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Introduction: Oral healthcare professionals play a crucial role in guiding patients toward evidence-based choices among the many available oral rinses. In this study, we explored how specific oral rinse formulations affect the viability and modulate critical virulence traits of the opportunistic fungal pathogen Candida albicans.Materials and Methods: We assessed the effects of these oral rinses on the production of germ tube, production of phospholipase and hemolysin, as well as biofilm formation. Results: We found that oral rinses containing cetylpyridinium chloride (CPC) and chlorhexidine (CHX) showed the greatest fungicidal activity with the lowest minimum fungicidal concentrations (0.38% and 0.78%, respectively). Oral rinses based on zinc chloride and sodium fluoride with Miswak bark extract (MIS) or essential oils (EO) had much lower fungicidal activity (8–16 times lower) compared to CHX and CPC. However, they had a significantly greater impact on the virulence traits of C. albicans. They reduced germ tube production by 86–89% (vs. 42% for CHX and 29% for CPC), completely inhibited phospholipase and hemolysin production, and together with the CPC-based oral rinse, exerted the greatest reductions in biofilm formation across all tested concentrations. This was in contrast to both the controls and CHX, which had a minimal effect on biofilm formation. Conclusion: By inhibiting the virulence factors, the oral rinse can have a crippling effect on C. albicans, weakening this opportunistic pathogen and hindering its potential to cause infection. Highlights of the Study: Oral rinses with cetylpyridinium chloride and chlorhexidine showed the most potent fungicidal activity. Zinc chloride and sodium fluoride-based rinses with Miswak bark extract or essential oils significantly affected the virulence traits of C. albicans. Chlorhexidine-based oral rinse had only a minimal effect on biofilm formation, in contrast to the other formulations which exerted high anti-biofilm activity. [ABSTRACT FROM AUTHOR]

The role of the fungal community, the mycobiota, in the health of the vagina is currently an important area of research. The emergence of new sequencing technologies and advances in bioinformatics made possible the discovery of novel fungi inhabiting this niche. Candida spp. constitutes the most important group of opportunistic pathogenic fungi, being the most prevalent fungal species in vulvovaginal infections. However, fungi such as Rhodotorula spp., Naganishia spp. and Malassezia spp. have emerged as potential pathogens in this niche, and therefore it is clinically relevant to understand their ecological interaction with Candida spp. The main aim of this study was to evaluate the impact of yeasts on Candida albicans' pathogenicity, focusing on in-vitro growth, and biofilm formation at different times of co-culture and germ tube formation. The assays were performed with isolated species or with co-cultures of C. albicans (ATCC10231) with one other yeast species: Rhodotorula mucilaginosa (DSM13621), Malassezia furfur (DSM6170) or Naganishia albida (DSM70215). The results showed that M. furfur creates a symbiotic relationship with C. albicans, enhancing the growth rate of the co-culture (149.69%), and of germ tube formation of C. albicans (119.8%) and inducing a higher amount of biofilm biomass of the co-culture, both when mixed (154.1%) and preformed (166.8%). As for the yeasts R. mucilaginosa and N. albida, the relationship is antagonistic (with a significant decrease in all assays), thus possibly repressing the mixture's pathogenicity. These results shed light on the complex interactions between yeasts in the vaginal mycobiome. [ABSTRACT FROM AUTHOR]

Background: Candida is the most common cause of fungal infections. Candida species are identified by different phenotypic methods. Accurate identification of Candida species enables appropriate selection of antifungal agents by clinicians. Azoles are the most frequently used antifungal drugs to treat Candida infections. However, resistance among previously susceptible Candida species has emerged which made antifungal susceptibility testing crucial. Aim: This study aimed to phenotypically identify the different Candida species isolated from various clinical specimens in Suez Canal University Hospitals (SCUHs), and to assess their antifungal susceptibility patterns. Method: One hundred and five clinical specimens were collected from different departments in SCUHs. Isolates were identified as Candida by colony morphology on Sabouraud dextrose agar and Gram staining. Candida species were phenotypically identified using germ tube test, hypertonic Sabouraud broth, corn meal agar, chromogenic Candida agar, KB006 HiCandida Identification Kit and Vitek 2 YST-ID system. Antifungal susceptibility to fluconazole, voriconazole and amphotericin B was done by disk diffusion method. Results: Prevalence of Candida was 54.3%. C. tropicalis was the most common species followed by C. albicans, C. dubliniensis, C. glabrata, C. parapsilosis and lastly C. kefyr. Only one strain was resistant to amphotericin B. Eight strains were susceptible dose dependent, and 2 were resistant to fluconazole. No resistance was detected to voriconazole. Conclusions: The prevalence of candidiasis is remarkable. Non-albicans Candida species (NACs) cause most of these infections. Fluconazole and amphotericin B showed low resistance rates. No resistance to voriconazole was reported in this study. Therefore, voriconazole could be more effective as empirical therapy than fluconazole and amphotericin B. Accurate identification of Candida species is essential for therapeutic and prognostic impact, appropriate selection of antifungal agents by clinicians and controlling the increase of resistant Candida strains.

Background: Candida is the most common cause of fungal infections. Candida species are identified by different phenotypic methods. Accurate identification of Candida species enables appropriate selection of antifungal agents by clinicians. Azoles are the most frequently used antifungal drugs to treat Candida infections. However, resistance among previously susceptible Candida species has emerged which made antifungal susceptibility testing crucial. Aim: This study aimed to phenotypically identify the different Candida species isolated from various clinical specimens in Suez Canal University Hospitals (SCUHs), and to assess their antifungal susceptibility patterns. Method: One hundred and five clinical specimens were collected from different departments in SCUHs. Isolates were identified as Candida by colony morphology on Sabouraud dextrose agar and Gram staining. Candida species were phenotypically identified using germ tube test, hypertonic Sabouraud broth, corn meal agar, chromogenic Candida agar, KB006 HiCandida Identification Kit and Vitek 2 YST-ID system. Antifungal susceptibility to fluconazole, voriconazole and amphotericin B was done by disk diffusion method. Results: Prevalence of Candida was 54.3%. C. tropicalis was the most common species followed by C. albicans, C. dubliniensis, C. glabrata, C. parapsilosis and lastly C. kefyr. Only one strain was resistant to amphotericin B. Eight strains were susceptible dose dependent, and 2 were resistant to fluconazole. No resistance was detected to voriconazole. Conclusions: The prevalence of candidiasis is remarkable. Non-albicans Candida species (NACs) cause most of these infections. Fluconazole and amphotericin B showed low resistance rates. No resistance to voriconazole was reported in this study. Therefore, voriconazole could be more effective as empirical therapy than fluconazole and amphotericin B. Accurate identification of Candida species is essential for therapeutic and prognostic impact, appropriate selection of antifungal agents by clinicians and controlling the increase of resistant Candida strains. [ABSTRACT FROM AUTHOR]

Candida spp. is one of the most common opportunistic human fungal pathogens, responsible for 90–100% of mucosal infections. Germ tube formation, hyphal morphogenesis, the production of tissue-damaging extracellular enzymes, and drug-resistant biofilm formation contribute to their pathogenicity, which can lead to systemic infections in the worst scenarios. Thus, there is an urgent need to discover new therapeutic agents to overcome the above virulence factors. Therefore, we aimed to prepare Crinum latifolium leaves-mediated biosynthesis of gold nanoparticles (AuNPs) that was characterized by various sophisticated techniques, and further their antifungal, antibiofilm, and anti-virulence activities was investigated. The AuNPs show a zone of inhibition between 19 and 22 mm for test strains of Candida spp. at 1000 µg/ml, whereas the MIC values were ranged from 250 to 500 µg/ml. AuNPs inhibit germ tube formation in C. albicans by 93.3% at 50 µg/ml. Furthermore, exposure to AuNPs significantly reduced the secretions of phospholipase, proteinase, hemolysin, esterase, and lipase. Confocal laser scanning microscopy (CLSM) investigation shows that 25 µg/ml of AuNPs significantly inhibit colonization and biofilm formation. Lastly, the interaction of Candidal cells with AuNPs revealed, ultrastructural changes in the cell wall and cell membranes as visualized by a transmission electron microscope (TEM).

The role of the fungal community, the mycobiota, in the health of the vagina is currently an important area of research. The emergence of new sequencing technologies and advances in bioinformatics made possible the discovery of novel fungi inhabiting this niche. Candida spp. constitutes the most important group of opportunistic pathogenic fungi, being the most prevalent fungal species in vulvovaginal infections. However, fungi such as Rhodotorula spp., Naganishia spp. and Malassezia spp. have emerged as potential pathogens in this niche, and therefore it is clinically relevant to understand their ecological interaction with Candida spp. The main aim of this study was to evaluate the impact of yeasts on Candida albicans’ pathogenicity, focusing on in-vitro growth, and biofilm formation at different times of co-culture and germ tube formation. The assays were performed with isolated species or with co-cultures of C. albicans (ATCC10231) with one other yeast species: Rhodotorula mucilaginosa (DSM13621), Malassezia furfur (DSM6170) or Naganishia albida (DSM70215). The results showed that M. furfur creates a symbiotic relationship with C. albicans, enhancing the growth rate of the co-culture (149.69%), and of germ tube formation of C. albicans (119.8%) and inducing a higher amount of biofilm biomass of the co-culture, both when mixed (154.1%) and preformed (166.8%). As for the yeasts R. mucilaginosa and N. albida, the relationship is antagonistic (with a significant decrease in all assays), thus possibly repressing the mixture’s pathogenicity. These results shed light on the complex interactions between yeasts in the vaginal mycobiome.

Infections caused by micro-organisms of the genus Candida are becoming a growing health problem worldwide. These fungi are opportunistic commensals that can produce infections—clinically known as candidiasis—in immunocompromised individuals. The indiscriminate use of different anti-fungal treatments has triggered the resistance of Candida species to currently used therapies. In this sense, propolis has been shown to have potent antimicrobial properties and thus can be used as an approach for the inhibition of Candida species. Therefore, this work aims to evaluate the anti-Candida effects of a propolis extract obtained from the north of Mexico on clinical isolates of Candida species. Candida species were specifically identified from oral lesions, and both the qualitative and quantitative anti-Candida effects of the Mexican propolis were evaluated, as well as its inhibitory effect on C. albicans isolate's germ tube growth and chemical composition. Three Candida species were identified, and our results indicated that the inhibition halos of the propolis ranged from 7.6 to 21.43 mm, while that of the MFC and FC50 ranged from 0.312 to 1.25 and 0.014 to 0.244 mg/mL, respectively. Moreover, the propolis was found to inhibit germ tube formation (IC50 ranging from 0.030 to 1.291 mg/mL). Chemical composition analysis indicated the presence of flavonoids, including pinocembrin, baicalein, pinobanksin chalcone, rhamnetin, and biochanin A, in the Mexican propolis extract. In summary, our work shows that Mexican propolis presents significant anti-Candida effects related to its chemical composition, and also inhibits germ tube growth. Other Candida species virulence factors should be investigated in future research in order to determine the mechanisms associated with antifungal effects against them. [ABSTRACT FROM AUTHOR]

Candida albicans infection mainly occurs in patients with suppressed immune function and is the main pathogen of nosocomial infections. The use of natural products aimed at controlling fungal diseases is considered an interesting alternative to synthetic fungicides due to their lower adverse reactions and the lower cost of plant preparations compared to modern conventional pharmaceuticals. Natural borneol has a long history of treating ulcers and local infections in traditional Chinese medicine. In this study, we present an analysis of the in vitro effects of natural borneol on planktonic cells of C albicans in the liquid and vapor phases. We also investigated the effects of natural borneol on germ tube formation and mature biofilm activity of C albicans. We found that vapor-phase borneol (minimum inhibitory concentration [MIC] 0.4 mg/cm3) inhibited C albicans more effectively than in the liquid phase (MIC 2 mg/mL). The C albicans germ tube decreased by 99% to 60% at sub-MICs of 0.5 to 0.125 mg/mL. The inhibitory effects of 0.25, 0.5, 1, 2, and 4 mg/mL borneol on the biofilm activity were 33.7%, 48.6%, 49.9%, 52.9%, and 58.2%, respectively. Natural borneol may have potential in the treatment and prevention of C albicans infections. [ABSTRACT FROM AUTHOR]

Abstract Background Candida species is considered one of the normal inhabitant commensal microbiota of the human body. However, it can also act as an opportunistic pathogen especially in hospitals (nosocomial infection) and among immunocompromised patients. The accurate, precise, rapid and reliable identification of Candida to the species level is of great importance for control and management of candidiasis. Results One hundred and eighteen different samples were collected (59 urine samples, 39 oral swabs, 5 vaginal swabs and 15 skin swabs) from immunocompromised patients (diabetics—pregnant women—patients underwent organ transplantation—cancer patients—burned and wounded patients) for probable existence of Candida species. Eighty-six out of 118 (72.8%) samples were typed macroscopically and microscopically and found to be Candida species. Upon streaking 86 Candida isolates on CHROMagar plates separately, 48 isolates gave green colonies, 25 isolates gave rose colonies, 10 isolates gave white colonies, 2 isolates gave pale coloured colonies and 1 isolate gave blue colonies. Forty-eight out of 86 isolates showed positive Germ tube test. API 20C assay was performed on some isolates with different coloured colonies, the results were similar to those of CHROMagar. Upon performing PCR assay on 14 isolates using ITS1 and ITS4 primers, 8 out of 14 PCR product bands appeared between 510 and 535 bp and this was difficult to differentiate among them (C. albicans, C. tropicalis, C. krusei and C. parapsilosis). Five out of 14 PCR products were found at 871 bp (C. glabrata) and the last one is negative control with no band appeared. Further molecular studies should be recommended to fully differentiate among Candida species especially those with very close bands. Antifungal activity (expressed by inhibitory zone) of zinc oxide nanoparticles in comparison with some commercially available antifungals (nystatin and Voriconazole) was carried upon the obtained Candida isolates. Zinc oxide nanoparticles with 100 μg/disc showed 9, 26, 40, 42 mm inhibitory zones for C. tropicalis, C. glabrata, C. albicans and C. parapsilosis, respectively. However, zinc oxide only showed no antifungal activity against C. krusei. Conclusions A sheet of identification profile for Candida should include morphotyping, biotyping and genotyping to reach a rapid, reliable and accurate diagnosis. Candida species causes a myriad of infections causing non-invasive, mucocutaneous infections and severe systemic and deep-seated disease. Repress of Candida growth by ZnONPs provides an insight towards their therapeutic application for the prevention of Candida-associated infections. Further studies on the antifungal effect of nanoparticles combined with commercially available antifungal medicines maybe recommended.

Candida albicans Als1 is a large cell-surface glycoprotein most often discussed for its role in mediating ligand-binding and aggregative interactions. Relative to a wild-type control, deletion of ALS1 produced a strain that showed delayed germ-tube formation and delayed disease progression in a murine model of disseminated candidiasis. Populations of Δals1/Δals1 cultured cells had a higher proportion of smaller cells compared to wild-type or ALS1 reintegrant control cultures. The goal of this work was to investigate whether this difference in cell-size distributions was responsible for delayed germ-tube formation and delayed disease progression. Flow cytometry was used to select populations of wild-type and Δals1/Δals1 cells with varied cell-size distributions. Delayed germ-tube formation was demonstrated for small cells sorted from a wild-type (ALS1/ALS1) culture population. Large cells sorted from a Δals1/Δals1 culture formed germ tubes as quickly as the wild-type control demonstrating clearly that the Δals1/Δals1 germ-tube formation delays were attributable to cell size. In vivo , smaller-sized cells of the wild-type control showed fewer colony-forming units (cfu) per gram of kidney tissue and less-severe histopathology lesions compared to larger cells of the same strain. The Δals1/Δals1 strain showed reduced cfu/g of kidney tissue and less-severe lesions compared to the wild-type control. However, isolation and testing of the larger cells from the Δals1/Δals1 population increased cfu/g of tissue and showed increased lesion severity compared to the overall mutant cell population. In vivo hypha lengths from the large, sorted Δals1/Δals1 cells were comparable to those for the wild-type control strain. These results demonstrated that a large share of the Δals1/Δals1 in-vivo phenotype was attributable to cell size. Collectively, the data suggest a role for Als1 in C. albicans cell size homeostasis, a novel hypothesis for further exploration. [ABSTRACT FROM AUTHOR]

Candida albicans Als1 is a large cell-surface glycoprotein most often discussed for its role in mediating ligand-binding and aggregative interactions. Relative to a wild-type control, deletion of ALS1 produced a strain that showed delayed germ-tube formation and delayed disease progression in a murine model of disseminated candidiasis. Populations of Δals1/Δals1 cultured cells had a higher proportion of smaller cells compared to wild-type or ALS1 reintegrant control cultures. The goal of this work was to investigate whether this difference in cell-size distributions was responsible for delayed germ-tube formation and delayed disease progression. Flow cytometry was used to select populations of wild-type and Δals1/Δals1 cells with varied cell-size distributions. Delayed germ-tube formation was demonstrated for small cells sorted from a wild-type (ALS1/ALS1) culture population. Large cells sorted from a Δals1/Δals1 culture formed germ tubes as quickly as the wild-type control demonstrating clearly that the Δals1/Δals1 germ-tube formation delays were attributable to cell size. In vivo, smaller-sized cells of the wild-type control showed fewer colony-forming units (cfu) per gram of kidney tissue and less-severe histopathology lesions compared to larger cells of the same strain. The Δals1/Δals1 strain showed reduced cfu/g of kidney tissue and less-severe lesions compared to the wild-type control. However, isolation and testing of the larger cells from the Δals1/Δals1 population increased cfu/g of tissue and showed increased lesion severity compared to the overall mutant cell population. In vivo hypha lengths from the large, sorted Δals1/Δals1 cells were comparable to those for the wild-type control strain. These results demonstrated that a large share of the Δals1/Δals1 in-vivo phenotype was attributable to cell size. Collectively, the data suggest a role for Als1 in C. albicans cell size homeostasis, a novel hypothesis for further exploration.

Abstract Background Alteration in the normal composition of gasses in the atmosphere referred to as air pollution can occur as a result of different processes, including emissions from vehicles and power generators. Gasses affect living things directly and indirectly by playing roles in respiration, membrane function, synthesis, and growth. The gasses contained in fumes emitted from vehicles and generators may likely have effect on microorganisms in the environment including microfungi. Two microfungi were selected to study the effect of generator emissions on their growth. Results The gaseous emissions from power generators fueled by gasoline caused reduction in spore germination and germ tube lengths of R. stolonifer and F. oxysporum. For the former, spore germination decreased with length of exposure after an initial increase by ~ 100%. The fungus exhibited a single major germination peak at 10 min and a minor one at 30–35 min exposures. Germ tube length of the fungus also decreased with increased exposure. F. oxysporum too showed reduced spore germination and germ tube length with exposure but the fungus seemed to adjust better to the unfavorable environment created by emitted gasses showing multiple peaks of reduced heights as time progressed, though another rise that could reach a peak appeared at the 45-min maximum exposure for germ tube length. The peaks were however more broad for spore germination experiments indicating more stability in adjustment than observed for germ tube length. Greatest reduction in spore germination was by 25% in R. stolonifer and 71% in F. oxysporum Germ tube length reduction for R. stolonifer was by 24–76%, the greatest occurring at 35-min exposure, while for F. oxysporum it was 5–83%, the greatest occurring at 40 min exposure. Conclusions These observations reveal the toxicity of the gasses emitted to the growth of the two filamentous fungi and the potential harmful effect to other fungi which might be useful in the ecosystem as decomposers and to those that may be pathogenic to higher plants.

Background: Candida species is considered one of the normal inhabitant commensal microbiota of the human body. However, it can also act as an opportunistic pathogen especially in hospitals (nosocomial infection) and among immunocompromised patients. The accurate, precise, rapid and reliable identification of Candida to the species level is of great importance for control and management of candidiasis. Results: One hundred and eighteen different samples were collected (59 urine samples, 39 oral swabs, 5 vaginal swabs and 15 skin swabs) from immunocompromised patients (diabetics—pregnant women—patients underwent organ transplantation—cancer patients—burned and wounded patients) for probable existence of Candida species. Eighty-six out of 118 (72.8%) samples were typed macroscopically and microscopically and found to be Candida species. Upon streaking 86 Candida isolates on CHROMagar plates separately, 48 isolates gave green colonies, 25 isolates gave rose colonies, 10 isolates gave white colonies, 2 isolates gave pale coloured colonies and 1 isolate gave blue colonies. Forty-eight out of 86 isolates showed positive Germ tube test. API 20C assay was performed on some isolates with different coloured colonies, the results were similar to those of CHROMagar. Upon performing PCR assay on 14 isolates using ITS1 and ITS4 primers, 8 out of 14 PCR product bands appeared between 510 and 535 bp and this was difficult to differentiate among them (C. albicans, C. tropicalis, C. krusei and C. parapsilosis). Five out of 14 PCR products were found at 871 bp (C. glabrata) and the last one is negative control with no band appeared. Further molecular studies should be recommended to fully differentiate among Candida species especially those with very close bands. Antifungal activity (expressed by inhibitory zone) of zinc oxide nanoparticles in comparison with some commercially available antifungals (nystatin and Voriconazole) was carried upon the obtained Candida isolates. Zinc oxide nanoparticles with 100 μg/disc showed 9, 26, 40, 42 mm inhibitory zones for C. tropicalis, C. glabrata, C. albicans and C. parapsilosis, respectively. However, zinc oxide only showed no antifungal activity against C. krusei. Conclusions: A sheet of identification profile for Candida should include morphotyping, biotyping and genotyping to reach a rapid, reliable and accurate diagnosis. Candida species causes a myriad of infections causing non-invasive, mucocutaneous infections and severe systemic and deep-seated disease. Repress of Candida growth by ZnONPs provides an insight towards their therapeutic application for the prevention of Candida-associated infections. Further studies on the antifungal effect of nanoparticles combined with commercially available antifungal medicines maybe recommended. [ABSTRACT FROM AUTHOR]

The conidia of a hemibiotrophic fungus, Colletotrichum gloeosporioides, can conventionally form a germ tube (GT) and develop into a fungal colony. Under certain conditions, they tend to get connected through a conidial anastomosis tube (CAT) to share the nutrients. CAT fusion is believed to be responsible for the generation of genetic variations in few asexual fungi, which appears problematic for effective fungal disease management. The physiological and molecular requirements underlying the GT formation versus CAT fusion remained underexplored. In the present study, we have deciphered the physiological prerequisites for GT formation versus CAT fusion in C. gloeosporioides. GT formation occurred at a high frequency in the presence of nutrients, while CAT fusion was found to be higher in the absence of nutrients. Younger conidia were found to form GT efficiently, while older conidia preferentially formed CAT. Whole transcriptome analysis of GT and CAT revealed highly differential gene expression profiles, wherein 11,050 and 9786 genes were differentially expressed during GT formation and CAT fusion, respectively. A total of 1567 effector candidates were identified; out of them, 102 and 100 were uniquely expressed during GT formation and CAT fusion, respectively. Genes coding for cell wall degrading enzymes, germination, hyphal growth, host-fungus interaction, and virulence were highly upregulated during GT formation. Meanwhile, genes involved in stress response, cell wall remodeling, membrane transport, cytoskeleton, cell cycle, and cell rescue were highly upregulated during CAT fusion. To conclude, the GT formation and CAT fusion were found to be mutually exclusive processes, requiring differential physiological conditions and sets of DEGs in C. gloeosporioides. This study will help in understanding the basic CAT biology in emerging fungal model species of the genus Colletotrichum. [ABSTRACT FROM AUTHOR]

Infections caused by micro-organisms of the genus Candida are becoming a growing health problem worldwide. These fungi are opportunistic commensals that can produce infections—clinically known as candidiasis—in immunocompromised individuals. The indiscriminate use of different anti-fungal treatments has triggered the resistance of Candida species to currently used therapies. In this sense, propolis has been shown to have potent antimicrobial properties and thus can be used as an approach for the inhibition of Candida species. Therefore, this work aims to evaluate the anti-Candida effects of a propolis extract obtained from the north of Mexico on clinical isolates of Candida species. Candida species were specifically identified from oral lesions, and both the qualitative and quantitative anti-Candida effects of the Mexican propolis were evaluated, as well as its inhibitory effect on C. albicans isolate’s germ tube growth and chemical composition. Three Candida species were identified, and our results indicated that the inhibition halos of the propolis ranged from 7.6 to 21.43 mm, while that of the MFC and FC50 ranged from 0.312 to 1.25 and 0.014 to 0.244 mg/mL, respectively. Moreover, the propolis was found to inhibit germ tube formation (IC50 ranging from 0.030 to 1.291 mg/mL). Chemical composition analysis indicated the presence of flavonoids, including pinocembrin, baicalein, pinobanksin chalcone, rhamnetin, and biochanin A, in the Mexican propolis extract. In summary, our work shows that Mexican propolis presents significant anti-Candida effects related to its chemical composition, and also inhibits germ tube growth. Other Candida species virulence factors should be investigated in future research in order to determine the mechanisms associated with antifungal effects against them.

This work reports the results concerning the antifungal activity of the essential oil obtained from Salvia desoleana, an endemic plant from folk medicine of Sardinia Island, Italy. Chemical analysis of S. desoleana essential oil isolated by hydrodistillation was carried out by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The essential oil contains high amounts of oxygenated monoterpenes and sesquiterpene hydrocarbons, being linalyl acetate (21.0%), α-terpinyl acetate (17.3%), 1,8-cineole (6.7%), linalool (3.6%), sclareol (3.5%) and germacrene D (22.1%) the main compounds. The oil was more active against the yeast Cryptococcus neoformans and the dermatophyte Trichophyton rubrum with MIC values of 0.16 μL/mL and 0.32 μL/mL, respectively. The oil revealed an important inhibitory effect on the germ tube formation in C. albicans. It was able to achieve about 40% of inhibition of filamentation at concentrations as low as 0.08 µL/mL. These findings add significant information to the biological activity of the essential oil of S. desoleana, specifically to its antifungal properties, thus justifying and reinforcing the use of this plant in traditional medicine. [ABSTRACT FROM AUTHOR]

Fungal infections remain a burden worldwide, thus underpinning the need for effective new therapeutic approaches. In the present study, the antifungal effect of the essential oils of two thyme species, Thymus camphoratus and Thymus carnosus, used in traditional medicine in Portugal, as well as their major compounds was assessed. A special focus was placed on their effect on Candida albicans virulence factors. Also, the safety profile of the essential oils was assessed on keratinocytes. The essential oils were analyzed by gas chromatography (GC) and gas chromatography/mass spectroscopy (GC/MS). The minimal inhibitory and minimal fungicidal concentrations of the essential oils and their main compounds were assessed on reference and clinical strains. Also, their effect on C. albicans germ tube formation, metabolism, and biofilm disruption were considered. T. camphoratus oil was rich in 1,8-cineole and α-pinene whereas T. carnosus oil showed high amounts of borneol and camphene. Regarding the antifungal effect, both oils were more active against Cryptococcus neoformans and dermatophytes and very effective in inhibiting C. albicans germ tube formation, at doses well below their MIC and in a higher extend than the isolated compounds and fluconazole, an antifungal drug widely used in the clinic. The oils also disrupted preformed C. albicans biofilms. Furthermore, no toxicity was observed at pharmacological relevant concentrations towards keratinocytes. Our study validates the traditional uses ascribed to these Iberian species. Furthermore, it brings new insights on the antifungal potential and mechanism of action of these thyme species, thus paving the way for the development of novel effective antifungal drugs.

The conidia of a hemibiotrophic fungus, Colletotrichum gloeosporioides, can conventionally form a germ tube (GT) and develop into a fungal colony. Under certain conditions, they tend to get connected through a conidial anastomosis tube (CAT) to share the nutrients. CAT fusion is believed to be responsible for the generation of genetic variations in few asexual fungi, which appears problematic for effective fungal disease management. The physiological and molecular requirements underlying the GT formation versus CAT fusion remained underexplored. In the present study, we have deciphered the physiological prerequisites for GT formation versus CAT fusion in C. gloeosporioides. GT formation occurred at a high frequency in the presence of nutrients, while CAT fusion was found to be higher in the absence of nutrients. Younger conidia were found to form GT efficiently, while older conidia preferentially formed CAT. Whole transcriptome analysis of GT and CAT revealed highly differential gene expression profiles, wherein 11,050 and 9786 genes were differentially expressed during GT formation and CAT fusion, respectively. A total of 1567 effector candidates were identified; out of them, 102 and 100 were uniquely expressed during GT formation and CAT fusion, respectively. Genes coding for cell wall degrading enzymes, germination, hyphal growth, host-fungus interaction, and virulence were highly upregulated during GT formation. Meanwhile, genes involved in stress response, cell wall remodeling, membrane transport, cytoskeleton, cell cycle, and cell rescue were highly upregulated during CAT fusion. To conclude, the GT formation and CAT fusion were found to be mutually exclusive processes, requiring differential physiological conditions and sets of DEGs in C. gloeosporioides. This study will help in understanding the basic CAT biology in emerging fungal model species of the genus Colletotrichum.

Fungal infections remain a major health concern with aromatic plants and their metabolites standing out as promising antifungal agents. The present study aims to assess, for the first time, the antifungal and anti-inflammatory potential of Bupleurum subsp. paniculatum (Brot.) H.Wolff essential oil from Portugal. The oil obtained by hydrodistillation and characterized by GC-MS, showed high amounts of monoterpene hydrocarbons, namely α-pinene (29.0–36.0%), β–pinene (26.1–30.7%) and limonene (10.5–13.5%). The antifungal potential was assessed, according to CLSI guidelines, against several clinical and collection strains. The essential oil showed a broad fungicidal effect being more potent against Cryptococcus neoformans and dermatophytes. Moreover, a significant germ tube inhibition was observed in Candida albicans as well as a disruption of mature biofilms, thus pointing out an effect of the oil against relevant virulent factors. Furthermore, fungal ultrastructural modifications were detected through transmission electron microscopy, highlighting the nefarious effect of the oil. Of relevance, the oil also evidenced anti-inflammatory activity through nitric oxide inhibition in macrophages activated with lipopolysaccharide. In addition, the essential oil’s bioactive concentrations did not present toxicity towards macrophages. Overall, the present study confirmed the bioactive potential of B. rigidum subsp. paniculatum essential oil, thus paving the way for the development of effective drugs presenting concomitantly antifungal and anti-inflammatory properties.

SUMMARY Infection by Candidaspp. is associated with high mortality rates, especially when treatment is not appropriate and/or not immediate. Therefore, it is necessary to correctly identify the genus and species of Candida. The aim of this study was to compare the identification of 89 samples of Candida spp. by the manual methods germ tube test, auxanogram and chromogenic medium in relation to the ID 32C automated method. The concordances between the methods in ascending order, measured by the Kappa index were: ID 32C with CHROMagar Candida(κ = 0.38), ID 32C with auxanogram (κ = 0.59) and ID 32C with germ tube (κ = 0.9). One of the species identified in this study was C. tropicalis,which demonstrated a sensitivity of 46.2%, a specificity of 95.2%, PPV of 80%, NPV of 81.1%, and an accuracy of 80.9% in tests performed with CHROMagar Candida;and a sensitivity of 76.9%, a specificity of 96.8%, PPV of 90.9%, NPV of 91%, and an accuracy of 91% in the auxanogram tests. Therefore, it is necessary to know the advantages and limitations of methods to choose the best combination between them for a fast and correct identification of Candidaspecies.

The extracts of Elaeocarpus sphaericus (Roxb.) have shown antimicrobial activities against many pathogenic microbes including fungi. However, the effects of Elaeocarpus sphaericus have not been investigated against key virulence attributes of Candida. In the present study, methanol extract of Elaeocarpus sphaericus leaves was analysed against planktonic cells, hyphal growth, adhesion and biofilm formation of two most important fungal pathogens, Candida albicans and Candida glabrata. Methanol extract of Elaeocarpus sphaericus leaves was prepared by pressurized liquid extraction method. Inhibitory concentration of methanol extract of Elaeocarpus sphaericus leaves for both pathogens was determined by broth microdilution assay. Germ tube formation assay was performed to study the effect of the extract on hyphal transition. Effect of methanol extract of Elaeocarpus sphaericus leaves on adhesion and biofilm formation was investigated in microtiter plate using 2,3-bis(2-methoxy-4-nitro-sulfophenyl)-2H-tetrazolium-5-carboxanilide reduction assay. IC50 values of the extract for Candida albicans and Candida glabrata were found between 0.625-1.25 mg/ml. Serum-induced germ tube development in Candida albicans was inhibited in presence of 5 mg/ml methanol extract. The extract remarkably inhibited in vitro adhesion and biofilm formation by Candida albicans and Candida glabrata in microtiter plates. The results of this study showed anticandida potential of methanol extract of Elaeocarpus sphaericus leaves. [ABSTRACT FROM AUTHOR]

Candida albicans is one of the most common causes of fungal infections in humans with a significant mortality rate. However, the factors involved in C. albicans gastrointestinal (GI) colonization remain unclear. We hypothesize that secondary bile acids have direct antifungal activity against C. albicans and may play a critical role in maintaining GI colonization resistance against C. albicans. In this study, we investigated the effect of secondary bile acids including lithocholic acid (LCA) and deoxycholic acid (DCA) on C. albicans growth and morphogenesis. Results indicate that LCA and DCA at in vivo cecal micelle concentrations inhibit C. albicans growth in vitro. Interestingly, LCA and DCA also significantly inhibited the germ tube, hyphae and biofilm formation in C. albicans. In addition, pre-treatment of C. albicans with LCA and DCA significantly reduced the percentage of C. albicans cells attached to a colon cancer cell line. Collectively, our results demonstrate that secondary bile acids play an important role in controlling the growth and morphological switching of C. albicans. Results from this study demonstrate that secondary bile acid possess direct antifungal activity against C. albicans, explaining a potential mechanism for gastrointestinal colonization resistance against C. albicans. [ABSTRACT FROM AUTHOR]

The amino sugar N-acetylglucosamine (GlcNAc) is increasingly recognized as an important signaling molecule in addition to its well-known structural roles at the cell surface. In the human fungal pathogen Candida albicans, GlcNAc stimulates several responses including the induction of the genes needed for its catabolism and a switch from budding to filamentous hyphal growth. We identified two genes needed for growth on GlcNAc (RON1 and NGS1) and found that mutants lacking these genes fail to induce the genes needed for GlcNAc catabolism. NGS1 was also important for growth on other sugars, such as maltose, but RON1 appeared to be specific for GlcNAc. Both mutants could grow on nonfermentable carbon sources indicating that they do not affect mitochondrial function, which we show is important for growth on GlcNAc but not for GlcNAc induction of hyphal morphogenesis. Interestingly, both the ron1Δ and ngs1Δ mutants were defective in forming hyphae in response to GlcNAc, even though GlcNAc catabolism is not required for induction of hyphal morphogenesis. The ron1Δ mutant showed a partial defect in forming hyphae, which was surprising since it displayed an elevated level of filamentous cells under noninducing conditions. The ron1Δ mutant also displayed an elevated basal level of expression of genes that are normally upregulated during hyphal growth. Consistent with this, Ron1 contains an Ndt80-like DNA-binding domain, indicating that it regulates gene expression. Thus, Ron1 is a key new component of the GlcNAc response pathway that acts as both an activator and a repressor of hyphal morphogenesis. [ABSTRACT FROM AUTHOR]

Candida spp. is one of the most common opportunistic human fungal pathogens, responsible for 90–100% of mucosal infections. Germ tube formation, hyphal morphogenesis, the production of tissue-damaging extracellular enzymes, and drug-resistant biofilm formation contribute to their pathogenicity, which can lead to systemic infections in the worst scenarios. Thus, there is an urgent need to discover new therapeutic agents to overcome the above virulence factors. Therefore, we aimed to prepare Crinum latifolium leaves-mediated biosynthesis of gold nanoparticles (AuNPs) that was characterized by various sophisticated techniques, and further their antifungal, antibiofilm, and anti-virulence activities was investigated. The AuNPs show a zone of inhibition between 19 and 22 mm for test strains of Candida spp. at 1000 µg/ml, whereas the MIC values were ranged from 250 to 500 µg/ml. AuNPs inhibit germ tube formation in C. albicans by 93.3% at 50 µg/ml. Furthermore, exposure to AuNPs significantly reduced the secretions of phospholipase, proteinase, hemolysin, esterase, and lipase. Confocal laser scanning microscopy (CLSM) investigation shows that 25 µg/ml of AuNPs significantly inhibit colonization and biofilm formation. Lastly, the interaction of Candidal cells with AuNPs revealed, ultrastructural changes in the cell wall and cell membranes as visualized by a transmission electron microscope (TEM). [ABSTRACT FROM AUTHOR]