Alkaloids solenopsins from fire ants display in vitro and in vivo activity against the yeast Candida auris.

The urgency surrounding Candida auris as a public health threat is highlighted by both the Center for Disease Control (CDC) and World Health Organization (WHO) that categorized this species as a priority fungal pathogen. Given the current limitations of antifungal therapy for C. auris, particularly due to its multiple resistance to the current antifungals, the identification of new drugs is of paramount importance. Some alkaloids abundant in the venom of the red invasive fire ant (Solenopsis invicta), known as solenopsins, have garnered attention as potent inhibitors of bacterial biofilms, and there are no studies demonstrating such effects against fungal pathogens. Thus, we herein investigated the antibiotic efficacy of solenopsin alkaloids against C. auris biofilms and planktonic cells. Both natural and synthetic solenopsins inhibited the growth of C. auris strains from different clades, including fluconazole and amphotericin B-resistant isolates. Such alkaloids also inhibited matrix deposition and altered cellular metabolic activity of C. auris in biofilm conditions. Mechanistically, the alkaloids compromised membrane integrity as measured by propidium iodide uptake in exposed planktonic cells. Additionally, combining the alkaloids with AMB yielded an additive antifungal effect, even against AMB-resistant strains. Finally, both extracted solenopsins and the synthetic analogues demonstrated protective effect in vivo against C. auris infection in the invertebrate model Galleria mellonella. These findings underscore the potent antifungal activities of solenopsins against C. auris and suggest their inclusion in future drug development. Furthermore, exploring derivatives of solenopsins could reveal novel compounds with therapeutic promise.

Effectiveness of Lemon Verbena (Cymbopogon citratus) in Oral Candidiasis: A Systematic Review.

The rise of phytotherapy has enabled the utilization of various plant species for medicinal purposes, such as Cymbopogon citratus (C. citratus), providing solutions for oral pathologies, such as oral candidiasis. The PubMed, Web of Science, Scopus, and SciELO databases were searched. In vivo and in vitro studies on the action of C. citratus against oral candidiasis were included, and ROBINS-I was used to determine study quality and risk of bias. The search yielded 1922 articles, of which 10 met the inclusion criteria. Limited scientific evidence exists regarding the use of C. citratus for oral candidiasis. However, studies have indicated its potent antifungal effects. Further studies, preferably clinical trials, are necessary to confirm this effect and to enable its clinical use as a therapeutic option.

Antibiotics stimulates the development of persistent cells in biofilms of Candida albicans bloodstream isolates.

Candida albicans invasive candidiasis is considered a global health problem. In such cases, biofilm formation on implanted devices represents a therapeutic challenge and the presence of metabolically inactive persistent cells (PCs) in these communities increases their tolerance to fungicidal drugs. This study investigated the influence of amoxicillin, AMX; cefepime, CEF; gentamicin, GEN; amikacin, AMK; vancomycin, VAN; and ciprofloxacin, CIP; on the production of PCs in biofilms of C. albicans bloodstream isolates. 48 h-mature biofilms (n = 6) grown in RPMI-1640 supplemented with antibiotics were treated with 100 µg ml-1 amphotericin B and then evaluated for PCs. Biofilms grown in the presence of antibiotics produced more PCs, up to 10×, when exposed to AMX and CIP; 5 × to CEF; and 6 × to GEN and VAN. The results indicate that antibiotics can modulate PC production in C. albicans biofilms. This scenario may have clinical repercussions in immunocompromised patients under broad-spectrum antibiotic therapy.

Biofilms are microbial communities tolerant to antifungals. Our research showed that antibiotics stimulate the formation of persistent cells within Candida albicans biofilms. These are dormant, metabolically silent cells that resist to therapy and can be related to metastatic and recalcitrant infections.

Long-read sequencing and de novo genome assembly data of Candida parapsilosis HMC1 and Rhodotorula mucilaginosa LBMH1012, two novel isolates with antifungal resistance signatures.

Candida parapsilosis and Rhodotorula mucilaginosa are opportunistic pathogens affecting mostly immunocompromised hosts. Both species have emerged as causes of invasive candidiasis and sepsis respectively. Here we present high-quality long-read genome assemblies for a strain of C. parapsilosis isolated from human breast milk, with multiple predicted signatures consistent with Candida Drug Resistance CDR1/CDR2 and Multi Drug Resistance MDR1-type genes, also for an environmental strain of R. mucilaginosa with multiresistance to azole antifungals. The genome sequencing was performed using the R9.4.1 flowcell with the MinION Mk1B sequencer (Oxford Nanopore Technologies, Oxford, UK). The draft genome of C. parapsilosis HMC1 was assembled from 85,745 long-reads and has 13,114,208 bp in length and comprises 10 contigs making it a highly contiguous assembly. The R. mucilaginosa LBMH1012 assembly has 23,636,156 bp in length and comprises 54 contigs. The genome completeness was estimated as 94.02 % and 91.40 % respectively using BUSCO. These data may be useful to explore the genetic diversity landscape in both species, infer potential causal genes for antifungal resistance and virulence, and represent an addition to the useful sequence space on emerging fungal pathogens.

Changes in fluconazole pharmacokinetics can impact on antifungal effectiveness in critically ill burn patients: a Pharmacokinetic-Pharmacodynamic (PK/PD) approach.

OBJECTIVES: The Fluconazole pharmacokinetic-pharmacodynamic relationship was investigated in a few clinical settings and only limited studies regarding burned patients are available. Thus, the authors aimed to investigate fluconazole pharmacokinetics changes and its impact on antifungal therapy coverage against dose-dependent Candida spp. applying the PK/PD approach in critically ill severely burned patients. METHODS: Fluconazole was administered as a one-hour intravenous infusion of 200 mg q12h. Doses were increased according to the coverage based on the PK/PD approach. Blood samples were collected at the end of the infusion (1st hour), two hours after (3rd hour), and before the next dose (12th or 24th hour). Serum concentrations were obtained by HPLC-UV. Pharmacokinetic parameters were estimated by noncompartmental analysis and compared with data described in healthy subjects. The effectiveness predictive index was based on the AUCss0-24h/MIC ratio, with a target above 25. RESULTS: Every pharmacokinetic parameter was reduced throughout all three sets of the study. Compared to healthy subjects, the volume of distribution was decreased about 3‒7 times, biological half-life was 2‒3 times shorter and total body clearance was slightly altered but statistically significant. Both half-life and total body clearance were correlated to the volume of distribution. Consequently, an increase in fluconazole daily dose was necessary to improve empiric coverage. CONCLUSIONS: Fluconazole pharmacokinetics is altered in critically ill severely burned patients, mainly related to the volume of distribution. Doses higher than usual may be necessary to reach the PK/PD target and guarantee antifungal coverage against dose-dependent Candida spp. up to MIC 32 mg/L.

Salivary proteins modulate Candida albicans virulence and may prevent oropharingeal candidiasis.

Oral candidiasis can be presented in different ways due to the virulence factors of its etiology such as Candida albicans that have developed an effective set of these factors that are able to improve its pathogenesis. The role of salivary immunological components in the development of candidiasis can provide insights for the development of new methodologies aiming to control this disease. The aim of this study was to evaluate the antifungal activity of two salivary components, histatin 5 and lactoferrin on C. albicans viability and virulence using a fluconazole resistant C. albicans clinical strain. Results showed that histatin 5 and lactoferrin decreased cell viability, and the cell surface hydrophobicity was increased by 18% in presence of 151 µg/mL of histatin 5 but was not altered by lactoferrin. It was observed the reduction of 69.3% in the expression of mannoproteins on C. albicans surface in the presence of 151 µg/mL of histatin, but proteolytic activity of serine proteinases was not inhibited by any of the proteins. Histatin 5 altered cell ultrastructure predominantly in the cytoplasmic compartment. However, this peptide does not interfere with mitochondrial function neither in membrane permeability of the yeasts. The association index between C. albicans and epithelial cells was increased by 51% in presence of 151 µg/mL of histatin. Results suggest that histatin 5 and lactoferrin affects viability and virulence of C. albicans at physiological levels, and the maintenance of these levels may be essential in the prevention of oropharyngeal candidiasis. Exogenous administration of these proteins may become a therapeutic alternative for resistant strains of C. albicans, circumventing toxicity issues, considering their constitutive features.

Especies de Candida aisladas en pacientes mujeres en edad reproductiva con candidiasis vaginal en Gualeguaychú, Entre Ríos, Argentina / Candida species isolated in female patients of reproductive age with vaginal candidiasis in Gualeguaychú, Entre Ríos, Argentina

Objetivo: Conocer las especies Candida aisladas en pa-cientes mujeres en edad reproductiva con candidiasis vaginal. Determinar el perfil de sensibilidad a antifúngi-cos (ATF) de las especies de Candida aisladas.Materiales y métodos: Estudio descriptivo transversal en el cual se aislaron en Sabouraud glucosado 124 cepas de Candida spp provenientes de muestras de flujo vaginal. Para la identificación de especie se utilizó CHROMagar Candida y se realizaron pruebas complementarias como formación de tubo germinativo, desarrollo de clamidoco-nidios y asimilación de trehalosa. La sensibilidad in vitrofue investigada por el método de difusión con discos de ATF fluconazol (FLU), itraconazol (ITRA) y anfotericina B (AMB).Resultados: Se observó C. albicans en 85,5% de los ais-lados seguida por C. glabrata con 7,3%, C. krusei 4%, C. tropicalis 2,4% y otras especies Candida. Para FLU, 0,9% de las cepas de C. albicans, 11,1% de Candida glabrata y 100% de C. krusei presentaron resistencia. Para ITRA, el 17% de los aislamientos de C. albicans, el 55,6% de C. glabrata y 100% de C. krusei fueron resistentes. No hubo aislamientos resistentes a AMB.Conclusiones: La candidiasis vaginal sigue teniendo como agente etiológico principal a Candida albicans, siendo ampliamente sensible a los ATF. Las especies C. glabrata y C. krusei presentan un aumento en la resis-tencia a los azoles. Los resultados obtenidos ratifican la necesidad de la realización de las pruebas de identifica-ción de especies de Candida y determinación de la sensi-bilidad in vitro a los ATF para lograr el éxito terapéutico.

Objective: To identify the Candida species isolated in female patients of reproductive age with vaginal candidiasis. To determine the antifungal (ATF) sensitivity profile of the isolated Candida species.Materials and methods: Cross-sectional descriptive study, in which 124 Candida spp strains from vaginal discharge samples were isolated in Sabouraud medium supplemented with glucose. CHROMagarCandida was used for species identification and complementary tests such as germ tube, chlamydoconidia development and investigation of trehalose assimilation were performed. In vitro sensitivity was investigated by diffusion method with ATF discs fluconazole (FLU), itraconazole (ITRA) and amphotericin B (AMB).Results:C. albicans was observed in 85.5% of the isolates followed by C. glabrata with 7.3%, C. krusei 4%, C. tropicalis 2.4% and other Candida species. For FLU, 0.9% of C. albicans, 11.1% of C. glabrata and 100% of C. krusei isolates showed resistance. For ITRA, 17% of C. albicansisolates, 55.6% of C. glabrata and 100% of C. krusei were resistant. There were no isolates resistant to AMB.Conclusions: Vaginal candidiasis continues to present Candida albicans as the main etiological agent, which is widely sensitive to ATFs. C. glabrata and C. krusei species show increased resistance to azoles. The results obtained ratify the growing need for Candida species identification tests and determination of in vitro sensitivity to ATFs in order to guide the treatment of vaginal candidiasis towards therapeutic success.

Monoterpene antifungal activities: evaluating geraniol, citronellal, and linalool on Candida biofilm, host inflammatory responses, and structure-activity relationships.

Introduction: Despite the rising concern with fungal resistance, a myriad of molecules has yet to be explored. Geraniol, linalool, and citronellal are monoterpenes with the same molecular formula (C10H18O), however, neither the effect of these compounds on inflammatory axis induced by Candida spp. nor the antibiofilm Structure-Activity Relationship (SAR) have been well-investigated. Herein we analyzed geraniol, linalool and citronellal antifungal activity, cytotoxicity, and distinctive antibiofilm SAR, also the influence of geraniol on Candida spp induced dysregulated inflammatory axis, and in vivo toxicity. Methods: Minimal inhibitory (MIC) and fungicidal (MFC) concentrations against Candida spp were defined, followed by antibiofilm activity (CFU-colony forming unit/mL/g of dry weight). Cytotoxic activity was assessed using human monocytes (THP-1) and oral squamous cell (TR146). Geraniol was selected for further analysis based on antifungal, antibiofilm and cytotoxic results. Geraniol was tested using a dual-chamber co-culture model with TR146 cells infected with C. albicans, and THP-1 cells, used to mimic oral epithelium upon fungal infection. Expression of Candida enzymes (phospholipase-PLB and aspartyl proteases-SAP) and host inflammatory cytokines (interleukins: IL-1ß, IL-6, IL-17, IL-18, IL-10, and Tumor necrosis factor-TNF) were analyzed. Lastly, geraniol in vivo toxicity was assessed using Galleria mellonella. Results: MIC values obtained were 1.25-5 mM/mL for geraniol, 25-100 mM/mL for linalool, and 100-200 mM/mL for citronellal. Geraniol 5 and 50 mM/mL reduced yeast viability during biofilm analysis, only 500 mM/mL of linalool was effective against a 72 h biofilm and no biofilm activity was seen for citronellal. LD50 for TR146 and THP-1 were, respectively: geraniol 5.883 and 8.027 mM/mL; linalool 1.432 and 1.709 mM/mL; and citronellal 0.3006 and 0.1825 mM/mL. Geraniol was able to downregulate expression of fungal enzymes and host pro-inflammatory cytokines IL-1ß, IL-6, and IL-18. Finally, safety in vivo parameters were observed up to 20 mM/Kg. Discussion: Despite chemical similarities, geraniol presented better antifungal, antibiofilm activity, and lower cytotoxicity when compared to the other monoterpenes. It also showed low in vivo toxicity and capacity to downregulate the expression of fungal enzymes and host pro-inflammatory cytokines. Thus, it can be highlighted as a viable option for oral candidiasis treatment.

Microbicidal Polymer Nanoparticles Containing Clotrimazole for Treatment of Vulvovaginal Candidiasis.

Vulvovaginal candidiasis (VVC) alters the innate cervicovaginal immunity, which provides an important barrier against viruses and other infections. The incidence of this disease has not decreased in the last 30 years, so effective treatments are still needed. Nanoparticles (NPs) of cellulose acetate phthalate (CAP) and clotrimazole (CLZ) were prepared by the emulsification-diffusion method. NPs were characterized using dynamic light scattering, atomic force microscopy and differential scanning calorimetry; their release profile was determined by the dialysis bag technique and mucoadhesion was evaluated with the mucin-particle method. The growth inhibition study of Candida albicans was carried out using the plate counting technique. Finally, accelerated physical stability tests of NPs were carried out, both in water and in SVF. The CAP-CLZ NPs had an average diameter of 273.4 nm, a PDI of 0.284, smooth surfaces and spherical shapes. In vitro release of CLZ from the CAP NPs was categorized with the Weibull model as a matrix system in which initial release was rapid and subsequently sustained. The inhibition of C. albicans growth by the CAP-CLZ NPs was greater than that of free CLZ, and the CAP-only NPs had a microbicidal effect on C. albicans. The NPs showed poor mucoadhesiveness, which could lead to studies of their mucopenetration capacities. An accelerated physical stability test revealed the erosion of CAP in aqueous media. A nanoparticulate system was developed and provided sustained release of CLZ, and it combined an antifungal agent with a microbial polymer that exhibited antifungal activity against C. albicans.

Bioprospecting, Synergistic Antifungal and Toxicological Aspects of the Hydroxychalcones and Their Association with Azole Derivates against Candida spp. for Treating Vulvovaginal Candidiasis.

Vulvovaginal candidiasis (VVC) remains a prevalent fungal disease, characterized by challenges, such as increased fungal resistance, side effects of current treatments, and the rising prevalence of non-albicans Candida spp. naturally more resistant. This study aimed to propose a novel therapeutic approach by investigating the antifungal properties and toxicity of 2-hydroxychalcone (2-HC) and 3'-hydroxychalcone (3'-HC), both alone and in combination with fluconazole (FCZ) and clotrimazole (CTZ). A lipid carrier (LC) was also developed to deliver these molecules. The study evaluated in vitro anti-Candida activity against five Candida species and assessed cytotoxicity in the C33-A cell line. The safety and therapeutic efficacy of in vivo were tested using an alternative animal model, Galleria mellonella. The results showed antifungal activity of 2-HC and 3'-HC, ranging from 7.8 to 31.2 as fungistatic and 15.6 to 125.0 mg/L as fungicide effect, with cell viability above 80% from a concentration of 9.3 mg/L (2-HC). Synergistic and partially synergistic interactions of these chalcones with FCZ and CTZ demonstrated significant improvement in antifungal activity, with MIC values ranging from 0.06 to 62.5 mg/L. Some combinations reduced cytotoxicity, achieving 100% cell viability in many interactions. Additionally, two LCs with suitable properties for intravaginal application were developed. These formulations demonstrated promising therapeutic efficacy and low toxicity in Galleria mellonella assays. These results suggest the potential of this approach in developing new therapies for VVC.

Might photobiomodulation therapy interfere with the frequency of severe mucositis and oral candidiasis? A retrospective analysis in patients with head and neck carcinoma.

PURPOSE: Considering the tumor in the oral cavity or the oropharynx and nasopharynx region might be an aggravating factor for oral mucositis (OM) manifestation, the present study aimed to evaluate whether the location of the tumor and the use of photobiomodulation therapy (PBMT) might affect the frequency of oral candidiasis (OC) during radiotherapy (RT) and/or chemotherapy (CT) treatments. METHODS: The medial records of seventy-four patients with head and neck cancer treated in a public service from 2016 to 2019 were evaluated. All these patients were submitted to RT in an accumulated dose of 48 to 70 Gy of radiation. Data about OM and OC were collected and presented according to the application of a therapeutic protocol with laser photobiomodulation (PBMT) to control oral mucositis, or not (No-PBM), and the location of tumor (head and neck or oral cavity). In the PBMT group patients, a low-power laser device composed of InGaAlP diode (maximum output power of 86.7 mW, active tip area of 0.1256 cm2, and continuous wavelength of 660 nm), was applied to the lips (three points each), right and left jugal mucosa (three points each), the limit between hard and soft palate (three points), buccal floor/sublingual gland (one point), lateral edge of the tongue (three points on each side), and back of the tongue (six points), three times weekly, for 5 weeks. The dosimetry used in each application was 2 J for 3 s, thus totaling 56 J. The correlation between clinical characteristics such as age, tumor size (T), metastatic lymph node (N), number of RT and CT sessions, candidiasis, and OM were analyzed. RESULTS: Mucositis grades 1 and 2 were the most common among all patients, especially before the 12th radiotherapy session, regardless of the treatment with PBM (p > 0.05). Additionally, no difference in the grade of OM and OC was significantly observed when comparing the two laser therapy groups. OC was more frequent after the 12th radiotherapy session in all groups. Nonetheless, OM and OC had a different correlation regarding to tumor location (head and neck and oral cavity) being PBMT a positive therapy to delay OM. It was observed a positive and statistically significant correlation between tumors at oral cavity and OM, regardless PBMT (R = 0.84, p < 0.05 to PBMT and R = 0.13, p < 0.05 to No-PBM). Otherwise, OC was positively correlated to local metastasis in patients with oral tumors undergoing PBMT (R = 0.84, p < 0.05). CONCLUSION: Patients with oral cavity tumor presented more OM, especially high grades, then patients with tumors in other regions of the head and neck, which seems to be related to the irradiation parameters of radiotherapy and/or with the limitation of conduction of PBMT in tumor areas. OM and OC were not changed by PBMT, although it helped to reduce the incidence of severe cases of OM.

Clinical and mycological analysis of colonization by Candida spp. in oral leukoplakia and oral lichen planus.

OBJECTIVE: This study aims to analyze the prevalence of Candida spp. colonization in oral leukoplakia and oral lichen planus lesions, verify the influence of systemic and local factors, besides identify and determine the in vitro antifungal susceptibility profile of Candida species. MATERIALS AND METHODS: Samples were collected by swabbing from oral lesions and healthy mucosa and cultured on Sabouraud Dextrose and CHROMagar® Candida plates. Species identification was confirmed with MALDI-TOF MS analysis. RESULTS: Candida spp. was found in 36.8% of cases of oral leukoplakia and 18.2% of cases of oral lichen planus. Candida albicans was the only species found in oral lichen planus lesions (n = 2, 100%) and the most prevalent in oral leukoplakia (n = 5, 76.4%). Among the non-albicans Candida species found in oral leukoplakia were C. parapsilosis (n = 2, 25.5%) and C. tropicalis (n = 1, 14.1%). Candida isolates were susceptible to all antifungals tested. CONCLUSION: C. albicans was the most commonly found species in the studied lesions. No correlation was found between systemic and local factors with positive cases of oral lichen planus. However, smoking and alcohol consumption may be associated with positive cases of oral leukoplakia, especially the non-homogeneous clinical form. In addition, there is a possible predisposition to associated Candida colonization in cases of epithelial dysplasia found in oral leukoplakia. The antifungal medications tested showed excellent efficacy against isolates.

Antileishmanial and Antifungal Activities of Volatile Oils from Cinnamomum Cassia Bark and Schinus Molle Leaves.

This study reports on the chemical composition and antileishmanial and anticandidal activities of volatile oils (VOs) of Schinus molle dried leaves (SM), Cinnamomum cassia branch bark (CC) and their blends. Major constituents of SM were spathulenol (26.93 %), ß-caryophyllene (19.90 %), and caryophyllene oxide (12.69 %), whereas (E)-cinnamaldehyde (60.11 %), cinnamyl acetate (20.90 %) and cis-2-methoxycinnamic acid (10.37 %) were predominant in CC. SM (IC50=21.45 µg/mL) and CC (IC50=23.27 µg/mL) displayed good activity against L. amazonensis promastigotes, besides having good or moderate activity against nine Candida strains, with Minimum Inhibitory Concentration (MIC) values ranging from 31.25 to 250 µg/mL. While the three SM and CC blends were not more active than the VOs tested individually, they exhibited remarkably high antileishmanial activity, with IC50 values ranging between 3.12 and 7.04 µg/mL, which is very similar to the IC50 of amphotericin B (positive control).

In Silico and In Vitro Evaluation of the Antifungal Activity of a New Chromone Derivative against Candida spp.

Candida species are frequently implicated in the development of both superficial and invasive fungal infections, which can impact vital organs. In the quest for novel strategies to combat fungal infections, there has been growing interest in exploring synthetic and semi-synthetic products, particularly chromone derivatives, renowned for their antimicrobial properties. In the analysis of the antifungal activity of the compound (E)-benzylidene-chroman-4-one against Candida, in silico and laboratory tests were performed to predict possible mechanisms of action pathways, and in vitro tests were performed to determine antifungal activity (MIC and MFC), to verify potential modes of action on the fungal cell membrane and wall, and to assess cytotoxicity in human keratinocytes. The tested compound exhibited predicted affinity for all fungal targets, with the highest predicted affinity observed for thymidylate synthase (-102.589 kJ/mol). MIC and CFM values ranged from 264.52 µM (62.5 µg/mL) to 4232.44 µM (1000 µg/mL). The antifungal effect likely occurs due to the action of the compound on the plasma membrane. Therefore, (E)-benzylidene-chroman-4-one showed fungicidal-like activity against Candida spp., possibly targeting the plasma membrane.

Clinical and epidemiological aspects of Candida yeast infections and rational use of antifungals.

Aim: The objective of this study was to evaluate the clinical and epidemiological aspects of Candida infections. Methods: The study relied on the analysis of electronic medical records. Results: Among 183 patients with positive fungal infections, 57 were from the community and 126 from hospitals. Females predominated in both groups (82.4% in the community, 54.7% in hospitals). Non-albicans Candida spp. accounted for 62.8% of cases. Antifungal therapy was prescribed for 67 patients, with a 55.6% mortality rate. Conclusion: The increasing prevalence of non-albicans Candida species highlights the need for better candidiasis monitoring and control, especially concerning antifungal use amidst rising antimicrobial resistance, particularly in empirical therapy scenarios.

Fungal infections, particularly those caused by a group of yeasts called Candida, are a major concern. This study looks at clinical laboratory and medical records. We found that certain species of Candida not previously associated with human disease are common. We also noted the inappropriate use of antifungal medication, highlighting the need for healthcare workers to carefully diagnose patients and make appropriate decisions when treating fungal infections.

Development of biopolymer films loaded with fluconazole and thymol for resistant vaginal candidiasis.

Vulvovaginal candidiasis (VVC) is an opportunistic infection caused by a fungus of the Candida genus, affecting approximately 75 % of women during their lifetime. Fungal resistance cases and adverse effects have been the main challenges of oral therapies. In this study, the topical application of thin films containing fluconazole (FLU) and thymol (THY) was proposed to overcome these problems. Vaginal films based only on chitosan (CH) or combining this biopolymer with pectin (PEC) or hydroxypropylmethylcellulose acetate succinate (HPMCAS) were developed by the solvent casting method. In addition to a higher swelling index, CH/HPMCAS films showed to be more plastic and flexible than systems prepared with CH/PEC or only chitosan. Biopolymers and FLU were found in an amorphous state, contributing to explaining the rapid gel formation after contact with vaginal fluid. High permeability rates of FLU were also found after its immobilization into thin films. The presence of THY in polymer films increased the distribution of FLU in vaginal tissues and resulted in improved anti-Candida activity. A significant activity against the resistant C. glabrata was achieved, reducing the required FLU dose by 50 %. These results suggest that the developed polymer films represent a promising alternative for the treatment of resistant vulvovaginal candidiasis, encouraging further studies in this context.

Evaluation of 1,9-Dimethyl-Methylene Blue nanoencapsulation using rhamnolipid nanoparticles to potentiate the Photodynamic Therapy technique in Candida albicans: In vitro study.

With the rapid development of nanotechnology, various functional nanomaterials have shown exciting potential in biomedical areas such as drug delivery, antitumor, and antibacterial therapy. These nanomaterials improve the stability and selectivity of loaded drugs, reduce drug-induced side effects, realize controlled and targeted drug release, and increase therapeutic efficacy. The increased resistance to antifungal microbicides in medical practice and their side effects stimulate interest in new therapies, such as Photodynamic Therapy (PDT), which do not generate resistance in microorganisms and effectively control the pathology. The present study aimed to evaluate, in vitro, the efficacy of photodynamic therapy on Candida albicans using 1,9-Dimethyl-Methylene Blue (DMMB) as photosensitizer, red LED (λ630), and nanoencapsulation of DMMB (RL-NPs/DMMB) using rhamnolipids produced by Pseudomonas aeruginosa to evaluate if there is better performance of DMMB + RL particles compared to DMMB alone via the characterization of DMMB + RL and colony forming count. The tests were carried out across six experimental groups (Control, DMMB, RL-NPs, RL-NPs/DMMB, PDT and PDT + RL-NPs/DMMB) using in the groups with nanoparticles, DMMB (750 ng/mL) encapsulated with rhamnolipids in a 1:1 ratio, the light source consisted of a prototype built with a set of red LEDs with an energy density of 20 J/cm2. The results showed that applying PDT combined with encapsulation (RL-NPs/DMMB) was a more practical approach to inhibit Candida albicans (2 log reduction) than conventional applications, with a possible clinical application protocol.

Pore-forming peptide C14R exhibits potent antifungal activity against clinical isolates of Candida albicans and Candida auris.

Introduction: Invasive candidiasis is a global public health problem as it poses a significant threat in hospital-settings. The aim of this study was to evaluate C14R, an analog derived from peptide BP100, as a potential antimicrobial peptide against the prevalent opportunistic yeast Candida albicans and the emergent multidrug-resistant yeast Candida auris. Methods: Antifungal susceptibility testing of C14R against 99 C. albicans and 105 C. auris clinical isolates from Colombia, was determined by broth microdilution. Fluconazole was used as a control antifungal. The synergy between C14R and fluconazole was assessed in resistant isolates. Assays against fungal biofilm and growth curves were also carried out. Morphological alterations of yeast cell surface were evaluated by scanning electron microscopy. A permeability assay verified the pore-forming ability of C14R. Results: C. albicans and C. auris isolates had a geometric mean MIC against C14R of 4.42 µg/ml and 5.34 µg/ml, respectively. Notably, none of the isolates of any species exhibited growth at the highest evaluated peptide concentration (200 µg/ml). Synergistic effects were observed when combining the peptide and fluconazole. C14R affects biofilm and growth of C. albicans and C. auris. Cell membrane disruptions were observed in both species after treatment with the peptide. It was confirmed that C14R form pores in C. albicans' membrane. Discussion: C14R has a potent antifungal activity against a large set of clinical isolates of both C. albicans and C. auris, showing its capacity to disrupt Candida membranes. This antifungal activity remains consistent across isolates regardless of their clinical source. Furthermore, the absence of correlation between MICs to C14R and resistance to fluconazole indicates the peptide's potential effectiveness against fluconazole-resistant strains. Our results suggest the potential of C14R, a pore-forming peptide, as a treatment option for fungal infections, such as invasive candidiasis, including fluconazole and amphotericin B -resistant strains.

Ascorbic acid as a modulator of inflammatory response against Candida albicans.

Aim: To evaluate the behavior of oral keratinocytes in the presence of Vitamin C (Vit C) and its anti-inflammatory potential. Materials & methods: Oral keratinocytes were initially exposed to 0.1-2.5 mM of Vit C and the metabolic activity and cell migration were evaluated using MTS assay and Ibidi culture inserts, respectively. After, the cells were challenged with Candida albicans and inflammatory markers were analyzed by qPCR. Results: The treatment was not cytotoxic, and the highest concentrations increased the metabolic activity at 24 h. Vit C delayed the cell migration at 48 and 72 h. Interestingly, it downregulated the genes IL-8 and IL-1ß. Conclusion: Vit C could be an interesting adjuvant to anti-fungal treatment due to its anti-inflammatory potential.

Vitamin C, also known as ascorbic acid, is a vitamin commonly found in fruits and vegetables. It is popular for supporting our immune system, so is commonly taken as a supplement. We looked at the action of vitamin C on cells from the mouth and its potential to reduce inflammation in a fungal disease of the mouth ­ oral candidiasis. We showed that vitamin C is not toxic to cells of the mouth and may reduce inflammation in cells infected by the fungus. This suggests that vitamin C could be used as a complementary therapy for oral candidiasis.

Patients with recurrent vulvovaginal candidiasis exhibit a decrease in both the fungicidal activity of neutrophils and the proliferation of peripheral blood mononuclear cells.

BACKGROUND: Recurrent vulvovaginal candidiasis (RVVC) is an important and underestimated fungal infection. OBJECTIVE: We aimed to determine the fungicidal and proliferative capacities of neutrophils and peripheral blood mononuclear cells (PBMCs), respectively and the clinical and microbiological characteristics of a cohort of Colombian patients diagnosed with RVVC. METHODS: A cross-sectional study was conducted. A total of 66 women were included (40 diagnosed with RVVC and 26 healthy women [HW]). Demographic and clinical data were recorded. Vaginal fluid samples were obtained for isolation, identification and antifungal susceptibility testing of Candida species using selective culture media and the Vitek 2.0® system. Blood samples were also obtained to evaluate cell subpopulations; furthermore, neutrophils and PBMCs were isolated to determine their fungicidal and proliferative capacities, respectively. RESULTS: The median age was 29 (IQR: 34-23) for RVVC and 24 (IQR: 30-23) for HW. Only two species of the genus Candida were identified: Candida albicans (92.5%) and Candida lusitaniae (7.5%). Resistance to fluconazole, voriconazole, flucytosine and amphotericin B was observed on six C. albicans isolates and one C. lusitaniae isolate. Only the family history of vulvovaginal candidiasis was associated with RVVC occurrence. The RVVC group exhibited a significantly higher number of neutrophils but with lower fungicidal activity in comparison to HW; likewise, PBMCs from RVVC patients presented a lower proliferation index when stimulated with C. albicans. CONCLUSION: Contrary to what has been reported worldwide, in Colombian patients with RVVC, C. albicans was the main isolated species without increased antifungal resistance. The diminished fungicidal and proliferative capacities of neutrophils and PBMCs, respectively, could suggest a possible alteration in the innate and adaptive immune responses.