Candida tropicalis has been reported to be one of the Candida species which is most likely to cause bloodstream and urinary tract infections in hospitalized patients. Accordingly, the aim of this ...study was to characterize the virulence of C. tropicalis by assessing antifungal susceptibility and comparing the expression of several virulence factors. This study was conducted with seven isolates of C. tropicalis from urine and blood cultures and from central venous catheter. C. tropicalis ATCC 750 was used as reference strain. Yeasts adhered (2 h) to epithelial cells and silicone and 24 h biofilm biomass were determined by crystal violet staining. Pseudohyphae formation ability was determined after growth in fetal bovine serum. Enzymes production (hemolysins, proteases, phospholipases) was assessed by halo formation on agar plates. Susceptibility to antifungal agents was determined by E-test. Regarding adhesion, it can be highlighted that C. tropicalis strains adhered significantly more to epithelium than to silicone. Furthermore, all C. tropicalis strains were able to form biofilms and to express total hemolytic activity. However, protease was only produced by two isolates from urine and by the isolates from catheter and blood. Moreover, only one C. tropicalis (from catheter) was phospholipase positive. All isolates were susceptible to voriconazole, fluconazole and amphotericin B. Four strains were susceptible-dose dependent to itraconazole and one clinical isolate was found to be resistant.
•New method to Aspergillus flavus identification in foods by HPLC-MS.•The method decreases the time of analysis from 15days to few hours.•The method is sensitive, selective and permits to estimate ...the time of fungus growing.•The article is the first to proposed chemical identification of the fungus in foods.
Aspergillus flavus is a filamentous fungus found in nature and characterized by the production of bright and colourful colonies. It grows on different substrates, producing secondary metabolites and, if present in foodstuffs, can be a source of health problems for humans and animals, as well as causing economic losses. Traditional methods for fungal identification are based on morphological characteristics, requiring specialists and being very time-consuming. The development of analytical alternatives might have advantages such as greater efficiency, more reproducibility and be less time-consuming. Thus, a qualitative analytical method to detect Aspergillus flavus in food samples, based on the identification of fungal chemical markers by HPLC-MS, was developed. The method comprises methanol extraction followed by HPLC-MS analysis, and was able to identify 14 fungus secondary metabolites, namely aflatoxin B1, aflatoxin G1, aspergillic acid, aspyrone, betaine, chrysogine, deacetyl parasiticolide A, flufuran, gregatin B, hydroxysydonic acid, nicotinic acid, phomaligin A, spinulosin and terrein.
Nosocomial infections caused by fungi have increased greatly in recent years, mainly due to the rising number of immunocompromised patients. However, the available antifungal therapeutic arsenal is ...limited, and the development of new drugs has been slow. Therefore, the search for alternative drugs with low resistance rates and fewer side effects remains a major challenge. Plants produce a variety of medicinal components that can inhibit pathogen growth. Studies of plant species have been conducted to evaluate the characteristics of natural drug products, including their sustainability, affordability, and antimicrobial activity. A considerable number of studies of medicinal plants and alternative compounds, such as secondary metabolites, phenolic compounds, essential oils and extracts, have been performed. Thus, this review discusses the history of the antifungal arsenal, surveys natural products with potential antifungal activity, discusses strategies to develop derivatives of natural products, and presents perspectives on the development of novel antifungal drug candidates.
The use of natural products such as propolis extract (PE) is a promising alternative when topically administered to replace conventional antifungals, mostly due to its therapeutic applications, ease ...of access and low toxicity. However, despite being the subject of several mycology studies, they focus primarily on exploiting their antimicrobial activity, lacking information on the mechanisms of action of PE on Candida spp., characterizing its antifungal potential.
To elucidate the bioactivity of PE on the cellular structure of Candida albicans.
A total of seven C. albicans clinical isolates plus a reference strain of C. albicans ATCC 90028 were used in this study. The PE was characterized and its effect on C. albicans was determined by susceptibility and growth kinetics assays; interference on C. albicans germination and filamentation; evaluation of the integrity of the C. albicans cell wall and membrane, as well as its mutagenic potential.
The PE presented strong inhibitory activity, which showed its greatest antifungal activity at 12 h with dose and time dependent fungistatic characteristics, effectively inhibiting and interfering on C. albicans filamentation. In addition, PE caused membrane and cell wall damage with intracellular content extravasation. Moreover, PE was not mutagenic.
The bioactivity of PE is mainly related to the loss of integrity membrane as well as the integrity of the cell wall and consequent increase in permeability, without mutagenic effects.
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Background
Intragastric balloon (IGB) is a medical device used in the endoscopic treatment of pre-obesity and obesity. The involvement of IGB with biofilms has been previously reported; however, ...little is still known. We determine the frequency of biofilms naturally formed on the external surface of IGB, as well as some variables related to IGB types and patients features, species of fungi involved, and biofilm evidence.
Methods
A retrospective study was conducted based on endoscopies and medical records of patients with explanted IGB between 2015 and 2018, which had masses strongly adhered to the surface of the balloon, suspecting the presence of a biofilm. From 2018, the samples of those masses were investigated seeking biofilm characterization based on mycological and structural aspects.
Results
A total of 149 endoscopies were surveyed; 27 IGBs (18.12%) showed signs suggesting biofilm formation. There was no significant difference between biofilm involvement in IGB and the anthropometric and demographic profile of the patients. On the other hand, there was a significant difference regarding the IGB type, 24.05% of the adjustable IGB were compromised by biofilm, while in non-adjustable IGB, it was 11.43% (
p
= 0.04; OR 2.45; 95% CI, 0.98–6.12).
Candida glabrata
was the most isolated fungal species from the well-organized fungal biofilm.
Conclusions
The frequency of fungal biofilm naturally formed on the external surface of IGB was elevated. The risk of biofilm formation was increased for the adjustable IGB, but it did not relate to the demographic data and anthropometric patient profile.
Graphical abstract
To evaluate the effect of propolis against Candida species planktonic cells and its counterpart's biofilms.
The MIC values, time-kill curves and filamentation form inhibition were determined in ...Candida planktonic cells. The effect of propolis on Candida biofilms was assessed through quantification of CFUs.
MIC values, ranging from 220 to 880 µg/ml, demonstrated higher efficiency on C. albicans and C. parapsilosis than on C. tropicalis cells. In addition, propolis was able to prevent Candida species biofilm's formation and eradicate their mature biofilms, coupled with a significant reduction on C. tropicalis and C. albicans filamentation.
Propolis is an inhibitor of Candida virulence factors and represents an innovative alternative to fight candidiasis.
•Photodynamic therapy is a therapeutic option with low toxicity and easy application.•Currently, few therapeutic options to treatment of sporotrichosis are available.•Photodynamic therapy against ...Sporothrix spp. has been proven in vitro and in vivo.•Methylene blue and aminolevulinic acid were fungicides against Sporothrix spp.
Sporotrichosis is a worldwide zoonosis, prevalent in tropical and subtropical regions. In recent years, there has been a substantial increase in human and feline cases reported in Brazil. Despite this, the antifungal treatment for sporotrichosis is still limited, and thus, research into new therapeutic modalities must be encouraged. Recently, photodynamic therapy has been introduced as a treatment for sporotrichosis. This work presents an overview of both in vitro and in vivo studies that have used photodynamic therapy in the context of photoinactivation of Sporothrix species. Until now, as far as the authors are aware, this is the first scope review specifically on photodynamic therapy for the treatment of sporotrichosis. A systematic electronic search was conducted in two databases: Web of Science and PubMed. Seven original articles published from 2010 to July 2021 were selected, six of which met the proposed inclusion and exclusion criteria and were considered in this scoping review. Concerning the photoinactivation of Sporothrix spp. the results have been promising as studies, in both animals and humans, have reported significant clinical and mycological effects. The most used photosensitizers were methylene blue and its derivatives, and aminolevulinic acid and its methyl derivative, methyl aminolevulinic acid. In conclusion, photodynamic therapy has great potential in treatment of sporotrichosis, as its fungicidal effect both in vitro and in vivo has clearly been demonstrated. Photodynamic therapy could be used in conjunction with classic antifungal agents to optimize treatment outcomes.
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Onychomycosis is a chronic fungal infection of nails, commonly caused by dermatophyte fungi, primarily species of
. Because of the limited drug arsenal available to treat general fungal infections ...and the frequent failure of onychomycosis treatment, the search for new therapeutic sources is essential, and topical treatment with natural products for onychomycosis has been encouraged. Propolis, an adhesive resinous compound produced by honeybees (
), has shown multiple biological properties including significant antifungal and anti-biofilm activities
. In spite of promising
results,
results have not been reported so far. This study assessed an ethanol propolis extract (PE) as a topical therapeutic option for onychomycosis, including its characterization
and its applicability as a treatment for onychomycosis (from bench to clinic). The
evaluation included analysis of the cytotoxicity and the antifungal activity against the planktonic cells and biofilm formed by
spp. We also evaluated the capacity of PE to penetrate human nails. Patients with onychomycosis received topical PE treatments, with a 6-month follow-up period. The results of the
assays showed that PE was non-toxic to the cell lines tested, and efficient against both the planktonic cells and the biofilm formed by
spp. The results also showed that PE is able to penetrate the human nail. The results for PE applied topically to treat onychomycosis were promising, with complete mycological and clinical cure of onychomycosis in 56.25% of the patients. PE is an inexpensive commercially available option, easy to obtain and monitor. Our results indicated that PE is a promising natural compound for onychomycosis treatment, due to its ability to penetrate the nail without cytotoxicity, and its good antifungal performance against species such as
spp. that are resistant to conventional antifungals, both
and in patients.
To evaluate and characterize the etiopathogenesis of the fusarial onychomycosis in an ex vivo study through fragments of sterile human nail, without the addition of any nutritional source.
The ...infection and invasion of Fusarium oxysporum in the nail were evaluated by scanning electron microscopy (SEM), CFU, matrix, histopathology and Fourier Transform Infrared Spectrometer coupled to an equipment with diamond accessory (FTIR-ATR).
F. oxysporum infected and invaded across the nail, regardless of application face. However, the dorsal nail surface was the strongest barrier, while the ventral was more vulnerable to infection and invasion process. The fungal-nail interaction resulted in the formation of a dense biofilm.
F. oxysporum infect and invade the healthy human nail, resulting in biofilm formation. Therefore, F. oxysporum is likely a primary onychomycosis agent.
This study evaluated the influence of the extract of
in adhesion to human buccal epithelial cells (HBEC) biofilm formation and cell surface hydrophobicity (CSH) of
spp. isolated from the oral cavity ...of kidney transplant patients. To evaluate virulence attributes in vitro, nine yeasts were grown in the presence and absence of 1000 μg/mL of the extract. Adhesion was quantified using the number of
cells adhered to 150 HBEC determined by optical microscope. Biofilm formation was evaluated using two methodologies: XTT (2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2
-tetrazolium-5-carboxanilide) and crystal violet assay, and further analyzed by electronic scan microscopy. CSH was quantified with the microbial adhesion to hydrocarbons test. We could detect that the extract of
was able to reduce adhesion to HBEC and CSH for both
and non-
species. We also observed a statistically significant reduced ability to form biofilms in biofilm-producing strains using both methods of quantification. However, two highly biofilm-producing strains of
had a very large reduction in biofilm formation. This study reinforces the idea that besides growth inhibition,
may interfere with the expression of some virulence factors of
spp. and may be possibly applied in the future as a novel antifungal agent.
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