High MICs for antifungal agents in yeasts from an anthropized lagoon in South America.

The lagoons are fragile ecosystems used by several species as a refuge and breeding area, and it is also a place where certain communities practice fishing activity. With increasing urbanization around this ecosystem, pesticides used in agriculture and untreated urban wastewater are drained into the river basin, resulting in the dispersion of organic matter and antifungals used by the population and farmers. These may favor the selection of resistant pathogens directly into the environment, a concern since several fungi have emerged as pathogens in the last decades. In this study, we investigated the presence in an impacted lagoon by potentially resistant yeasts to antifungal agents. We evaluated their capacity for producing extracellular enzymes that could act as virulence factors. Water samples from the Tramandaí lagoon were analyzed for the presence of pesticides using the SPE-LC-ESI-MS/MS. Tricyclazole, carbendazim, azoxystrobin, thiabendazole, and tebuconazole were found. Twenty-eight yeast species were isolated, including the multidrug-resistant Candida haemulonii, and species with high minimal inhibitory concentrations (MICs) for clinical antifungal agents. Around 93% of the isolates had MIC values above the resistance breakpoints established for Candida species for at least two antifungal agents. And 27% had high MICs values for fluconazole, terbinafine, amphotericin B, and caspofungin. Tebuconazole MICs values were highly associated with MICs for fluconazole, terbinafine, and amphotericin B, and significant correlations between high MICs for antifungal agents and enzyme production were found. The results indicated that the lagoon is a reservoir of resistance genes and a potential source for fungal infection, highlighting the importance of the One Health approach and the integrated vision of the ecosystem when managing these environments.

Wickerhamiella martinezcruziae f. a., sp. nov., a yeast species isolated from tropical habitats.

Four yeast isolates with an affinity to the genus Wickerhamiella were obtained from beach sand, a marine zoanthid and a tree exudate at different localities in Brazil. Two other isolates with almost identical ITS and D1/D2 sequences of the large subunit rRNA gene were isolated from the small intestine of cattle and a grease trap in Thailand. These isolates represent a novel species phylogenetically related to Wickerhamiella verensis, Wickerhamiella osmotolerans, Wickerhamiella tropicalis, Wickerhamiella sorbophila and Wickerhamiella infanticola. The novel species differs by 15-30 nucleotide differences from these species in the D1/D2 sequences. The name Wickerhamiella martinezcruziae f.a., sp. nov. is proposed. The holotype of Wickerhamiella martinezcruziae sp. nov. is CBS 16104T. The MycoBank number is MB 839328.

Melanin and chromoblastomycosis agents: Characterization, functions, and relation with antifungals.

Melanins are a diverse group of dark pigments with similar properties. In fungi, the most studied is the dihydroxynaphtalene (DHN)-melanin, present in several species including all the chromoblastomycosis agents, a chronic, disabling, and recalcitrant subcutaneous mycosis. It is synthesized in a pathway known as the pentaketide pathway, which has the agrochemical tricyclazole as an inhibitor, widely used in in vitro studies because it does not prevent the growth of fungi. There are different methodologies for qualitative and quantitative analyses of DHN-melanin, which made it possible to discover its important structural and antioxidant functions, with melanin acting as a protective factor against the host's immune system. Also, it can interact with some of the main antifungals of medical interest, reducing its activity and the susceptibility of fungi to these agents. This review aims to discuss the aspects of DHN-melanin, focusing on chromoblastomycosis, bringing the main findings of the published scientific studies, and highlighting the need for further research to understand this important fungal pathogenicity and a virulence factor.

Chromoblastomycosis caused by Rhinocladiella similis: Case report.

We report a case of chromoblastomycosis in lesions on the chest and foot. Itraconazole was chosen as the initial treatment for this patient, who was followed up for 8 months before becoming noncompliant. The pathogenic fungal species was identified as Rhinocladiella similis by ITS region sequencing. In vitro analyses indicate that the fungus was sensitive to posaconazole and itraconazole. This report presents R. similis as a new agent of chromoblastomycosis and raises the hypothesis that this species could be more resistant to some antifungals than R. aquaspersa.

Susceptibility to antifungal agents and enzymatic activity of Candida haemulonii and Cutaneotrichosporon dermatis isolated from soft corals on the Brazilian reefs.

Candida is a common fungus with the capacity to cause infections in humans. However, most studies have concentrated on clinical isolates and little is known about the identity, ecology and drug resistance of free living species/strains. Here, we isolate eight strains of Candida haemulonii and four strains of Cutaneotrichosporon dermatis from three marine cnidarian zoanthids species (Palythoa caribaeorum, Palythoa variabilis and Zoanthus sociatus) collected from Brazilian coral reefs. Strains were identified by sequencing of the D1/D2 domain LSU rDNA and ITS region. We tested these environmental isolates for their capacity to grow in media with increasing concentration of NaCl, capacity to grow in different temperatures, enzymatic activity and antifungal susceptibility. For C. haemulonii, all strains strongly produced gelatinase, esterase and albuminase and were either able to express lipase, phospholipase and keratinase, but not express urease and DNase. The strains were able to grow at 37 °C, but not at 39 °C, and except for LMS 40, all of them could grow in a 10 % NaCl medium. All isolates were resistant to all antifungals tested, with exception for ketoconazole and tioconazole (MIC = 2 µg/mL). For C. dermatis, all strains could grow at 39 °C and could not express phospholipase, keratinase or gelatinase. However, all were capable of expressing urease, lipase and esterase. Three out of four strains could grow in a 10 % NaCl medium, but none grew in a 30 % NaCl medium. The strains showed high values of minimal inhibitory concentration. LMPV 90 was resistant to tioconazole, terbinafine, fluconazole and posaconazole, and LMS 38 was resistant to all antifungal agents tested. We discuss the characterization of C. haemulonii and C. dermatis as a possible emerging pathogen due to its animal-related enzymatic arsenal and antifungal resistance.

Enzymatic Activity and Susceptibility to Antifungal Agents of Brazilian Environmental Isolates of Hortaea werneckii.

Four strains of Hortaea werneckii were isolated from different substrates in Brazil (a salt marsh macrophyte, a bromeliad and a marine zoanthid) and had their identification confirmed by sequencing of the 26S rDNA D1/D2 domain or ITS region. Most of the strains were able to express amylase, lipase, esterase, pectinase and/or cellulase, enzymes that recognize components of plant cells as substrates, but did not express albuminase, keratinase, phospholipase and DNAse, whose substrates are animal-related. Urease production was positive for all isolates, while caseinase, gelatinase and laccase production were variable among the strains. All the strains grew in media containing up to 30% NaCl. We propose that the primary substrate associated with H. werneckii is plant-related, in special in saline environments, where the fungus may live as a saprophyte and decomposer. Infection of animal-associated substrates would be secondary, with the fungus acting as an opportunistic animal pathogen. All strains were resistant to fluconazole and presented high MIC for amphotericin B, while they were susceptible to all the other antifungal agents tested.

Bullera vrieseae sp. nov., a tremellaceous yeast species isolated from bromeliads.

Two independent surveys of yeasts associated with different bromeliads in different Brazilian regions led to the proposal of a novel yeast species, Bullera vrieseae sp. nov., belonging to the Tremellales clade (Agaricomycotina, Basidiomycota). Analysis of the sequences in the internal transcribed spacer (ITS) region and D1/D2 domain of the LSU rRNA gene suggested affinity to a phylogenetic lineage that includes Bullera miyagiana and Bullera sakaeratica. Six isolates of the novel species were obtained from different bromeliads and regions in Brazil. Sequence analysis of the D1/D2 domains of the large subunit of the rRNA gene showed that the novel species differs from B. miyagiana and B. sakaeratica by 85 and 64 nt substitutions, respectively and by more than 75 nt substitutions in the ITS region. Phenotypically, Bullera vrieseae sp. nov. can be distinguished from both species based on the assimilation of meso-erythritol, which was negative for B. vrieseae sp. nov. but positive for the others, assimilation of d-glucosamine, which was positive for B. vrieseae sp. nov. but negative for B. miyagiana and of l-sorbose, which was negative for B. vrieseae sp. nov. but positive for B. sakaeratica. The novel species Bullera vrieseae sp. nov. is proposed to accommodate these isolates. The type strain of Bullera vrieseae sp. nov. is UFMG-CM-Y379T (BRO443T; ex-type CBS 13870T).