Antifungal Research Articles

Antifungal Potential of Struchium sparganophora (Antsbush): A Promising Candidate for Treating Candidiasis and Cryptococcosis

Aims: The incidence of Candidiasis and Cryptococcosis, and the emergence of acquired antifungal resistance have increased rapidly. This study aimed to evaluate the effectiveness of S. sparganophora leaf extracts against C. albicans and C. neoformans; and to determine whether there was any difference between the antifungal effects of S. sparganophora leaf extracts and two conventional antifungal agents (AFAs). Study Design: Experiment-based study. Place and Duration of Study: S. sparganophora leaves was obtained from a site in Kimbia, Berbice River, Guyana; identified by the Biodiversity Centre and tested at the Main Laboratory at the College of Medical Sciences, University of Guyana during January- August 2023. Methodology: Dried pulverised leaves were macerated using different solvents and concentrated using a rotary evaporator. Sterile filter paper discs were soaked in different concentrations of the various extracts. Antifungal discs were placed on Sabouraud’s Dextrose Agar plates seeded with fungi. All plates were incubated and zones of inhibitions (ZOIs) were measured and expressed as mean ± SD. Results: S. sparganophora leaf extracts showed large ZOI especially at the 100 mg/ml concentrations against all organisms tested. The largest ZOI was seen for the hexane extract against C. neoformans (35.5±5 mm) and C. Albicans In-House B (18.5±3.5 mm) at 100 mg/ml concentrations. No ZOI was observed against the AFA fluconazole by C. albicans In-House B, while large ZOI were observed with the hexane and ethyl acetate extracts at 100 mg/ml concentrations. Statistical analysis showed correlation between the ZOI and concentrations, ZOI and solvent extract, and ZOI and type of fungi. Conclusion: In conclusion, S. sparganophora leaf extracts have great antifungal activity and in some cases showed greater activity when compared to conventional AFAs.

Nanoparticulate Herbal Formulation for the Management of Fungal Infection

Abstract: Fungal infections have been more common during the past few years as a result of an increase in the population of immunocompromised people, including those with cancer, HIV/AIDS, and organ transplant recipients. It has been reported that fungal infection is brought on by different pathogens. The main focus of this review is the use of nanosized plant components to stop fungal infections for the pharmaceutical industry and research projects. According to research about 40 million people have fungal infections. Echinocandins, griseofulvin, azoles, allylamines, and flucytosine are only a few antifungal medications used in clinical settings to treat fungal infections. Skin infections caused by fungi are among the most prevalent dermatological issues of today. Fungal infections at the skin's surface or under the skin's surface may harm the skin, keratinous tissues, and mucous membranes. Therefore, there is a high need for producing an antifungal agent that may act selectively on new targets while having minor side effects and can belong to a variety of structural classes. Natural goods offer limitless prospects for innovative medicine development due to their typically unrivaled chemical variety, whether in the form of pure phyto-compounds or standardized plant extracts. Plants have been an excellent source of medicine since the beginning of time. When compared to synthetically produced medications, phytochemicals from various plant species have been versicolor as a more potent source of therapy. Novel cell targets and antifungal chemicals, as well as new methods for the delivery of drugs based on nanotechnology, are all currently being studied.

Unveiling the roles of CaSDH8 in Candida albicans: Implications for virulence and azole resistance

ABSTRACT Candida albicans is the most common pathogen in systemic fungal diseases, exhibits a complex pathogenic mechanism, and is increasingly becoming drug tolerant. Therefore, it is particularly important to study the genes associated with virulence and resistance of C. albicans. Here, we identified a gene (orf19.1588) that encodes a conserved mitochondrial protein known as CaSDH8, upon deletion of CaSdh8, the deleted strain (Casdh8Δ/Δ) experienced impaired growth, hyphal development, and virulence. Casdh8Δ/Δ displayed a reduced capacity to utilize alternative carbon sources, along with detrimental alterations in reactive oxygen species (ROS), mitochondrial membrane potential (MMP) depolarization, and adenosine triphosphate (ATP) levels. Interestingly, Casdh8Δ/Δ demonstrated resistance to azole drugs, and under the influence of fluconazole, the cell membrane permeability and mitochondrial function of Casdh8Δ/Δ were less compromised than those of the wild type, indicating a reduction in the detrimental effects of fluconazole on Casdh8Δ/Δ. These findings highlight the significance of CaSDH8 as a crucial gene for the maintenance of cellular homoeostasis. Our study is the first to document the effects of the CaSDH8 gene on the virulence and azole resistance of C. albicans at both the molecular and animal levels, providing new clues and directions for the antifungal infection and the discovery of antifungal drug targets.

Shining a light on the impact of antifungals on Aspergillus fumigatus subcellular dynamics through fluorescence imaging.

Fluorescent proteins (FPs) are indispensable tools used for molecular imaging, single-cell dynamics, imaging in infection models, and more. However, next-generation FPs have yet to be characterized in Aspergillus. Here, we characterize 18 FPs in the pathogenic filamentous fungus Aspergillus fumigatus spanning the visible light spectrum. We report on in vivo FP brightness in hyphal and spore morphotypes and show how a fluoropyrimidine-based selection system can be used to iteratively introduce four distinct FPs enabling the simultaneous visualization of the cell membrane, mitochondria, peroxisomes, and vacuoles. Using this strain, we describe and compare the dynamic responses of organelles to stresses induced by voriconazole, amphotericin B, and the novel antifungal drugs olorofim and manogepix. The expansion to the fluorescent genetic toolbox will overcome boundaries in research applications that involve fluorescence imaging in filamentous fungi.

Therapeutic Contact Lenses for Intraocular Drug Administration: Innovations and Applications in Treating Fungal Keratitis

This review examines the advancements in ocular medication administration, focusing on therapeutic contact lenses (TCLs) as a novel approach for treating fungal keratitis. Traditional eye Drops' bioavailability is poor due to various anatomical and physiological barriers, necessitating frequent administration and leading to poor patient compliance. TCLs offer a promising alternative, providing extended drug release, improved bioavailability, and enhanced patient comfort. This review explores different antifungal drugs, innovative methods for drug incorporation into TCLs, and their therapeutic efficacy. The potential of TCLs to revolutionize ocular drug delivery and improve treatment outcomes for fungal keratitis is discussed.

Retrospective Investigation of the Utility of Potassium Hydroxide Smear in the Diagnosis and Management of Cutaneous Fungal Infections by Dermatologists

Abstract Background: Superficial cutaneous fungal infections are common dermatologic conditions. A significant proportion do not present with typical clinical findings. However, the 10% potassium hydroxide (KOH) smear, a simple bedside test, is often underused when diagnosing cutaneous fungal infections. Aims: We aimed to evaluate whether KOH smear results altered dermatologists’ diagnosis and management, and the factors that influenced its ability to detect cutaneous fungal infections. Methods: A total of 373 patients with suspected cutaneous fungal infection were identified retrospectively from the dermatology database of inpatient referrals in a Singapore tertiary hospital between 1 January 2017 and 30 June 2020. The dermatologists’ eventual diagnoses, based on their assessment until 2 months post-discharge to allow consideration of KOH smear results and response to treatment, were taken as a gold standard. Statistical analyses evaluated for changes between initial and eventual diagnoses and management relative to the KOH smear. Use of topical steroids, topical and/or systemic antifungals before skin sampling, and whether sampling was done by dermatologically-trained personnel, were assessed for association with KOH smear positivity in eventually diagnosed cases. Results: The percentage of uncertain diagnoses was reduced, and the use of topical antifungal as the sole treatment significantly changed after the KOH smear result was available. The adjusted odds ratio of a positive KOH smear in eventually diagnosed cases was 0.19 when systemic antifungals were used before skin sampling, and 3.03 if sampling was performed by a dermatologically-trained person. Limitations: Limitations of our study include dependence on retrospective medical records which may result in misclassification bias and the limited generalisability of our results to patients managed by non-dermatologists. Conclusions: KOH smear is a useful adjunct in diagnosing and managing cutaneous fungal infections. Clinicians should consider the presence of confounders affecting KOH smears when making an overall clinical diagnosis. Focused training of personnel on skin sample collection may improve the detection rate of KOH smear.

Biofilm formation and increased mortality among cancer patients with candidemia in a Peruvian reference center

BackgroundCandidemia is an invasive mycosis with an increasing global incidence and high mortality rates in cancer patients. The production of biofilms by some strains of Candida constitutes a mechanism that limits the action of antifungal agents; however, there is limited and conflicting evidence about its role in the risk of death. This study aimed to determine whether biofilm formation is associated with mortality in cancer patients with candidemia.MethodsThis retrospective cohort study included patients treated at Peru’s oncologic reference center between June 2015 and October 2017. Data were collected by monitoring patients for 30 days from the diagnosis of candidemia until the date of death or hospital discharge. Statistical analyses evaluated the association between biofilm production determined by XTT reduction and mortality, adjusting for demographic, clinical, and microbiological factors assessed by the hospital routinary activities. Survival analysis and bivariate and multivariate Cox regression were used, estimating the hazard ratio (HR) as a measure of association with a significance level of p < 0.05.ResultsA total of 140 patients with candidemia were included in the study. The high mortality observed on the first day of post-diagnosis follow-up (81.0%) among 21 patients who were not treated with either antifungal or antimicrobial drugs led to stratification of the analyses according to whether they received treatment. In untreated patients, there was a mortality gradient in patients infected with non-biofilm-forming strains vs. low/medium and high-level biofilm-forming strains (25.0%, 66.7% and 82.3%, respectively, p = 0.049). In treated patients, a high level of biofilm formation was associated with increased mortality (HR, 3.92; 95% p = 0.022), and this association persisted after adjusting for age, comorbidities, and hospital emergency admission (HR, 6.59; CI: 1.87–23.24, p = 0.003).ConclusionsThe association between candidemia with in vitro biofilm formation and an increased risk of death consistently observed both in patients with and without treatment, provides another level of evidence for a possible causal association. The presence of comorbidities and the origin of the hospital emergency, which reflect the fragile clinical condition of the patients, and increasing age above 15 years were associated with a higher risk of death.

Design, synthesis, and mechanism study of novel tetrahydroisoquinoline derivatives as antifungal agents.

In screening for natural-derived fungicides, a series of 32 novel tetrahydroisoquinoline derivatives were designed and synthesized based on tetrahydroisoquinoline alkaloids. Their structures were verified by 1H NMR, 13C NMR, HRMS, and single X-ray crystal diffraction analysis. Most of the target products exhibited medium to excellent antifungal activity against 6 phytopathogenic fungi in vitro at a concentration of 50mg/L. Interestingly, compounds A13 and A25 with EC50 values of 2.375 and 2.251mg/L against A. alternate were similar to boscalid (EC50 = 1.195mg/L). The in vivo experiments revealed that A13 presented 51.61 and 70.97% protection activities against A. alternate at the dosage of 50 and 100mg/L, respectively, which were equal to that of boscalid (64.52 and 77.42%). SDH enzyme assays and molecular docking studies indicated that compound A13 may act on SDH. In addition, the SEM analysis showed that compound A13 could strongly damage the mycelium morphology. These results revealed that A13 may be a promising lead compound for the development of natural-derived fungicides.

The first prevalence and antifungal susceptibility profile of Candida infections in Palestine, 2022

BackgroundCandida spp. are the most common cause of opportunistic fungal infections and are associated with a high mortality rate worldwide. In Palestine, the prevalence of Candida spp. infections remains elusive.MethodsWe performed our study at two hospitals in Palestine (Istishari Arab Hospital, and Najah National University Hospital). All patients diagnosed with candidiasis during the year 2022 have participated in the study. The prevalence of Candida spp., their distribution, and the activity of selected antifungals against Candida pathogens were assessed. In combination with phenotypic properties, Candida isolates were identified and tested for antifungal susceptibility using the colorimetric VITEK-2 Compact system.ResultsOur results showed that the prevalence of Candida spp. among infected samples was 11.6%. A total of eleven different Candida spp. were identified. Among these isolates, C. albicans (46.54%) was the most frequent, followed by C. glabrata (16.14%), C. tropicalis (13.83%), C. parapsilosis (4.82%), C. krusei (3.56%), C. dubliniensis (2.09%), C. ciferrii (1.67%), C. lusitaniae (0.83%), C. guilliermondii (0.62%), C. kefyer (0.41%) and C. spherica (0.20%). Among C. albicans, all isolates were 100% susceptible to fluconazole and micafungin. The susceptibility rates to Amphotericin B and flucytosine were 95% and 99%, respectively. The susceptibility rates of non-albicans Candida spp. (NAC) to fluconazole, voriconazole, amphotericine B, caspofungin, flucytosine and micafungin were 70%, 99%, 97%, ,72%, 92% and 100%, respectively. The incidence of Candida infections was higher in the intensive care unit and surgery department as compared to other hospital departments.ConclusionsFour pathogens are responsible for the most invasive infections: C. albicans, C. glabrata, C. tropicalis, and C. parapsilosis. A notable characteristic of this study was the high frequency of NAC species which were often more resistant to antifungal agents. A quick and accurate system like Vitek 2 compact was suggested for the careful species identification of clinical isolates of Candida. We suggest that continued surveillance of species distribution and susceptibility to antifungals will enhance future burden estimates and assist in evaluating preventative measures’ effectiveness.

Antifungal Efficacy of Ultrashort β-Peptides against Candida Species: Mechanistic Understanding and Therapeutic Implications.

Candidiasis, a condition spurred by the unchecked proliferation of Candida species, poses a formidable global health threat, particularly in immunocompromised individuals. The emergence of drug-resistant strains complicates management strategies, necessitating novel therapeutic avenues. Antimicrobial peptides (AMPs) have garnered attention for their potent antifungal properties and broad-spectrum activity against Candida species. This study assessed the antifungal effectiveness of ultrashort β-peptides against Candida strains, with a specific focus on peptide P3 (LAU-β3,3-Pip-β2,2-Ac6c-PEA). Our findings showed P3's remarkable fungistatic and fungicidal activities against Candida albicans, exhibiting an MIC of 4 μg/mL, comparable to those of standard antifungal drugs. The MIC value remained unchanged in the presence of ADC and BSA, indicating that serum albumin does not diminish the activity of P3. P3 demonstrates synergistic effects when combined with Fluconazole (FLU), Itraconazole (ITR), and Nystatin (NYS) to the extent that it becomes effective at 0.125, 0.125, and 0.03125 μg/mL, respectively. Concentration versus time-kill kinetics showed its time-dependent activity up to the first 12 h against C. albicans, and later concentration also played a role; indeed, at 24 h the whole culture was sterilized at 8× MIC. Post-antifungal effect assays confirmed prolonged suppression of pathogen growth after the removal of P3 from the media for significant durations. More importantly, P3 inhibits hyphae formation and biofilm development of Candida, outperforming Fluconazole with respect to these properties. Mechanistic insights display P3's potential to disrupt fungal cell membrane integrity and dose-dependent inhibition of ergosterol biosynthesis, essential for fungal cell wall integrity. Using the Bradford assay, it was observed that extracellular protein concentrations increased with higher doses of the compound, thereby validating the effect of P3 on membrane integrity. A comparative gene analysis using RT-PCR showed that P3 downregulates ERG3, ERG11, and HWP1, which are crucial for the survival and pathogenicity of C. albicans. The impact of P3 on ERG11 and ERG3 is more effective than that of Fluconazole. Molecular docking studies revealed strong binding of P3 to various isoforms of lanosterol 14-α-demethylase, a key enzyme in ergosterol synthesis. Furthermore, molecular dynamic simulations validated the stability of the most promising docking complex. Overall, our findings underscore P3's potential as a leading candidate for the development of innovative antifungal therapies, warranting further investigation and optimization.

Design and synthesis aldehydes-thiourea and thiazolyl hydrazine derivatives as promising antifungal agents against Monilinia fructicola.

Fungal diseases present a significant threat to global agriculture, necessitating the development of new, safe, and effective fungicides. Existing fungicides face resistance and health risks, prompting the synthesis of novel compounds. Researchers have synthesized aldehyde-based thiourea and thiazolyl hydrazine derivatives, evaluating their antifungal activities to identify impactful pesticide molecules. The results showed that most of the compounds had broad-spectrum antifungal activity against six plant pathogenic fungi and four post-harvest fungi. Notably, compound LN18 showed the best antifungal activity against Monilinia fructicola with a half-maximal effective concentration (EC50) of 0.17 μg mL-1, which was better than the commercial fungicide natamycin. A structure-activity relationship (SAR) study showed that the presence of unsaturated double bonds in the structure and the length of the carbon chain were the main factors affecting antifungal activity. The presence of unsaturated double bonds and an increase in the length of the carbon chain greatly improved inhibitory activity against the tested pathogens. The preliminary mechanism study showed that LN18 could damage the integrity of the mycelial plasma membrane, leading to leakage of intracellular nucleic acid and protein. LN18 also induced an increase in the intracellular reactive oxygen species level to exert its antifungal effects. In addition, compound LN18 had a stronger antifungal effect in vivo, and better phytotoxicity than natamycin, indicating broad application prospects in agriculture. Aldehydes-thiourea and thiazolyl hydrazine derivatives demonstrate remarkable antifungal efficacy against plant pathogenic and post-harvest fungi, offering a promising avenue for commercialization as highly efficacious, cost-effective and safe antifungal agents. © 2024 Society of Chemical Industry.

Overcoming amphotericin B resistance in Candida auris using the antiemetic drug rolapitant.

The emergence of Candida auris poses a significant health challenge that has led to a new era of multidrug-resistant fungal infections. Invasive infections caused by C. auris are usually associated with remarkable morbidity and mortality. For many years, amphotericin B (AmB) remained the most efficient and the last line of treatment against most hard-to-treat fungal infections. However, strains of C. auris possess extraordinary resistance to most antifungal agents, including AmB. In this study, we screened ~2,600 FDA-approved drugs and clinical compounds to identify the antiemetic drug rolapitant as a promising enhancer to AmB against C. auris. Rolapitant exhibited potent synergistic interactions with AmB against all tested (29/29) C. auris isolates. In a time-kill assay, rolapitant restored the fungicidal activity of AmB within 4 h. Additionally, the synergistic relationship between rolapitant and AmB was observed against other medically crucial Candida, Cryptococcus, and Aspergillus species. A transcriptomic study revealed that exposure to rolapitant affects oxidation reduction processes, ion transporters, and ATP production. Rolapitant triggers an elevation in cytosolic and mitochondrial calcium levels and induces oxidative stress within fungal cells. An ATP luminescence assay confirmed that rolapitant, at sub-inhibitory concentrations, significantly interfered with ATP production in C. auris. Moreover, rolapitant enhanced the in vivo activity of AmB in a mouse model of disseminated C. auris infection, as the combination reduced the fungal burden in murine kidneys by ~1 log (~90%) colony forming units. Our findings warrant further investigation of using rolapitant to overcome AmB resistance in C. auris and other fungal species.

Valorization of oil refinery by-products: production of sophorolipids utilizing fatty acid distillates and their potential antibacterial, anti-biofilm, and antifungal activities.

Starmerella bombicola is a native yeast strain producing sophorolipids as secondary metabolites. This study explores the production, characterization, and biological activities of sophorolipids and investigates the antimicrobial, anti-biofilm, and antifungal properties of sophorolipids produced from oil refinery wastes by the yeast Starmerella bombicola. The present work demonstrated that S. bombicola MTCC 1910 when grown in oil refinery wastes namely palm fatty acid distillates and soy fatty acid distillates enhanced the rate of sophorolipids production drastically in comparison to vegetable oil, sunflower oil used as hydrophobic feedstock. Sophorolipid yields were 18.14, 37.21, and 46.1g/L with sunflower oil, palm, and soy fatty acid distillates respectively. The crude biosurfactants were characterized using TLC, FTIR, and HPLC revealing to be acetylated sophorolipids containing both the acidic and lactonic isomeric forms. The surface lowering and emulsifying properties of the sophorolipids from refinery wastes were significantly higher than the sunflower oil-derived sophorolipids. Also, all the sophorolipids exhibited strong antibacterial properties (minimum inhibitory concentrations were between 50 and 200µgmL-1) against Salmonella typhimurium, Bacillus cereus, and Staphylococcus epidermidis and were validated with morphological analysis by Scanning electron microscopy. All the sophorolipids were potent biofilm inhibitors and eradicators (minimum biofilm inhibitory and eradication concentrations were between12.5to1000µgmL-1) for all the tested organisms. Furthermore, antifungal activities were also found to exhibit about 16-56% inhibition at 1mgmL-1 for fungal mycelial growth. Therefore, this endeavour of sophorolipids production using palm and soy fatty acid distillates not only opens up a window for the bioconversion of industrial wastes into productive biosurfactants but also concludes that sophorolipids from oil refinery wastes are potent antimicrobial, anti-biofilm, and antifungal agents, highlighting their potential in biotechnological and medical applications.

Improved genome assembly of Candida auris strain B8441 and annotation of B11205.

Candida auris is a fungal pathogen of significant worldwide concern, typically resistant to one or more antifungal drugs. We report a completed genome for clade Ia isolate B8441 and gene annotations of clade Ic isolate B11205. These resources will support public health investigations and population genomic studies of this pathogen.

Altered sterol composition mediates multiple tolerance of Kluyveromyces marxianus for xylitol production

BackgroundCurrently, the synthesis of compounds based on microbial cell factories is rapidly advancing, yet it encounters several challenges. During the production process, engineered strains frequently encounter disturbances in the cultivation environment or the impact of their metabolites, such as high temperature, acid-base imbalances, hypertonicity, organic solvents, toxic byproducts, and mechanical damage. These stress factors can constrain the efficiency of microbial fermentation, resulting in slow cell growth, decreased production, significantly increased energy consumption, and other issues that severely limit the application of microbial cell factories.ResultsThis study demonstrated that sterol engineering in Kluyveromyces marxianus, achieved by overexpressing or deleting the coding genes for the last five steps of ergosterol synthase (Erg2-Erg6), altered the composition and ratio of sterols in its cell membrane, and affected its multiple tolerance. The results suggest that the knockout of the Erg5 can enhance the thermotolerance of K. marxianus, while the overexpression of the Erg4 can improve its acid tolerance. Additionally, engineering strain overexpressed Erg6 improved its tolerance to elevated temperature, hypertonic, and acid. YZB453, obtained by overexpressing Erg6 in an engineering strain with high efficiency in synthesizing xylitol, produced 101.22 g/L xylitol at 45oC and 75.11 g/L xylitol at 46oC. Using corncob hydrolysate for simultaneous saccharification and fermentation (SSF) at 46oC that xylose released from corncob hydrolysate by saccharification with hemicellulase, YZB453 can produce 45.98 g/L of xylitol, saving 53.72% of the cost of hemicellulase compared to 42oC.ConclusionsThis study elucidates the mechanism by which K. marxianus acquires resistance to various antifungal drugs, high temperatures, high osmolarity, acidity, and other stressors, through alterations in the composition and ratio of membrane sterols. By employing sterol engineering, the fermentation temperature of this unconventional thermotolerant K. marxianus was further elevated, ultimately providing an efficient platform for synthesizing high-value-added xylitol from biomass via the SSF process at temperatures exceeding 45 °C.

Environment by environment interactions (ExE) differ across genetic backgrounds (ExExG).

While the terms "gene-by-gene interaction" (GxG) and "gene-by-environment interaction" (GxE) are widely recognized in the fields of quantitative and evolutionary genetics, "environment-byenvironment interaction" (ExE) is a term used less often. In this study, we find that environmentby-environment interactions are a meaningful driver of phenotypes, and moreover, that they differ across different genotypes (suggestive of ExExG). To support this conclusion, we analyzed a large dataset of roughly 1,000 mutant yeast strains with varying degrees of resistance to different antifungal drugs. Our findings reveal that the effectiveness of a drug combination, relative to single drugs, often differs across drug resistant mutants. Remarkably, even mutants that differ by only a single nucleotide change can have dramatically different drug x drug (ExE) interactions. We also introduce a new framework that more accurately predicts the direction and magnitude of ExE interactions for some mutants. Understanding how ExE interactions change across genotypes (ExExG) is crucial not only for modeling the evolution of pathogenic microbes, but also for enhancing our knowledge of the underlying cell biology and the sources of phenotypic variance within populations. While the significance of ExExG interactions has been overlooked in evolutionary and population genetics, these fields and others stand to benefit from understanding how these interactions shape the complex behavior of living systems.

Chemical Survey and Antifungal Efficacy of Sargassum muticum's Alkaloids and Phenolic-Rich Fraction Against Airborne Toxigenic and Nosocomial Opportunistic Molds Isolates.

The Atlantic coastline of El-Jadida, Morocco, is renowned for its plentiful algae, especially brown seaweed, which is rich in active compounds known for their antifungal properties. This valuable resource offers an exciting opportunity to tackle the numerous challenges posed by invasive fungal infections, allergies, mycotoxin-related food poisoning, and drug-resistant strains. Underscoring the urgent need to explore alternative, sustainable, and environmentally friendly antifungal agents derived from algae. This study aimed to evaluate the antifungal activity of total alkaloids and phenolic-rich fractions derived from seven species of Pheophyceae: Sargassum muticum, Sargassum vulgare, Bifurcaria bifurcata, Cystoseira tamariscifolia, Cystoseira humilis, Laminaria ochroleuca, and Fucus spiralis against four fungi: airborne toxigenic isolates of Aspergillus westerdijkiae and Chaetomium globosum as well as nosocomial opportunistic isolates of Aspergillus nidulans and Scopulariopsis brevicaulis. The study also aimed to identify the most effective alga and its specific active compounds through LC-MS and GC-MS analysis. The invasive Sargassum muticum was chosen as the most potent alga in inhibiting the growth of mycelium. For the first time, the alkaloids palmatine and jatrorrhizine, along with caulerpin, have been identified. The chloroform fraction revealed the prevalence of phenolic compounds including, phenolic acids, flavonoids, and phlorotannins. The lowest minimum inhibitory concentrations (MICs), with a maximum fungal load of 108 colony-forming unit (CFU), recorded ranged from 3.12 to 6.25μg/mL by the phenolic-rich fraction against airborne toxigenic isolates, and from 100 to 200μg/mL against nosocomial opportunistic isolates by the total alkaloids. In comparison, the positive control, ketoconazole, showed higher MICs and resistance against A. nidulans. The valorization of Sargassum muticum is proposed as a green strategy to preserve the ecological balance, combat antifungal resistance, and address public health challenges.

Successful treatment of Keratitis caused by Mycobacterium chelonae and an overview of previous cases in Europe

Introduction and purposeMycobacterium (M.) chelonae is responsible for a half of relatively rare nontuberculous mycobacteria (NTM) keratitis. We report a case of M. chelonae keratitis in a woman following sclerocorneal suture extraction after cataract surgery.ResultsA 70-year-old woman presented with a red eye and corneal infiltration of her left eye six weeks following sclerocorneal suture extraction after an elective cataract surgery in another institute. She complained of a sharp, cutting pain and photophobia. Since initial corneal scrapes and conjunctival swabs proved no pathogen using culture and PCR methods, non-specific antibiotics and antifungal agents were administered. As keratitis was complicated by an inflammation in the anterior chamber and vitreous, samples of the vitreous fluid were sent for microbiologic examination. DNA of Epstein-Barr virus (EBV) was repeatedly detected. Since the intrastromal abscess had formed, corneal re-scrapings were performed and M. chelonae was detected using culture, MALDI-TOF MS and PCR methods. Therapy was changed to a combination of oral and topical clarithromycin, intravitreal, topical and intracameral amikacin, and oral and topical moxifloxacin. The successful therapy led to stabilization. The optical penetrating keratoplasty was performed and no signs of the infection recurrence were found.ConclusionsThe diagnosis of nontuberculous mycobacterial keratitis is difficult and often delayed. An aggressive and prolonged antimicrobial therapy should include systemic and topical antibiotics. Surgical intervention in the form of corneal transplantation may be required in the active and nonresponsive infection. In the presented case this was necessary for visual rehabilitation due to scarring.

Vapor-Phase Essential Oils as Antifungal Agents against Penicillium olsonii Causing Postharvest Cherry Tomato Rot.

Recent reports of P. olsonii causing postharvest rot of cherry tomatoes emphasize the need for effective strategies to prolong fruit shelf life. This study is the first to explore the use of essential oils (EOs), recognized for their antimicrobial properties, as a potential method to prevent postharvest losses from P. olsonii. Antifungal activity was tested for ten EOs at a concentration of 625 μL/L using the vapor diffusion method. Thyme, wild thyme, savory, oregano, and marjoram completely inhibited fungal growth over 14 days. Thyme EO, at a minimum inhibitory concentration (MIC) of 250 μL/L, fully inhibited all strains, while oregano, wild thyme, and savory were effective at 500 μL/L. Marjoram EO showed weaker activity. The lowest IC90 values, ranging from 35.72 to 162.72 μL/L, were estimated for thyme and oregano. In cherry tomatoes, oregano EO completely halted P. olsonii growth at 250 μL/L; thyme was effective for seven days; wild thyme and savory for two days. Thyme EO prevented P. olsonii spore germination at 500 μL/L for seven days, though germination occurred at half that concentration. The IC90 values varied between 256.2 and 138.7 μL/L depending on the strain. The vapor phase of EOs at 125 μL/L influenced the sensory characteristics of cherry tomatoes; however, for thyme and oregano, this effect was not negative due to their culinary association with tomato flavor. The selected EOs could be used to control and prevent postharvest fruit losses, but further research is needed to optimize their application.

Cold atmospheric plasma as a promising tool in treatment of Trichophyton rubrum-induced skin infection in a guinea pig model of experimental dermatophytosis

The emergence of high-resistance strains to known antifungal drugs has highlighted the urgency of developing novel therapies for chronic dermatophytosis as a global health problem. An experimental dermatophytosis model in guinea pigs was developed to investigate the in vivo wound healing effects of cold atmospheric plasma (CAP) on T. rubrum skin invasion. Guinea pigs were experimentally infected with T. rubrum and wound healing was evaluated at 1, 4, 8 and 12 days post infection in the CAP-treated, terbinafine-treated and non-treated controls. Our results showed that CAP strongly inhibited the fungal virulence in vitro in culture media and in vivo on the skin lesions of experimentally infected guinea pigs even more efficient than that of terbinafine, resulting in complete wound healing at 8 days post infection. These results indicate that CAP would be considered as a promising tool comparable to conventional chemical therapies, for the treatment of drug-resistant chronic dermatophytosis caused by T. rubrum.