Susana Johann

Aquatic environments receiving anthropogenic inputs can act as reservoirs for opportunistic microorganisms and antifungal resistance, representing a potential environmental and public health concern. This study evaluated microbial contamination and antifungal susceptibility patterns in surface waters along a rural–urban gradient in a subtropical watershed using an integrated environmental monitoring approach. Physicochemical parameters and conventional microbial (Escherichia coli, Enterococcus spp., and heterotrophic bacteria) were quantified, and yeast abundance was determined using CHROMagar™ Candida. A total of 327 yeast isolates were evaluated for susceptibility to itraconazole (ITZ) and fluconazole (FCZ) using the CLSI M27-A4 broth microdilution method. Urban sites exhibited markedly higher microbial contamination compared with rural areas, with Enterococcus spp. reaching 36,000 colony-forming units (CFU)/100 ml and E. coli 19,863 most probable number (MPN)/100 ml. Yeast densities reached up to 351 CFU/100 ml in urban samples, exceeding concentrations typically reported for oligotrophic aquatic systems. Antifungal susceptibility testing revealed a high frequency of resistance among environmental isolates, ITZ (44.3%) compared with FCZ (24.46%). Statistical analyses indicated no significant spatial or seasonal differences in resistance patterns (p > 0.05), whereas resistance to ITZ was significantly higher than to FCZ (p < 0.001). The results indicate that anthropogenic pressure in urbanized watersheds may contribute to increased microbial contamination and the occurrence of antifungal-resistant yeasts in surface waters. This suggests a potential environmental pathway for the dissemination of resistance traits. The integration of conventional microbial indicators, environmental yeast monitoring, and antifungal susceptibility profiling provides a practical framework for environmental surveillance. Graphical Abstract The alternative text for this image may have been generated using AI.

Background: Malassezia spp. are part of the microbiota of many animals, including humans. However, under certain conditions, they can become pathogenic. Diseases associated with Malassezia include pityriasis versicolor (PV), seborrheic dermatitis (SD), Malassezia folliculitis, atopic dermatitis, psoriasis and fungemia. Objective: The present study aimed to describe the distribution of Malassezia species among Brazilian patients with PV and SD and to evaluate their susceptibility profiles to common antifungals. Methods: In this study, 102 clinical samples from patients with PV or SD were analysed. Clinical isolates of Malassezia were identified at the species level by sequencing the D1/D2 variable domains of the large subunit rRNA gene. Antifungal susceptibility was assessed using a modified microbroth dilution method adapted for the growth of Malassezia species. Results: Among the 40 cultures obtained, six Malassezia species were identified. M. furfur was the most prevalent species (40.0%), followed by M. sympodialis (27.5%), M. globosa (15.0%), M. japonica (7.5%) and both M. yamatoensis and M. slooffiae (5.0% each). All isolates exhibited high MICs to caspofungin (> s16 μg/mL) and to isoconazole (MIC₅₀ = 8 μg/mL). Miconazole and clotrimazole showed MIC₅₀ values of 4 μg/mL, while itraconazole and ketoconazole were more active, with an MIC₅₀ of 0.125 μg/mL. Conclusion: This study showed the diversity of Malassezia species causing PV and SD in Brazil, including the rare species M. yamatoensis and M. japonica . These findings highlight the importance of antifungal susceptibility testing for these species to guide appropriate therapy.

Six yeast isolates were recovered from Ipomoea flowers collected in the Cerrado biome of Tocantins, Brazil. Sequence analyses of the ITS–5.8S region and the D1/D2 domains of the large subunit (LSU) rRNA gene indicated that these isolates represent a novel species of the genus Candidozyma , phylogenetically related to Candidozyma auris and Ca. ruelliae . A phylogenomic analysis based on 2116 single‐copy orthologs from Candidozyma species with available whole‐genome sequences showed that the new species, represented by strain UFMG‐CM‐Y6065, is a sister species to Ca. ruelliae . The name Candidozyma cisalpinoae sp. nov. (MycoBank no. 861366) is proposed to accommodate the new species. The holotype is CBS16108. Sporulation or other evidence of sexual reproduction was not observed, although the genome sequence showed the presence of a functional mating type locus ( MAT a) and functional pheromone peptides, indicating that the species is haplontic and heterothallic. The species exhibited resistance to multiple antifungals, growth at 42°C, biofilm formation, adhesion to buccal epithelial cells, and expression of efflux pumps, traits of clinical relevance that have been reported for other species in the genus Candidozyma .

Candida albicans is a yeast extensively studied for its role in the human microbiota and as a crucial opportunistic pathogen. Despite a vast body of information about this organism, its ecology in natural habitats remains poorly understood. Most studies suggest that C. albicans is typically isolated only from endothermic hosts or human-associated substrates. However, several reports have demonstrated the presence of C. albicans in environmental samples such as rivers, soils, and plant materials. In this mini-review, we present studies that have isolated C. albicans from natural environments and discuss the importance of expanding research efforts to gain a more comprehensive understanding of the ecology of this yeast.

Fungal infections have become a growing concern in healthcare, particularly in immunocompromised individuals, with species like Candida, Cryptococcus, and Sporothrix posing significant challenges due to rising resistance and limited treatment options. In response, novel antifungal agents are being explored, including thiazolyl hydrazones. This study focuses on the development of a novel thiazolylhydrazone derivative, RW3. RW3 was synthesized to improve its water solubility and pharmacokinetic properties. The compound demonstrated a broad antifungal spectrum, particularly effective against Cryptococcus neoformans and Candida auris, with minimal irritant potential and low cytotoxicity. RW3 showed favorable solubility and high intestinal permeability, indicating potential for oral administration. The results suggest RW3 as a promising lead for further development as a therapeutic agent for systemic fungal infections. These findings underscore the importance of optimizing drug properties to enhance efficacy and safety profiles, opening the path for the development of innovative antifungal treatments.

Fungal infections have become a growing concern in healthcare, particularly in immuno-compromised individuals, with species like Candida, Cryptococcus, and Sporothrix pos-ing significant challenges due to rising resistance and limited treatment options. In re-sponse, novel antifungal agents are being explored, including thiazolyl hydrazones. This study focuses on the development of a novel thiazolylhydrazone derivative, RW3. RW3 was synthesized to improve water solubility and pharmacokinetic properties. The com-pound demonstrated a broad antifungal spectrum, particularly effective against Crypto-coccus neoformans and Candida auris, with minimal irritant potential and low cytotoxi-city. RW3 showed favorable solubility and high intestinal permeability, indicating poten-tial for oral administration. The results suggest RW3 as a promising lead for further de-velopment as a therapeutic agent for systemic fungal infections. These findings under-score the importance of optimizing drug properties to enhance efficacy and safety profiles, opening the path for the development of innovative antifungal treatments.

Sporotrichosis’ clinical manifestations, lesions in the cutaneous or subcutaneous tissues, it is caused by dimorphic fungi of the Sporothrix complex, is a cosmopolitan mycosis that affects humans and animals. This study aimed to identify prevalent species in Minas Gerais, Brazil, and characterize virulence profiles and antifungal susceptibility associated with Sporothrix isolates. Isolates were identified using macro and micro-morphological traits as well molecular biology techniques. Antifungal susceptibility was determined using the Minimal Inhibitory Concentration test, while, virulence factors such as growth at different temperatures, biofilm formation, melanin production, and urease activity were assessed. Our findings revealed S. brasiliensis as a predominant species isolated. Urease activity was a crucial factor associated with growth at 50°C in S. brasiliensis isolates, highlighting their high thermotolerance. Furthermore, strains isolated from humans produced a more robust biofilm compare to those from felines. Strains of S. brasiliensis isolated from Felis catus exhibited faster melanin production, decreased susceptible to antifungal agents tested, and superior growth capacity at 50°C to strains isolated from humans. Therefore, our study highlights the prevalence of S. brasiliensis causing sporotrichosis in both human and felines. However, it underscores the circulation of different strains, with varying levels of virulence and susceptibility to antifungal agents.

Plants from Salacia genus are used in traditional medicine for a wide range of diseases. Previous studies reported bioactive pentacyclic triterpenoids from S. elliptica leaves and branches. In this study, the novel pentacyclic triterpenoid 7α,15α‐dihydroxyfriedelan‐3‐one (1) was obtained from the roots of Salacia elliptica, along with seven known compounds: friedelan‐3‐one (2), friedelan‐3β‐ol (3), friedelan‐1,3‐dione (4), friedelan‐3,15‐dione (5), 15α‐hydroxyfriedelan‐3‐one (6), 15α,26‐dihydroxyfriedelan‐3‐one (7), and 26‐hydroxyfriedelan‐3,15‐dione (8). Additionally, one steroid, spinasterol (9), was also identified. The chemical structures of all compounds were established through ¹H and ¹³C‐NMR. Compound 1 was analysed by additional 2D experiments (HMBC, HSQC, COSY, and NOESY) for complete elucidation. Furthermore, the cytotoxicity of compounds 2, 3, 6, 7 and 8 against the A549 lung cancer cells model was evaluated. The flow cytometry analysis revealed a significant cytotoxic activity similar to that exhibited by the triterpenoid lupeol. Additionally, compounds 2, 3, 6, and 7 were tested for in vitro antifungal activity against Candida, Cryptococcus and Sporothrix strains. However, all compounds showed no activity at the tested concentrations.

Sporotrichosis, a cosmopolitan mycosis caused by dimorphic fungi of the Sporothrix complex, affects humans and animals. This study aimed to develop new molecular markers for Sporothrix genome detection in biological samples using PCR. A specific region of DNA sequences from the Sporothrix genus, publicly available in GenBank, was chosen for primer design. After testing the in silico specificity of these primers, in vitro specificity was evaluated using the PCR technique. Three specific primers with 100% specificity for the Sporothrix genus were generated. PCR using the designed primers can be used to develop molecular diagnostics for sporotrichosis.

Background: Diseases associated to Candida spp. are recurrent and can be difficult to treat, mainly due to the new strains resistant to the limited number of available antifungals. Objectives: The objective of this study is to evaluate the in vitro and in vivo activity of Brazilian green propolis (GrProp) and red propolis (RdProp) ethanolic extracts against standard strains of Candida albicans, C. tropicalis, C. krusei, C. glabrata, C. parapsilosis and 10 clinical isolates of C. albicans. Methods: Antifungal activity in vitro was tested using the M-27-A3/CLSI protocol. The in vivo antifungal activity was evaluated using Tenebrio molitor model and, the effect of extracts on adhesion of C. albicans in human buccal epithelial cells (BECs) was also studied. Results: GrProp and RdProp exhibited antifungal activity against at least one of the Candida strains tested. The adhesion inhibition of C. albicans in BECs was 45% (GrProp28), 60% (Gr- Prop50) and 82% (RdProp), in comparison to amphotericin B (82%). All propolis extracts showed synergistic activity with fluconazole and amphotericin B. GrProp50 (10 mg/kg) showed better protection of T. molitor, blocking the progression of C. albicans infection, increasing survival and delayed the larvae death. Conclusion: Brazilian GrProp and RdProp extracts inhibit the in vitro C. albicans growth and protect T. molitor against infection by this yeast. The physiochemical parameters found for the analyzed samples were in accordance to the standards established by the Brazilian Legislation for propolis and derivatives. GrProp and RdProp have potential to be used against Candida spp. infections, mainly in association with fluconazole or amphotericin B.