Geographic Expansion of Sporotrichosis, Brazil

Brazil has experienced geographic expansion of zoonotic sporotrichosis. Social problems in the country contribute substantially to the expansion. A comprehensive sporotrichosis control program is beyond the sphere of public health. A One Health approach is needed to control the disease in animals and humans.

Deep mycoses and pseudomycoses of the foot: a single-center retrospective study of 160 cases, in a tertiary-care center in Mexico

BACKGROUND

Deep mycoses and pseudomycoses (DMP) may cause significant disability and even death; however, the reports regarding these diseases, mainly affecting the foot, are scarce.

OBJECTIVE

To describe the epidemiological, clinical, and diagnostic characteristics of DMP of the foot in 160 patients.

METHODS

A retrospective and observational study of DMP affecting the foot was carried out in a tertiary-care center in Mexico for 20 years (from January 2000 to December 2019). Cases with confirmatory microbiological studies were included; the identification of the isolated fungi was based on the forms of reproduction. For actinomycetes, morphological analysis in an automated system ATB Vitek® 1574 (Biomèrieux) was used. The fungi were identified by PCR, using several primers from the ITS regions and for actinomycetes in the 16S rRNA region. Data from histopathological studies were also collected.

RESULTS

One hundred and sixty proven cases of DMP of the foot were included. The cases were categorized into nine types of infections including mycetoma (actinomycetoma and eumycetoma) in 102 cases (63.7%); sporotrichosis in 21 cases (13.1%); chromoblastomycosis, 18 cases (11.2%); phaeohyphomycosis, 3 cases (1.8%); histoplasmosis, 12 cases (7.5%); coccidioidomycosis 2 cases (1.2%) and botryomycosis and nocardiosis with one case respectively (0.6%). Most cases developed after traumatic implantation (147 cases, 91.8%). One hundred fifteen cases (71.8%) were men. The evolution was chronic in 125 cases (78.2%); bone involvement was observed in 64 cases (40%). Parasitic forms were observed In 139 cases (86.8%). The isolation and identification of the etiological agents were confirmed in all cases.

CONCLUSION

The main DMP affecting the foot were infections due to traumatic implantation; most were endemic mycoses. The clinical characteristics and the evolution of the diseases are easily misdiagnosed, and thus, diagnostic tests are usually required.

Guideline for the management of feline sporotrichosis caused by Sporothrix brasiliensis and literature revision

We herein present a Brazilian guideline for the management of feline sporotrichosis, a mycosis caused by Sporothrix brasiliensis. This guideline is an effort of a national technical group organized by the Working Group on Sporothrix and Sporotrichosis of the International Society for Human and Animal Mycology (ISHAM). This publication intends to provide information on clinical-epidemiological aspects of this zoonosis, as well as a literature revision. Moreover, it gives some practical information on diagnosis and treatment of feline sporotrichosis. It also contains information that can be helpful for the prevention and control of S. brasiliensis transmission.

Molecular identification of Sporothrix species in a hyperendemic area in Peru

To date, there have been no molecular typing studies to identify the Sporothrix species circulating in Abancay, a hyperendemic area of sporotrichosis in Peru. To identify six clinical isolates of the Sporothrix schenckii complex from Abancay, Peru, we used PCR-sequencing of the calmodulin gene, and a phylogenetic analysis was conducted with these and additional sequences from GenBank. All clinical isolates were identified as S. schenckii (sensu stricto). Phylogenetic analysis revealed that the six clinical isolates from Abancay, Peru clustered in a clade along with sequences from Costa Rica, Iran, South Africa, and four other sequences from Peru. These findings reveal the presence of S. schenckii (sensu stricto) in Abancay, Peru.

Sporotrichosis refractory to conventional treatment: therapeutic success with potassium iodide

Sporotrichosis is a subcutaneous mycosis caused by dimorphic fungi of the genus Sporothrix. The authors report a case of fixed cutaneous sporotrichosis with therapeutic failure after 18 months of itraconazole and terbinafine associated with cryosurgery. The patient was cured after the introduction of saturated potassium iodide solution. Sporothrix brasiliensis was the identified species, presenting a susceptibility profile to itraconazole and terbinafine. This fact suggests that therapeutic failure is probably related to the host-fungus interaction rather than drug resistance. It is possible that the immunomodulatory action of the saturated potassium iodide solution may have played an important role in curing this patient.

Exogenous Local Hyperthermia at 41℃ Is Effective to Eliminate Mouse Model of Sporotrichosis, Independent of Neutrophil Extracellular Traps Formation

Background

Local hyperthermia is recommended for the treatment of patients with fixed cutaneous sporotrichosis, though the effectiveness and mechanisms of action remain elusive. While neutrophils represent the main inflammatory cells associated with sporotrichosis lesions, the issue of whether hyperthermia is involved with interactions between neutrophils and Sporothrix globosa remains unclear.

Objective

To evaluate the effect of local hyperthermia on sporotrichosis and determine whether local hyperthermia involves effects of neutrophils against Sporothrix.

Methods

For the in vivo study, mice were infected with yeast cells of S. globosa followed by treatment with local hyperthermia. In vitro, an isolated Sporothrix strain was co-cultured with or without neutrophils and subjected under different temperatures. Immunofluorescence was used to assess the formation of neutrophil extracellular trap (NETs) were formed under these different culture conditions and the number of fungi colony forming units were compared.

Results

Hyperthermia was significantly more effective in clearing the lesions in the mouse model, as compared to sham treatment. Neutrophils failed to exert any fungicidal effects against S. globosa in response to hyperthermia. Moreover, NETs were formed after interaction with S. globosa, and the percentage of NETs formed was not significantly different at 41℃ or 37℃.

Conclusion

While hyperthermia could serve as an effective therapy for fixed cutaneous sporotrichosis, this ability does not involve the formation of NETs.

Molecular-based assessment of diversity and population structure of Sporothrix spp. clinical isolates from Espírito Santo-Brazil

BACKGROUND

Sporotrichosis is a subcutaneous mycosis caused by Sporothrix species that affects humans and animals. Little information on the genetic diversity and population structure of the pathogen is available for Brazil, which is needed to design effective strategies to tackle the advance of sporotrichosis in endemic areas.

OBJECTIVES

We assessed the genetic diversity and mating-type distribution of Sporothrix isolates recovered from human and feline cases of sporotrichosis in Espírito Santo-Brazil to better understand the population structure, epidemiology and diversification of this pathogen, as well as to explore the possible routes of transmission involved in the ongoing outbreaks.

METHODS

In all, 75 Sporothrix isolates were identified with phenotypic characteristics. Then, fungal DNA extraction was performed, and the species-specific PCR technique was applied, using markers directed to the calmodulin gene. The mating-type idiomorph of species was identified by PCR using primers targeting the MAT1-1 and MAT1-2 loci.

RESULTS

Among the 75 Sporothrix isolates, 76% were confirmed as S brasiliensis and 24% as S schenckii sensu stricto. S brasiliensis was more prevalent in the metropolitan area and S schenckii s. str. in the mountainous region of the state. In both species, the presence of the two sexual idiomorphs was detected, suggesting that they are heterothallic species.

CONCLUSIONS

Our data suggest that sporotrichosis takes on an epidemic-urban character involving S brasiliensis. This species in Espírito Santo is likely to originate from Rio de Janeiro, as most isolates harbour the same MAT 1-2 locus. We confirm that S brasiliensis has significantly broadened its area of occurrence, an essential feature of emerging pathogens.

Zoonotic sporotrichosis in renal transplant recipients from Rio de Janeiro, Brazil

Sporotrichosis is the main subcutaneous mycosis in the world. In the last two decades, zoonotic sporotrichosis transmitted by cats has become hyperendemic in Rio de Janeiro, Brazil. Renal transplant recipients are subject to invasive fungal infection because of the effects of immunosuppressive therapy, but sporotrichosis is rarely reported. The authors conducted a retrospective study describing epidemiological, clinical, and therapeutic data related to adult renal-transplant-recipient patients diagnosed with sporotrichosis. The molecular identification of fungal isolates was performed. Minimal inhibitory concentration (MIC) of amphotericin B (AMB), itraconazole (ITZ), posaconazole (POS), isavuconazole, and terbinafine (TRB) against the strains was determined using the protocol described by the Clinical and Laboratory Standards Institute (CLSI). Six cases were identified from a cohort with 2429 sporotrichosis patients. They were five men and one woman, with a mean age of 44.2 years (range: 34-54 years). Four of them had cutaneous limited forms, and two patients had disseminated forms. The mean time between transplant and the onset of sporotrichosis symptoms was 25.5 (range: 6-36) months. Sporothrix brasiliensis was identified as the causative agent. The isolates were classified as wild type for all antifungal drugs tested. Treatment schemes included AMB (deoxycholate and liposomal), ITZ, and TRB. Five patients evolved to cure, and one died as a result of disseminated disease. Renal transplant recipients may be a vulnerable group for sporotrichosis in endemic countries. The authors highlight the importance of sporotrichosis prevention, early diagnosis, and treatment to prevent disseminated disease and poor prognosis.

Influence of iron on growth and on susceptibility to itraconazole in Sporothrix spp

We evaluated the growth and the susceptibility to oxidative stress of Sporothrix spp., exposed to different iron concentrations in culture medium, and the susceptibility of Sporothrix spp. to itraconazole, alone and in combination with to the iron chelator deferasirox. The results showed that the growth of S. brasiliensis isolates was more affected by iron availability in comparison to S. schenckii, but both fungal species conidia became more prone to oxidative stress when iron was added to culture medium. Conversely, the combination of itraconazole and deferasirox only resulted in synergism against a minority of S. schenckii isolates.

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.

Ocular Sporotrichosis

Purpose

To present 10 cases of Parinaud oculoglandular syndrome caused by sporotrichosis.

Observations

We report 10 cases of Parinaud oculoglandular syndrome after contact with domestic cats diagnosed with sporotrichosis. They all showed ocular hyperemia associated with unilateral tarsal conjunctival granulomas. After histopathological study and culture of the scrapings and conjunctival secretions, six patients were positive for Sporothrix schenkii and four had a presumed diagnosis of Parinaud oculoglandular syndrome due to sporotrichosis. Treatment with 200 mg/day of oral itraconazole was started, and all patients had a favorable therapeutic response.

Conclusion and importance

These case reports are essential for characterizing a rare etiology of Parinaud oculoglandular syndrome.

Ocular and cutaneous sporotrichosis

Purpose

Sporotrichosis is the most common subcutaneous mycosis in the world and it is presented usually in the lymphocutaneous form. When the eye is involved, it typically includes the conjunctival and periorbital tissues or even the intraocular tissues.

Observations

We present a case of a 13-year-old girl complaining about nodules in the left malar region and in both the outer nasal corner and the lower eyelid of the left eye, which had appeared one month earlier.

Conclusions

and significance: Sporotrichosis is a hyperendemic disease in Brazil and its diagnosis is based on clinical aspects, epidemiological history, and culture. Ophthalmologists and other professionals should be aware of this condition.

Immunoreactive cutaneous sporotrichosis

Sporothrix spp. infection can occur through the inoculation of the organism in the skin through direct contact with the soil (sapronotic infection), through contact with animals, such as infected cats and dogs (zoonotic infection), or less frequently via inhalation. With a subacute or chronic evolution, approximately 80% of patients affected by the disease present with the lymphocutaneous form; episodes associated with a hypersensitivity reaction are rare. The authors report the case of a 12-year-old child with immunoreactive sporotrichosis manifested clinically as erythema nodosum lesions in the lower limbs, associated with an ulcerated lesion in the left arm.

Transient Foxp3(+) regulatory T-cell depletion enhances protective Th1/Th17 immune response in murine sporotrichosis caused by Sporothrix schenckii

The role of regulatory T cells (Tregs) on protective immunity in fungal infections, is controversial. Sporotrichosis is an emerging and worldwide-distributed subcutaneous mycosis caused by various related thermodimorphic fungi of the genus Sporothrix. Previously, we showed an elevated percent of Tregs around 21 days post-infection (dpi) in C57BL/6 mice infected with either Sporothrix schenckii or Sporothrix brasiliensis, but the effect of these cells in the ongoing infection was not evaluated. Here, we aim to characterize the role of Foxp3+ Tregs in a subcutaneous S. schenckii infection model. The flow cytometric analyses showed that S. schenckii infection elicited an expansion of a splenic CD4+Foxp3+ population, including a subset of Helios^low+ after ex vivo stimulation with S. schenckii-heat killed yeast. Depletion of Tregs in DEREG mice revealed a reduction of fungal burden in the skin and systemically in liver and kidneys, associated with enhanced Th1 and Th17 responses. Altogether, our results reveal for the first time that Tregs depletion in ongoing S. schenckii infection improves the protective antifungal immunity and these data suggest that Tregs modulation could be explored as a potential therapeutic strategy in sporotrichosis.

Fungal Infections of the Hand

Clinically significant fungal infections of the upper extremity are uncommon but increasing They are classified based on anatomic location and epidemiology. The anatomic categories that affect the hand include cutaneous, subcutaneous, and deep. Cutaneous infections are caused by organisms that metabolize keratin and can cause serious morbidity but are rarely fatal. Subcutaneous infections are similar to the cutaneous infections and are produced by low virulence organisms. Cutaneous and subcutaneous infections are most common and can be treated by primary care physicians and dermatologists. Deep infections are less common but can be fatal. Epidemiologic classifications include endemic and opportunistic infections.

Phenotypic and molecular characterisation of Sporothrix globosa of diverse origin from India

Sporotrichosis is one of the neglected tropical diseases causing subcutaneous chronic granulomatous lesion by thermally dimorphic fungi belonging to Sporothrix species. Sporothrix brasiliensis, Sporothrix mexicana and Sporothrix globosa are the common pathogenic species. In Asian countries, S. globosa constitutes nearly 99.3% of all Sporothrix species. We studied 63 cases of sporotrichosis of geographically diverse origin from India and Sporothrix isolates were characterised for its growth in different media, temperatures, ability to assimilate sugars and antifungal susceptibility profile. Molecular characterization was performed by sequencing of the calmodulin (CAL), beta tubulin (BT) and translational elongation factor 1-alpha (TEF-1α) and typing by fluorescent amplified fragment length polymorphism (FAFLP). In patients who presented with fixed (49.2%), lymphocutaneous lesions (23.8%), in 26.9% the details were not known, none had systemic dissemination. All the isolates tested were Sporothrix globosa and that could grow up to 35 °C and unable to grow at and beyond 37 °C. The assimilation of sucrose, ribitol and raffinose helps in identifying S. globosa. Sequences of CAL or BT or TEF-1α can differentiate S. globosa from other species in the complex. FAFLP results exhibited low genetic diversity. No correlation was noted between genotypes and clinical presentation, or geographic distribution. Itraconazole, terbinafine and posaconazole showed good in vitro antifungal activity against S. globosa whereas fluconazole and micafungin had no activity. S. globosa of Indian origin is relatively less pathogenic than other pathogenic Sporothrix species as it does not cause systemic dissemination and in the diagnostic laboratory, incubation of the cultures below 37 °C is essential for effective isolation.

Sporotrichosis in the Highlands of Madagascar, 2013-20171

Sporotrichosis is a saprozoonotic fungal infection found mostly in tropical and subtropical areas. Few case reports in Madagascar have been published. To document sporotrichosis epidemiology in Madagascar, we conducted a cross-sectional study. During March 2013–June 2017, we recruited from select hospitals in Madagascar patients with chronic cutaneous lesions suggestive of dermatomycosis. Sporotrichosis was diagnosed for 63 (42.5%) of 148 patients. All but 1 patient came from the central highlands, where the prevalence was 0.21 cases/100,000 inhabitants. Frequency was high (64.7%) among patients <18 years of age. Sporotrichosis was diagnosed for 73.8% of patients with arm lesions, 32.3% with leg lesions, and 15.4% with lesions at other sites. Molecular identification identified 53 Sporothrix schenckii isolates. Among the 32 patients who were followed up, response to itraconazole was complete or major for 15 and minor for 17. Overall, endemicity of sporotrichosis in Madagascar was high, concentrated in the highlands.

Serological tests using Sporothrix species antigens for the accurate diagnosis of sporotrichosis: a meta-analysis

Some species of the fungus Sporothrix cause a chronic granulomatous infection in humans and animals called sporotrichosis. In the last decades, some research into serological tests has been carried out by different groups for the rapid detection of this infection. We performed a systematic review of the literature with meta-analysis to evaluate studies using Sporothrix spp. antigens and to evaluate their accuracy for sporotrichosis diagnostic. We searched Scopus, MEDLINE, Web of Science, GALE, Technology Research Database, DOA, Elsevier, SciELO, and Google Scholar Databases. The united results of sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio with their corresponding 95% confidence intervals (CI) were assessed. A total of 15 assays from 8 studies using 7 different serological methods and 8 different antigens were analyzed. The studies were performed in the USA, Brazil, and Venezuela from 1973 until 2015 and presented good quality. A high heterogeneity for sensitivity [I² = 90.7%; 87% CI = (84-89), P < 0.001] and specificity [I² = 89.2%; 93% CI = (92-95), P < 0.001] was observed. The performance of diagnostic tests was 0.93. Enzyme-linked immunosorbent assay was the main tool used, and the ConA-binding fraction antigen of the strain 1099-18 appears as a promising diagnostic biomarker candidate.

Canine sporotrichosis: polyphasic taxonomy and antifungal susceptibility profiles of Sporothrix species in an endemic area in Brazil

Sporotrichosis, a mycosis caused by pathogenic species of the genus Sporothrix, affects diverse species of mammals. Until 2007, Sporothrix schenckii was considered the unique etiologic agent of sporotrichosis. Canine sporotrichosis is a poorly reported disease, and the majority of cases are from Rio de Janeiro, Brazil. There are scarce studies on the characterization of canine isolates of Sporothrix schenckii complex, as well as few antifungal susceptibility data available. The aim of this study was to characterize the clinical isolates of Sporothrix from dogs from Brazil at species level and evaluate their antifungal susceptibility profile. Polyphasic taxonomy was used to characterization at species level (morphological, phenotypical characteristics, and molecular identification). Antifungal susceptibility profiles (amphotericin B, itraconazole, ketoconazole, posaconazole, and terbinafine) were determined using the Clinical and Laboratory Standards Institute broth microdilution method (M38-A2). According to phenotypic identification and molecular analysis, 46 isolates included in this study were identified as S. brasiliensis and one as S. schenckii. Amphotericin B presented the highest minimum inhibitory concentration values, and the other drugs showed effective in vitro antifungal activity. This is the first report of S. schenckii in dogs from Brazil, since S. brasiliensis is the only species that has been described in canine isolates from Rio de Janeiro to date. Nevertheless, no differences were observed in the antifungal susceptibility profiles between the S. brasiliensis and S. schenckii isolates, and it is important to continuously study new canine clinical isolates from Rio de Janeiro, Brazil.

Bibliometric assessment and key messages of sporotrichosis research (1945-2018)

Background: Sporotrichosis has recently emerged as an important mycosis worldwide, with diverse transmission and epidemiologic profiles. For instance, in Brazil most cases are related to zoonotic transmission from naturally infected cats, and the majority of cases in China are due to external injury with environmental materials. Publications on sporotrichosis and on its etiologic agent may guide the direction of the research in this field. It can also define priorities for future studies.

Methods: In this study, we evaluated the trends of global research in Sporothrix and sporotrichosis, based on publications records retrieved from Scopus and Web of Science databases for the period of 1945 to 2018. The overall productivity in the field, its geographical and temporal distribution, research themes, co-authorship networks, funding sources, and if audience and research findings are addressed in the abstracts.

Results: A total of 4,007 unique publications involving 99 countries were retrieved, most of them published after 2000. Authors based on institutions from the United States of America and Brazil accounted for 57.4% of the publications. Brazil was the leading country in terms of research collaboration and networking, with co-authorship with 45 countries. The thematic mapping revealed a temporal shift from clinical to applied research. Despite the large number of countries publishing in this field, most of funded studies came from Brazil, Mexico, China, South Africa, or the United States of America. The analysis of content identified few specific public health recommendations for prevention, case-management, or research. Moreover, most papers do not have a clearly defined intended audience.

Conclusion: As the research in this field is emerging in several countries, with the generation of a large amount of data, it is necessary that scientists strengthen efforts to translate the research results into practice to curb this neglected infection.

Sporotrichosis in renal transplant patients: two case reports and a review of the literature

INTRODUCTION

Sporotrichosis is a rare fungal infection in transplant patients; among these patients, it occurs mostly in renal transplant patients. Sporothrix schenkii is the primary pathogen responsible. A high index of suspicion is required to make the diagnosis keeping important differential diagnoses in mind. History of trauma through recreational or occupational exposure to the fungus may assist in making the diagnosis. Treatment is difficult, with long-term use of potentially nephrotoxic and cytochrome P450 inhibitor antifungal agents leading to potential calcineurin inhibitors toxicity. We describe two renal transplant patients presenting with distinct sporotrichosis infection: "Case 2" being only the second reported case ever of meningeal sporotrichosis. We subsequently review the general aspects of sporotrichosis, specifically in renal transplant patients as described in the medical literature.

CASE PRESENTATION

Case 1, a 43-year-old mixed ancestry male patient presented with a non-healing ulcer on the left arm for 1 year, he was diagnosed with cutaneous sporotrichosis and was successfully treated with itraconazole monotherapy. Case 2, a 56-year-old mixed ancestry male patient presented with a slow decline in functions, confusion, inappropriate behavior, rigors and significant loss of weight and appetite over the past 4 months, he was diagnosed with meningeal sporotrichosis and was successfully treated with a combination of deoxycholate amphotericin B and itraconazole.

CONCLUSION

Physicians taking care of renal transplant patients should have a high index of suspicion for sporotrichosis infection particularly when conventional therapy for common conditions fails. Susceptibility testing is recommended to identify the most effective antifungal agent and its dose. The slow nature of growth of Sporothrix schenkii necessitates patients to be on amphotericin B until the time results are available. Finally, there is a need to be aware of potential drug-drug interactions of the azoles with calcineurin inhibitors and the required dose adjustments to prevent therapy related adverse events.

Infection caused by Sporothrix schenckii: an autochthonous case in Bari, Southern Italy

An autochthonous case of lymphocutaneous sporotrichosis caused by Sporothrix schenckii is reported. The patient developed skin lesions localized along the lymphatics that appeared after he suffered an injury while collecting wicker canes in marshy water. The fungus was identified as Sporothrix schenckii by MALDI-TOF and sequencing. Phylogenetic analysis was also performed. Low MIC values were detected for all tested echinocandins and azoles except for fluconazole. The patient was treated with itraconazole without significant improvement. A regression of lesions was observed after 3 months of therapy with voriconazole. Few cases of sporotrichosis have been reported in Europe. However, several cases of sporotrichosis have been described in Italy. The incidence of sporotrichosis in Italy may be underestimated and microbiologists, and clinicians must be aware of this fungal infection.

Fixed cutaneous sporotrichosis in a patient with numerous fungal elements

Sporotrichosis generally shows no or a small number of fungal cells in tissue. Numerous fungal elements are usually associated with suppression of cellular immunity, either acquired or innate. The present case demonstrates that also topical immunosuppression can lead to increased fungal load at the affected site.

Antifungal resistance on Sporothrix species: an overview

INTRODUCTION

The treatment of human and animal sporotrichosis is often performed with antifungal agents; however, the emergence of antifungal-resistant strains of Sporothrix species has been reported. We aimed to discuss the ability of Sporothrix species in developing resistance to the conventional antifungals and mechanisms for this.

METHODOLOGY

Published data on databases (PubMed, Science Direct, Google Scholar) were investigated using a combination of keywords from 2008 to 2019 by the StArt tool.

RESULTS

The minimal inhibitory concentrations values based on the Clinical and Laboratory Standards Institute (CLSI) from eight references were classified according to the epidemiological cutoff values in wild-type or non-wild-type strains. In this way, non-wild-type S. schenckii and, mainly, S. brasiliensis isolates were recognized on itraconazole, amphotericin B, terbinafine, and voriconazole, which are strains that deserve more attention toward antifungal control, with a probable risk of mutation to antifungal resistance. Among the few reviewed studied on antifungal resistance, the melanin production capacity (DHN-melanin, L-DOPA melanin, and pyomelanin), the low genetic diversity due to the abnormal number of chromosomes, and the mutation in cytochrome P450 are some of the factors for developing resistance mechanism.

CONCLUSIONS

The emergence of Sporothrix species with in vitro antifungal resistance was evidenced and the possible mechanisms for resistance development may be due to the melanin production capacity, genetic diversity and mutations in cytochrome P450. Further studies should be carried out targeting gene expression for the development of antifungal resistance on Sporothrix species in order to prospect new therapeutic targets for human and veterinary use.

Geographical distribution and ecological niche modeling of the etiological agents of human sporotrichosis in Venezuela

The geographical distribution and ecological niche of the two circulating species of the Sporothrix genus in Venezuela was established. For this, 68 isolates of Sporothrix spp. from patients of different regions of the country were analyzed. A molecular taxonomy analysis was conducted using a fragment of the calmodulin gene (CAL), and ITS regions, confirming the presence of S. schenckii (62%) and S. globosa (38%). Computational models of ecological niche for each species were obtained by the maximum entropy method using the MaxEnt software, which predicted the best environmental conditions for the presence of the two species. These models predict that the main variables influencing the presence of S. schenckii were altitude and annual mean temperature, while for S. globosa, the more influent variable was the land use, with 82% of S. globosa located at urban areas vs 56% for S. schenckii. The results here presented could contribute to understand the specific environmental factors that might modulate the occurrence of Sporothrix spp. as well as its transmission. To our knowledge, our analyses show for the first time Sporothrix spp.-specific ecological niche data, a valuable tool to promote evidence-based public health policymaking within endemic areas of sporotrichosis.