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.

Differential recognition and cytokine induction by the peptidorhamnomannan from Sporothrix brasiliensis and S. Schenckii.

Sporotrichosis is a deep mycosis caused by dimorphic species of the genus Sporothrix, with differences in pathogenicity between S. schenckii and S. brasiliensis species. Recently, it was discovered that the cell wall peptidorhamnomannan (PRM) from S. brasiliensis has additional unknown rhamnose residues. We hypothesize that the structural differences of Sporothrix spp PRMs impact the host's immune response and may explain the severity of sporotrichosis caused by S. brasiliensis. We demonstrate that S. brasiliensis yeasts and its PRM (S.b PRM) induced a strong inflammatory response in human PBMCs, with high production of TNF-α, IL-6 and IL-1ß and induction of T-helper cytokines IFN-γ, IL-17 and IL-22. In contrast, S. schenckii yeasts and its PRM induced higher concentrations of interleukin-1 receptor antagonist (IL-1Ra), which resulted in low production of T-helper cytokines such as IL-17 and IL-22. CR3 and dectin-1 were required for cytokine induction by both PRMs, while TLR2 and TLR4 were required for the response of S.s PRM and S.b PRM, respectively. IL-1ß and IL-1α production induced by S. brasiliensis yeasts and S.b PRM were dependent on inflammasome and caspase-1 activation. S. schenckii and S.s PRM were able to induce IL-1ß independent of ROS. In conclusion, these findings improve our understanding of the pathogenesis of Sporothrix spp. by reporting differences of immunological responses induced by S. schenckii and S. brasiliensis. The study also opens the gateway for novel treatment strategies targeting local inflammation and tissue destruction induced by S. brasiliensis infection through IL-1 inhibition.

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

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

Complement-Mediated Differential Immune Response of Human Macrophages to Sporothrix Species Through Interaction With Their Cell Wall Peptidorhamnomannans.

In this study, the human immune response mechanisms against Sporothrix brasiliensis and Sporothrix schenckii, two causative agents of human and animal sporotrichosis, were investigated. The interaction of S. brasiliensis and S. schenckii with human monocyte-derived macrophages (hMDMs) was shown to be dependent on the thermolabile serum complement protein C3, which facilitated the phagocytosis of Sporothrix yeast cells through opsonization. The peptidorhamnomannan (PRM) component of the cell walls of these two Sporothrix yeasts was found to be one of their surfaces exposed pathogen-associated molecular pattern (PAMP), leading to activation of the complement system and deposition of C3b on the Sporothrix yeast surfaces. PRM also showed direct interaction with CD11b, the specific component of the complement receptor-3 (CR3). Furthermore, the blockade of CR3 specifically impacted the interleukin (IL)-1ß secretion by hMDM in response to both S. brasiliensis and S. schenckii, suggesting that the host complement system plays an essential role in the inflammatory immune response against these Sporothrix species. Nevertheless, the structural differences in the PRMs of the two Sporothrix species, as revealed by NMR, were related to the differences observed in the host complement activation pathways. Together, this work reports a new PAMP of the cell surface of pathogenic fungi playing a role through the activation of complement system and via CR3 receptor mediating an inflammatory response to Sporothrix species.

Immunoproteomic and Immunopeptidomic Analyses of Histoplasma capsulatum Reveal Promiscuous and Conserved Epitopes Among Fungi With Vaccine Potential.

As there are more than 6 million human deaths due to mycoses each year, there is an urgent need to develop fungal vaccines. Moreover, given the similarities among pathogenic fungi, it may be possible to create a multi-fungi vaccine. In this study, we combined immunoproteomic and immunopeptidomic methods, for which we have adapted a technique based on co-immunoprecipitation (Co-IP) that made it possible to map Histoplasma capsulatum epitopes for the first time in a natural context using murine dendritic cells (DCs) and macrophages (Mφ). Although polysaccharide epitopes exist, this research focused on mapping protein epitopes as these are more immunogenic. We used different algorithms to screen proteins and peptides identified by two-dimensional electrophoresis (2-D) and Co-IP. Seventeen proteins were revealed by 2-D gels, and 45 and 24 peptides from distinct proteins were presented by DCs and Mφ, respectively. We then determined which epitopes were restricted to MHC-I and II from humans and mice and showed high promiscuity, but lacked identity with human proteins. The 4 most promising peptides were synthesized, and the peptides with and without incorporation into glucan particles induced CD4+ and CD8+ T cell proliferation and produced a Th1 and Th17 response marked by the secretion of high levels of IFN-γ, IL-17 and IL-2. These epitopes were from heat shock protein 60, enolase, and the ATP-dependent molecular chaperone HSC82, and they each have a high degree of identity with proteins expressed by other medically important pathogenic fungi. Thus, the epitopes described in this study have the potential for use in the development of vaccines that could result in cross-protection among fungal species.

Antibody- Based Immunotherapy Combined With Antimycotic Drug TMP- SMX to Treat Infection With Paracoccidioides brasiliensis.

Monoclonal antibodies (mAbs) are promising alternatives to treat infectious diseases, especially given their potential for applications in combination therapies with antimicrobial drugs to enhance the antifungal efficacy. Protection mediated by mAbs used to treat experimental paracoccidioidomycosis (PCM) has been demonstrated previously. Our aim in the present work was to characterize a monoclonal antibody (mAbF1.4) raised against a cell wall glycoconjugate fraction of Paracoccidioides spp. and to analyze its efficacy combined with trimethoprim-sulfamethoxazole (TMP/SMX) as treatment for experimental PCM. We demonstrated that the epitope recognized by mAbF1.4 is consistent with branched glucose residues present on a cell wall ß-glucan polymer. In vitro, mAbF1.4 increased the phagocytic capacity and nitric oxide concentration induced by the macrophage cell line J774.1A, and this resulted in a significant reduction in the viability of the opsonophagocytized yeasts. In vivo, we detected a significant reduction in pulmonary fungal burdens of mice treated with mAbF1.4 in association with TMP/SMX, which correlated with increased pulmonary concentrations (determined by ELISA) of IFN- Î³, TNF-α, IL-10 and IL-17. In parallel, we observed a decrease in IL-4, suggesting that the treatment was associated with a mixed Th1-Th17 type immune response. Histopathology of lung segments from mice receiving the combination therapy showed a significant reduction in granulomas, which were well-defined, and improved maintenance of lung architecture. These findings demonstrate that mAbF1.4 + TMP/SMX therapy is a promising approach to combat PCM as well as decrease disease sequelae and highlights the potential benefits of immune mediators in PCM combined immunotherapy.

Comparison of Cell Wall Polysaccharide Composition and Structure Between Strains of Sporothrix schenckii and Sporothrix brasiliensis.

Sporothrix schenckii, Sporothrix brasiliensis, and Sporothrix globosa are the main causative agents of sporotrichosis, a human subcutaneous mycosis. Differences in virulence patterns are associated with each species but remain largely uncharacterized. The S. schenckii and S. brasiliensis cell wall composition and virulence are influenced by the culturing media, with little or no influence on S. globosa. By keeping constant the culturing media, we compared the cell wall composition of three S. schenckii and two S. brasiliensis strains, previously described as presenting different virulence levels on a murine model of infection. The cell wall composition of the five Sporothrix spp. strains correlated with the biochemical composition of the cell wall previously reported for the species. However, the rhamnose-to-ß-glucan ratio exhibits differences among strains, with an increase in cell wall rhamnose-to-ß-glucan ratio as their virulence increased. This relationship can be expressed mathematically, which could be an important tool for the determination of virulence in Sporothrix spp. Also, structural differences in rhamnomannan were found, with longer side chains present in strains with lower virulence reported for both species here studied, adding insight to the importance of this polysaccharide in the pathogenic process of these fungi.

Global guideline for the diagnosis and management of the endemic mycoses: an initiative of the European Confederation of Medical Mycology in cooperation with the International Society for Human and Animal Mycology.

The global burden of the endemic mycoses (blastomycosis, coccidioidomycosis, emergomycosis, histoplasmosis, paracoccidioidomycosis, sporotrichosis, and talaromycosis) continues to rise yearly and these infectious diseases remain a leading cause of patient morbidity and mortality worldwide. Management of the associated pathogens requires a thorough understanding of the epidemiology, risk factors, diagnostic methods and performance characteristics in different patient populations, and treatment options unique to each infection. Guidance on the management of these infections has the potential to improve prognosis. The recommendations outlined in this Review are part of the "One World, One Guideline" initiative of the European Confederation of Medical Mycology. Experts from 23 countries contributed to the development of these guidelines. The aim of this Review is to provide an up-to-date consensus and practical guidance in clinical decision making, by engaging physicians and scientists involved in various aspects of clinical management.

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.

Promising application of the SsCBF ELISA test to monitor the therapeutic response of feline sporotrichosis caused by Sporothrix brasiliensis from Brazilian epidemics.

Sporotrichosis zoonotic transmission by cats has obtained hyperendemic magnitude in Rio de Janeiro, Brazil. Atypical cases, relapses, and reinfections as well as reduced diagnostic sensitivity of conventional methods have been reported. Previously, the anti-SsCBF enzyme-linked immunosorbent assay (ELISA) test was shown to be useful as a diagnostic tool for human sporotrichosis. Effective diagnosis and treatment are critical to interrupt the chain of transmission of this major pathogen in Brazilian Public Health. To evaluate its applicability for feline sporotrichosis diagnosis and/or therapeutic follow-up, 15 domestic cats from Rio de Janeiro were clinically and laboratory monitored by cytopathology, culture, Sporothrix genotyping, and anti-SsCBF IgG levels. Subsequently, animals were divided into satisfactory and non-satisfactory therapeutic responders. Averages of antibody serum levels obtained for diagnosis (first consultation) compared with the levels found after follow-up (last consultation) were significantly different in both groups (p = 0.0002 and p = 0.038, respectively). We conclude that the SsCBF ELISA test can predict feline sporotrichosis therapeutic responses even for animals with distinct clinical evolutions.

Coinfection of domestic felines by distinct Sporothrix brasiliensis in the Brazilian sporotrichosis hyperendemic area.

Microbial interactions may impact patient's diagnosis, prognosis and treatment. Sporotrichosis is a hyperendemic neglected zoonosis in Brazil, caused by Sporothrix brasiliensis. Four pairs of clinical isolates of Sporothrix were recovered from four diseased cats (CIM01-CIM04, two isolates per animal) raising the possibility of coinfection in a sporotrichosis hyperendemic area, Brazil. Each isolate of the pair had distinct pigmentation in mycological culture, and was designated as "Light" or "Dark", for low and high pigmentation, respectively. Dark isolates reacted strongly with monoclonal antibodies to melanin (p ≤ 0.05) by both ELISA and FACS quantitation, and displayed a ring pattern with some regions exhibiting higher punctuated labeling at cell wall by immunofluorescence. In turn, Light isolates reacted less intensely, with few and discrete punctuated labeling at the cell wall. PCR identified all isolates as S. brasiliensis, MAT1-2 idiomorph. Sequencing of ß-tubulin and calmodulin genes followed by phylogenetic analysis placed all eight isolates within the same cluster as others from the Brazilian hyperendemic area. The ability of these strains to stimulate cytokine production by human PBMCs (Peripheral blood mononuclear cells) was also analyzed. CIM01 and CIM03 Light and Dark isolates showed similar cytokine profiles to the control strain, while CIM02 and CIM04 behaved differently (p < 0.001), suggesting that differences in the surface of the isolates can influence host-fungus interaction. MICs for amphotericin B, terbinafine, caspofungin, micafungin, itraconazole, fluconazole, and voriconazole were obtained (CLSI M38-A2/M27-A3). Pairwise comparisons showed distinct MICs between Sporothrix Light and Dark isolates, higher than at least two-fold dilutions, to at least one of the antifungals tested. Isolates from the same pair displayed discrepancies in relation to fungistatic or fungicidal drug activity, notably after itraconazole exposure. Since S. brasiliensis Light and Dark isolates show disparate phenotypic parameters it is quite possible that coinfection represents a common occurrence in the hyperendemic area, with potential clinical implications on feline sporotrichosis dynamics. Alternatively, future studies will address if this specie may have, as reported for other fungi, broad phenotypic plasticity.

Ploidy Determination in the Pathogenic Fungus Sporothrix spp.

The pathogenic clade of the Sporothrix genus comprises the etiological agents of sporotrichosis, a worldwide emergent disease. Despite the growing understanding of their successful pathogen traits, there is little information on genome sizes and ploidy within the genus. Therefore, in this work, we evaluated the ploidy of four species of the Sporothrix genus, specifically Sporothrix brasiliensis, Sporothrix schenckii, Sporothrix globosa, and Sporothrix pallida. Through cell cycle analysis of the yeast-phase cells, we showed that the DNA content of G0/G1 cells was similar to the genome size determined by whole genome sequencing. Moreover, ploidy of S. schenckii, S. brasiliensis, and S. pallida that was determined by allele composition using next-generation sequencing (NGS) data is consistent with monomorphic positions at each allele. These data show that the analyzed strains of Sporothrix are haploid, or at least aneuploid, thereby laying the foundation for the development of a molecular toolbox for Sporothrix spp.

Analysis of some immunogenic properties of the recombinant Sporothrix schenckii Gp70 expressed in Escherichia coli.

AIM: Sporothrix schenckii is the causative agent of sporotrichosis. A 70-kDa glycoprotein, Gp70, is a candidate for the development of prophylactic alternatives to control the disease, and its gene (GP70) is predicted to encode for a protein of 43 kDa, contrasting with the molecular weight of the native protein. MATERIALS & METHODS: The GP70 was expressed in bacteria, the recombinant protein purified, used in immunoassays and injected to Galleria mellonella. RESULTS & CONCLUSION: The recombinant protein was detected by anti-Gp70 antibodies, confirming that the Gp70 backbone is a 43-kDa peptide. This protein showed enzyme activity of cyclase and was recognized by sera of patients with sporotrichosis. Although it was not useful for serodiagnosis of sporotrichosis, it conferred protection to animals against experimental sporotrichosis.

Correction to: Effects of metaperiodate and urea solutions on the serological diagnosis of human sporotrichosis using an indirect ELISA test.

In the article mentioned above an author's name was misspelled. The correct author name reads as follows: Leila Maria Lopes-Bezerra. We apologize for the inconvenience.

Effects of metaperiodate and urea solutions on the serological diagnosis of human sporotrichosis using an indirect ELISA test.

Sporotrichosis is an infection of the skin caused by traumatic inoculation of the fungus Sporothrix schenckii. Definitive diagnosis relies on direct visualization of the fungus or its isolation on culture medium, although both have low sensitivity. Alternatively, the detection of the antibody response offers a more rapid alternative for diagnosis. Although the available immunoassays possess good sensitivity and specificity, cross-reactivity is still a problem. This study aimed to evaluate the effect of sodium metaperiodate and 6 M urea solutions on the serological diagnosis of sporotrichosis using an enzyme-linked immunosorbent assay (ELISA) test. Ninety-six-well plates were sensitized with exoantigens from the yeast phase of S. schenckii. Sera of patients with confirmed sporotrichosis, sera of patients with paracoccidioidomycosis, and sera of individuals with a sporotrichin-negative skin test were tested. Two strategies were used; the first consisted of treating the antigen with sodium metaperiodate solution for different incubation times, and the second consisted of treating the serum with 6 M urea solution for different incubation times. ROC curve analysis revealed that the best discrimination parameters were obtained using 6 M urea solution incubated for 5 min and serum dilution at 1/600. The use of 6 M urea solution improves the performance of the ELISA test in the diagnosis of sporotrichosis.

Silencing of OCH1 unveils the role of Sporothrix schenckii N-linked glycans during the host-fungus interaction.

BACKGROUND: Sporothrix schenckii is a neglected fungal pathogen for the human being and other mammals. In several fungal systems, Och1 is a Golgi α1,6-mannosyltransferase with a key function in the synthesis of N-linked glycans; which are important elements during the host-fungus interplay. The role of OCH1 in fungal virulence seems to be species-specific, being an essential component for Candida albicans virulence and dispensable during the interaction of Aspergillus fumigatus with the host. METHODS: Here, we silenced S. schenckii OCH1 and characterized the phenotype of the mutant strains. RESULTS: The mutant strains did not show defects in the cell or colony morphology, the growth rate or the ability to undergo dimorphism; but the cell wall changed in both composition and exposure of inner components at the surface. When interacting with human monocytes, the silenced strains had a reduced ability to stimulate TNFα and IL-6 but stimulated higher levels of IL-10. The interaction with human macrophages was also altered, with reduced numbers of silenced cells phagocytosed. These strains showed virulence attenuation in both Galleria mellonella and in the mouse model of sporotrichosis. Nonetheless, the cytokine levels in infected organs did not vary significantly when compared with the wild-type strain. CONCLUSION: Our data demonstrate that OCH1 silencing affects different aspects of the S. schenckii-host interaction.

Generation of Sporothrix schenckii mutants expressing the green fluorescent protein suitable for the study of host-fungus interactions.

Sporotrichosis is an infection caused by members of the Sporothrix genus, and among them, Sporothrix schenckii is one of the etiological agents. Both, the disease and the causative agent have gained interest in the recent years, because of the report of epidemic outbreaks, and the description of the disease transmission from animals to human beings. Despite the relevance of S. schenckii in the clinical field, there are basic aspects of its biology poorly explored. So far, Agrobacterium tumefaciens-mediated transformation has been reported as an alternative for genetic manipulation of this fungal pathogen. Here, we report the optimization of the transformation method and used this to generate insertional mutants that express the green fluorescent protein in S. schenckii. We obtained five mutant strains that showed mitotic stability and expression of the reporter gene. The strains displayed normal cell wall composition, and a similar ability to interact ex vivo with human monocytes and monocyte-derived macrophages. Moreover, the virulence in larvae of Galleria mellonella was similar to that obtained with the wild-type control strains. These data indicate that these fluorescent mutants with normal ability to interact with the host could be used in bioimaging to track the host-Sporothrix interaction in vivo.

Cell walls of the dimorphic fungal pathogens Sporothrix schenckii and Sporothrix brasiliensis exhibit bilaminate structures and sloughing of extensive and intact layers.

Sporotrichosis is a subcutaneous mycosis caused by pathogenic species of the Sporothrix genus. A new emerging species, Sporothrix brasiliensis, is related to cat-transmitted sporotrichosis and has severe clinical manifestations. The cell wall of pathogenic fungi is a unique structure and impacts directly on the host immune response. We reveal and compare the cell wall structures of Sporothrix schenckii and S. brasiliensis using high-pressure freezing electron microscopy to study the cell wall organization of both species. To analyze the components of the cell wall, we also used infrared and 13C and 1H NMR spectroscopy and the sugar composition was determined by quantitative high-performance anion-exchange chromatography. Our ultrastructural data revealed a bi-layered cell wall structure for both species, including an external microfibrillar layer and an inner electron-dense layer. The inner and outer layers of the S. brasiliensis cell wall were thicker than those of S. schenckii, correlating with an increase in the chitin and rhamnose contents. Moreover, the outer microfibrillar layer of the S. brasiliensis cell wall had longer microfibrils interconnecting yeast cells. Distinct from those of other dimorphic fungi, the cell wall of Sporothrix spp. lacked α-glucan component. Interestingly, glycogen α-particles were identified in the cytoplasm close to the cell wall and the plasma membrane. The cell wall structure as well as the presence of glycogen α-particles varied over time during cell culture. The structural differences observed in the cell wall of these Sporothrix species seemed to impact its uptake by monocyte-derived human macrophages. The data presented here show a unique cell wall structure of S. brasiliensis and S. schenckii during the yeast parasitic phase. A new cell wall model for Sporothrix spp. is therefore proposed that suggests that these fungi molt sheets of intact cell wall layers. This observation may have significant effects on localized and disseminated immunopathology.

Sporotrichosis between 1898 and 2017: The evolution of knowledge on a changeable disease and on emerging etiological agents.

The description of cryptic species with different pathogenic potentials has changed the perspectives on sporotrichosis. Sporothrix schenckii causes a benign chronic subcutaneous mycosis, Sporothrix brasiliensis is highly virulent, and Sporothrix globosa mainly causes fixed cutaneous lesions. Furthermore, S. brasiliensis is the prevalent species related to cat-transmitted sporotrichosis. Sources of infection, transmission, and distribution patterns also differ between species, and variability differs between species because of different degrees of clonality. The present review article will cover several aspects of the biology of clinically relevant agents of sporotrichosis, including epidemiological aspects of emerging species. Genomic information of Sporothrix spp. is also discussed. The cell wall is an essential structure for cell viability, interaction with the environment, and the host immune cells and contains several macromolecules involved in virulence. Due to its importance, aspects of glycosylation and cell wall polysaccharides are reviewed. Recent genome data and bioinformatics analyses helped to identify specific enzymes of the biosynthetic glycosylation routes, with no homologs in mammalian cells, which can be putative targets for development of antifungal drugs. A diversity of molecular techniques is available for the recognition of the clinically relevant species of Sporothrix. Furthermore, antigens identified as diagnostic markers and putative vaccine candidates are described. Cell-mediated immunity plays a key role in controlling infection, but Sporothrix species differ in their interaction with the host. The adaptive branch of the immune response is essential for appropriate control of infection.