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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]

Aims Focusing on phytochemicals to target the virulence factors of Candida albicans is a promising avenue for novel antifungal compounds. Given the limited prior research on essential oil (EO) components and their specific effects on C. albicans virulence, our study aimed to explore their impact and uncover the underlying mechanisms. Methods and results We examined the effects on viability, dimorphic transition, biofilm formation, and changes in the expression of critical virulence-related genes. The results showed that Dehydrocostus lactone, displayed the most potent growth-inhibiting activity with the lowest MIC value, followed by Thymol and Costunolide. A substantial, dose-dependent decrease in germ tube formation occurred after exposure to sub-inhibitory concentrations of the EO components, with Carvacrol, Dehydrocostus Lactone, and Thymol exerting the most potent inhibitory effects. Across sub-inhibitory concentrations, Alpha Bisabolol consistently showcased the most potent antibiofilm activity, followed by lower but significant inhibitory effects with Dehydrocostus Lactone, Thymol, Alpha Pinene, Costunolide, Carvone, and Carvacrol. Alpha Bisabolol, Alpha Pinene, and Dehydrocostus Lactone caused almost total downregulation of ACT1 while minimal changes occurred in expression of HWP1, SAP4, ALS3, and ECE1. Conclusions Considering that actin is essential for various cellular processes, including budding, cell shape maintenance, and the formation of filaments in C. albicans , it is a plausible hypothesis that inhibiting ACT1 or disturbing actin's normal functioning could potentially affect the fungus's virulence, which warrants additional research and exploration. This study underscores the potent antifungal and anti-virulence properties of various EO components, which effectively cripple C. albicans and reduce its disease-causing ability. This innovative approach holds promise for effective clinical therapies. [ABSTRACT FROM AUTHOR]

Candidiasis is an infection caused by Candida spp., mostly Candida albicans. Infection with Candida spp. in immunocompetent individuals is often limited to the mouth, genital area or skin. However, patients who are immunocompromised due to infections or medications including corticosteroids or anticancer drugs are more susceptible to systemic candidiasis and candidemia. Upon C. albicans infections, the pathogenic yeasts enter the bloodstream and disseminate to the remote organs, leading to the formation of germ tube. Dimorphic adaptation is one of contributing virulent factors in C. albicans, which is responsible for disease pathogenesis and severity. However, little is known about whether differences among human ABO blood groups facilitate the development of C. albicans germ tube. Therefore, this study investigated the germ tube formation of C. albicans that grown in human serums from different ABO blood groups. Human pool serums varying ABO blood groups from healthy individuals were tested for C. albicans germ tube induction. After incubation for 2 h at 37 °C, the rate of germ tube formation at 15-min intervals was determined. Serum from human blood group A exhibited the highest rate of germ tube formation. Humans with blood group A exhibited the unique serum biochemical structure that possibly helps facilitate germ tube formation during C. albicans infection. [ABSTRACT FROM AUTHOR]

Fusarium wilt disease of banana, caused by the notorious soil-borne pathogen Fusarium oxysporum f. sp. cubense Tropical Race 4 (Foc TR4), is extremely difficult to manage. Manipulation of soil pH or application of synthetic iron chelators can suppress the disease through iron starvation, which inhibits the germination of pathogen propagules called chlamydospores. However, the effect of iron starvation on chlamydospore germination is largely unknown. In this study, scanning electron microscopy was used to assemble the developmental sequence of chlamydospore germination and to assess the effect of iron starvation and pH in vitro. Germination occurs in three distinct phenotypic transitions (swelling, polarized growth, outgrowth). Outgrowth, characterized by formation of a single protrusion (germ tube), occurred at 2 to 3 h, and a maximum value of 69.3% to 76.7% outgrowth was observed at 8 to 10 h after germination induction. Germination exhibited plasticity with pH as over 60% of the chlamydospores formed a germ tube between pH 3 and pH 11. Iron-starved chlamydospores exhibited polarized-growth arrest, characterized by the inability to form a germ tube. Gene expression analysis of rnr1 and rnr2, which encode the iron-dependent enzyme ribonucleotide reductase, showed that rnr2 was upregulated (p < 0.0001) in iron-starved chlamydospores compared to the control. Collectively, these findings suggest that iron and extracellular pH are crucial for chlamydospore germination in Foc TR4. Moreover, inhibition of germination by iron starvation may be linked to a different mechanism, rather than repression of the function of ribonucleotide reductase, the enzyme that controls growth by regulation of DNA synthesis. [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.

Pomegranate (Punica granatum L.) cultivation was first practiced in eastern nations like India and the Mediterranean regions. India stands first in pomegranate production and cultivated area in the world. During the year 2021, powdery mildew symptoms were observed on pomegranate plants of the cultivar G-37 and P-23 at the research farm (Dhanda) of ICAR-IARI Regional Station, Amartara Cottage, Shimla, 171,004 Himachal Pradesh, India. The research farm comes under the southwestern ranges of the Himalayas. The disease incidence was recorded to be 40% in both cultivars. The premature leaves and buds were covered in the dense, white mycelium and conidial mass patches that were powdery in appearance. Microscopic examination revealed the presence of enormous ellipsoid conidium structures associated with the diseased specimen. The conidiophores foot-cells were slightly tapered to straight measuring 70–190 × 4–7 μm. Conidia was hyaline, 37–27 × 14–11 μm (average 31.96 × 12.93 μm), however, chasmothecia could not be observed in the specimen. The molecular identification based on internal transcribed spacer region primers disclosed the fungus identity as Erysiphe punicae. The pathogenicity test was subsequently performed to prove the Koch postulates on the initially identified host cultivar P-23. To the best of our knowledge, this is the first report of powdery mildew of pomegranate caused by Erysiphe punicae in India. [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. [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.

Aims: To synthesize and evaluate the antifungal activity of poly(methacrylic acid)‐silver nanoparticles (PMAA‐AgNPs) against nine Candida albicans isolated from clinical specimens. Methods and Results: The effects of PMAA‐AgNPs‐fluconazole combination was analysed by checkerboard methodology. The synergistic potential of PMAA‐AgNPs‐fluconazole was determined by the fractional inhibitory concentration index (FICI). The inhibition of germ tube formation and the determination of PMAA‐AgNPs cytotoxicity were also performed. All C. albicans strains were susceptible to PMAA‐AgNPs and resistant to fluconazole. PMAA‐AgNPs at subinhibitory concentrations restored the susceptibility of resistant C. albicans to fluconazole, whose FICI ranged from 0.3 to 0.5. The synergistic interaction of the combination was observed in eight of nine strains. The PMAA‐AgNPs‐fluconazole combination was also able to inhibit the germ tube formation. PMAA‐AgNPs showed a dose‐dependent decrease in viability for cells tested, with 50% cytotoxic concentration (CC50) values of 6.5, 4.9 and 6.8 μg ml−1 for macrophages, fibroblasts and Vero cells, respectively. Conclusions: This study demonstrated that, in general, PMAA‐AgNPs acts synergistically in combination with fluconazole, inhibiting fluconazole‐resistant C. albicans strains. PMAA‐AgNPs‐fluconazole combination was also able to inhibit germ tube formation, an important virulence factor. Inhibitory effect of PMAA‐AgNPs alone or in combination was higher in C. albicans than in mammalian cells. Significance and Impact of Study: This study shows the potential of PMAA‐AgNPs combined with fluconazole to inhibit fluconazole‐resistant C. albicans strains. [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 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.

Penicillium roqueforti is used for the production of blue-veined cheeses but is a spoilage fungus as well. It reproduces asexually by forming conidia. Germination of these spores can start the spoilage process of food. Germination is typically characterized by the processes of activation, swelling and germ tube formation. Here, we studied nutrient requirements for germination of P. roqueforti conidia. To this end, > 300 conidia per condition were monitored in time using an oCelloScope imager and an asymmetric model was used to describe the germination process. Spores were incubated for 72 h in NaNO3, Na2HPO4/NaH2PO4, MgSO4 and KCl with 10 mM glucose or 10 mM of 1 out of the 20 proteogenic amino acids. In the case of glucose, the maximum number of spores (Pmax) that had formed germ tubes was 12.7%, while time needed to reach 0.5 Pmax (τ) was about 14 h. Arginine and alanine were the most inducing amino acids with a Pmax of germ tube formation of 21% and 13%, respectively, and a τ of up to 33.5 h. Contrary to the typical stages of germination of fungal conidia, data show that P. roqueforti conidia can start forming germ tubes without a detectable swelling stage. [ABSTRACT FROM AUTHOR]

Santolina insularis is a Sardinian endemism that is widely used in traditional medicine. The essential oil was obtained with a yield of 2.7% and is mainly characterized by β-phellandrene (22.6%), myrcene (11.4%) and artemisia ketone (7.6%). The oil significantly reduced NO production without affecting macrophages viability. In addition, it substantially inhibited the expression of two key pro-inflammatory enzymes, iNOS and COX-2 (71% and 25% at 0.54 mg/mL). Furthermore, the oil had a promising antifungal activity being Cryptococcus neoformans (MIC = 0.13 mg/mL) and the majority of dermatophytes (MIC = 0.13 mg/mL) the most susceptible fungi. Moreover, it significantly decreased the yeast-to-hypha transition (80% inhibition at 0.13 mg/mL) on C. albicans long before showing inhibitory effects. Overall, these results show that S. insularis could be applied in the treatment of fungal infections and associated inflammatory response. [ABSTRACT FROM AUTHOR]

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.

The antifungal activity of Pelargonium capitatum essential oil (PCEO) and Cymbopogon martini essential oil (CMEO) against C.albicans were evaluated. The main components of essential oils were β-cytronellol 58.81% and geraniol 83.94% in PCEO and CMEO, respectively. PCEO was more activity than CMEO for all C.albicans strains tested with values MIC50 or MIC90 of 780 µg/ml. PCEO used in combination with fluconazole or CMEO shows synergistic effect with FICI values ≤ 0.5. Moreover both essential oils are able to inhibit the major virulence factor of C.albicans as the germ tube formation at sub-inhibitory concentration of 195 µg/ml. In conclusion, it is possible to hypothesize that PCEO can be used in combination with fluconazole or CMEO. Further studies are in due course to confirm these results. [ABSTRACT FROM AUTHOR]

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.

Rust disease, caused by Puccinia menthae, is one of the main factors that reduces the yield of peppermint and affects the overall quality of peppermint oils. On the infected plants, light yellow spots on the upper surface of the leaves and orange-brown or dark pustules the under side of the leaves and on the stems are formed. Falling out of leaves on the severly infected plants is very common. During the observations conducted in Aydın Province, it was determined that the severity of the disease has changed significantly throughout the growing season and it was considered that the climatic conditions of Aydın province may be the effect on this. There are limited number of studies demonstrating the effect of climatic factors in the development of the disease. For better understanding of the seasonal development of peppermint rust in Aydın province, this study aimed to determine the effect of temperature on the germ tube development from P. menthae urediospores. For this purpose, urediospores collected from naturally infected plants were tested on water agar layeredglass slides for germination and germ tube development under different temperature conditions. After each inoculated slide was placed in a sterile petri dish, it was placed to incubate for 16 hours in incubators adjusted to 5, 10, 15, 20, 25, 30 and 35 °C temperature conditions in the dark. At the end of incubation, germ tube length of 45 urediospores germinated in each glass slide was measured by using a computer software. At the end of the incubation period, no germination was observed at 5, 30 and 35 °C, while almost all spores germinated at the temperature of 10, 15, 20, 25 °C. The longest germ tube formation was observed at 20 °C with an average of 661.8 μm. Average of the germ tube length was 602.5 μm at 15 °C, 489.3 μm at 10 °C and 245.5 μm at 25 °C. When all data were analysed according to regression analysis, the optimum temperature for germination of urediospore was determined as 18.13 °C. As a result, the findings obtained in this study indicated that P. menthae is a pathogen that grows better in cool weather. [ABSTRACT FROM AUTHOR]

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]

In this paper, we present a mathematical model to describe filamentous fungal growth based on intracellular secretory vesicles (SVs), which transport cell wall components to the hyphal tip. Vesicular transport inside elongating hyphae is modeled as an advection–diffusion–reaction equation with a moving boundary, transformed into fixed coordinates, and discretized using a high‐order weighted essentially nonoscillatory discretization scheme. The model describes the production and the consumption of SVs with kinetic functions. Simulations are subsequently compared against distributions of SVs visualized by enhanced green fluorescent protein in young Aspergillus niger hyphae after germination. Intensity profile data are obtained using an algorithm scripted in ImageJ that extracts mean intensity distributions from 3D time‐lapse confocal measurement data. Simulated length growth is in good agreement with the experimental data. Our simulations further show that a decrease of effective vesicle transport velocity towards the tip can explain the observed tip accumulation of SVs. [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.

Aims: Focusing on phytochemicals to target the virulence factors of Candida albicans is a promising avenue for novel antifungal compounds. Given the limited prior research on essential oil (EO) components and their specific effects on C. albicans virulence, our study aimed to explore their impact and uncover the underlying mechanisms., Methods and Results: We examined the effects on viability, dimorphic transition, biofilm formation, and changes in the expression of critical virulence-related genes. The results showed that Dehydrocostus Lactone, displayed the most potent growth-inhibiting activity with the lowest MIC value, followed by Thymol, and Costunolide. A substantial, dose-dependent decrease in germ tube formation occurred after exposure to sub-inhibitory concentrations of the EO components, with Carvacrol, Dehydrocostus Lactone, and Thymol exerting the most potent inhibitory effects. Across sub-inhibitory concentrations, Alpha Bisabolol consistently showcased the most potent antibiofilm activity followed by lower but significant inhibitory effects with Dehydrocostus Lactone, Thymol, Alpha Pinene, Costunolide, Carvone, and Carvacrol. Alpha Bisabolol, Alpha Pinene and Dehydrocostus Lactone caused almost total downregulation of ACT1 whilst minimal changes occurred in expression of HWP1, SAP4, ALS3 and ECE1., Conclusions: Considering that actin is essential for various cellular processes, including budding, cell shape maintenance, and the formation of filaments in C. albicans, it is a plausible hypothesis that inhibiting ACT1 or disturbing actin's normal functioning could potentially affect the fungus's virulence, which warrants additional research and exploration. This study underscores the potent antifungal and anti-virulence properties of various EO components which effectively cripple C. albicans and reduce its disease-causing ability. This innovative approach holds promise for effective clinical therapies., (© The Author(s) 2024. Published by Oxford University Press on behalf of Applied Microbiology International.)

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.

DNA polymerases are evolved to extend the 3′-OH of a growing primer annealed to a template DNA substrate. Since replicative DNA polymerases have a limited role while replicating structurally distorted template, translesion DNA polymerases mostly from Y-family come to the rescue of stalled replication fork and maintain genome stability. DNA polymerase eta is one such specialized enzyme whose function is directly associated with casual development of certain skin cancers and chemo-resistance. More than 20 years of extensive studies are available to support TLS activities of Polη in bypassing various DNA lesions, in addition, limited but crucial growing evidence also exist to suggest Polη possessing TLS-independent cellular functions. In this review, we have mostly focused on non-TLS activities of Polη from different organisms including our recent findings from pathogenic yeast Candida albicans. [ABSTRACT FROM AUTHOR]