Epidemiological features and geographical expansion of sporotrichosis in the state of Pernambuco, northeastern Brazil

Rapid Molecular Diagnosis of Sporotrichosis Directly from Biological Samples from a Reference Center in Brazil

The gold standard diagnosis of sporotrichosis is the isolation of Sporothrix sp. in culture media, but this is a time-consuming test that is susceptible to contamination and can be affected by the fungal load. Molecular methods such as nested PCR are gaining more ground in the management of several infections as they are tools for the rapid and accurate identification of microorganisms from pure cultures or directly from biological samples. This study aimed to apply a nested PCR molecular protocol for the rapid detection of Sporothrix spp. directly from clinical samples. Thirteen samples-six from skin biopsies, five from skin exudates, and two from conjunctival secretions-were obtained from patients diagnosed with sporotrichosis due to S. brasiliensis. Calmodulin gene sequencing identified all the isolates as S. brasiliensis. Nested PCR was able to detect all the Sporothrix sensu lato directly from clinical samples as well as the CBS 120339 reference strain. The nested PCR protocol stands out as a diagnostic alternative, as it allows the identification of Sporothrix spp. directly from clinical samples without the need for fungal isolation.

Sporothrix brasiliensis Causing Atypical Sporotrichosis in Brazil: A Systematic Review

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

Antifungal efficacy of imidazo[1,2-a]pyrazine-based thiosemicarbazones and thiazolidinediones against Sporothrix species

Aim: To evaluate antifungal potential of 5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine hybrids based on thiosemicarbazones and thiazolidinediones against pathogenic Sporothrix species. Methods: Antifungal activity of nine compounds were assessed by broth microdilution. Interactions between active compounds and itraconazole were evaluated by the checkerboard assay using non-wild-type isolates. Cytotoxicity of the compounds was determined. Results: Four C-3 substituted analogs showed antifungal activity, unrelated to thiosemicarbazone or thiazolidinedione functions. Synergistic interactions between the four compounds and itraconazole, and low toxicity on mouse fibroblast cells were observed. Activity of 5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine hybrids against Sporothrix depended on the substitution on the imidazopyrazine ring. Conclusion: Antifungal potential, overcoming itraconazole resistance and low toxicity indicate the possible use of that series of compounds in a therapeutic alternative for treatment of sporotrichosis.

First Cases of Feline Sporotrichosis Caused by Sporothrix brasiliensis in Paraguay

Sporothrix brasiliensis is an emerging fungal pathogen causing cat-transmitted sporotrichosis, an epi-zoonosis affecting humans, cats and dogs in Brazil and now spreading to neighboring South American countries. Here, we report the first two autochthonous cases of cat-transmitted sporotrichosis in Paraguay. The first case was a four-year-old male cat showing several ulcerative lesions, nasal deformity and respiratory symptoms. The second case was a one-year-old male cat showing a single ulcerated lesion, respiratory symptoms and nasal deformity. Both cases were admitted to a veterinary clinic in Ciudad del Este, Paraguay. Isolates were recovered from swabs of the two cases. Using molecular methods, the isolates were identified as S. brasiliensis.

Effectiveness of diphenyl diselenide against experimental sporotrichosis caused by Sporothrix brasiliensis

Diphenyl diselenide (PhSe)2 is a stable organoselenium compound with promising in vitro antifungal activity against several fungi, including Sporothrix brasiliensis. This species is associated with feline and zoonotic sporotrichosis, an emergent mycosis in Latin America. We evaluated the activity of (PhSe)2, alone and in association with itraconazole, in the treatment of sporotrichosis caused by S. brasiliensis, in a murine model. Sixty mice were subcutaneously infected with S. brasiliensis in the footpad and treated by gavage for 30 consecutive days. The six treatment groups received: no active treatment, itraconazole (50 mg/kg), (PhSe)2 at 1, 5, and 10 mg/kg dosages, or itraconazole (50 mg/kg) + (PhSe)2 1 mg/kg, once a day, starting seven days post-inoculation. A significant reduction in the fungal burden of internal organs was achieved in the groups treated with (PhSe)2 1 mg/kg or itraconazole alone in comparison with the untreated group. Higher dosages (5 and 10 mg/kg) of (PhSe)2 increased the clinical manifestation of sporotrichosis and mortality rate. Treatment with both itraconazole and (PhSe)2 1 mg/kg was better than their activities alone (P < .001). This is the first demonstration of the potential use of (PhSe)2, alone or with the present drug of choice, in the treatment of sporotrichosis.

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

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

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

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