A novel Sporothrix brasiliensis genomic variant in Midwestern Brazil: evidence for an older and wider sporotrichosis epidemic

Novel Insights into Sporotrichosis and Diabetes

Sporotrichosis is a type of zoonotic subcutaneous mycosis caused by different species of dimorphic fungus of the genus Sporothrix, and it is the most common form of subcutaneous mycosis in Latin America. Sporotrichosis is generally restricted to cutaneous and lymphatic tissue (i.e., localized forms), and involvement in the viscera (i.e., disseminated or disseminated cutaneous form) is uncommon, especially in the central nervous system. However, immunosuppression in individuals with diabetes mellitus can lead to the disseminated form of the disease due to a failure to eliminate the pathogen and poor infection treatment outcomes. Possible correlations between patients with diabetes and their greater susceptibility to disseminated cases of sporotrichosis include a decreased cytokine response after stimulation, increased oxidative stress, decreased chemotaxis, phagocytic activity, adhesion and rolling of neutrophils and monocytes/macrophages, and increased macrophage/monocyte and polymorphonuclear cell apoptosis. Therefore, this review highlights novel insights into diabetes and sporotrichosis by investigating how chronic inflammation affects and aggravates the infection, the possible causes of the greater susceptibility of Sporothrix sp. to hematogenous dissemination in immunocompromised patients, and the main alterations that this dissemination can cause.

Zoonotic Sporotrichosis outbreak: Emerging public health threat in the Amazon State, Brazil

BACKGROUND

Sporotrichosis is the most common subcutaneous mycosis caused by Sporothrix spp. Traditionally, it is transmitted through injuries involving plant debris. However, over the past few decades, there has been an epidemic increase in human cases resulting from contact with infected animals, particularly cats, in various regions of Brazil. In this report, we report a notable increase in both human and animal cases within the Brazilian Amazon state.

METHODOLOGY/PRINCIPAL FINDINGS

An ecological study was conducted by analyzing official records of human and animal sporotrichosis diagnosed in the state of Amazon from 2020 to 2023. Data including patient demographics, clinical manifestations, mycological examination results, and species identification through PCR confirmation were evaluated. During this period, a total of 950 human cases and 2,823 animal cases of sporotrichosis were reported at an exponential rate, since no human cases were registered in 2020. The spatial and temporal dispersion of human sporotrichosis followed that of animal cases, moving from downtown areas to the periphery. Contact with infected animals was reported in 77.7% of cases, with cats being the most commonly implicated (73.5%). Only 66.7% of individuals underwent mycological examination. Among the positive cultures for Sporothrix spp., 65.4% were identified as S. brasiliensis. All patients were treated with systemic antifungals.

CONCLUSIONS/SIGNIFICANCE

This study highlights a rising incidence of sporotrichosis among animals and humans in the Brazilian Amazon region over the past four years, with S. brasiliensis being the predominant agent. Collaborative efforts involving healthcare professionals, veterinarians, and public health authorities are crucial to implement effective control measures, educate populations at risk, and promote responsible guidance for pet guardians. These measures are essential to mitigate the burden of epidemic sporotrichosis in Brazil.

In vitro activity of the anthelmintic drug niclosamide against Sporothrix spp. strains with distinct genetic and antifungal susceptibility backgrounds

The drugs available to treat sporotrichosis, an important yet neglected fungal infection, are limited. Some Sporothrix spp. strains present reduced susceptibility to these antifungals. Furthermore, some patients may not be indicated to use these drugs, while others may not respond to the therapy. The anthelmintic drug niclosamide is fungicidal against the Sporothrix brasiliensis type strain. This study aimed to evaluate whether niclosamide also has antifungal activity against Sporothrix globosa, Sporothrix schenckii and other S. brasiliensis strains with distinct genotypes and antifungal susceptibility status. Minimal inhibitory and fungicidal concentrations (MIC and MFC, respectively) were determined using the microdilution method according to the CLSI protocol. The checkerboard method was employed to evaluate niclosamide synergism with drugs used in sporotrichosis treatment. Metabolic activity of the strains under niclosamide treatment was evaluated using the resazurin dye. Niclosamide was active against all S. brasiliensis strains (n = 17), but it was ineffective (MIC > 20 µM) for some strains (n = 4) of other pathogenic Sporothrix species. Niclosamide MIC values for Sporothrix spp. were similar for mycelial and yeast-like forms of the strains (P = 0.6604). Niclosamide was fungicidal (MFC/MIC ratio ≤ 2) for most strains studied (89%). Niclosamide activity against S. brasiliensis is independent of the fungal genotype or non-wild-type phenotypes for amphotericin B, itraconazole, or terbinafine. These antifungal drugs presented indifferent interactions with niclosamide. Niclosamide has demonstrated potential for repurposing as a treatment for sporotrichosis, particularly in S. brasiliensis cases, instigating in vivo studies to validate the in vitro findings.

Sporothrix brasiliensis Causing Atypical Sporotrichosis in Brazil: A Systematic Review

Zoonotic sporotrichosis, a subcutaneous mycosis caused by Sporothrix brasiliensis, has become hyperendemic and a serious public health issue in Brazil and an emerging disease throughout the world. Typical sporotrichosis is defined as fixed or lymphocutaneous lesion development, however, reports of atypical presentations have been described in hyperendemic areas, which may result in a worse prognosis. Thus, considering an increase in atypical cases and in more severe extracutaneous cases and hospitalizations reported in Brazil, we aimed to perform a systematic review to search for hypersensitivity reactions (HRs) and extracutaneous presentations associated with zoonotic sporotrichosis. A systematic review was performed, following the PRISMA guidelines to search for atypical/extracutaneous cases (mucosal, osteoarthritis, HRs, pulmonary, meningeal) of zoonotic sporotrichosis. A total of 791 published cases over 26 years (1998-2023) in eleven Brazilian states were reviewed. Most cases corresponded to a HR (47%; n = 370), followed by mucosal (32%; n = 256), multifocal (8%; n = 60), osteoarthritis (7%; n = 59), meningeal (4%; n = 32), and pulmonary (2%; n = 14) infections. When available (n = 607), the outcome was death in 7% (n = 43) of cases. Here, we show a frequent and worrisome scenario of zoonotic sporotrichosis in Brazil, with a high and dispersed incidence of atypical/extracutaneous cases throughout the Brazilian territory. Therefore, educational measures are necessary to make health professionals and the overall population aware of this fungal pathogen in Brazil as well as in other countries in the Americas.

First occurrence of feline sporotrichosis in a metropolitan area of Central-West Brazil

Sporotrichosis is a neglected mycosis that affects human and animal hosts, including domestic cats. In Brazil, its most frequently diagnosed etiological agent is Sporothrix brasiliensis. Zoonotic transmission of S. brasiliensis occurs via direct contact between an infected cat and a susceptible human host. Notification of confirmed cases of feline sporotrichosis is not mandatory in Brazil. The metropolitan area of Goiania city can be considered a silent area for the occurrence of feline sporotrichosis. In this context, voluntary reporting of feline sporotrichosis cases is recommended for all healthcare professionals. This study aimed to report the first occurrence of S. brasiliensis in a cat from the metropolitan area of Goiania city. Cytopathology, mycology, thermal dimorphism and calmodulin gene amplification tests were performed. The mycological and molecular biological diagnoses corresponded to S. brasiliensis. The etiological agent of zoonotic sporotrichosis was detected in the metropolitan area of Goiania city, and therefore there is a risk of the emergence of new cases of cats infected with S. brasiliensis and the occurrence of zoonotic transmission of this fungus.

Emergence of zoonotic sporotrichosis in Brazil: a genomic epidemiology study

BACKGROUND

Zoonotic sporotrichosis is a neglected fungal disease, whereby outbreaks are primarily driven by Sporothrix brasiliensis and linked to cat-to-human transmission. To understand the emergence and spread of sporotrichosis in Brazil, the epicentre of the current epidemic in South America, we aimed to conduct whole-genome sequencing (WGS) to describe the genomic epidemiology.

METHODS

In this genomic epidemiology study, we included Sporothrix spp isolates from sporotrichosis cases from Brazil, Colombia, and the USA. We conducted WGS using Illumina NovaSeq on isolates collected by three laboratories in Brazil from humans and cats with sporotrichosis between 2013 and 2022. All isolates that were confirmed to be Sporothrix genus by internal transcribed spacer or beta-tubulin PCR sequencing were included in this study. We downloaded eight Sporothrix genome sequences from the National Center for Biotechnology Information (six from Brazil, two from Colombia). Three Sporothrix spp genome sequences from the USA were generated by the US Centers for Disease Control and Prevention as part of this study. We did phylogenetic analyses and correlated geographical and temporal case distribution with genotypic features of Sporothrix spp isolates.

FINDINGS

72 Sporothrix spp isolates from 55 human and 17 animal sporotrichosis cases were included: 67 (93%) were from Brazil, two (3%) from Colombia, and three (4%) from the USA. Cases spanned from 1999 to 2022. Most (61 [85%]) isolates were S brasiliensis, and all were reported from Brazil. Ten (14%) were Sporothrix schenckii and were reported from Brazil, USA, and Colombia. For S schenckii isolates, two distinct clades were observed wherein isolates clustered by geography. For S brasiliensis isolates, five clades separated by more than 100 000 single-nucleotide polymorphisms were observed. Among the five S brasiliensis clades, clades A and C contained isolates from both human and cat cases, and clade A contained isolates from six different states in Brazil. Compared with S brasiliensis isolates, larger genetic diversity was observed among S schenckii isolates from animal and human cases within a clade.

INTERPRETATION

Our results suggest that the ongoing epidemic driven by S brasiliensis in Brazil represents several, independent emergence events followed by animal-to-animal and animal-to human transmission within and between Brazilian states. These results describe how S brasiliensis can emerge and spread within a country.

FUNDING

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brazil; the São Paulo Research Foundation; Productivity in Research fellowships by the National Council for Scientific and Technological Development, and Ministry of Science and Technology of Brazil.

The present and future research agenda of sporotrichosis on the silver anniversary of zoonotic sporotrichosis in Rio de Janeiro, Brazil

Twenty-five years have passed since the initial observation of endemic zoonotic sporotrichosis in Rio de Janeiro, Brazil. Since then, this disease has spread throughout South America. Accompanying the emergence of this mycosis, some progress has been made, including the expansion of a research network in this field and higher visibility of sporotrichosis within government authorities and funding agencies. However, there are still some challenges to curbing the expansion of this disease in the coming years. These include the development of rapid and accurate diagnostic tests, new antifungal drugs, particularly for the treatment of extracutaneous manifestations of sporotrichosis, and more comprehensive care for cats with sporotrichosis. Including these actions in the sporotrichosis research agenda is required so as to change the development of this disease in the years to come.

Multi-locus sequencing typing reveals geographically related intraspecies variability of Sporothrix brasiliensis

Sporotrichosis is a subcutaneous mycosis caused by pathogenic Sporothrix species. Among them, Sporothrix brasiliensis is the main species associated with endemic regions in South America, especially Brazil. It is highly virulent and can be spread through zoonotic transmission. Molecular epidemiological surveys are needed to determine the extent of genetic variation, to investigate outbreaks, and to identify genotypes associated with antifungal resistance and susceptibility. This study investigated the sequence variation of different constitutive genes and established a novel multilocus sequence typing (MLST) scheme for S. brasiliensis. Specific primers were designed for 16 genes using Primer-BLAST software based on the genome sequences of three S. brasiliensis strains (ATCC MYA-4823, A001 and A005). Ninety-one human, animal, and environmental S. brasiliensis isolates from different Brazilian geographic regions (South, Southeast, Midwest and Northeast) andtwo isolates from Paraguay were sequenced. The loci that presented the highest nucleotide diversity (π) were selected for the MLST scheme. Among the 16 studied genetic loci, four presented increased π value and were able to distinguish all S. brasiliensis isolates into seven distinct haplotypes. The PCR conditions were standardized for four loci. Some of the obtained haplotypes were associated with the geographic origin of the strains. This study presents an important advance in the understanding of this important agent of sporotrichosis in Brazil. It significantly increased the discriminatory power for genotyping of S. brasiliensis isolates, and enabled new contributions to the epidemiological studies of this human and animal pathogen in Brazil and in other countries.

Emergence of zoonotic sporotrichosis due to Sporothrix brasiliensis in Minas Gerais, Brazil: A molecular approach to the current animal disease

Sporotrichosis is a neglected fungal zoonosis with significant impacts on human and animal health. Accurate diagnosis, treatment, and understanding of the transmission dynamics of Sporothrix species are essential for mitigating the spread of sporotrichosis. This study aimed to identify the Sporothrix species involved in the ongoing outbreaks of animal sporotrichosis in the metropolitan region of Belo Horizonte, Minas Gerais, Brazil, and analyse the phylogenetic relationships between pathogenic species to investigate the outbreak origin. Additionally, to better understand the evolution of the disease, we conducted a retrospective survey of positive feline and canine cases from November 2017 to July 2021 with proven cultures for Sporothrix. A significant increase in animal cases over the last 4 years was observed, with cats being the most affected host. Sporothrix brasiliensis was the predominant agent in 100% of the clinical isolates (n = 180) molecularly identified. Phylogenetic and haplotype analysis points towards the cases isolated from Minas Gerais sharing the haplotype originating from a long-lasting outbreak of cat-transmitted sporotrichosis in Rio de Janeiro, however, with a secondary contribution from genotypes circulating in other outbreaks in Brazil. Thus, we present clear evidence of the circulation of different S. brasiliensis genotypes associated with animal sporotrichosis in the metropolitan region of Belo Horizonte. Genetic monitoring can contribute to understanding the causal agent for zoonotic sporotrichosis in epidemiological processes and help to implement disease prevention and control measures.

Sporothrix brasiliensis: Epidemiology, Therapy, and Recent Developments

Sporotrichosis caused by Sporothrix brasiliensis is an emergent mycosis that is now a worldwide concern. One important step to sporotrichosis control is its correct treatment. However, limitations abound; thus, new antifungals, mainly focused on S. brasiliensis, are urgently needed. We performed a systematic review (following the PRISMA guideline) focused on (1) the global distribution of human and animal sporotrichosis by S. brasiliensis, especially outside of Brazil; (2) appraising therapies tested against this pathogen. We identified sporotrichosis caused by S. brasiliensis reported in five countries (Paraguay, Chile, Argentina, the United Kingdom, and the United States) in addition to Brazil, occurring on three continents, highlighting the epidemiological scenario in Argentina with an important increase in reported cases in recent years. Regarding the antifungal activity of drugs, 25 articles described the in vitro action of 20 unique chemicals and eight repurposed drugs against S. brasiliensis. Only five studies reported in vivo activity against S. brasiliensis (five drugs) using invertebrate and vertebrate models. Sporotrichosis caused by S. brasiliensis has a global impact and it is no longer specifically a Brazilian problem. We review the need for understanding the disease epidemiology, education of clinicians and of the populace, organization of health care delivery to respond to a spreading epidemic, and research on therapy for sporotrichosis.

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.

Sporothrix pathogenic clade: Molecular analysis of animal and human clinical isolates

Sporotrichosis is a subcutaneous mycosis that affects animals and humans. Varying in severity, occurrences range from local lesions to systemic involvement. It is caused by thermodimorphic and saprobic fungi from the Sporothrix pathogenic clade. This study aimed to identify the species and the sexual idiomorph distribution patterns responsible for diagnosed cases of sporotrichosis in São José do Rio Preto, Brazil. We included 188 isolates of Sporothrix sp. from feline lesions and 27 of human origin, which underwent molecular identification and genotyping for mating-type MAT1-1 and MAT1-2. The results showed that Sporothrix brasiliensis is the prevalent species in feline sporotrichosis outbreaks with the overwhelming presence of a single mating-type, MAT1-2 (P <.0001), suggesting a prevalently clonal form of spread. Morphological analyses did not discriminate among cryptic species in the genus Sporothrix, and molecular identification was essential for the correct identification of the species responsible for the observed cases of sporotrichosis. Distribution analyses of MAT1-2 isolates support the hypothesis of unidirectional migration from the current epidemics in São Paulo and Rio de Janeiro to the municipality of São José do Rio Preto.

Single nucleotide polymorphisms and chromosomal copy number variation may impact the Sporothrix brasiliensis antifungal susceptibility and sporotrichosis clinical outcomes

Feline-transmitted sporotrichosis has garnered attention due to the recent high incidence and the lack of efficient control in the epicenter of the epidemic, Rio de Janeiro, Brazil. Sporothrix brasiliensis is the major pathogen involved in feline-to-human sporotrichosis in Brazil and displays more virulent genotypes than the closely related species S. schenckii. Over the last two decades, several reports of antifungal-resistant strains have emerged. Sequencing and comparison analysis of the outbreak strains allowed us to observe that the azole non-wild-type S. brasiliensis strain CFP 1054 had significant chromosomal variations compared to wild-type strains. One of these variants includes a region of 231 Kb containing 75 duplicated genes, which were overrepresented for lipid and isoprenoid metabolism. We also identified an additional strain (CFP 1055) that was resistant to itraconazole and amphotericin B, which had a single nucleotide polymorphism in the tac1 gene. The patients infected with these two strains showed protracted clinical course and sequelae. Even though our sample size is modest, these results suggest the possibility of identifying specific point mutations and large chromosomal duplications potentially associated with antifungal resistance and clinical outcomes of sporotrichosis.

Trends in Molecular Diagnostics and Genotyping Tools Applied for Emerging Sporothrix Species

Sporotrichosis is the most important subcutaneous mycosis that affects humans and animals worldwide. The mycosis is caused after a traumatic inoculation of fungal propagules into the host and may follow an animal or environmental transmission route. The main culprits of sporotrichosis are thermodimorphic Sporothrix species embedded in a clinical clade, including S. brasiliensis, S. schenckii, S. globosa, and S. luriei. Although sporotrichosis occurs worldwide, the etiological agents are not evenly distributed, as exemplified by ongoing outbreaks in Brazil and China, caused by S. brasiliensis and S. globosa, respectively. The gold standard for diagnosing sporotrichosis has been the isolation of the fungus in vitro. However, with the advance in molecular techniques, molecular assays have complemented and gradually replaced the classical mycological tests to quickly and accurately detect and/or differentiate molecular siblings in Sporothrix. Nearly all techniques available for molecular diagnosis of sporotrichosis involve PCR amplification, which is currently moving towards detecting Sporothrix DNA directly from clinical samples in multiplex qPCR assays. From an epidemiological perspective, genotyping is key to tracing back sources of Sporothrix infections, detecting diversity in outbreak areas, and thus uncovering finer-scale epidemiological patterns. Over the past decades, molecular epidemiological studies have provided essential information to policymakers regarding outbreak management. From high-to-low throughput genotyping methods, MLSA, AFLP, SSR, RAPD, PCR-RFLP, and WGS are available to assess the transmission dynamics and sporotrichosis expansion. This review discusses the trends in the molecular diagnosis of sporotrichosis, genotyping techniques applied in molecular epidemiological studies, and perspectives for the near future.

Current Progress on Epidemiology, Diagnosis, and Treatment of Sporotrichosis and Their Future Trends

Sporotrichosis, a human and animal disease caused by Sporothrix species, is the most important implantation mycosis worldwide. Sporothrix taxonomy has improved in recent years, allowing important advances in diagnosis, epidemiology, and treatment. Molecular epidemiology reveals that S. brasiliensis remains highly prevalent during the cat-transmitted sporotrichosis outbreaks in South America and that the spread of S. brasiliensis occurs through founder effects. Sporothrix globosa and S. schenckii are cosmopolitan on the move, causing major sapronoses in Asia and the Americas, respectively. In this emerging scenario, one-health approaches are required to develop a creative, effective, and sustainable response to tackle the spread of sporotrichosis. In the 21st century, it has become vital to speciate Sporothrix, and PCR is the main pillar of molecular diagnosis, aiming at the detection of the pathogen DNA from clinical samples through multiplex assays, whose sensitivity reaches remarkably three copies of the target. The treatment of sporotrichosis can be challenging, especially after the emergence of resistance to azoles and polyenes. Alternative drugs arising from discoveries or repositioning have entered the radar of basic research over the last decade and point to several molecules with antifungal potential, especially the hydrazone derivatives with great in vitro and in vivo activities. There are many promising developments for the near future, and in this review, we discuss how these trends can be applied to the Sporothrix-sporotrichosis system to mitigate the advance of an emerging and re-emerging disease.

Sporothrix brasiliensis and Feline Sporotrichosis in the Metropolitan Region of Rio de Janeiro, Brazil (1998–2018)

Feline sporotrichosis is enzootic in different regions of Brazil, especially in Rio de Janeiro. This study compared the genotype profiles of Sporothrix sp. isolated from cats in Rio de Janeiro between 1998 and 2018 and evaluated their association with clinical and epidemiological characteristics. One hundred nineteen Sporothrix sp. isolates from a cohort of cats with sporotrichosis seen at INI/Fiocruz were included. Clinical and epidemiological data were obtained from the medical records of the animals. T3B PCR fingerprinting was used for molecular identification of the Sporothrix species. All isolates were characterized as Sporothrix brasiliensis, with the observation of low intraspecific variation in 31 isolates (31.3%). The interval between lesion onset and first medical visit at INI/Fiocruz, as well as treatment duration until clinical cure, was longer in cats from the first decade of the epizootic. In addition, the frequency of the variables “good general status” and “presence of lymphadenomegaly” was higher among cats whose strains did not exhibit intraspecific variation. So far, S. brasiliensis has been the only species identified in feline cases of sporotrichosis since the beginning of the epizootic in Rio de Janeiro at INI/Fiocruz.

A neglected disease. Human sporotrichosis in a densely populated urban area in São Paulo, Brazil: clinical-epidemiological and therapeutic aspects

Human sporotrichosis is caused by different Sporothrix species; however, Sporothrix brasiliensis is the main species, usually related to cat transmission in urban areas. A retrospective descriptive study was conducted at the Institute of Infectology Emílio Ribas from 2010 to 2018. Demography, clinical, diagnostic, and therapeutic data were obtained from medical records. Polymerase chain reaction of the calmodulin gene was performed to identify Sporothrix species. In addition, to evaluate the spread of the disease across São Paulo metropolitan region, TerraView version 4.2.2 software was used for geocoding cases according to residence addresses. Kernell's maps using QGIS software version 2.16.3 were constructed to determine the concentration of cases. Results: 260 cases of sporotrichosis were diagnosed between 2010 and 2018. We observed a 700% increment in the number of human cases in the 2016-2018 triennium compared with the 2013-2015 triennium. Female adults with a median age of 46 years old were the predominant infected group associated with cats' exposition at home care, although the age range of all patients was 01 to 86 years old. The main epidemiological risk of acquiring sporotrichosis was contact with cats, reported by 96.5% of the patients. Molecular identification showed that most of the tested isolates were Sporothrix brasiliensis. Lymphocutaneous form was observed in 59.2% and fixed cutaneous form in 37.5% of the patients. Regarding treatment, itraconazole was the main drug used (94.2%) with a cure rate of 98.8%. We observed an important spread of human sporotrichosis involving cat transmission caused by Sporothrix brasiliensis in a densely populated area of São Paulo state. These results are important to alert clinicians and dermatologists about the occurrence and progression of a neglected tropical disease in an urban area and the urgent necessity to include sporotrichosis as a differential diagnosis in the clinical investigation routine.

Epidemiology of Clinical Sporotrichosis in the Americas in the Last Ten Years

BACKGROUND

Sporotrichosis is a fungal infection caused by species of the Sporothrix genus. Presently, the prevalence of sporotrichosis in the Americas is unknown, so this study aims to analyze the cases reported in the past 10 years.

METHODS

An advanced search was conducted from 2012 to 2022 in English and Spanish in PUBMED, SciELO, and Cochrane, with the terms: "sporotrichosis", "lymphocutaneous sporotrichosis", "fixed sporotrichosis", "mycosis", "Sporothrix spp.", "Sporothrix complex", "S. schenckii sensu stricto", "S. schenckii sensu lato", "S. globose", "S. brasiliensis", "S. luriei". Sporotrichosis is a fungal infection caused by species of the Sporothrix genus associated with "pathogenicity" or "epidemiology".

RESULTS

A total of 124 articles were found in the Americas, corresponding to 12,568 patients. Of these, 87.38% of cases were reported in South America, 11.62% in North America, and 1.00% in Central America and the Caribbean. Brazil, Peru, and Mexico had the highest number of cases. The most prevalent etiological agents were S. schenckii complex/Sporothrix spp. (52.91%), S. schenckii (42.38%), others (4.68%), and Not Determined (ND) (0.03%). The most frequent form of the disease was lymphocutaneous infection; however, the infection type was not determined in 5639 cases. Among the diagnostic methods, culture was the most used.

CONCLUSIONS

There is a high occurrence of cases reported in the literature. South America is the region with the highest number of reports because of its environment (climate, inhalation of spores, etc.), zoonotic transmission (scratches and sneezes from contaminated animals), and possible traumatic inoculation due to outdoor activities (agriculture, gardening, and related occupations). Molecular diagnosis has not been sufficiently developed due to its high cost.

Environmental Isolation of Sporothrix brasiliensis in an Area With Recurrent Feline Sporotrichosis Cases

Sporotrichosis has been expanding throughout the Brazilian territory in recent years. New outbreaks have emerged, and consequently, the sporotrichosis agents, mainly Sporothrix brasiliensis, should remain in the environment somehow. Therefore, the aim of this study was to investigate the presence of Sporothrix spp. in the environment from an area of ​​the Rio de Janeiro state, Brazil, with recurrent cases of human and animal sporotrichosis. Abandoned demolition timber wood samples were collected in the garden of a house where the cases of human and feline sporotrichosis have occurred in the last 10 years. The environmental survey revealed a Sporothrix spp. colony from the serial dilution cultures of one abandoned demolition wood sample. In addition, a fungal strain isolated from a cat with skin lesions that lived in the house was also included in the study. The species-specific PCR, and calmodulin partial sequencing identified the environmental and cat isolates as S. brasiliensis. Furthermore, the phylogenetic analysis performed with the partial sequences of internal transcribed spacer region and constitutive genes (calmodulin, β-tubulin, and chitin synthase) showed high similarity between environmental and cat isolates from the same geographic region. Moreover, the antifungal susceptibility test revealed that the minimal inhibitory concentration of itraconazole from the environment isolate was lower than the cat isolate, while amphotericin B and terbinafine were similar. Our results show that S. brasiliensis is able to maintain itself in the environmental material for years. With this, we corroborate that the eco-epidemiology of sporotrichosis is not well understood, and despite the major occurrence of S. brasiliensis in Brazil, it is rarely isolated from the environment.

Molecular Diagnosis of Two Major Implantation Mycoses: Chromoblastomycosis and Sporotrichosis

Chromoblastomycosis and sporotrichosis are the two main implantation mycoses that are now recognized as fungal neglected tropical diseases (NTDs). Their laboratory diagnosis mainly relies on direct microscopy, histopathology, and identification of the fungus by culture. However, to be appropriately used, these techniques require mycological expertise that is not widely available and may be absent in peripheral health care facilities in endemic areas. In addition, they lack sensitivity and specificity, and the culture for isolation and identification can have a long time-to-results period. Molecular methods, including matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), have been developed in well-equipped reference laboratories. They greatly improve the rapidity and accuracy of diagnosis; in particular, for species identification. Recently, PCR and sequencing have paved the way for more user-friendly point-of-care tests, such as those based on LAMP or RCA technologies, which can be used in basic healthcare settings and even in field consultations.

Clinical and Epidemiological Characteristics of Sporotrichosis in a Reference Center of Uruguay

Background: Sporotrichosis is a fungal implantation disease of subacute/ chronic course caused by species of the dimorphic fungus Sporothrix spp. This infection usually develops after traumatic inoculation of contaminated soil, plants or organic material contaminated by Sporothrix spp. conidia into skin or mucosa. The objective of this work is to contribute to the knowledge of sporotrichosis in Uruguay by providing a report of a series of cases diagnosed in a reference center. Methods: We conducted a retrospective, observational, descriptive and cross-sectional study of cases of sporotrichosis diagnosed in the last 38 years. Results: In the period analyzed, 157 cases of sporotrichosis were diagnosed, 152 of those corresponded to male patients. The most frequent clinical presentation was nodular lymphatic in 120 patients. In relation to epidemiological antecedents, 128 patients had been scratched by armadillos during hunting. Conclusions: Sporotrichosis in Uruguay is a sporadic disease with a clear seasonal pattern related to particular social practices, such as hunting armadillos. Related to this practice, the affectation is greater in males and in young adults.

Human sporotrichosis: recommendations from the Brazilian Society of Dermatology for the clinical, diagnostic and therapeutic management

BACKGROUND

The increase in the zoonotic epidemic of sporotrichosis caused by Sporothrix brasiliensis, which started in the late 1990s in Rio de Janeiro and is now found in almost all Brazilian states, has been equally advancing in neighboring countries of Brazil. Changes in the clinical-epidemiological profile, advances in the laboratory diagnosis of the disease, and therapeutic difficulties have been observed throughout these almost 25 years of the epidemic, although there is no national consensus. The last international guideline dates from 2007.

OBJECTIVES

Update the clinical classification, diagnostic methods and recommendations on the therapeutic management of patients with sporotrichosis.

METHODS

Twelve experts in human sporotrichosis were selected from different Brazilian regions, and divided into three work groups: clinical, diagnosis and treatment. The bibliographic research was carried out on the EBSCOHost platform. Meetings took place via electronic mail and remote/face-to-face and hybrid settings, resulting in a questionnaire which pointed out 13 divergences, resolved based on the opinion of the majority of the participants.

RESULTS

The clinical classification and laboratory diagnosis were updated. Therapeutic recommendations were made for the different clinical forms.

CONCLUSION

Publication of the first national recommendation, carried out by the Brazilian Society of Dermatology, aimed at the Brazilian scientific community, especially dermatologists, infectologists, pediatricians, family medicine personnel, and laboratory professionals who work in the management of human sporotrichosis.

Trends in the molecular epidemiology and population genetics of emerging Sporothrix species

Sporothrix (Ophiostomatales) comprises species that are pathogenic to humans and other mammals as well as environmental fungi. Developments in molecular phylogeny have changed our perceptions about the epidemiology, host-association, and virulence of Sporothrix. The classical agent of sporotrichosis, Sporothrix schenckii, now comprises several species nested in a clinical clade with S. brasiliensis, S. globosa, and S. luriei. To gain a more precise view of outbreaks dynamics, structure, and origin of genetic variation within and among populations of Sporothrix, we applied three sets of discriminatory AFLP markers (#3 EcoRI-GA/MseI-TT, #5 EcoRI-GA/MseI-AG, and #6 EcoRI-TA/MseI-AA) and mating-type analysis to a large collection of human, animal and environmental isolates spanning the major endemic areas. A total of 451 polymorphic loci were amplified in vitro from 188 samples, and revealed high polymorphism information content (PIC = 0.1765-0.2253), marker index (MI = 0.0001-0.0002), effective multiplex ratio (E = 15.1720-23.5591), resolving power (Rp = 26.1075-40.2795), discriminating power (D = 0.9766-0.9879), expected heterozygosity (H = 0.1957-0.2588), and mean heterozygosity (Havp  = 0.000007-0.000009), demonstrating the effectiveness of AFLP markers to speciate Sporothrix. Analysis using the program structure indicated three genetic clusters matching S. brasiliensis (population 1), S. schenckii (population 2), and S. globosa (population 3), with the presence of patterns of admixture amongst all populations. AMOVA revealed highly structured clusters (PhiPT = 0.458-0.484, P < 0.0001), with roughly equivalent genetic variability within (46-48 %) and between (52-54 %) populations. Heterothallism was the exclusive mating strategy, and the distributions of MAT1-1 or MAT1-2 idiomorphs were not significantly skewed (1:1 ratio) for S. schenckii (χ2 = 2.522; P = 0.1122), supporting random mating. In contrast, skewed distributions were found for S. globosa (χ2 = 9.529; P = 0.0020) with a predominance of MAT1-1 isolates, and regional differences were highlighted for S. brasiliensis with the overwhelming occurrence of MAT1-2 in Rio de Janeiro (χ2 = 14.222; P = 0.0002) and Pernambuco (χ2 = 7.364; P = 0.0067), in comparison to a higher prevalence of MAT1-1 in the Rio Grande do Sul (χ2 = 7.364; P = 0.0067). Epidemiological trends reveal the geographic expansion of cat-transmitted sporotrichosis due to S. brasiliensis via founder effect. These data support Rio de Janeiro as the centre of origin that has led to the spread of this disease to other regions in Brazil. Our ability to reconstruct the source, spread, and evolution of the ongoing outbreaks from molecular data provides high-quality information for decision-making aimed at mitigating the progression of the disease. Other uses include surveillance, rapid diagnosis, case connectivity, and guiding access to appropriate antifungal treatment.

The spread of cat-transmitted sporotrichosis due to Sporothrix brasiliensis in Brazil towards the Northeast region

BACKGROUND

Sporotrichosis is a worldwide subcutaneous mycosis caused by Sporothrix spp. In the past, this infection was associated with armadillo hunting, horticulturists, miners, and gardeners, being considered an implantation mycosis acquired by plant debris injury. Nevertheless, since the late nineties, it has been considered a zoonotic disease in Brazil. Here we report a case series of 121 patients with cat-transmitted sporotrichosis seen in Northeast Brazil.

METHODOLOGY/PRINCIPAL FINDINGS

Patient's demographic, clinical data, and length of treatment were recorded. In addition, a mycological examination and further PCR confirmation of species identification were performed. One hundred and twenty two patients were diagnosed with subcutaneous sporotrichosis from October 2016 to December 2019, while PCR revealed that 71 of them were due to S. brasiliensis. The majority of the individuals were female (n = 86; 70.5%). Patient's age ranged from 5 to 87 years old. The clinical forms found were lymphocutaneous (58.2%) and fixed cutaneous (39.4%). Interestingly, 115 patients reported previous contact with cats diagnosed with sporotrichosis. Patients were successfully treated with itraconazole and potassium iodide.

CONCLUSIONS/SIGNIFICANCE

Our study adds important contributions for the investigation of the spread of cat-transmitted subcutaneous sporotrichosis in Brazil, specifically towards the Northeast region of a continental-size country. It will also help clinicians to be aware of the existence and importance to accurately diagnose sporotrichosis and treat patients with this infectious disease in the lowest income region of Brazil.