Successful treatment of experimental murine vulvovaginal candidiasis with gentian violet.

Aim: This study evaluated the antifungal efficacy of gentian violet (GV) in an experimental vulvovaginal candidiasis (VVC) model. Materials & methods: In vitro susceptibility and cytotoxicity assays were performed to validate the antifungal potential and safety of GV. The antifungal efficacy was then evaluated in vivo through comparative analysis of the fungal burden following treatment with GV or nystatin, as well as assessment of the vaginal tissue by histology and electron microscopy. Results: GV demonstrated a safe antifungal profile against C. albicans, with a significant decrease in fungal burden and an improvement in the inflammatory process evaluated histologically. Conclusion: The results of this study motivate further assessment of GV as a promising alternative for VVC therapy.

Cell wall associated proteins involved in filamentation with impact on the virulence of Candida albicans.

Candida albicans is a commensal microorganism of the human microbiota that can be associated with superficial to disseminated infections. This species possesses several attributes that contribute to pathogenesis and virulence, such as the ability to transition from yeast to hyphae forms. During this transition, several changes occur in the fungal cell wall, which is the first point of contact between the pathogen and the host. The cell wall is a bi-layered structure, containing chitin, glucan, and proteins, the latter of which play important roles in pathogenesis. Given the importance of this structure, particularly in filamentation, this review focuses on the studies of C. albicans mutants for genes that encode cell wall-associated proteins that have an important role in the virulence, and also have a role in hyphal morphogenesis. Thus, we highlight some proteins whose mutation is associated with attenuated virulence in vivo and have defective filamentation. We also provide examples of proteins whose inactivation does not impair the filamentation yet are still important for C. albicans virulence.

New approach to the use of propolis against dermatomycosis.

In recent years, propolis extract (PE) has demonstrated antimicrobial and anti-inflammatory properties. The aim of this study was to evaluate the antifungal activity of a bioadhesive thermoresponsive system containing 16% propolis (BTSP 16%) against Microsporum canis, Nannizzia gypsea, Trichophyton mentagrophytes and T. rubrum. We also evaluated PE alone against the same strains. The results showed that both PE and BTSP 16% significantly reduced the fungal viability of all evaluated strains. In addition, they interacted with the biofilm of these species in different stages of biofilm formation. We observed that the bioadhesive and thermoresponsive properties of BTSP 16% prolonged propolis presence at infection sites, leading to positive results against planktonic fungal cells and mature biofilms. These characteristics make this formulation a valuable alternative treatment for dermatomycosis.

Hypericin-P123-photodynamic therapy in an ex vivo model as an alternative treatment approach for onychomycosis caused by Fusarium spp.

BackgroundFusarium has been considered an opportunistic pathogen, causing several infections in humans, including onychomycosis. In addition, a high resistance to conventional antifungals has been linked to this genus. Photodynamic Therapy (PDT), known as a non-invasive therapy, can be an alternative treatment for fungal infections, based on the excitation of a photosensitizing compound (PS) by a specific length of light, causing damage to the target. The aim of this study was to evaluate the effects of a formulation of Hypericin (Hyp) encapsulated in Pluronic™ (P123), via photodynamic therapy (PDT), on planktonic cells and biofilms in Fusarium spp. using in vitro and ex vivo assays. Materials & Methods epidemiology studies about Fusarium spp. in onychomycosis was perfomed, carried out molecular identification, compared the antifungal activity of the conventional antifungals with PDT with encapsulated Hypericin (Hyp-P123), carried out detection of reactive oxygen species, and measured the antibiofilm effect of the Hyp-P123-PDT in vitro and in an ex vivo model of onychomycosis. Results Hyp-P123-PDT exhibited a fungicidal effect in vitro with reductions ≥ 3 log10. ROS generation increased post-Hyp-P123-PDT in Fusarium spp. Hyp-P123-PDT showed a potent inhibitory effect on adhesion-phase and mature biofilms in vitro tests and an ex vivo model of onychomycosis (p<0.0001). Conclusion Hyp-P123-PDT had a potent effect against Fusarium spp., suggesting that photodynamic therapy with Hyp-P123 is a safe and promising treatment for onychomycosis in clinical practice.

A systematic review of photodynamic therapy as an antiviral treatment: Potential guidance for dealing with SARS-CoV-2.

BACKGROUND: SARS-CoV-2, which causes the coronavirus disease (COVID-19), presents high rates of morbidity and mortality around the world. The search to eliminate SARS-CoV-2 is ongoing and urgent. This systematic review seeks to assess whether photodynamic therapy (PDT) could be effective in SARS-CoV-2 inactivation. METHODS: The focus question was: Can photodynamic therapy be used as potential guidance for dealing with SARS-CoV-2?". A literature search, according to PRISMA statements, was conducted in the electronic databases PubMed, EMBASE, SCOPUS, Web of Science, LILACS, and Google Scholar. Studies published from January 2004 to June 2020 were analyzed. In vitro and in vivo studies were included that evaluated the effect of PDT mediated by several photosensitizers on RNA and DNA enveloped and non-enveloped viruses. RESULTS: From 27 selected manuscripts, 26 publications used in vitro studies, 24 were exclusively in vitro, and two had in vitro/in vivo parts. Only one analyzed publication was exclusively in vivo. Meta-analysis studies were unfeasible due to heterogeneity of the data. The risk of bias was analyzed in all studies. CONCLUSION: The in vitro and in vivo studies selected in this systematic review indicated that PDT is capable of photoinactivating enveloped and non-enveloped DNA and RNA viruses, suggesting that PDT can potentially photoinactivate SARS-CoV-2.

Different expression levels of ALS and SAP genes contribute to recurrent vulvovaginal candidiasis by Candida albicans.

Aim: To study the behavior of Candida albicans in women with vulvovaginal candidiasis (VVC), recurrent VVC (RVVC) and asymptomatic (AS), regarding adhesion on HeLa cells and their ability to express secreted aspartic proteinases (SAP) genes, agglutinin-like sequence (ALS) genes and HWP1. Materials & methods: The adhesion of Candida albicans to HeLa cells was evaluated by colony-forming units, and the expressed genes were evaluated by qRT-PCR. Results: AS and VVC isolates showed greater ability to adhere HeLa cells when compared with RVVC isolate. Nevertheless, RVVC isolate exhibited upregulation of a large number of genes of ALS and SAP gene families and HWP1 gene. Conclusion: The results demonstrated that RVVC isolate expressed significantly important genes for invasion and yeast-host interactions.

Impact of serial systemic infection on Candida albicans virulence factors.

Aim: To evaluate changes in virulence and pathogenicity approaches from Candida albicans after successive passages in a murine model of systemic candidiasis. Materials & methods: Phenotypic assays were performed using colonies recovered from animals infected serially, totalizing five passages. Results: A progressive infection was observed along the passages, with increased fungal burden and the presence of greater inflammatory areas in the histopathological findings. Recovered strains exhibited increased filamentation and biofilm abilities, along with modulation of phospholipase and proteinase activities. Conclusion: Repeated contact between yeast and host increased the expression of virulence factors. Furthermore, a correspondence between phenotypic profile and proteomic data obtained previously was observed.

Copolymeric micelles as efficient inert nanocarrier for hypericin in the photodynamic inactivation of Candida species.

Aim: To evaluate the efficacy of photodynamic inactivation (PDI) mediated by hypericin encapsulated in P-123 copolymeric micelles (P123-Hyp) alone and in combination with fluconazole (FLU) against planktonic cells and biofilm formation of Candida species Materials & methods: PDI was performed using P123-Hyp and an LED device with irradiance of 3.0 mW/cm2 . Results: Most of isolates (70%) were completely inhibited with concentrations up to 2.0 µmol/l of HYP and light fluence of 16.2 J/cm2. FLU-resistant strains had synergic effect with P123-HYP-PDI and FLU. The biofilm formation was inhibited in all species, in additional the changes in Candida morphology observed by scanning electron microscopy. Conclusion: P123-Hyp-PDI is a promising option to treat fungal infections and medical devices to prevent biofilm formation and fungal spread.