RESUMEN
Chromoblastomycosis (CBM) is a chronic subcutaneous infection caused by genera of melanized fungi: Fonsecaea, Cladophialophora, Phialophora, Exophiala, and Rhinocladiella. Melanin is a virulence factor known to influence antifungal susceptibility. A specific inhibitor of melanin biosynthesis is tricyclazole. The aim of this study was to evaluate the effect of melanin inhibition on antifungal susceptibility of chromoblastomycosis agents and describe the susceptibility profiles of some unusual CBM agents. Seventy-six clinical isolates, representing 13 species of the five main genera of CBM agents, were studied. The antifungal susceptibility testing was performed according to the M38-A2 protocol of CLSI (Reference Method for Broth Dilution Antifungal Susceptibility Testing of Filamentous Fungi, 3rd ed., CLSI Standard M38, 2017). In the melanin inhibition test, 16 mg/liter of tricyclazole was added to the medium used in the inoculum preparation and the susceptibility assay. CBM agents were less susceptible to amphotericin B than azoles and terbinafine. The unusual species showed similar susceptibility profiles to those of other species of the same genera. With tricyclazole exposure, MICs of terbinafine, posaconazole, and itraconazole for Fonsecaea spp. significantly decreased (P < 0.05). For Phialophora spp., this reduction was significant for posaconazole and itraconazole. For the other genera, there was a reduction in MICs of terbinafine and itraconazole; however, the statistical tests were not significant. Melanin inhibition can increase the antifungal susceptibility of most CBM agents to itraconazole and terbinafine, the main drugs used in the disease treatment. This increased susceptibility may open up new possibilities for therapy in refractory cases of CBM and/or cases caused by resistant fungal strains. Further studies are needed to confirm the same results in vivo.
Asunto(s)
Ascomicetos , Cromoblastomicosis , Antifúngicos/farmacología , Cromoblastomicosis/tratamiento farmacológico , Humanos , Itraconazol/farmacología , Melaninas , Pruebas de Sensibilidad Microbiana , TerbinafinaRESUMEN
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.
Asunto(s)
Antifúngicos/farmacología , Antioxidantes/farmacología , Ascomicetos/efectos de los fármacos , Cromoblastomicosis/tratamiento farmacológico , Melaninas/farmacología , Naftoles/farmacología , Ascomicetos/patogenicidad , Humanos , Melaninas/análisis , Naftoles/análisisRESUMEN
Tetranychus urticae Koch and Polyphagotarsonemus latus Banks are mite species considered capable of attaining pest levels, damaging a range of agricultural crops. The Pampa biome is characterized by the high biodiversity it houses, particularly microbial diversity, which highlights its potential for developing microorganisms that can provide biological control of arthropods. The aim of this study was to evaluate the activity of four fungal isolates from the soil of the Pampa biome in the biological control of T. urticae (females and eggs) and P. latus (females). Experiments consisted of isolating and identifying fungal isolates for spore quantification and aspersion at 108, 106, and 104 spores/mL concentrations in arenas containing T. urticae females and eggs, and P. latus females, separately. Results indicated that only three isolates (Aspergillus brunneoviolaceus, Clonostachys chloroleuca, and Penicillium adametzii) showed high control of T. urticae females, yet they did not exhibit any control of T. urticae eggs and P. latus females. Therefore, the present study confirms the viability of some of these fungi as biological control agents of mites, which implies the importance of new prospects with other fungal species, considering the richness of resources in the Pampa biome, or even the need to test higher concentrations and other variables using the microorganisms of the present study.
Asunto(s)
Ácaros , Tetranychidae , Animales , Aspergillus , Ecosistema , Femenino , Hongos , Hypocreales , Penicillium , Control Biológico de Vectores , SueloRESUMEN
Cephalexin (CEX) is an antibiotic commonly used to treat bacterial infections in humans and animals. However, it is also a micropollutant. Thus, this study evaluated the degradation of CEX using ultraviolet irradiation (UV-C) and analyzed the by-products as well as their residual antimicrobial activity. A reactor with a mercury vapor lamp was used for the degradation. Irradiated CEX solutions were collected over a period of 4 hours and analyzed using high-performance liquid chromatography coupled with mass spectrometry. For the residual antimicrobial activity the susceptibility test was performed using Staphylococcus aureus and Escherichia coli microorganisms by broth microdilution. It was found that CEX, after treatment, generated a metabolite with a mass of 150 m/z in 15 min. A four- and eightfold increase in the minimum inhibitory concentration of the drug against S. aureus and E. coli could be observed, respectively, after 20 min. Therefore, this treatment proved to be effective in the degradation of CEX, being able to degrade 81% of the initial molecule of the drug in 20 min. Furthermore, the antimicrobial activity of the CEX solution decreased as the irradiation time increased, indicating loss of antimicrobial function of the initial CEX molecule and the resulting by-products.
Asunto(s)
Cefalexina , Staphylococcus aureus , Animales , Antibacterianos/farmacología , Escherichia coli , Humanos , Pruebas de Sensibilidad MicrobianaRESUMEN
Chromoblastomycosis (CBM) is a chronic cutaneous and subcutaneous infection caused by melanized fungal species. We quantified the extractable melanin of 77 strains of CBM agents distributed within five genera. Moreover, resistance to oxidative stress was evaluated in strains exposed or not to the melanin inhibitor tricyclazole. The median percentage of melanin mass extracted from dry fungal mass varied from 0.69 (Rhinocladiella similis) to 3.81 (Phialophora americana). Inhibition of melanin synthesis decreased survival rates to hydrogen peroxide. Together, these data highlight the importance of melanin in CBM agents.
Asunto(s)
Ascomicetos/química , Ascomicetos/fisiología , Cromoblastomicosis/microbiología , Melaninas/análisis , Estrés Oxidativo , Antifúngicos/farmacología , Ascomicetos/efectos de los fármacos , Ascomicetos/aislamiento & purificación , Humanos , Peróxido de Hidrógeno/farmacología , Melaninas/biosíntesis , Viabilidad Microbiana/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Phialophora/química , Phialophora/efectos de los fármacos , Phialophora/aislamiento & purificación , Phialophora/fisiología , Especificidad de la Especie , Esporas Fúngicas/fisiología , Tiazoles/farmacologíaRESUMEN
The stored food mite Tyrophagus putrescentiae (Schrank) (Acari: Acaridae) has been associated with the presence of several fungal species. The aims of this work were to evaluate T. putrescentiae population growth associated to environmental and medically important fungal species to determine on which fungal species populations of T. putrescentiae performs best, and to evaluate their ability to disperse each fungal species. First, 24 fungal species were inoculated separately in Petri dishes containing Sabouraud agar medium. One week after inoculation, 50 mites were added to each plate. On the 28th evaluation day, mites and eggs were counted in each plate, and 50 mites randomly collected from each replicate were transferred to new plates containing only Sabouraud agar medium. Then, mites, eggs, and fungal population were evaluated in each plate on day 28 again. The highest population increases were on Trichophyton mentagrophytes, Alternaria sp., Microsporum gypseum, and Aspergillus chevalieri. With Fusarium guttiforme and the medically important fungi Microsporum canis, M. gypseum, T. mentagrophytes, and Sporothrix sp., mites were observed to feed on whole mycelium. Only eight fungal species were dispersed by T. putrescentiae to the new Petri dishes: Aspergillus clavatus, Candida tropicalis, Candida albicans, Fusarium guttiforme, Hyphopichia burtonii, Penicillium citrinum, Rhizophus azygosporus, and Trichophyton mentagrophytes. The best performance of T. putrescentiae was found feeding on F. guttiforme, P. citrinum, and T. mentagrophytes. In conclusion, T. putrescentiae successfully used fungi as a food source, and it proved to be an important tool for disseminating both environmental and medically important fungi.
Asunto(s)
Acaridae/fisiología , Cadena Alimentaria , Hongos/fisiología , Herbivoria , Animales , Crecimiento DemográficoRESUMEN
PURPOSE: To evaluate the in vitro activity of 8% rosemary, 2% castor oils, and 12% propolis glycolic extract against Candida albicans, as well as the physical changes of properties in colorless and pink acrylic resins after immersion in these liquids. MATERIALS AND METHODS: Colorimetric, roughness, and Knoop microhardness assays were evaluated in 25 specimens distributed into five groups (3 test groups and 2 control groups - distilled water and hypochlorite 1%), totaling five specimens per group for each acrylic resin (colorless and pink). The specimens were individually immersed for 30 minutes in 10 mL of these liquids, washed, and dried once a week. They were maintained in distilled water at 37°C between processes during all experiments. The analyses were performed before immersion and in the 4th and/or 12th month. In vitro, 18 acrylic resins were exposed to C. albicans and, after a process of 30 minutes in immersion in the five groups cited and oil vehicle control of vesicle (liquid Vaseline), the specimens were washed and incubated for 24 hours in 37°C. The growth was determined by colony counting. For comparisons between the groups in each trial and the disinfection test, paired Student's t-tests and ANOVA with post hoc Tukey were performed by the SPSS program, considering α = 0.05. RESULTS: None of the liquids altered the microhardness, but all the natural compounds and 1% sodium hypochlorite (control) altered color and roughness after the 12th month of immersion in these agents. In the colorless specimens, 8% rosemary oil caused a color change similar to water, and less color and roughness alterations when compared to 2% castor oil and 1% sodium hypochlorite, respectively. There was no growth of yeast colonies after immersion in rosemary oil, propolis glycolic extract, and 1% sodium hypochlorite. CONCLUSION: Eight percent rosemary oil has the potential to be used as an acrylic resin disinfectant.
Asunto(s)
Resinas Acrílicas/química , Candida albicans/efectos de los fármacos , Aceite de Ricino/farmacología , Extractos Vegetales/farmacología , Própolis/farmacología , Rosmarinus , Colorimetría , Desinfectantes/farmacología , Dureza , Técnicas In Vitro , Hipoclorito de Sodio/química , Propiedades de Superficie , Agua/químicaRESUMEN
Fusarium species have emerged as an important human pathogen in skin disease, onychomycosis, keratitis and invasive disease. Onychomycosis caused by Fusarium spp. The infection has been increasingly described in the immunocompetent and immunosuppressed hosts. Considering onychomycosis is a difficult to treat infection, and little is known about the genetic variability and susceptibility pattern of Fusarium spp., further studies are necessary to understand the pathogenesis and better to define the appropriate antifungal treatment for this infection. Accordingly, the objective of this study was to describe the in vitro susceptibility to different antifungal agents and the genetic diversity of 35 Fusarium isolated from patients with onychomycosis. Fusarium spp. were isolated predominantly from female Caucasians, and the most frequent anatomical location was the nail of the hallux. Results revealed that 25 (71.4%) of isolates belonged to the Fusarium solani species complex, followed by 10 (28.5%) isolates from the Fusarium oxysporum species complex. Noteworthy, the authors report the first case of Neocosmospora rubicola isolated from a patient with onychomycosis. Amphotericin B was the most effective antifungal agent against the majority of isolates (60%, MIC ≤4 µg/mL), followed by voriconazole (34.2%, MIC ≤4 µg/mL). In general, Fusarium species presented MIC values >64 µg/mL for fluconazole, itraconazole and terbinafine. Accurate pathogen identification, characterisation and susceptibility testing provide a better understanding of pathogenesis of Fusarium in onychomycosis.
Asunto(s)
Antifúngicos/farmacología , Fusarium/efectos de los fármacos , Fusarium/genética , Variación Genética , Onicomicosis/microbiología , Anfotericina B/farmacología , Femenino , Fluconazol/farmacología , Fusariosis/microbiología , Fusarium/aislamiento & purificación , Fusarium/patogenicidad , Humanos , Itraconazol/farmacología , Pruebas de Sensibilidad Microbiana , Uñas/microbiología , Naftalenos/farmacología , Terbinafina , Voriconazol/farmacologíaRESUMEN
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.
Asunto(s)
Antozoos/microbiología , Antifúngicos/farmacología , Basidiomycota/efectos de los fármacos , Basidiomycota/aislamiento & purificación , Candida/efectos de los fármacos , Candida/aislamiento & purificación , Farmacorresistencia Fúngica Múltiple , Animales , Basidiomycota/genética , Brasil , Candida/genética , ADN Ribosómico/genética , Esterasas/biosíntesis , Fluconazol/farmacología , Gelatinasas/biosíntesis , Humanos , Imidazoles/farmacología , Pruebas de Sensibilidad Microbiana , Naftalenos/farmacología , Análisis de Secuencia de ADN , Terbinafina , Triazoles/farmacologíaRESUMEN
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.
Asunto(s)
Antifúngicos/farmacología , Ascomicetos/efectos de los fármacos , Ascomicetos/enzimología , Microbiología Ambiental , Hidrolasas/análisis , Animales , Ascomicetos/clasificación , Ascomicetos/aislamiento & purificación , Brasil , Medios de Cultivo/química , ADN de Hongos/química , ADN de Hongos/genética , ADN Ribosómico/química , ADN Ribosómico/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Humanos , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , ARN Ribosómico/genética , Análisis de Secuencia de ADN , Cloruro de Sodio/metabolismoRESUMEN
Sporotrichosis is a subacute or chronic mycosis caused worldwide by the dimorphic species complex, Sporothrix schenckii. We studied 85 isolates recovered in Brazil to verify their identification and evaluate their in vitro antifungal susceptibility patterns. Based on phenotypic tests (microscopic features, ability to grow at 30°C and 37°C, colony diameters, as well as assimilation of sucrose and raffinose) and molecular assays (amplification of a fragment of the calmodulin gene), the strains were identified as S. schenckii, S. brasiliensis and S. globosa, with a predominance of S. schenckii isolates. There was 37.7% disagreement between the phenotypic and genotypic identification methodologies. In general, terbinafine was the most active drug, followed by ketoconazole and itraconazole, and the less active fluconazole and voriconazole. Five isolates (one S. globosa and four S. schenckii) were found to be itraconazole-resistant strains but, in general, there were no differences in the in vitro antifungal susceptibility profiles among the Sporothrix species.
Asunto(s)
Antifúngicos/farmacología , Sporothrix/clasificación , Esporotricosis/microbiología , Brasil , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación Molecular , Técnicas de Tipificación Micológica , Sporothrix/genética , Sporothrix/aislamiento & purificación , Sporothrix/fisiologíaRESUMEN
Chromoblastomycosis is a chronic mycosis that affects the skin and subcutaneous tissues caused by several genera of dematiaceous fungi. There is not a treatment of choice. Thus, tools that help guide clinical practice are fundamental. In this sense, antifungal activity tests in vitro could be useful. However, trials with chromoblastomycosis agents are scarce. The aim of this study was to evaluate both the in vitro susceptibility of 60 chromoblastomycosis agents to five antifungals and the combination of amphotericin B (AMB) and terbinafine (TRB). TRB, itraconazole (ITZ) and ketoconazole (KTZ) were, in this order, the drugs which showed better activity against the chromoblastomycosis agents. The less active drugs were voriconazole (VRZ) and AMB. The more differentiated group was Exophiala spinifera. Cladophialophora carrionii and Fonsecaea spp. are significantly more susceptible to KTZ than Phialophora verrucosa, whereas C. carrionii is significantly more sensitive to VRZ than P. verrucosa and E. spinifera. Assays in this direction allow the knowledge of the susceptibility of the causative agents which may help the management of patients with this disease. This study includes the largest number of these agents and of genera found in the literature.
Asunto(s)
Anfotericina B/farmacología , Antifúngicos/farmacología , Cromoblastomicosis/microbiología , Sinergismo Farmacológico , Hongos/efectos de los fármacos , Naftalenos/farmacología , Animales , Hongos/aislamiento & purificación , TerbinafinaRESUMEN
The Sporothrix schenckii complex is the etiologic agent of sporotrichosis, a subacute or chronic mycosis which can affect humans and animals. Killer yeasts have been used in the medical field for development of novel antimycotics and biotyping of pathogenic fungi. The action of 18 killer yeasts on the growth of 88 characterized S. schenckii, Sporothrix globosa, Sporothrix brasiliensis, and Sporothrix mexicana clinical and environmental isolates was evaluated. Killer studies were performed on Petri dishes containing cheese black starch agar. The yeasts Candida catenulata (QU26, QU31, QU127, LV102); Trichosporon faecale (QU100); Trichosporon japonicum (QU139); Kluyveromyces lactis (QU30, QU99, QU73); Kazachstania unispora (QU49), Trichosporon insectorum (QU89), and Kluyveromyces marxianus (QU103) showed activity against all strains of the S. schenckii complex tested. Observation by optical microscopy of S. brasiliensis 61 within the inhibition haloes around the colonies of the killer yeasts QU100, QU139, and LV102 showed that there was no conidiation, but there was hyphal proliferation. The toxins were fungistatic against S. brasiliensis 61. There was no difference in susceptibility to the toxins among the S. schenckii species complex. Further investigations are necessary to clearly establish the mechanism of action of the toxins.
Asunto(s)
Antibiosis , Sporothrix/crecimiento & desarrollo , Levaduras/fisiología , Argentina , Brasil , Medios de Cultivo/química , Microbiología Ambiental , Humanos , Hifa/crecimiento & desarrollo , Esporas Fúngicas/crecimiento & desarrollo , Sporothrix/aislamiento & purificación , Esporotricosis/microbiologíaRESUMEN
The Coronavirus Disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has required the search for sensitive, rapid, specific, and lower-cost diagnostic methods to meet the high demand. The gold standard method of laboratory diagnosis is real-time reverse transcription polymerase chain reaction (RT-PCR). However, this method is costly and results can take time. In the literature, several studies have already described the potential of Fourier transform infrared spectroscopy (FTIR) as a tool in the biomedical field, including the diagnosis of viral infections, while being fast and inexpensive. In view of this, the objective of this study was to develop an FTIR model for the diagnosis of COVID-19. For this analysis, all private clients who had performed a face-to-face collection at the Univates Clinical Analysis Laboratory (LAC Univates) within a period of six months were invited to participate. Data from clients who agreed to participate in the study were collected, as well as nasopharyngeal secretions and a saliva sample. For the development of models, the RT-PCR result of nasopharyngeal secretions was used as a reference method. Absorptions with high discrimination (p < 0.001) between GI (28 patients, RT-PCR test positive to SARS-CoV-2 virus) and GII (173 patients who did not have the virus detected in the test) were most relevant at 3512 cm-1, 3385 cm-1 and 1321 cm-1 after 2nd derivative data transformation. To carry out the diagnostic modeling, chemometrics via FTIR and Discriminant Analysis of Orthogonal Partial Least Squares (OPLS-DA) by salivary transflectance mode with one latent variable and one orthogonal signal correction component were used. The model generated predictions with 100 % sensitivity, specificity and accuracy. With the proposed model, in a single application of an individual's saliva in the FTIR equipment, results related to the detection of SARS-CoV-2 can be obtained in a few minutes of spectral evaluation.
Asunto(s)
COVID-19 , Humanos , COVID-19/diagnóstico , SARS-CoV-2 , Saliva , Quimiometría , Espectrofotometría Infrarroja , Sensibilidad y EspecificidadRESUMEN
Fungal melanin contributes to the survival and virulence of pathogenic fungi, such as Fonsecaea pedrosoi, which is responsible for causing chromoblastomycosis. The objective of this study was to employ Fourier transform infrared spectroscopy (FTIR) to predict the melanin content of F. pedrosoi. The melanin content, in percentage, was previously determined using gravimetry for twenty-six clinical isolates. Quintuplicate spectra of each isolate were obtained using attenuated total reflection (ATR) within the range of 4000 to 650 cm-1. To predict the melanin content, modeling was performed using partial least squares regression (PLS) in the region 1800 - 750 cm-1. Two models were tested: PLS and successive projections algorithms for interval selection in partial least squares (iSPA-PLS). The best modeling results were achieved using iSPA-PLS with one factor. The calibration set exhibited a determination coefficient (R2) of 0.9745 and a root mean square error of cross-validation (RMSECV) of 0.0977. In the prediction set, the R2 value was 0.9711, and the root mean square error of prediction (RMSEP) was 0.0999. Modeling with FTIR and multivariate calibration provides a valuable means of predicting fungal melanin content, which is simpler and more robust, thereby contributing to the advancement of this field of study.
Asunto(s)
Quimiometría , Fonsecaea , Melaninas , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Análisis de los Mínimos CuadradosRESUMEN
Baccharis vulneraria Baker is used popularly for the treatment of skin infections. So, this study aimed investigate the antimicrobial activity and chemical characterization of the essential oil (EO) against microorganisms that cause cutaneous infections. The EO was analyzed by GC-MS. The antimicrobial test was performed using the serial microdilution method, and the antimicrobial activity was determined by the minimum inhibitory concentration against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Trichophyton interdigitale, Trichophyton rubrum, Fusarium solani and Fusarium oxysporum within the 32-0.0625 mg/mL concentration range. Were identified 31 EO compounds. Its major compounds are bicyclogermacrene, trans-cadin-1,4-diene, ß-caryophyllene, and germacrene A. EO showed antifungal action against T. rubrum and T. interdigitale (2 and 4 mg/mL MIC, respectively). The growth of C. albicans, at 4 mg/mL, decreased by 50% compared to control. The oil had no significant potential for other microorganisms at the selected concentrations.
Asunto(s)
Antiinfecciosos , Baccharis , Aceites Volátiles , Aceites Volátiles/química , Antiinfecciosos/farmacología , Antifúngicos/farmacología , Candida albicans , Pruebas de Sensibilidad MicrobianaRESUMEN
Malassezia pachydermatis is often reported as the causative agent of dermatitis in dogs. This study aims to evaluate the in vitro and in vivo antifungal activity of azoles and terbinafine (TRB), alone and in combination with the 8-hydroxyquinoline derivatives (8-HQs) clioquinol (CQL), 8-hydroxyquinoline-5-(n-4-chlorophenyl)sulfonamide (PH151), and 8-hydroxyquinoline-5-(n-4-methoxyphenyl)sulfonamide (PH153), against 16 M. pachydermatis isolates. Susceptibility to the drugs was evaluated by in vitro broth microdilution and time-kill assays. The Toll-deficient Drosophila melanogaster fly model was used to assess the efficacy of drugs in vivo. In vitro tests showed that ketoconazole (KTZ) was the most active drug, followed by TRB and CQL. The combinations itraconazole (ITZ)+CQL and ITZ+PH151 resulted in the highest percentages of synergism and none of the combinations resulted in antagonism. TRB showed the highest survival rates after seven days of treatment of the flies, followed by CQL and ITZ, whereas the evaluation of fungal burden of dead flies showed a greater fungicidal effect of azoles when compared to the other drugs. Here we showed for the first time that CQL is effective against M. pachydermatis and potentially interesting for the treatment of malasseziosis.
Asunto(s)
Antifúngicos , Azoles , Dermatomicosis , Drosophila melanogaster , Malassezia , Pruebas de Sensibilidad Microbiana , Animales , Antifúngicos/farmacología , Malassezia/efectos de los fármacos , Malassezia/crecimiento & desarrollo , Azoles/farmacología , Dermatomicosis/tratamiento farmacológico , Dermatomicosis/microbiología , Drosophila melanogaster/microbiología , Drosophila melanogaster/efectos de los fármacos , Perros , Terbinafina/farmacología , Sinergismo Farmacológico , Quimioterapia Combinada , Enfermedades de los Perros/microbiología , Enfermedades de los Perros/tratamiento farmacológico , Cetoconazol/farmacología , Oxiquinolina/farmacología , Sulfonamidas/farmacología , Itraconazol/farmacología , Clioquinol/farmacología , Modelos Animales de EnfermedadRESUMEN
Coumarins are benzopyrones found in several plant genera, including Pterocaulon (Asteraceae). These compounds represent an important source of new treatments, especially as antimicrobial and antifungal agents. In this study, two coumarin-rich extracts from Pterocaulon balansae using green technologies were obtained through aqueous maceration (AE) and supercritical fluid extraction (SFE). Such extracts were incorporated into nanoemulsions (NAE and NSFE) composed of a medium-chain triglyceride oil core stabilized by phospholipids. The nanoemulsions exhibited droplet sizes between 127 and 162 nm, pH above 5.0, and viscosity of approximately 1.0 cP, properties compatible with the topical route. The coumarins permeation/retention from formulations through ear porcine skin using Franz-type diffusion cells were evaluated. Whatever the extract, coumarins were distributed in skin layers, especially in the dermis in both intact and impaired (tape stripping) skin. In addition, a significant increase in coumarins that reached up to the receptor fluid was observed for impaired skin, with increases of approximately threefold for NAE and fourfold for NSFE. Finally, antifungal activity of nanoemulsions was evaluated according to minimum inhibitory concentrations, and the values were 250 µg/mL for all strains tested. The overall results demonstrated the feasibility of incorporating P. balansae extracts into nanoemulsions and showed a potential alternative for the treatment of sporotrichosis.
RESUMEN
Chromoblastomycosis is a chronic cutaneous and subcutaneous mycosis. The management of this infection continues to be challenging because there is no consensus on the therapeutic regimen. We report here a case of a 69-year-old male patient with cauliflower-like lesions on his left leg and foot. He had already been treated with itraconazole at a dose of 200 mg/day for 5 months, with mycological cure for all the affected areas. However, the lesions relapsed at both sites, and treatment with itraconazole was resumed at the dose previously used. Initially, direct mycological examination, cultural, and microculture slide observation were performed. Afterward, sequencing of the ITS1-5.8S rDNA-ITS2 region of the fungal DNA and evaluation of its susceptibility to antifungal agents alone and in combination were performed. In direct mycological examination, the presence of sclerotic cells was verified, and the fungus was identified as Fonsecaea based on cultural and microscopic examinations. Identification as Fonsecaea monophora was confirmed after sequencing of the ITS region and phylogenetic analysis. The isolate was susceptible to itraconazole and terbinafine. The combinations of amphotericin B and terbinafine and terbinafine and voriconazole were synergistic. The use of drugs for which the causative agent is susceptible to singly or in combination may be an alternative for the treatment of mycosis. Furthermore, the identification of the agent by molecular techniques is important for epidemiological purposes. To the best of our knowledge, this is the first case of relapsed chromoblastomycosis caused by F. monophora in Brazil.
Asunto(s)
Antifúngicos/farmacología , Ascomicetos/efectos de los fármacos , Ascomicetos/aislamiento & purificación , Cromoblastomicosis/diagnóstico , Cromoblastomicosis/microbiología , Anciano , Ascomicetos/clasificación , Ascomicetos/genética , Brasil , Cromoblastomicosis/patología , ADN de Hongos/química , ADN de Hongos/genética , ADN Ribosómico/química , ADN Ribosómico/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Sinergismo Farmacológico , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Técnicas Microbiológicas , ARN Ribosómico 5.8S/genética , Recurrencia , Análisis de Secuencia de ADNRESUMEN
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.