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AIM: The antifungal activity was studied on sessile and persister cells (PCs) of Candida tropicalis biofilms of gold nanoparticles (AuNPs) stabilized with cetyltrimethylammonium bromide (CTAB-AuNPs) and those conjugated with cysteine, in combination with Amphotericin B (AmB). MATERIALS/METHODS: The PC model was used and synergistic activity was tested by the checkerboard assay. Biofilms were studied by crystal violet and scanning electron microscopy. RESULTS/CONCLUSIONS: After the combination of both AuNPs and AmB the biofilm biomass was reduced, with significant differences in architecture being observed with a reduced biofilm matrix. In addition, the CTAB-AuNPs-AmB combination significantly reduced PCs. Understanding how these AuNPs aid in the fight against biofilms and the development of new approaches to eradicate PCs has relevance for chronic infection treatment.
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Anfotericina B , Antifúngicos , Biofilmes , Candida tropicalis , Sinergismo Farmacológico , Ouro , Nanopartículas Metálicas , Testes de Sensibilidade Microbiana , Candida tropicalis/efeitos dos fármacos , Ouro/química , Ouro/farmacologia , Biofilmes/efeitos dos fármacos , Anfotericina B/farmacologia , Anfotericina B/química , Nanopartículas Metálicas/química , Antifúngicos/farmacologia , Antifúngicos/química , Cetrimônio/química , Compostos de Cetrimônio/farmacologia , Compostos de Cetrimônio/químicaRESUMO
Enzymatic compounds can be found abundantly and provide numerous advantages in microbial organisms. Xylanases are used in various pharmaceutical, food, livestock, poultry, and paper industries. This study aimed to investigate xylanase-producing yeasts, xylose concentration curve and their enzymatic activity under various factors including carbon and nitrogen sources, temperature, and pH. Enzyme activity was evaluated under different conditions before, during, and after purification. The yeast strains were obtained from the wood product workshop and were subsequently cultivated on YPD (yeast extract peptone dextrose) medium. Additionally, the growth curve of the yeast and its molecular identification were conducted. The optimization and design process of xylan isolated from corn wood involved the use of Taguchi software to test different parameters like carbon and nitrogen sources, temperature, and pH, with the goal of determining the most optimal conditions for enzyme production. In addition, the Taguchi method was utilized to conduct a multifactorial optimization of xylanase enzyme activity. The isolated species were partially purified using ammonium sulfate precipitation and dialysis bag techniques. The results indicated that 3 species (8S, 18S, and 16W) after molecular identification based on 18S rRNA gene sequencing were identified as Candida tropicalis SBN-IAUF-1, Candida tropicalis SBN-IAUF-3, and Pichia kudriavzevii SBN-IAUF-2, respectively. The optimal parameters for wheat carbon source and peptone nitrogen source were found at 50 °C and pH 9.0 through single-factor optimization. By using the Taguchi approach, the best combination for highest activity was rice-derived carbon source and peptone nitrogen source at 50 °C and pH 6.0. The best conditions for xylanase enzyme production in single-factor optimization of wheat bran were 2135.6 U/mL, peptone 4475.25 U/mL, temperature 50 °C 1868 U/mL, and pH 9.0 2002.4 U/mL. Among the tested yeast, Candida tropicalis strain SBN-IAUF-1 to the access number MZ816946.1 in NCBI was found to be the best xylanase product. The highest ratio of enzyme production at the end of the delayed phase and the beginning of the logarithmic phase was concluded by comparing the growth ratio of 8S, 16W, and 18S yeasts with the level of enzymatic activity. This is the first report on the production of xylan polymer with a relative purity of 80% in Iran. The extracellular xylanases purified from the yeast species of C. tropicalis were introduced as a desirable biocatalyst due to their high enzymatic activity for the degradation of xylan polymers.
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Pichia , Madeira , Xilanos , Madeira/microbiologia , Xilanos/metabolismo , Candida tropicalis/genética , Candida tropicalis/metabolismo , Peptonas/metabolismo , Fermentação , Leveduras , Carbono/metabolismo , Nitrogênio/metabolismo , Endo-1,4-beta-Xilanases/genética , Endo-1,4-beta-Xilanases/metabolismoRESUMO
Fungal infections affect millions of people worldwide, and the several cases are related to invasive infections, which is a problem mainly for immunocompromised people, such as transplant and cancer patients with high mortality and morbidity rates. In addition, the number of emerging and multidrug-resistant fungal species has increased in the last decade. The search for new antifungal compounds is necessary, due to the increase in cases of resistance and the toxicity of drugs used in fungal infection treatment. This work aimed to study the antifungal activity of cercosporamide produced by Phaeosphaeriaceae GV-1. Cercosporamide was tested against pathogenic fungi by determining the minimum inhibitory (MIC) and minimum fungicidal (MFC) concentrations, using the broth microdilution method. Cercosporamide showed antifungal activity in vitro against 13 of 16 strains of medical importance tested, with the most susceptible species being Candida tropicalis, with MIC and MFC of 15.6 µg/mL. Thus, cercosporamide might be considered a promising therapeutic antifungal agent.
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Antifúngicos , Benzofuranos , Humanos , Antifúngicos/farmacologia , Fungos , Testes de Sensibilidade MicrobianaRESUMO
Candida tropicalis, an opportunistic pathogen, ranks among the primary culprits of invasive candidiasis, a condition notorious for its resistance to conventional antifungal drugs. The urgency to combat these drug-resistant infections has spurred the quest for novel therapeutic compounds, with a particular focus on those of natural origin. In this study, we set out to evaluate the impact of isoespintanol (ISO), a monoterpene derived from Oxandra xylopioides, on the transcriptome of C. tropicalis. Leveraging transcriptomics, our research aimed to unravel the intricate transcriptional changes induced by ISO within this pathogen. Our differential gene expression analysis unveiled 186 differentially expressed genes (DEGs) in response to ISO, with a striking 85% of these genes experiencing upregulation. These findings shed light on the multifaceted nature of ISO's influence on C. tropicalis, spanning a spectrum of physiological, structural, and metabolic adaptations. The upregulated DEGs predominantly pertained to crucial processes, including ergosterol biosynthesis, protein folding, response to DNA damage, cell wall integrity, mitochondrial activity modulation, and cellular responses to organic compounds. Simultaneously, 27 genes were observed to be repressed, affecting functions such as cytoplasmic translation, DNA damage checkpoints, membrane proteins, and metabolic pathways like trans-methylation, trans-sulfuration, and trans-propylamine. These results underscore the complexity of ISO's antifungal mechanism, suggesting that it targets multiple vital pathways within C. tropicalis. Such complexity potentially reduces the likelihood of the pathogen developing rapid resistance to ISO, making it an attractive candidate for further exploration as a therapeutic agent. In conclusion, our study provides a comprehensive overview of the transcriptional responses of C. tropicalis to ISO exposure. The identified molecular targets and pathways offer promising avenues for future research and the development of innovative antifungal therapies to combat infections caused by this pathogenic yeast.
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Candida tropicalis is a nonconventional yeast with medical and industrial significance, belonging to the CTG clade. Recent advancements in whole-genome sequencing and genetic analysis revealed its close relation to other unconventional yeasts of biotechnological importance. C. tropicalis is known for its immense potential in synthesizing various valuable biomolecules such as ethanol, xylitol, biosurfactants, lipids, enzymes, α,ω-dicarboxylic acids, single-cell proteins, and more, making it an attractive target for biotechnological applications. This review provides an update on C. tropicalis biological characteristics and its efficiency in producing a diverse range of biomolecules with industrial significance from various feedstocks. The information presented in this review contributes to a better understanding of C. tropicalis and highlights its potential for biotechnological applications and market viability.
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Biotecnologia , Candida tropicalis , Candida tropicalis/genética , Candida tropicalis/metabolismoRESUMO
Candida tropicalis is one of the most pathogenic species within the genus. Increased antifungal resistance has been reported, which is in part due to the organism's ability to form biofilms. In natural products derived from plants, such as essential oils (EOs) or their major components, there is significant potential to develop new antifungals or to both enhance the efficacy and reduce the toxicity of conventional antifungals. This study aimed to evaluate the effect of combining an EO of Lippia origanoides or thymol with fluconazole on an azole-resistant C. tropicalis strain. Synergism was observed in the combination of fluconazole with the EO and with thymol, and minimal inhibitory concentrations for fluconazole decreased at least 32-fold. As a consequence of the synergistic interactions, mitochondrial membrane potential was reduced, and mitochondrial superoxide production increased. Alteration in nuclear morphology, cell surface, and ultrastructure was also observed. In conclusion, the synergistic interaction between L. origanoides EO or thymol with fluconazole reverted the azole-resistant C. tropicalis phenotype. These findings suggest that L. origanoides EO or thymol alone, or in combination with fluconazole, have the potential for development as antifungal therapies for this yeast, including resistant strains.
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INTRODUCTION: Drug resistance to azoles is a growing problem in the Candida genus. OBJECTIVE: To analyze molecularly the genes responsible for fluconazole resistance in Candida tropicalis strains. MATERIALS AND METHODS: Nineteen strains, with and without exposure to fluconazole, were selected for this study. The expression of MDR1, CDR1, ERG11, and ERG3 genes was analyzed in sensitive, dose-dependent sensitive, and resistant strains exposed to different concentrations of the antifungal drug. RESULTS: MDR1, ERG11 and ERG3 genes were significantly overexpressed in the different sensitivity groups. CDR1 gene expression was not statistically significant among the studied groups. Seven of the eight fluconazole-resistant strains showed overexpression of one or more of the analyzed genes. In some dose-dependent sensitive strains, we found overexpression of CDR1, ERG11, and ERG3. CONCLUSION: The frequency of overexpression of ERG11 and ERG3 genes indicates that they are related to resistance. However, the finding of dose-dependent resistant/sensitive strains without overexpression of these genes suggests that they are not exclusive to this phenomenon. More basic research is needed to study other potentially involved genes in the resistance mechanism to fluconazole.
Introducción: La farmacorresistencia a los azoles es un problema creciente en el género Candida. Objetivo: Analizar molecularmente los genes responsables de la resistencia a fluconazol en cepas de Candida tropicalis. Materiales y métodos: Para este estudio, se seleccionaron 19 cepas, con exposición a fluconazol y sin ella. Se analizó la expresión de los genes MDR1, CDR1, ERG11 y ERG3 en cepas sensibles, sensibles dependiente de la dosis, y resistentes, previamente expuestas a diferentes concentraciones del fármaco antifúngico. Resultados: Se encontró que los genes MDR1, ERG11 y ERG3 estaban significativamente sobreexpresados en los diferentes grupos de sensibilidad. La expresión del gen CDR1 no fue estadísticamente significativa entre los grupos estudiados. Siete de las ocho cepas resistentes a fluconazol mostraron sobreexpresión de uno o más de los genes analizados. En algunas cepas sensibles dependientes de la dosis, se encontró sobreexpresión de CDR1, ERG11 y ERG3. Conclusión: La sobreexpresión de los genes ERG11 y ERG3 indica que están relacionados con la resistencia de las cepas de Candida. Sin embargo, el hallazgo de cepas resistentes o sensibles según la dosis, sin sobreexpresión de estos genes, sugiere que pueden existir otros genes involucrados en este fenómeno. Se necesitan más investigaciones básicas que contribuyan al estudio de otros genes potencialmente involucrados en el mecanismo de resistencia al fluconazol.
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Candida tropicalis , Fluconazol , Candida tropicalis/genética , Fluconazol/farmacologia , Candida , Antifúngicos/farmacologiaRESUMO
INTRODUCTION: Candida tropicalis is a common non-albicans Candida (NAC) species that causes numerous fungal infections. Increasing antifungal resistance to azoles in NAC is becoming a major health problem worldwide; however, in Egypt, almost no data is available regarding fluconazole resistance mechanisms in C. tropicalis. The current study aims to investigate two possible important molecular mechanisms involved in fluconazole resistance in C. tropicalis isolates. MATERIALS: Fifty-four clinical C. tropicalis isolates were included. Identification and antifungal susceptibility profiles of the isolates were carried out using the VITEK 2 compact system. The molecular investigation of fluconazole resistance included the expression of the CDR1 and MDR1 genes by quantitative real-time RT-PCR as well as the sequence analysis of the ERG11 gene. RESULTS: Antifungal susceptibility testing identified 30 fluconazole-non-susceptible isolates. Statistically, CDR1 gene expression in fluconazole-non-susceptible isolates was significantly higher than that in fluconazole-susceptible isolates, with MDR1 gene expression levels that were similar in both non-susceptible and susceptible isolates. Sequence analysis of the ERG11 gene of 26 fluconazole-resistant isolates identified two missense mutations: A395T (Y132F) and G1390A (G464S). CONCLUSIONS: This study has highlighted the role of overexpression of the CDR1 gene and ERG11 gene mutations in fluconazole non-susceptibility. Further studies in Egypt are required to investigate other possible molecular mechanisms involved in azole resistance.
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Antifúngicos , Candidíase , Humanos , Antifúngicos/farmacologia , Fluconazol/farmacologia , Candida tropicalis/genética , Candida tropicalis/metabolismo , Egito , Candidíase/microbiologia , Azóis/farmacologia , Candida/genética , Candida/metabolismo , Expressão Gênica , Farmacorresistência Fúngica/genética , Testes de Sensibilidade Microbiana , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Candida albicans/genéticaRESUMO
Candida tropicalis is a notable species of the Candida genus representing an impressive epidemiology in tropical regions, especially in South America and Asia, where India already presents the species as the first in Candida epidemiology. Candida tropicalis has also shown a worrying antifungal resistance profile in recent years. It is essential to highlight that each pathogenic species of the Candida genus has a particular biology; however, Candida virulence factors are almost entirely based on studies with C. albicans. The intrinsic resistance of C. krusei to some azoles, the intrinsic osmotolerance of C. tropicalis, and the multidrug resistance of C. auris are just a few examples of how the biology of each Candida species is unique. Despite being a phylogenetically close species, C. tropicalis can support 15% NaCl, antagonistically metabolize and signal N-acetylglucosamine, encode 16 reported ALS genes, and other specificities discussed here compared to C. albicans. It is essential to clarify the details of the C. tropicalis infectious process, including identifying the participating secreted enzyme(s), the factors responsible for tissue damage, and the mechanisms underlying the morphogenesis and tolerance signaling pathways. In this review, we thoroughly assembled what is known about the main virulence factors of C. tropicalis, highlighting the missing pieces to stimulate further research with C. tropicalis and other non-Candida albicans species.
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Antifúngicos , Candida tropicalis , Animais , Candida tropicalis/genética , Antifúngicos/uso terapêutico , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Candida , Candida albicans , Farmacorresistência Fúngica , Testes de Sensibilidade Microbiana/veterináriaRESUMO
The growing increase in infections caused by C. tropicalis, associated with its drug resistance and consequent high mortality, especially in immunosuppressed people, today generates a serious global public health problem. In the search for new potential drug candidates that can be used as treatments or adjuvants in the control of infections by these pathogenic yeasts, the objective of this research was to evaluate the action of isoespintanol (ISO) against the formation of fungal biofilms, the mitochondrial membrane potential (ΔΨm), and its effect on the integrity of the cell wall. We report the ability of ISO to inhibit the formation of biofilms by up to 89.35%, in all cases higher than the values expressed by amphotericin B (AFB). Flow cytometric experiments using rhodamine 123 (Rh123) showed the ability of ISO to cause mitochondrial dysfunction in these cells. Likewise, experiments using calcofluor white (CFW) and analyzed by flow cytometry showed the ability of ISO to affect the integrity of the cell wall by stimulating chitin synthesis; these changes in the integrity of the wall were also observed through transmission electron microscopy (TEM). These mechanisms are involved in the antifungal action of this monoterpene.