Sporotrichosis Cluster in Domestic Cats and Veterinary Technician, Kansas, USA, 2022.

We describe a feline sporotrichosis cluster and zoonotic transmission between one of the affected cats and a technician at a veterinary clinic in Kansas, USA. Increased awareness of sporotrichosis and the potential for zoonotic transmission could help veterinary professionals manage feline cases and take precautions to prevent human acquisition.

Bimodal distribution of azole susceptibility in Sporothrix brasiliensis isolates in Brazil.

Sporothrix brasiliensis is an emerging zoonotic fungal pathogen that can be difficult to treat. Antifungal susceptibility testing was performed on the mold phase of a convenience sample of 61 Sporothrix spp. isolates from human and cat sporotrichosis cases in Brazil using the Clinical and Laboratory Standards Institute standard M38. A bimodal distribution of azole susceptibility was observed with 50% (28/56) of S. brasiliensis isolates showing elevated itraconazole minimum inhibitory concentrations ≥16 µg/mL. Phylogenetic analysis found the in vitro resistant isolates were not clonal and were distributed across three different S. brasiliensis clades. Single nucleotide polymorphism (SNP) analysis was performed to identify potential mechanisms of in vitro resistance. Two of the 28 resistant isolates (MIC ≥16 mg/L) had a polymorphism in the cytochrome P450 gene, cyp51, corresponding to the well-known G448S substitution inducing azole resistance in Aspergillus fumigatus. SNPs corresponding to other known mechanisms of azole resistance were not identified in the remaining 26 in vitro resistant isolates.

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.

Human interleukin-36γ plays a crucial role in cytokine induction during Sporothrix brasiliensis and S. schenckii infection in keratinocytes and PBMCs.

Cytokines of the interleukin (IL)-1 superfamily including the different IL-36 isoforms, have been reported as mediators of acute and chronic inflammation in human skin diseases, such as psoriasis. Here, we demonstrated for the first time that Sporothrix schenckii and S. brasiliensis, the fungi that cause subcutaneous infection sporotrichosis, can induce the expression of IL-36α, IL-36γ and IL-36Ra in human keratinocytes and primary peripheral blood mononuclear cells (PBMCs). Specifically, IL-36γ was differentially expressed by keratinocytes stimulated with Sporothrix yeasts when compared to the commensal microorganism Staphylococcus epidermidis. The exposure of keratinocytes to 24 h or 7-days culture supernatant of PBMCs stimulated with Sporothrix induced higher IL-36γ production compared to direct stimulation of keratinocytes with the live fungus. We identified that IL-36γ mRNA expression in keratinocytes is increased in the presence of IL-17, TNF, IL-1ß and IL-1α and these cytokines may act synergistically to maintain IL-36γ production. Lastly, using a cohort of 164 healthy individuals, we showed that individuals carrying variants of the IL36G gene (rs11690399 and rs11683399) exhibit increased IL-36γ production as well as increased innate cytokine production after Sporothrix exposure. Importantly, stimulation of PBMCs with recombinant IL-36γ increased the production of IL-1ß and IL-6, while IL-36Ra were able to decrease the concentration of these cytokines. Our findings contribute to the understanding of the pathogenesis of sporotrichosis and suggest that IL-36γ may be involved in maintaining the cytokine loop that leads to tissue destruction by exacerbating the immune response in sporotrichosis. Of high interest, we present the IL-36 signalling pathway as a potential new therapeutic target.

Development of a Rapid Diagnostic Method for Sporotrichosis.

INTRODUCTION: Sporotrichosis, a prevalent deep fungal infection in clinical settings, currently lacks rapid and accurate diagnostic methodologies. This study explores a novel rapid diagnosis method for sporotrichosis by combining FTA cards and nested PCR with fungal fluorescence staining. METHODS: The study involved skin lesion tissues from 26 patients diagnosed with sporotrichosis (Experimental Group). The Positive Control Group consisted of fungal suspensions from clinical strains of Sporothrix, while the Negative Control Group included fungal solutions of other fungi, namely Trichophyton rubrum, Trichophyton mentagrophyte, and Candida albicans. DNA was extracted from the slurry of skin lesions in the Experimental Group and from fungal suspensions in the Control Group using FTA cards, followed by nested PCR amplification. Subsequently, nested PCR amplification was performed. Histopathological examinations, including HE and fluorescence staining, were conducted on paraffin sections prepared from skin lesion tissues in the Experimental Group. RESULTS: Among the 26 clinical skin lesion tissues in the Experimental Group, 8 cases showed a specific positive band upon nested PCR amplification, resulting in a positive rate of 30.8%. In the Control Group, the fungal solution of the clinical strain of Sporothrix showed a specific positive band upon nested PCR amplification, while all other fungi Negative Control Group tested negative. Histopathological examination revealed granulomatous inflammatory changes in most samples after HE staining. Fluorescence staining detected spores in 17 cases, resulting in a detection rate of 65.4% (17/26). CONCLUSION: The combination of FTA cards with nested PCR method proved to be simple and rapid but demonstrated a relatively low positive rate. Fungal fluorescence staining significantly improved the sensitivity of detecting sporotrichosis in histopathological examinations, thereby improving the speed and efficiency of diagnosis.

Proceedings of the second international meeting on endemic mycoses of the Americas (IMEMA) and first international symposium on implantation mycoses (ISIM).

The second international meeting on endemic mycoses of the Americas (IMEMA) and the first international symposium on implantation mycoses (ISIM) took place in Santiago del Estero, Argentina, on September 25-27, 2023. The conference provided a platform for researchers, clinicians, and experts to discuss the latest developments in the field of endemic and implantation mycoses. Topics included epidemiology, diagnostic advances, treatment strategies, and the impact of environmental factors on the spread of these fungal diseases. IMEMA and ISIM contributed to the regional discourse on the mycoses, emphasizing the importance of international cooperation in addressing these public health challenges.

IMEMA/ISIM, held in Santiago del Estero, Argentina, convened experts to discuss endemic and implantation mycoses, covering topics such as epidemiology, diagnostics, treatment, and advocacy. The event highlighted ongoing efforts in combating these diseases.

Dermatologic Fungal Neglected Tropical Diseases-Part II. Management and Morbidity.

In this part 2 of a 2-part continuing medical education series, the management, outcomes, and morbidities for fungal skin neglected tropical diseases (NTDs), including eumycetoma, chromoblastomycosis, paracoccidioidomycosis, sporotrichosis, emergomycosis, talaromycosis, and lobomycosis are reviewed. While fungal skin NTDs are associated with poverty in resource-limited settings, they are more often associated with immunosuppression and global migration in the United States. These infections have a high morbidity burden, including disfigurement, physical disability, coinfection, malignant transformation, mental health issues, and financial impact. For most fungal skin NTDs, management is difficult and associated with low cure rates. Dermatologists play a central role in initiating appropriate treatment early in disease course in order to improve patient outcomes.

Dermatologic Fungal Neglected Tropical Diseases-Part I. Epidemiology and Clinical Features.

In this part 1 of a 2-part continuing medical education series, the epidemiology, clinical features, and diagnostic methods for fungal skin neglected tropical diseases (NTDs), which include eumycetoma, chromoblastomycosis, paracoccidioidomycosis, sporotrichosis, emergomycosis, talaromycosis, and lobomycosis, are reviewed. These infections, several of which are officially designated as NTDs by the World Health Organization (WHO), cause substantial morbidity and stigma worldwide and are receiving increased attention due to the potential for climate change-related geographic expansion. Domestic incidence may be increasing in the setting of global travel and immunosuppression. United States dermatologists may play a central role in early detection and initiation of appropriate treatment, leading to decreased morbidity and mortality.

Clinical characteristics, diagnosis, and treatment of central nervous system sporotrichosis: Systematic review and meta-analysis.

BACKGROUND: The clinical features of central nervous system (CNS) sporotrichosis are derived from case reports and a limited series of cases. Our objective was to carry out a systematic review and meta-analysis of CNS sporotrichosis. METHODS: We searched PubMed/MEDLINE, Embase, Scopus, and LILACS on 9 September 2023. Our inclusion criteria were documentation of Sporothrix and demonstrated CNS involvement. A metaproportion or metamean analysis was performed to estimate a summary proportion with 95% confidence intervals. RESULTS: We included 52 cases of CNS sporotrichosis published from 1966 to 2023. Forty-six patients were male (88%, 95% CI: 77-95), and the mean age was 39 years (95% CI: 36-43). Close contact with cats was reported in 55% of cases (95% CI: 37-72). Thirty-two (61.5%) patients were from Brazil, 18 patients from the United State of America (34.6%). Only two Sporothrix species were reported: S. schenckii (26/41, 63%), and S. brasiliensis (15/41, 37%). The most common neurological symptom was headache. Meningitis was chronic in approximately 80% of cases. A significant majority of the patients were immunocompromised. HIV infection was the primary cause of immunosuppression (85%, 95% CI: 61-95). Overall mortality was 56% (22/39). The comparison of Kaplan-Meier survival curve showed a higher mortality with a statistically significant difference in immunosuppressed patients (p = .019). CONCLUSION: CNS sporotrichosis represents a notable cause of chronic meningitis, especially in individuals living in the Americas with HIV infection and concurrent skin lesions.

Low toxicity contributes to Sporothrix globosa invade the skin of patients in low-epidemic areas of China.

OBJECTIVE: This study aims to assess the clinical characteristics of sporotrichosis in low-endemic areas of China, including the prevalence geography, genotypic traits of patients, clinical manifestations, and strain virulence and drug sensitivities. The objective is to improve the currently used clinical management strategies for sporotrichosis. METHODS: Retrospective data were collected from patients diagnosed with sporotrichosis through fungal culture identification. The isolates from purified cultures underwent identification using CAL (Calmodulin) gene sequencing. Virulence of each strain was assessed using a Galleria mellonella (G. mellonella) larvae infection model. In vitro susceptibility testing against commonly used clinical antifungal agents for sporotrichosis was conducted following CLSI criteria. RESULTS: In our low-endemic region for sporotrichosis, the majority of cases (23) were observed in middle-aged and elderly women with a history of trauma, with a higher incidence during winter and spring. All clinical isolates were identified as Sporothrix globosa (S. globosa). The G. mellonella larvae infection model indicated independent and dose-dependent virulence among strains, with varying toxicity levels demonstrated by the degree of melanization of the G. mellonella. Surprisingly, lymphocutaneous types caused by S. globosa exhibited lower in vitro virulence but were more common in affected skin. In addition, all S.globosa strains displayed high resistances to fluconazole, while remaining highly susceptible to terbinafine, itraconazole and amphotericin B. CONCLUSION: Given the predominance of elderly women engaged in agricultural labour in our region, which is a low-epidemic areas, they should be considered as crucial targets for sporotrichosis monitoring. S. globosa appears to be the sole causative agent locally. However, varying degrees of melanization in larvae were observed among these isolates, indicating a divergence in their virulence. Itraconazole, terbinafine and amphotericin B remain viable first-line antifungal options for treating S.globosa infection.

Clinical factors associated with systemic sporotrichosis in Brazil.

BACKGROUND: Systemic sporotrichosis occurs when organs, other than subcutaneous tissues and lymph nodes, are infected. Interestingly, systemic sporotrichosis in apparently immunocompetent individuals is increasing in Brazil, but data on clinical manifestations and risk factors are scarce. Most of the existing data on such condition relate to people living with HIV. We aimed to study the risk factors associated with systemic sporotrichosis among HIV-negative and HIV-positive patients. METHODS: We performed a retrospective cross-sectional study with 80 patients from Brazil, diagnosed between 2014 and 2021. The association between disease classification, clinical presentation and risk factors were analysed by logistic regression. RESULTS: Of the 80 patients, 29 (36.3%) presented with systemic sporotrichosis. All HIV-positive patients developed the systemic form, with increased mortality (p = .002). Alcohol ingestion (p = .009) and diabetes (p = .010) were associated with systemic disease. Alcohol ingestion seemed to favour pulmonary infection (p = .013) and, diabetes favoured osteoarticular (p = .009) and ocular involvement (p = .033). The occurrence of fever (p = .001) and weight loss (p = .006) were significantly associated with systemic sporotrichosis, while meningeal involvement (p = .001) increased mortality risk. Nine (11.3%) patients died from sporotrichosis. The presence of fungal structures in the mycological examination of the patients' lesions were associated with the systemic form (p = .017) and death (p = .002). CONCLUSION: Our study points to the factors that drive systemic sporotrichosis other than HIV, such as alcohol ingestion and diabetes. Considering the high number of patients presenting severe sporotrichosis, the recognising these factors may contribute to timely diagnosis and proper treatment.

The Emergence of New Sporothrix brasiliensis Genotypes in Current Epidemic of Sporotrichosis in Southeastern Brazil.

BACKGROUND: Zoonotic sporotrichosis caused by Sporothrix brasiliensis has become the main subcutaneous mycosis in Brazil. Minas Gerais (MG) is located in southeast Brazil and since 2015 has experienced an epidemic of zoonotic sporotrichosis. OBJECTIVES: This study aimed to reconstruct the epidemiological scenario of sporotrichosis from S. brasiliensis in recent epizooty in the Metropolitan Region of Belo Horizonte (MRBH), MG. METHODS: A total of 95 Sporothrix spp. isolates (Sporothirx brasiliensis n = 74, S. schenckii n = 11 and S. globosa n = 10) were subjected to Amplified Fragment Length Polymorphism (AFLP) genotyping and mating-type analysis to determine genetic diversity and population structure. Of these, 46 S. brasiliensis isolates were recovered from animals (cats n = 41 and dogs n = 5) from MRBH. RESULTS: Our study describes the high interspecific differentiation power of AFLP-based genotyping between the main phylogenetic Sporothrix groups. S. brasiliensis presents high genetic variability and pronounced population structure with geographically focused outbreaks in Brazil. The genetic groups include older genotypes from the prolonged epidemic in Southeast (Rio de Janeiro and São Paulo), South (Rio Grande do Sul), Northeast (Pernambuco) and new genotypes from the MRBH. Furthermore, we provide evidence of heterothallism mating strategy in pathogenic Sporothrix species. Genotypes originating in Rio de Janeiro and Pernambuco carry the predominant MAT1-2 idiomorph as opposed to genotypes from Rio Grande do Sul, which have the MAT1-1 idiomorph. We observed an overwhelming occurrence of MAT1-1 among MRBH isolates. CONCLUSION: Our study provides clear evidence of the predominance of a genetic group profile circulating in animals in Minas Gerais, independent of that disseminated from Rio de Janeiro. Our data can help us understand the genetic population processes that drive the evolution of this fungus in Minas Gerais and contribute to future mitigation actions for this ongoing epidemic.

Hyperthermia is a promising potential adjunct to treating sporotrichosis: A refractory case of HIV sporotrichosis and in vitro experiments on Sporothrix spp.

BACKGROUND: Hyperthermia is a common monotherapy for sporotrichosis, but only in patients with special conditions, such as pregnancy and nursing. However, hyperthermia has not been used more widely for sporotrichosis in clinical practice. PATIENTS/METHODS: An HIV-positive adult male with lymphocutaneous sporotrichosis caused by Sporothrix globosa that did not respond to conventional itraconazole therapy lasting >2 months received adjunctive therapy with local hyperthermia. To simulate the effects of heat exposure on the growth and morphology of Sporothrix spp. in vitro, S. globosa, S. schenckii and S. brasiliensis were exposed to intermittent heat (42°C) for 1 h a day for 7 or 28 days and observed under transmission electron microscopy. RESULTS: Itraconazole combined with local hyperthermia significantly improved the lesions, and the patient was successfully cured of sporotrichosis, with no recurrence after 2 years of follow-up. Cultures of Sporothrix spp. treated with 7 days of daily heat exposure in vitro showed obvious decreases in colony diameters, but not numbers, compared with untreated cultures (p < .001). After 28 days of heat exposure in vitro, Sporothrix spp. were unable to thrive (p < .001), and ultrastructural alterations, including loose cell wall structure, incomplete cell membrane, disrupted vacuoles and fragmented nuclei, were noticeable. CONCLUSIONS: Our case findings and in vitro experiments on Sporothrix spp., together with a literature review of previous sporotrichosis cases, suggest that hyperthermia has a clinical role as a treatment adjunct. Large-scale clinical trials are required to examine the utility of hyperthermia in various forms of cutaneous sporotrichosis.

Sporothrix and Sporotrichosis: A South African Perspective on a Growing Global Health Threat.

Sporotrichosis is a disease that arises from a fungal infection caused by members of the Ascomycete genus Sporothrix. The disease has a unique history in South Africa, due to an association with gold mines, where large numbers of mine workers were infected in the 1930s and 1940s. This was likely driven by hot humid conditions and timber supports used in these mine shafts. Furthermore, the disease is the most common subcutaneous fungal infection amongst the general population in South Africa, and the large number of immunocompromised individuals increases the public health risk in the country. Sporothrix is a genus in the Ophiostomatales, a fungal order primarily associated with environmental habitats. Unsurprisingly, sporotrichosis therefore has a documented history of sapronotic transmission from contaminated plant material. This review provides insights into the understanding of sporotrichosis and Sporothrix species, with a particular emphasis on the South African situation. We highlight knowledge gaps, particularly regarding the ecological factors influencing the occurrence and distribution of these species, which in turn affect the patterns of sporotrichosis. We also emphasise a need for ongoing proactive research and surveillance to prevent future outbreaks of sporotrichosis, an emerging disease with growing health implications worldwide.

Feline sporotrichosis: Characterization of cutaneous and extracutaneous lesions using different diagnostic methods.

Sporotrichosis is a mycotic infection of the cutaneous and subcutaneous tissues caused by Sporothrix spp. that can also cause extracutaneous manifestations. This study aimed to characterize cutaneous and extracutaneous sporotrichosis lesions in cats. Over 1 year, 102 cats rescued by the Zoonoses Control Center of Belo Horizonte, Brazil, euthanized with clinical suspicion of feline sporotrichosis were evaluated. After euthanasia, the animals were evaluated by macroscopic, cytological, histopathological, and immunohistochemistry (IHC) examinations; fungal culture; and polymerase chain reaction (PCR). Sporothrix infection was identified by at least one diagnostic technique in all cats (n = 102) evaluated by postmortem examination, including 26/28 cases (93%) evaluated by IHC, 66/90 cases (73%) evaluated by cytology, 70/102 cases (68.6%) evaluated by histopathology, and 62/74 cases (84%) evaluated by fungal culture. Two cats had positive results only by fungal culture. Cytology and histopathology examinations were effective in diagnosing sporotrichosis, although IHC was needed to confirm the diagnosis in cats with low fungal loads. Sporothrix brasiliensis was confirmed by the sequencing of 3 samples. Skin lesions were characterized mainly by pyogranulomatous to granulomatous dermatitis (frequently with subcutaneous inflammation) with different intensities of Sporothrix spp. yeast. Extracutaneous findings associated with sporotrichosis included rhinitis or rhinosinusitis, lymphadenitis, pneumonia, meningitis, periorchitis, conjunctivitis, and glossitis. Extracutaneous infections were observed in 74/102 cases, and a possible association between the chronicity of the disease and the higher pathogenicity of this fungal species in cats requires further investigation.

Imaging features for the evaluation of skin and nail infections.

Clinical manifestations of dermatological and musculoskeletal conditions can sometimes overlap, leading to confusion in diagnosis. Patients with nail and skin infections may undergo imaging examinations with suspicions of muscle, tendon, or joint injuries. Dermatological infections often involve soft tissues and musculoskeletal structures, and their etiology can range from fungi, bacteria, viruses, to protozoa. Relying solely on physical examination may not be sufficient for accurate diagnosis and treatment planning, necessitating the use of complementary imaging exams. The objective of this paper is to present and discuss imaging findings of the main infectious conditions affecting the nail apparatus and skin. The paper also highlights the importance of imaging in clarifying diagnostic uncertainties and guiding appropriate treatment for dermatological conditions.

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

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

Feline sporotrichosis due to Sporothrix globosa in the Metropolitan region of Buenos Aires: A case study.

We describe here the first case of feline sporotrichosis caused by Sporothrix globosa, occurring outside the epizootic area of Buenos Aires province, Argentina. Unlike cases reported with Sporothrix brasiliensis, on this occasion there was no clinical or serological evidence of zoonotic transmission through scratches or bites from the sick cat to the attending veterinarian or the person responsible for its care. This report aimed to improve the knowledge about the pathogenic profile of S. globosa.

Rising Incidence of Sporothrix brasiliensis Infections, Curitiba, Brazil, 2011-2022.

Zoonotic outbreaks of sporotrichosis are increasing in Brazil. We examined and described the emergence of cat-transmitted sporotrichosis (CTS) caused by the fungal pathogen Sporothrix brasiliensis. We calculated incidence and mapped geographic distribution of cases in Curitiba, Brazil, by reviewing medical records from 216 sporotrichosis cases diagnosed during 2011-May 2022. Proven sporotrichosis was established in 84 (39%) patients and probable sporotrichosis in 132 (61%). Incidence increased from 0.3 cases/100,000 outpatient visit-years in 2011 to 21.4 cases/100,000 outpatient visit-years in 2021; of the 216 cases, 58% (n = 126) were diagnosed during 2019-2021. The main clinical form of sporotrichosis was lymphocutaneous (63%), followed by localized cutaneous (24%), ocular (10%), multisite infections (3%), and cutaneous disseminated (<0.5%). Since the first report of CTS in Curitiba in 2011, sporotrichosis has increased substantially, indicating continuous disease transmission. Clinician and public awareness of CTS and efforts to prevent transmission are needed.

Development and validation of a new quantitative reverse transcription PCR assay for the diagnosis of human sporotrichosis.

Sporotrichosis is an emergent public health problem. The mycological diagnosis of this infection is based on culture, which is fastidious and may represent a biohazard for technicians. Although not widely implemented in routine diagnosis, molecular methodologies are fast, have good accuracy, and can be easily standardized, aiding in the early diagnosis of neglected mycoses. This study aimed at implementing a new pan-Sporothrix quantitative reverse transcription PCR (RT-qPCR) assay, and then validating it on clinical samples from confirmed human sporotrichosis cases. A total of 68 human samples with culture-confirmed diagnosis of sporotrichosis were collected from 64 patients followed at a Brazilian reference center for endemic mycoses. These samples were submitted to whole nucleic acid extraction, followed by an RT-qPCR protocol. The limit of detection was 244 fg, the efficiency was 2.0 (100%), and the assay could amplify the genetic material of the three major clinically relevant species of the genus Sporothrix. Among the 68 samples analyzed, 62 were positive in RT-qPCR, showing an overall sensitivity of 91.18%, which variated according to the type of biological sample: 96.72% in skin samples (n = 61) and 100% in respiratory samples (n = 3), whereas all cerebrospinal fluid specimens (n = 4) were negative. The specificity was 100% when tested in 25 samples from patients with other mycoses and tuberculosis. In addition, DNA from 93 fungal species did not yield positive results, confirming the high specificity of this test. Our RT-qPCR presented high sensitivity and specificity, representing an excellent tool for a fast and reliable diagnosis of human sporotrichosis.

Sporotrichosis is a deep mycosis with limited laboratorial techniques for fast diagnosis. We developed an assay able to detect the genetic material of fungal agents of sporotrichosis, and validated it in human specimens from patients with this disease, obtaining high positivity and specificity.