Sporothrix Schenckii Research Articles

ESPOROTRICOSE FELINA

Sporotrichosis is a zoonotic disease caused by dimorphic fungi of the Sporothrix schenckii complex. Cats, due to their semi-domiciled lifestyle and species-specific behaviors, are most affected. Transmission occurs mainly through direct contact with infected animals, through scratches or bites, in addition to contact with the agent in the environment, such as contaminated soil and plants. The disease is more prevalent in countries in tropical and subtropical zones, with subcutaneous mycosis being more common in Latin America. Although the prognosis is generally favorable, sporotrichosis has become a growing public health problem, due to its expansion in regions of Brazil and the fact that it is a zoonosis. In humans, especially in immunosuppressed individuals, it can evolve into extracutaneous forms, with a risk of becoming fatal. Early diagnosis of sporotrichosis is essential for the prevention and control of this disease in Brazil.

Photodynamic inactivation strategies for maximizing antifungal effect against Sporothrix spp. and Candida albicans in an in vitro investigation.

Sporotrichosis is a zoonotic disease caused by the dimorphic fungus Sporothrix spp., leading to skin lesions that can, in some cases, progress and result in the death of infected individuals. Candida albicans is another fungus involved in several skin, oral, and vaginal mucosal infections. Fungal diseases are concerning due to increasing incidence and the limited variety of antifungal classes available for treatment. Furthermore, antifungal medications can cause various side effects, exacerbated by their prolonged use during infection treatment. There is a need to explore alternatives to conventional drugs that are effective, fast, and safe in combating sporotrichosis. This study aimed to achieve in vitro elimination of the fungi Sporothrix brasiliensis and Sporothrix schenckii through Photodynamic Inactivation (PDI), using curcumin as a photosensitizer and in combination with antifungal agents used in the treatment of sporotrichosis. Yeasts of Candida albicans, Sporothrix brasiliensis, and Sporothrix schenckii were subjected to Photodynamic Inactivation (PDI) using light at a wavelength of 450 ± 10 nm, irradiance of 35 mW/cm2, delivering a fluence of 31.5 J/cm2, with curcumin as the photosensitizer at doses ranging from 0.75 to 150 μg/mL. After determining the Minimum Inhibitory Concentration (MIC) values of the antifungal drugs itraconazole, ketoconazole, and potassium iodide, sub-MIC doses of these antifungals were combined with sub-MIC doses of curcumin in a new PDI session. Photodynamic inactivation is a promising technique in the treatment of sporotrichosis, as well as its combination with antifungals. The combination of curcumin in concentrations ranging from 0.75 g/mL a 7.5 g/mL with sub-MIC concentrations of itraconazole, ketoconazole, and potassium iodide was able to completely inactivate the fungi C. albicans, S. brasiliensis and S. schenckii, indicating that PDI may increase the effectiveness of antifungals. However, further studies are needed to establish protocols for future clinical applications.

ASPECTOS CLÍNICOS E TERAPÊUTICOS DA ESPOROTRICOSE FELINA: REVISÃO DE LITERATURA

Feline sporotrichosis is a subcutaneous mycosis caused by the fungus Sporothrix schenckii. The disease can range from isolated cutaneous lesions to severe and disseminated forms, mainly affecting adult male cats that are not neutered. The clinical aspects of feline sporotrichosis are explored, including the presentation of cutaneous lesions, respiratory signs, and systemic manifestations such as lethargy, anorexia, and fever. Treatment is detailed, emphasizing the importance of accurate diagnosis and the need for prolonged treatment, which can last weeks to months. Therapeutic options include potassium iodide, azoles (such as itraconazole and ketoconazole), terbinafine, and amphotericin B, as well as non-pharmacological measures such as thermotherapy, cryosurgery and surgical excision. The paper also discusses the combination of potassium iodide and itraconazole as an effective therapeutic option, as well as addressing recommendations for managing drug toxicity, indications for euthanasia in severe cases, and general recommendations for disease management and prevention. Finally, the persistence of sporotrichosis as a neglected disease in Brazil is highlighted, with the treatment of cats representing a continuous and longterm challenge.

Sustainable Solution to Antibiotic Resistance: Pavetta indica-Based Nanomedicine

The escalating global health crisis, characterized by the emergence of antimicrobial-resistant pathogens, necessitates innovative strategies. This study explores the potential of Pavetta indica, a previously underutilized plant, as a multifaceted resource for addressing this critical challenge. A comprehensive phytochemical investigation unveiled a rich repertoire of bioactive compounds within P. indica, including essential metabolites Moisture (9.14%), Crude Protein (10.93%), and Crude Fiber (15.46%). Additionally, significant levels of Calcium, Phosphorus, and Ether Extract were identified, suggesting its potential contribution to a balanced diet and a diverse array of secondary metabolites identified through GC-MS analysis identified diverse bioactive compounds including Dodecanoic acid, Lupeol, and β-D-Glucopyranose among others, highlighting its potential health benefits and paving the way for further research on specific bioactivities. P. indica extract exhibited concentration-dependent ABTS and DPPH scavenging activities, comparable to ascorbic acid. This underscores its potential as a natural antioxidant source to combat oxidative stress-related diseases. Leveraging the bio-reducing capabilities of P. indica extract, we embarked on the green synthesis of silver nanoparticles. P. indica extract successfully synthesized silver nanoparticles, confirmed by UV-Vis spectroscopy (SPR band at 420 nm) and TEM (spherical particles, 25-50 nm). These nanoparticles showed potent antimicrobial activity against Bacillus subtilis, E. coli, and Pseudomonas aeruginosa, comparable to Gentamicin. The synthesized silver nanoparticles demonstrated concentration-dependent antifungal activity against Candida albicans, Aspergillus fumigatus, and Sporothrix schenckii, suggesting their potential as effective antifungal agents. Our findings underscore the significance of exploring underutilized plant resources for developing innovative solutions to pressing global health challenges. By integrating phytochemistry, nanotechnology, and microbiology, this research offers a promising approach to combating antimicrobial resistance. The study's outcomes lay the groundwork for future investigations into the underlying mechanisms of antimicrobial action, optimization of nanoparticle properties, and preclinical evaluation of their therapeutic efficacy.

The rising incidence of feline and cat-transmitted sporotrichosis in Latin America.

Sporotrichosis is a subcutaneous mycosis caused by different species of thermodimorphic fungi belonging to the genus Sporothrix. These fungi may affect a wide range of warm-blooded animals, including humans, dogs and, mainly, cats. In this article, we conducted a narrative literature review about the status of feline and cat-transmitted sporotrichosis in Latin American countries, with emphasis on Brazil. From a global perspective, Latin America is one of the main foci of human and feline sporotrichosis. In humans, the disease has been reported in several countries, with endemic transmission occurring in Brazil, Colombia, Costa Rica, Guatemala, Mexico and Uruguay. Sporothrix brasiliensis is the most common species identified in human cases in Brazil, whereas Sporothrix schenckii predominates in other countries. Domestic cats are the main source of infection in the zoonotic transmission cycle of sporotrichosis in Latin America. Cases of feline sporotrichosis have been reported in several countries, including Argentina, Brazil, Chile, Colombia, Mexico, Panama, Paraguay and Peru.

Microsporum canis and Sporothrix schenckii: Fungi Causing Skin Infections in Cats

Companion animals such as cats help to reduce stress among people as they delight their owners in their ways. Good management and hygiene practices of pets help in keeping them in a healthy condition. Nevertheless, since fungal infection develops rapidly, there is a high tendency for them to get infected. The paucity of data regarding skin mycoses among cats in Malaysia leads to this study. Private veterinary clinics from the Central Region of Peninsular Malaysia were approached for participation in this study. Sampling was conducted for one year, collecting hair plucked, skin scrapings, and swabs from lesions of the cats with skin problems and inoculating onto Sabouraud Dextrose Agar media. Diagnosing the fungal colony was conducted through a direct examination method using lactophenol cotton blue stain and molecular identification of the isolates using polymerase chain reaction targeting the fungi species’ internal transcribed spacer region and β-tubulin gene. Of the 127 cats, 93 were positively infected, mainly with Microsporum canis (n = 38) and Sporothrix schenckii (n = 26). Saprophytic fungi detected on cats were Alternaria sp., Aspergillus sp., Candida sp., Chaetomium sp., Chrysosporium sp., Curvularia sp., Fusarium sp., Geotrichum sp., Penicillium sp., Talaromyces sp., Trichoderma sp., Trichosporon sp., and Xylaria sp. This finding represents the number of cats infected with fungal dermatitis in Selangor, Negeri Sembilan, the Federal Territory of Kuala Lumpur, and Putrajaya.

Silencing of Sporothrix schenckii GP70 Reveals Its Contribution to Fungal Adhesion, Virulence, and the Host-Fungus Interaction.

Sporothrix schenckii is one of the etiological agents of sporotrichosis, a cutaneous and subcutaneous infection distributed worldwide. Like other medically relevant fungi, its cell wall is a molecular scaffold to display virulence factors, such as protective pigments, hydrolytic enzymes, and adhesins. Cell wall proteins with adhesive properties have been previously reported, but only a handful of them have been identified and characterized. One of them is Gp70, an abundant cell wall protein mainly found on the surface of yeast-like cells. Since the protein also has a role in the activity of 3-carboxy-cis,cis-muconate cyclase and its abundance is low in highly virulent strains, its role in the Sporothrix-host interaction remains unclear. Here, a set of GP70-silenced strains was generated, and the molecular and phenotypical characterization was performed. The results showed that mutants with high silencing levels showed a significant reduction in the adhesion to laminin and fibrinogen, enzyme activity, and defects in the cell wall composition, which included reduced mannose, rhamnose, and protein content, accompanied by an increment in β-1,3-glucans levels. The cell wall N-linked glycan content was significantly reduced. These strains induced poor TNFα and IL-6 levels when interacting with human peripheral blood mononuclear cells in a dectin-1-, TLR2-, and TLR4-dependent stimulation. The IL-1β and IL-10 levels were significantly higher and were stimulated via dectin-1. Phagocytosis and stimulation of neutrophil extracellular traps by human granulocytes were increased in highly GP70-silenced strains. Furthermore, these mutants showed virulence attenuation in the invertebrate model Galleria mellonella. Our results demonstrate that Gp70 is a versatile protein with adhesin properties, is responsible for the activity of 3-carboxy-cis,cis-muconate cyclase, and is relevant for the S. schenckii-host interaction.

An ELISA-based method for Galleria mellonella apolipophorin-III quantification.

Mammalian models, such as murine, are used widely in pathophysiological studies because they have a high degree of similarity in body temperature, metabolism, and immune response with humans. However, non-vertebrate animal models have emerged as alternative models to study the host-pathogen interaction with minimal ethical concerns. Galleria mellonella is an alternative model that has proved useful in studying the interaction of the host with either bacteria or fungi, performing drug testing, and assessing the immunological response to different microorganisms. The G. mellonella immune response includes cellular and humoral components with structural and functional similarities to the immune effectors found in higher vertebrates, such as humans. An important humoral effector stimulated during infections is apolipophorin III (apoLp-III), an opsonin characterized by its lipid and carbohydrate-binding properties that participate in lipid transport, as well as immunomodulatory activity. Despite some parameters, such as the measurement of phenoloxidase activity, melanin production, hemocytes counting, and expression of antimicrobial peptides genes are already used to assess the G. mellonella immune response to pathogens with different virulence degrees, the apoLp-III quantification remains to be a parameter to assess the immune response in this invertebrate. Here, we propose an immunological tool based on an enzyme-linked immunosorbent assay that allows apoLp-III quantification in the hemolymph of larvae challenged with pathogenic agents. We tested the system with hemolymph coming from larvae infected with Escherichia coli, Candida albicans, Sporothrix schenckii, Sporothrix globosa, and Sporothrix brasiliensis. The results revealed significantly higher concentrations of apoLp-III when each microbial species was inoculated, in comparison with untouched larvae, or inoculated with phosphate-buffered saline. We also demonstrated that the apoLp-III levels correlated with the strains' virulence, which was already reported. To our knowledge, this is one of the first attempts to quantify apoLp-III, using a quick and easy-to-use serological technique.

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 > 20µM) 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.

Emergence of zoonotic sporotrichosis in Brazil: a genomic epidemiology study

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. 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. 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 Sbrasiliensis isolates, larger genetic diversity was observed among S schenckii isolates from animal and human cases within a clade. 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. 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.

Sporothrix schenckii complex in felines: Analysis of clinical, mycological, environmental and epidemiological factors

Sporotrichosis is an infectious and chronic fungal disease caused by fungi belonging to the Sporothrix schenckii complex that affects humans and animals through traumatic implantation of the fungus in the skin. They are dimorphic, saprophytic and geophilic fungi that are widely distributed in nature, especially in soils rich in organic matter. The aim of this study was to understand the clinical, mycological, environmental and epidemiological aspects of the Sporothrix schenckii complex in felines. In order to meet the objectives of this research, a qualitative, descriptive and exploratory data survey was carried out through a bibliographic review based on works published in the last 23 years. Sporothrix spp. is considered to be a complex of at least six cryptic species, in other words, they have similar morphological characteristics but different genotypes. In cats, the incubation period is variable; it usually lasts 14 days. On penetrating the tissue, the micellar form transforms into yeast, which generates an inflammatory response and proliferation of the microorganism at the site, causing papular and nodular lesions which, in some cases, heal spontaneously. Therefore, it is clear that sporotrichosis is caused by dimorphic fungi of the Sporothrix schenkii complex. It is a zoonotic disease of great importance in the context of public health, since it is still a neglected disease and requires robust measures to control. As well as being the most seriously affected, felines are the main transmitters to humans and animals, making them a key point in controlling outbreaks of the disease.

Invasive Fungal Infections and Oomycoses in Cats: 1. Diagnostic approach.

In contrast to superficial fungal infections, such as dermatophytosis, invasive fungal infections (IFIs) are characterised by penetration of tissues by fungal elements. Disease can spread locally within a region or can disseminate haematogenously or via the lymphatics. The environment is the most common reservoir of infection. Since fungal spores are airborne, indoor cats are also susceptible to IFIs. Some environmental fungi are ubiquitous and present globally, while others are endemic or hyperendemic within specific geographic regions. Zoonotic pathogens include Microsporum canis, Sporothrix schenckii and Sporothrix brasiliensis. In the first of a two-part article series, the approach to the investigation of feline IFIs and oomycoses is reviewed. As well as tips for diagnosis, and information on the ecological niche and distribution of fungal pathogens, the review covers clinical presentation of the most common IFIs, including cryptococcosis, histoplasmosis, blastomycosis, coccidioidomycosis, sporotrichosis, phaeohyphomycosis, aspergillosis and dermatophytic pseudomycetoma, as well as the oomycoses pythiosis, lagenidiosis and paralagenidiosis. In Part 2, the spectrum of activity, mechanisms of action, pharmacokinetic and pharmacodynamic properties and adverse effects of antifungal drugs are reviewed, and the treatment and prognosis for specific IFIs and oomycoses are discussed. The review draws on published evidence and the authors' combined expertise in feline medicine, mycology, dermatology, clinical pathology and anatomical pathology.

The Mating Type (MAT) and Virulence of Sporothrix schenckii sensu stricto Isolates Maintained in Culture Collection.

In an attempt to determine the mating type of different Sporothrix schenckii sensu stricto isolates that remained viable after a long period of preservation in a culture collection and to correlate them with the degree of virulence/pathogenicity, a PCR technique using primers designed for the sequences of MAT1-1-1 and MAT1-2-1 genes and a murine experimental model were used. The results showed that there was no correlation between the mating type and virulence among the isolates. Furthermore, different degrees of virulence/pathogenicity, ranging from high to low, were found among them based on different virulence parameters. It was assumed that the long period of preservation favored the changes, yielding the isolation of variants. Thus, we believe that new technologies for studies on factors can improve our knowledge of the pathogenesis of sporotrichosis.

Phenotypic and genotypic characterization of Colombian clinical isolates of Sporothrix spp.

For over a century, Sporothrix schenckii was considered the sole species responsible for sporotrichosis. In 2007, scientific community confirmed the disease could be caused by various Sporothrix species. These species differed in their virulence factors and their antifungal sensitivity. This study aims to characterize 42 Colombian clinical isolates of Sporothrix spp. phenotypically and genotypically. Forty-two clinical isolates were characterized using phenotypic methods. It involved various culture media to determine their growth range at different temperatures and to assess the type and distribution of pigment and colony texture. Microscopic morphology was evaluated through microcultures, as well as the conidia diameter, type of sporulation, and morphology. Additionally, the assimilation of carbohydrates was selected as a physiological trait for species identification. Genotyping of 40 isolates was performed through partial amplification of the calmodulin gene, followed by sequence analysis. Molecular studies enabled the identification of 32 isolates of S. schenckii and 8 isolates of S. globosa. The combination of phenotypic and genotypic methods eased these species characterizations and the recognition keys development based on parameters such as growth diameter at 25 and 30 ºC, colony texture (membranous or velvety) on potato dextrose agar, and microscopic morphology with predominance of pigmented triangular, elongated oval globose, or subglobose conidia. Confirmation of the phenotypic characteristics and molecular analysis is crucial for identifying Sporothrix species and determining adequate treatment. This study represents the first phenotypical and genotypical characterization of clinical isolates of Sporothrix spp. reported in Colombia.

Sporotrichosis: A Comprehensive Review on Epidemiology, Clinical and Treatment of an Emerging Mycosis

Sporotrichosis is an emerging subcutaneous mycosis caused by the fungus Sporothrix schenckii. In this article, a comprehensive review of the epidemiology, clinical and treatment of this disease is presented. Relevant aspects of its geographical distribution, risk factors, zoonotic transmission and epidemic outbreaks are discussed. In addition, the clinical variability of sporotrichosis is analyzed in detail, describing its various forms of presentation, including cutaneous, lymphangitic and systemic. Diagnostic challenges associated with its similarity to other mycoses and skin diseases are highlighted, and guidelines for its microbiological diagnosis are provided. Therapeutic options are also discussed, with emphasis on the use of systemic antifungals and the consideration of surgical treatment in selected cases. Finally, the importance of comprehensive knowledge of sporotrichosis to improve early detection, effective clinical management and prevention of complications in patients affected by this fungal infection is highlighted.

Development of loop-mediated isothermal amplification for rapid detection of sporotrichosis caused by Sporothrix schenckii.

Sporothrix schenckii is the causative agent of sporotrichosis, which most commonly causes lymphocutaneous infections in immunocompromised hosts. This pathogen infects dogs, cats, cattle, and buffaloes and can potentially infect humans. Diagnosis by fungal culture is lengthy, and although there are several clinical diagnoses and molecular methods, these are complicated and time-consuming for veterinarians. This study aimed to develop a visual diagnostic assay that is less time-consuming and can be used by veterinarians to screen for sporotrichosis. To develop a loop-mediated isothermal amplification (LAMP) assay for sporotrichosis, primers specific for fragments of the 18S rRNA gene of S. schenckii were designed. Then, the time and temperature were optimized to successfully achieve LAMP. Ten-fold serial dilutions of DNA were used to determine the detection limit using both LAMP and nested polymerase chain reaction (nPCR) assays. The optimal LAMP conditions were incubation at 73°C for 30 min. Agarose gel electrophoresis revealed a ladder-like pattern of the LAMP product, and a sky-blue color indicated a positive result. A comparison of the LAMP assay with nPCR revealed that it was 10 times more sensitive than nPCR, with a detection limit of 10 pg. The use of a heat box compared with a thermocycler gave the same results. Loop-mediated isothermal amplification gives good results and may represent a future alternative diagnostic tool for screening fungal pathogens before the results of conventional fungal cultures are received. However, this method should be further studied to clarify its use with clinical samples.

Inclusion complex of O-allyl-lawsone with 2-hydroxypropyl-β-cyclodextrin: Preparation, physical characterization, antiparasitic and antifungal activity.

The subclass naphthoquinone represents a substance group containing several compounds with important activities against various pathogenic microorganisms. Accordingly, we evaluated O-allyl-lawsone (OAL) antiparasitic and antifungal activity free and encapsulated in 2-hydroxypropyl-β-cyclodextrin (OAL MKN) against Trypanosoma cruzi and Sporothrix spp. OAL and OAL MKN were synthesized and characterized by physicochemical methods. The IC50 values of OAL against T. cruzi were 2.4 µM and 96.8 µM, considering epimastigotes and trypomastigotes, respectively. At the same time, OAL MKN exhibited a lower IC50 value (0.5 µM) for both trypanosome forms and low toxicity for mammalian cells. Additionally, the encapsulation showed a selectivity index approximately 240 times higher than that of benznidazole. Regarding antifungal activity, OAL and OAL MKN inhibited Sporothrix brasiliensis growth at 16 µM, while Sporothrix schenckii was inhibited at 32 µM. OAL MKN also exhibited higher selectivity toward fungus than mammalian cells. In conclusion, we described the encapsulation of O-allyl-lawsone in 2-hydroxypropyl-β-cyclodextrin, increasing the antiparasitic activity compared with the free form and reducing the cytotoxicity and increasing the selectivity towardSporothrix yeasts and the T. cruzi trypomastigote form. This study highlights the potential development of this inclusion complex as an antiparasitic and antifungal agent to treat neglected diseases.

Phenotypic and Genotypic Characterization and Antifungal Susceptibility of Sporothrix schenckii sensu stricto Isolated from a Feline Sporotrichosis Outbreak in Bangkok, Thailand.

Sporotrichosis, an invasive fungal infection caused by Sporothrix schenckii, has emerged in Southeast Asia, affecting cats and posing a potential zoonotic risk to humans. We evaluated 38 feline sporotrichosis cases in and around Bangkok, Thailand, from 2017 to 2021. The isolates were phenotypically and genotypically characterized. The cats infected with sporotrichosis were mainly young adults, males, and domestic short hairs with uncontrolled outdoor access, and they lived in Bangkok. All isolates showed low thermotolerance and converted to the yeast phase at 35 °C. Based on the internal transcribed spacer region of rDNA sequences, our strains belonged to S. schenckii sensu stricto and clustered with clinical clade D. Based on the concatenated tree of calmodulin and beta-tubulin genes, five groups of S. schenckii were generated, and the monophyletic clade, Group II, of Thai strains was recognized. In vitro antifungal susceptibility testing demonstrated that the MIC50 of our isolates to amphotericin B, itraconazole, and posaconazole were within the limit of the species-specific epidemiological cutoff values, suggesting that the organisms were the wild type. Addressing the outbreak of feline sporotrichosis in Thailand by providing guidelines for diagnosis and effective treatment may help control the spread of disease and reduce the risk of cat-transmitted sporotrichosis to humans.

Seasonality of sporotrichosis in Brazil: A modelled analysis of the epidemic in São Paulo, 2011-2020.

Sporotrichosis is an endemic subcutaneous mycosis classically caused by the Sporothrix schenckii species complex. Recently, sporotrichosis has emerged in Brazil as a cat-transmitted epidemic caused by a new species, Sporothrix brasiliensis. To survey the clinical-epidemiological profile of all sporotrichosis cases diagnosed between 2011 and 2020 at a reference hospital in São Paulo metropolitan area and evaluate the annual distribution of cases in relation to seasonality. Patients' demographic and clinical-epidemiological data were surveyed. A generalized linear model was fitted to relate the quarterly number of sporotrichosis cases detected between 2015 and 2019 with precipitation and temperature series. Prediction of the number of cases from 2011 to 2014 was attempted based on the fitted model without the trend component that appears from 2015. Among 271 suspected cases admitted during 2011-2020, 254 were confirmed by fungal isolation and/or clinical-epidemiological criteria. We observed that 2015 onwards the number of cases regularly increased during Autumn and Winter, the driest and coldest stations of the year. We verified that temperature series affected the number of cases (p = .005) because an increase of 1°C in the temperature series was associated with a 14.24% decrease in the average cases number, with the average number of cases increasing by 10.96% (p < .0001) every quarter, corresponding to an annual increase of 52%. Between 2011 and 2014, the predicted number of sporotrichosis cases averaged 10-12 per year, with 33%-38% occurring in the winter. We hypothesize that sporotrichosis seasonality is associated with the felines' oestrus cycle, which may provide alternative, cat-directed approaches to the sporotrichosis epidemic control.

Current Progress in Sporothrix brasiliensis Basic Aspects

Sporotrichosis is known as a subacute or chronic infection, which is caused by thermodimorphic fungi of the genus Sporothrix. It is a cosmopolitan infection, which is more prevalent in tropical and subtropical regions and can affect both humans and other mammals. The main etiological agents causing this disease are Sporothrix schenckii, Sporothrix brasiliensis, and Sporothrix globosa, which have been recognized as members of the Sporothrix pathogenic clade. Within this clade, S. brasiliensis is considered the most virulent species and represents an important pathogen due to its distribution and prevalence in different regions of South America, such as Brazil, Argentina, Chile, and Paraguay, and Central American countries, such as Panama. In Brazil, S. brasiliensis has been of great concern due to the number of zoonotic cases that have been reported over the years. In this paper, a detailed review of the current literature on this pathogen and its different aspects will be carried out, including its genome, pathogen-host interaction, resistance mechanisms to antifungal drugs, and the caused zoonosis. Furthermore, we provide the prediction of some putative virulence factors encoded by the genome of this fungal species.