of 15 highly polymorphic SSR markers suitable for genotyping S. brasiliensis, S. schenckii, and S. globosa. PCR amplification revealed 240 alleles in 180 Sporothrix isolates with excellent polymorphic information content (PIC = 0.9101), expected heterozygosity (H = 0.9159), and discriminating power (D = 0.7127), supporting the effectiveness of SSR markers in uncovering cryptic genetic diversity. A systematic population genetic study estimated three clusters, corresponding to S. brasiliensis (population 1, n = 97), S. schenckii (population 2, n = 49), and S. globosa (population 3, n = 34), with a weak signature of mixed ancestry between populations 1 and 2 or 3 and 2. Partitioning of genetic variation via AMOVA revealed highly structured populations (ΦPT = 0.539; Nm = 0.213; p < 0.0001), with approximately equivalent genetic variability within (46%) and between (54%) populations. Analysis of SSR diversity supports Rio de Janeiro (RJ) as the center of origin for contemporary S. brasiliensis infections. The recent emergence of cat-transmitted sporotrichosis in northeastern Brazil indicates an RJ-Northeast migration resulting in founder effects during the introduction of diseased animals into sporotrichosis-free areas. Our results demonstrated high cross-species transferability, reproducibility, and informativeness of SSR genetic markers, helping dissect deep and fine-scale genetic structures and guiding decision making to mitigate the harmful effects of the expansion of cat-transmitted sporotrichosis.