Diagnosis and management of oral candidosis

The Impact of Maternal Antibiotic Consumption on the Development of Oral Thrush Infection in Breastfeeding Infants: A Quasi-Experimental Study

Background: Oral thrush is a common yeast infection caused by Candida albicans in infants during their first few weeks or months. Infant mothers' antibiotics consumption can contribute to this opportunistic fungal growth due to their weaker immune systems. Objectives: To investigate the relationship between maternal antibiotic consumption and oral thrush infection in breastfeeding infants, this study aims to provide insights for health care professionals regarding antibiotic prescriptions and preventive strategies for managing oral thrush. Methods: A quasi-experimental design with a control group was used. Eighty-two breastfeeding infants were divided into two groups: Group 1 (n = 40) infants of antibiotic-consuming mothers and Group 2 (n = 42) infants of nonantibiotic-consuming mothers. The oral samples were collected using sterile cotton swabs and cultured on Sabouraud's dextrose agar C. albicans, confirmed by simple staining and a germ tube test. Results: Infants aged 1-11 months with a mean ± standard deviation of 4.8 ± 3.51. Within all 82 oral swabs, 42.7% were positive for C. albicans growth and 57.3% were negative. The highest percentage was in 1-month-old infants (n = 9, 25.71%), and the lowest was in 11 months old (n = 2, 5.71%). Group 2 infants had significantly fewer positive C. albicans growth (n = 12, 28.57%) compared with group 1 (n = 23; 57.5%) (χ2 = 7.0, p = 0.007; odds ratio = 3.332, 95% confidence interval = 1.35-8.46). Oral thrush clinical signs were identified in 66.6% and 33.4% of group 1 and 2 infants, respectively, while 31.4% of C. albicans-positive colonization showed no clinical manifestations. Conclusion: Maternal antibiotic consumption for more than 1 week is associated with the occurrence of oral thrush in breastfeeding infants. Differences in clinical signs in two groups of infants indicate the importance of laboratory tests for early oral thrush diagnosis. This can help health care professionals understand oral thrush causes, enable early detection, improve treatment, and enhance appropriate antibiotic use in breastfeeding mothers.

Candida albicans enhances iron uptake to maintain fluconazole resistance

Widespread use of fluconazole has led to the emergence of fluconazole-resistant (FR) Candida spp. causing challenges in clinical treatment. Iron, an essential nutrient, affects the levels of ergosterol (a fluconazole target) in fungal membranes. Our lab-generated FR strain (fluconazole minimum inhibitory concentration [MIC] >125 µg/mL) showed a twofold lower MIC (4.66 µg/mL) for the iron chelator deferasirox (DFX), compared to its patent strain CAI4 (DFX MIC 9.34 µg/mL), suggesting a greater sensitivity to iron chelation. A sublethal dose of DFX (2.33 µg/mL) was able to effectively synergize with 125 µg/mL fluconazole to kill the FR strain. Iron estimation revealed significantly enhanced intracellular iron accumulation in the FR strain compared to CAI4. Expression of iron-uptake genes (FRP1, FRE10, and RBT5) was also significantly upregulated in the FR strain, particularly under high iron. FR strain also showed an increase in the levels of cellular ergosterol, along with an increase in the expression of ergosterol biosynthesis genes (ERG11 and ERG9), compared to CAI4, under both low and high iron. The strain further showed increased β-glucan levels and exposure. Additionally, FR strain showed significantly higher survival in high-iron mice compared to low-iron mice, during fluconazole treatment. Finally, we observed a synergistic fungicidal response between 2.33 µg/mL DFX and 125 µg/mL fluconazole, for FR clinical strains. Overall, this suggests that FR C. albicans actively uptakes more iron to maintain cellular conditions needed to support its resistance against fluconazole; and that DFX alone or in conjugation with fluconazole has the potential to overcome fluconazole drug resistance.

Candida albicans and NCAC species: acidogenic and fluoride-resistant oral inhabitants

Objective

Although Candida species are thought to contribute to dental caries, their acid production under anaerobic conditions and susceptibility to fluoride have not been thoroughly studied. We therefore investigated the growth, acid production, and effect of fluoride on Candida species.

Methods

Aerobic growth, acid production from glucose and its end-products under aerobic and anaerobic conditions, and enolase activity were measured in C. albicans and non-Candida-albicans-Candida (NCAC) species (C. tropicalis, C. parapsilosis, C. maltosa, and C. glabrata), and the effect of fluoride on these abilities was evaluated.

Results

All Candida species produced acids under aerobic and anaerobic conditions, and acetate and TCA cycle metabolites were detected. However, these organic acids only accounted for 1.9-57.6% of the acids produced. Up to 80 mM fluoride hardly inhibited growth and did not inhibit acid production except for C. glabrata, despite the low 50% inhibitory fluoride concentration of 0.19-0.34 mM for enolase.

Conclusion

Candida species produced acids under aerobic and anaerobic conditions, indicating their significant cariogenicity. Their growth and acid production were highly fluoride-resistant, whereas their enolase was fluoride-sensitive, suggesting mechanisms for maintaining low intracellular fluoride. The mechanisms underlying the fluoride resistance remain underexplored. Approaches other than fluoride may be needed to control Candida-associated caries.

Factors associated with the presence of Candida spp. in the oral and tracheobronchial secretions of patients admitted to an adult intensive care unit

OBJECTIVE

to verify factors associated with the presence of Candida spp. in oral and tracheobronchial secretions of 135 patients admitted to an adult ICU, general of the Santa Casa de Caridade, of Diamantina, Minas Gerais, Brazil. Oral samples showed significant differences between colonized and non-colonized patients in the variables age (p < 0.01), people with two or more comorbidities (p < 0.04), hypertensive patients (p < 0.01) and Congestive Heart Failure (CHF) (p < 0.01). In multivariate logistic regression, we verified that age (p = 0.02, OR = 1.03), Systemic Arterial Hypertension (SAH) (p = 0.01, OR = 2.89) and CHF (p = 0.05, OR = 2.49) are associated with the presence of Candida spp. in oral samples. Removing the age variable, comorbid hypertension (p = 0.04, OR = 2.18) and CHF (p = 0.04, OR = 2.64) increase the chance of having Candida spp. twice in the oral sample. The results showed that CHF, SAH and increasing age are factors associated with Candida spp. in the oral cavity of ICU patients.

Evaluation of the Disinfection Efficacy of Er: YAG Laser Light on Single-Species Candida Biofilms-An In Vitro Study

Background/Objectives: Oral candidiasis is an opportunistic infection caused by Candida species. Recently, antifungal drugs have become less effective due to yeast resistance, emphasizing the need for new treatment strategies. This study aimed to assess the effect of the Er:YAG laser on the inhibition of growth and elimination of mature single-species Candida biofilms. Methods: The study utilized reference strains of C. albicans, C. glabrata, C. parapsilosis, and C. krusei organized in single-species biofilms on Sabouraud dextrose agar (SDA). First part: Candida suspensions (0.5 McFarland standard) were spread on SDA plates-two for each strain. Er:YAG laser irradiation was applied in a single pulse mode, 30 to 400 mJ, to 32 predetermined points. The growth inhibition zones (GIZs) were measured at 24-96 h of incubation. Second part: biofilms were prepared similarly and, after 96 h of incubation, exposed to Er:YAG laser irradiation at different energies (50, 100, 150, 200 mJ) for 180 s, per 1.44 cm area. Post-irradiation, impressions were taken using Rodac Agar to determine yeast counts. The count of colony-forming units (CFU) after irradiation was measured and results were analysed statistically. Results: First part: GIZ was found in all irradiated sites, with various Candida strains. The results showed a significant increase in the width of GIZ in the energy range of 30-280 mJ and a non-significant increase in the energy range of 300-400 mJ. Second part: the number of CFU remaining after the irradiation of biofilms with 150 mJ energy differed statistically significantly from other results obtained after using 50, 100, or 200 mJ energy, regardless of the Candida strain tested. Conclusions: The Er:YAG is shown to have good disinfecting properties (inhibiting biofilm growth, even at low-energy doses (50 mJ), and eliminating maturity, Candida spp. biofilms most effective on the 150 mJ energy dose).

Effect of Nd:YAG Laser Irradiation on the Growth of Oral Biofilm

BACKGROUND

Oral microbiota comprises a wide variety of microorganisms. The purpose of this study was to evaluate the effects of Nd:YAG laser with a 1064 nm wavelength on the in vitro growth of Candida albicans, Candida glabrata, and Streptococcus mutans clinical strains, as well as their biofilm. The study also aimed to determine whether the parameters recommended for photobiomodulation (PBM) therapy, typically used for tissue wound healing, have any additional antibacterial or antifungal effects.

MATERIAL AND METHODS

Single- and dual-species planktonic cell solution and biofilm cultures of Streptococcus mutans, Candida albicans, and Candida glabrata were irradiated using an Nd:YAG laser (LightWalker; Fotona; Slovenia) with a flat-top Genova handpiece. Two test groups were evaluated: Group 1 (G-T1) exposed to low power associated parameters (irradiance 0.5 W/cm2) and Group 2 (G-T2) with higher laser parameters (irradiance 1.75 W/cm2). Group 3 (control) was not exposed to any irradiation. The lasers' effect was assessed both immediately after irradiation (DLI; Direct Laser Irradiation) and 24 h post-irradiation (24hLI) of the planktonic suspension using a quantitative method (colony-forming units per 1 mL of suspension; CFU/mL), and the results were compared with the control group, in which no laser was applied. The impact of laser irradiation on biofilm biomass was assessed immediately after laser irradiation using the crystal violet method.

RESULTS

Nd:YAG laser irradiation with photobiomodulation setting demonstrated an antimicrobial effect with the greatest immediate reduction observed in S. mutans, achieving up to 85.4% reduction at the T2 settings. However, the laser's effectiveness diminished after 24 h. In single biofilm cultures, the highest reductions were noted for C. albicans and S. mutans at the T2 settings, with C. albicans achieving a 92.6 ± 3.3% reduction and S. mutans reaching a 94.3 ± 5.0% reduction. Overall, the T2 settings resulted in greater microbial reductions compared to T1, particularly in biofilm cultures, although the effectiveness varied depending on the microorganism and culture type. Laser irradiation, assessed immediately after using the crystal violet method, showed the strongest biofilm reduction for Streptococcus mutans in the T2 settings for both single-species and dual-species biofilms, with higher reductions observed in all the microbial samples at the T2 laser parameters (p < 0.05) Conclusion: The Nd:YAG laser using standard parameters typically applied for wound healing and analgesic effects significantly reduced the number of Candida albicans; Candida glabrata; and Streptococcus mutans strains.

Clinical aPDT's effect on Candida albicans: Antifungal susceptibility, virulence gene expression, and correlation with leukocyte and neutrophil counts

BACKGROUND

Our previous clinical trial demonstrated that antimicrobial photodynamic therapy (aPDT) with methylene blue (MB) and potassium iodide (KI) effectively killed Candida albicans (C. albicans) in adult AIDS patients with oral candidiasis, regardless of biofilm formation or 25S rDNA genotype. This study evaluated changes in antifungal susceptibility and virulence gene expression in C. albicans before and after aPDT, and explored factors related to clinical aPDT efficacy.

METHODS

Twenty-one adult AIDS patients with C. albicans oral candidiasis were divided into Group a (400 μM MB, N = 11) and Group b (600 μM MB, N = 10). Both groups received two aPDT treatments, where MB was applied for 5 min, followed by 300 mM KI, and illuminated for 30 min (37.29 J/cm²). C. albicans isolates were collected before and after treatment to assess antifungal susceptibility (fluconazole, itraconazole, flucytosine, amphotericin B) and gene expression (CAT1, HWP1). Peripheral blood tests were analyzed for correlations with aPDT efficacy.

RESULTS

aPDT reduced minimum inhibitory concentration (MIC) values for amphotericin B, fluconazole, and flucytosine, with significant reductions primarily after the first treatment. MIC reductions differed between groups, with Group a showing greater decreases in flucytosine and fluconazole MICs, and Group b in amphotericin B MICs. No significant changes in CAT1 or HWP1 expression were observed. Clinical efficacy of aPDT negatively correlated with leukocyte and neutrophil levels.

CONCLUSIONS

aPDT effectively reduces MICs of antifungal drugs against C. albicans isolated from treated patients, particularly after the first treatment. The concentration of MB required to reduce MICs varies among different antifungal drugs. aPDT does not alter CAT1 or HWP1 expression, and its clinical efficacy in eradicating C. albicans is negatively associated with leukocyte and neutrophil levels.

Callistemon citrinus: A plant‐mediated synthesis of sustainable Rhodium nanoparticles and their antimicrobial activity

This work investigates the potential of using Callistemon citrinu flower extract, commonly known as bottlebrush, in the environmentally friendly synthesis of Rhodium nanoparticles (Rh NPs). Callistemon citrinu flower extract contains a high concentration of flavonoids and other phytochemicals. Hence, the extract was used to provide the essential components for an environmentally, sustainable synthesis method of Rh NPs. Different characterization analyses were used to evaluate the different properties of the synthesized particles. UV spectroscopy analysis demonstrated a continuous UV absorption spectrum attributed to the formation of Rh NPs. The XRD data and SAED analysis showed an amorphous nature of the synthesized Rh NPs. The HRTEM imaging provided morphological information about the Rh NPs tested sample, where the efficiency of Callistemon citrinu flower extract as a capping agent was reported. Furthermore, Raman spectra displayed the characteristic vibrational bands of the synthesized Rh NPs. The antimicrobial activity of the synthesized samples was tested against several dental pathogens, that play a role in dental caries, Staphylococcus aureus (SA), Bacillus subtilis (BS), Candida albicans (CA), Escherichia coli (Eco), and Staphylococcus epidermidis (S. Epi). In comparison with the control, Chlorhexidine (CHX), Rh NPs showed a greater impact on C. albicans (20 ≤ Zone of inhibition (ZOI) (mm) ≤ 26). The statistical analysis demonstrated that Rh NPs had a greater mean ZOI than the Callistemon citrinu flower extract. These results reveal the considerable potential and biological capacity Rh NPs have as an antifungal agent for dental applications.

Mechanisms of action of Lactobacillus spp. in the treatment of oral candidiasis

Candida albicans is often associated with oral candidiasis, and drug-resistance profiles have contributed to an increase in morbidity and mortality. It is known that Lactobacillus spp. acts by competing for adhesion to the epithelium, absorption of nutrients and modulation of the human microbiota. Therefore, they are important to assist in the host's microbiological balance and reduce the growth of Candida spp. Until now, there have been no reports in the literature of reviews correlating to the use of Lactobacillus spp. in the treatment of oral candidiasis. Thus, this review aims to highlight the mechanisms of action of Lactobacillus spp. and methods that can be used in the treatment of oral candidiasis. This is a study carried out through the databases PubMed Central and Scientific Electronic Library Online, using the following keywords: Oral Candidiasis and Lactobacillus. Original articles about oral candidiasis were included, with both in vitro and in vivo analyses, and published from 2012 to 2022. Lactobacillus rhamnosus was the most common microorganism used in the experiments against Candida, acting mainly in the reduction of biofilm, filamentation, and competing for adhesion sites of Candida spp. Among in vivo studies, most researchers used immunosuppressed mouse modelsof Candida infection. The studies showed that Lactobacillus has a great potential as a probiotic, acting mainly in the prevention and treatment of mucosal diseases. Thus, the use of Lactobacillus may be a good strategy for the treatment of oral candidiasis.

Mucoadhesive delivery systems for oral candidiasis treatment: A systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis aimed to evaluate the clinical and mycological effectiveness of mucoadhesives as vehicles for drugs or natural products in the treatment of oral candidiasis.

MATERIALS AND METHODS

The search for articles was carried out in the Medline/PubMed, SCOPUS, EMBASE, Web of Science, Cochrane Library, and SciELO databases before August 2023. We selected the studies, extracted the data, evaluated the study quality, graded the evidence, performed the risk of bias, and carried out meta-analysis.

RESULTS

A total of 389 potentially relevant articles were identified, and 11 studies (1869 participants) met the inclusion criteria of the systematic review. The overall risk of bias was considered low. The most common presentation of mucoadhesives was tablets, with miconazole being the most frequently drug used in the delivery system. Mucoadhesives demonstrated comparable efficacy with topical or systemic antifungal agents, with no significant differences between treatments in terms of clinical (RR = 0.907; 95CI = 0.3-1.297; p = 0.591; I2 = 64.648) or mycological (RR = 0.95; 95CI = 0.667-1.360; p = 0.789; I2 = 73.271) efficacy.

CONCLUSIONS

Mucoadhesives may be a suitable alternative to conventional treatments, with the advantage of reducing the frequency of application by up to 5 times and the daily dosage by up to 20 times.

Oral Microbiome: A Review of Its Impact on Oral and Systemic Health

PURPOSE OF REVIEW

This review investigates the oral microbiome's composition, functions, influencing factors, connections to oral and systemic diseases, and personalized oral care strategies.

RECENT FINDINGS

The oral microbiome is a complex ecosystem consisting of bacteria, fungi, archaea, and viruses that contribute to oral health. Various factors, such as diet, smoking, alcohol consumption, lifestyle choices, and medical conditions, can affect the balance of the oral microbiome and lead to dysbiosis, which can result in oral health issues like dental caries, gingivitis, periodontitis, oral candidiasis, and halitosis. Importantly, our review explores novel associations between the oral microbiome and systemic diseases including gastrointestinal, cardiovascular, endocrinal, and neurological conditions, autoimmune diseases, and cancer. We comprehensively review the efficacy of interventions like dental probiotics, xylitol, oral rinses, fluoride, essential oils, oil pulling, and peptides in promoting oral health by modulating the oral microbiome.

SUMMARY

This review emphasizes the critical functions of the oral microbiota in dental and overall health, providing insights into the effects of microbial imbalances on various diseases. It underlines the significant connection between the oral microbiota and general health. Furthermore, it explores the advantages of probiotics and other dental care ingredients in promoting oral health and addressing common oral issues, offering a comprehensive strategy for personalized oral care.

Clinical features and risk factors for Sjogren's syndrome patients suffering from oral candidiasis in Shanxi, China

OBJECTIVES

To investigate the clinical features and risk factors of Sjogren's Syndrome (SS) patients suffering from oral candidiasis and to provide a foundation for the prevention and treatment of oral candidiasis in SS patients.

METHODS

The medical records of 479 SS patients admitted to the Second Hospital of Shanxi Medical University from 2018 to 2020 were analysed to determine the clinical characteristics and risk factors that influence the occurrence of oral candidiasis infection in SS patients.

RESULTS

Patients with oral candidiasis were older than those without oral candidiasis (P < 0.05). Male SS patients had greater oral candidiasis rates (P < 0.05). Unstimulated whole saliva (UWS) and stimulated whole saliva (SWS) were both shown to be adversely associated with oral Candida infections (P < 0.001). Logistic regression revealed that a low UWS was an independent risk factor for oral Candida infections in SS patients (OR: 0.004, P = 0.023). Greater WBC counts (OR: 1.22, P < 0.001), lower haemoglobin levels (OR: 0.97, P = 0.007), lower serum albumin levels (OR: 0.88, P < 0.001), lower IgG levels (OR: 0.91, P = 0.011), lower IgA levels (OR: 0.75, P = 0.011), and lower IgM levels (OR: 0.91, P = 0.015) were found in patients with oral Candida infections. Patients on immunosuppressive medications (OR: 0.32, P = 0.011), particularly rapamycin (P < 0.001), had a decreased rate of oral Candida infections.

CONCLUSIONS

Patients with oral candidiasis were older than those without oral candidiasis. Male SS patients are more likely to have oral candidiasis. Individuals with lower UWS and SWS are more susceptible to oral Candida infection. Oral Candida infections in SS patients depend on their immunological status. Rapamycin may increase the abundance of Treg cells to reduce oral Candida infection in SS patients.

Oral candida lesions and Candida tropicalis: Potential prognostic markers in end-of-life cancer patients

AIMS

Oral candidosis is common in patients with end-of-life cancer; however, its prognosis is unclear. We aimed to assess oral candidosis and Candida species as prognostic indicators in palliative care for these patients.

METHODS

We consecutively included palliative care patients, assessed for candidosis via microbiological techniques, and classified into three groups by the extent of oral lesions. The association between oral candidosis and overall survival was assessed using a Cox proportional hazards model adjusted by performance status (PS).

RESULTS

We studied 142 patients (median age 77; 52.8% women) with a 76.1% oral candidosis prevalence. Candida albicans (80.6%) was the most common species. Oral lesions were classified as none, grade 1 (28.7%), or ≥ grade 2 (14.8%). During follow-up, Cox models identified ≥grade 2 lesions (aHR = 2.04; 95% CI: 1.18-3.54; p = .011) and Candida tropicalis (aHR = 2.38; 95% CI: 1.03-5.55; p = .044) as predictors.

CONCLUSION

The extent of oral candidosis lesions or the presence of C. tropicalis may serve as prognostic indicator in patients with end-of-life cancer. Therefore, solely concentrating on the prevalence and frequency of fungal species may be insufficient for predicting life prognosis; it is advisable to assess these parameters through both visual examination and culture.

Syzygium aromaticum essential oil and its major constituents: Assessment of activity against Candida spp. and toxicity

Syzigium aromaticum essential oil (EO), eugenol, and β-caryophyllene were evaluated regarding antifungal, antibiofilm, and in vitro toxicity. Additionally, in vivo toxicity of EO was observed. Anti-Candida activity was assessed through broth microdilution assay for all compounds. Time-kill assay (0, 1, 10, 30 min, 1, 2, and 4 h) was used to determine the influence of EO and eugenol on Candida Growth kinetics. Thereafter, both compounds were evaluated regarding their capacity to act on a biofilm formation and on mature biofilm, based on CFU/ml/g of dry weight. Cell Titer Blue Viability Assay was used for in vitro cytotoxicity, using oral epithelial cells (TR146) and human monocytes (THP-1). Lastly, Galleria mellonella model defined the EO in vivo acute toxicity. All compounds, except β-cariofilene (MIC > 8000 μg/ml), presented antifungal activity against Candida strains (MIC 500-1000 μg/ml). The growth kinetics of Candida was affected by the EO (5xMIC 30 min onward; 10xMIC 10 min onward) and eugenol (5xMIC 10 min onward; 10xMIC 1 min onward). Fungal viability was also affected by 5xMIC and 10xMIC of both compounds during biofilm formation and upon mature biofilms. LD50 was defined for TR146 and THP1 cells at, respectively, 59.37 and 79.54 μg/ml for the EO and 55.35 and 84.16 μg/ml for eugenol. No sign of toxicity was seen in vivo up to 10mg/ml (20 x MIC) for the EO. S. aromaticum and eugenol presented antifungal and antibiofilm activity, with action on cell growth kinetics. In vivo acute toxicity showed a safe parameter for the EO up to 10 mg/ml.

Lactoferrin as a potential therapeutic for the treatment of Candida-associated denture stomatitis

BACKGROUND

The use of prostheses in the oral cavity creates favorable conditions for Candida colonization, which may subsequently lead to Candida-associated denture stomatitis (CADS). Due to its many contributing factors and frequent relapses, CADS is difficult to manage. Given the rise in drug resistance among fungal species, it is critical to develop new therapeutic approaches, reduce the required dosage of medications, and minimize the toxicity and side effects of therapy.

HIGHLIGHT

Salivary lactoferrin, a multifunctional glycoprotein, is thought to be the first line of defense against microbial invasion of mucosal surfaces.

CONCLUSION

Current research emphasizes the capability of lactoferrin and its derivatives to eliminate a broad spectrum of Candida species. It may be an appealing option for use in monotherapy or in combination with common medications for oral stomatitis treatment. This review provides an overview of the current understanding of lactoferrin's anti-fungal effects in oral candidiasis.

Modulation of host immunity by sensory neurons

Recent studies have uncovered a new role for sensory neurons in influencing mammalian host immunity, challenging conventional notions of the nervous and immune systems as separate entities. In this review we delve into this groundbreaking paradigm of neuroimmunology and discuss recent scientific evidence for the impact of sensory neurons on host responses against a wide range of pathogens and diseases, encompassing microbial infections and cancers. These valuable insights enhance our understanding of the interactions between the nervous and immune systems, and also pave the way for developing candidate innovative therapeutic interventions in immune-mediated diseases highlighting the importance of this interdisciplinary research field.

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-1β. Conclusion: Vit C could be an interesting adjuvant to anti-fungal treatment due to its anti-inflammatory potential.

Transdermal administration of farnesol-ethosomes enhances the treatment of cutaneous candidiasis induced by Candida albicans in mice

Cutaneous candidiasis, caused by Candida albicans, is a severe and frustrating condition, and finding effective treatments can be challenging. Therefore, the development of farnesol-loaded nanoparticles is an exciting breakthrough. Ethosomes are a novel transdermal drug delivery carrier that incorporates a certain concentration (10-45%) of alcohols into lipid vesicles, resulting in improved permeability and encapsulation rates compared to conventional liposomes. Farnesol is a quorum-sensing molecule involved in morphogenesis regulation in C. albicans, and these ethosomes offer a promising new approach to treating this common fungal infection. This study develops the formulation of farnesol-loaded ethosomes (farnesol-ethosomes) and assesses applications in treating cutaneous candidiasis induced by C. albicans in vitro and in vivo. Farnesol-ethosomes were successfully developed by ethanol injection method. Therapeutic properties of farnesol-ethosomes, such as particle size, zeta potential, and morphology, were well characterized. According to the results, farnesol-ethosomes demonstrated an increased inhibition effect on cells' growth and biofilm formation in C. albicans. In Animal infection models, treating farnesol-ethosomes by transdermal administration effectively relieved symptoms caused by cutaneous candidiasis and reduced fungal burdens in quantity. We also observed that ethosomes significantly enhanced drug delivery efficacy in vitro and in vivo. These results indicate that farnesol-ethosomes can provide future promising roles in curing cutaneous candidiasis.

IMPORTANCE

Cutaneous candidiasis attributed to Candida infection is a prevalent condition that impacts individuals of all age groups. As a type of microbial community, biofilms confer benefits to host infections and mitigate the clinical effects of antifungal treatments. In C. albicans, the yeast-to-hypha transition and biofilm formation are effectively suppressed by farnesol through its modulation of multiple signaling pathway. However, the characteristics of farnesol such as hydrophobicity, volatility, degradability, and instability in various conditions can impose limitations on its effectiveness. Nanotechnology holds the potential to enhance the efficiency and utilization of this molecule. Treatment of farnesol-ethosomes by transdermal administration demonstrated a very remarkable therapeutic effect against C. albicans in infection model of cutaneous candidiasis in mice. Many patients suffering fungal skin infection will benefit from this study.

Oral Rinses: Some Kill and Some Cripple Candida albicans

OBJECTIVES

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 MFCs (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% (versus 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.

Modulation of myeloid-derived suppressor cell functions by oral inflammatory diseases and important oral pathogens

The oral cavity presents a diverse microbiota in a dynamic balance with the host. Disruption of the microbial community can promote dysregulation of local immune response which could generate oral diseases. Additionally, alterations in host immune system can result in inflammatory disorders. Different microorganisms have been associated with establishment and progression of the oral diseases. Oral cavity pathogens/diseases can modulate components of the inflammatory response. Myeloid-derived suppressor cells (MDSCs) own immunoregulatory functions and have been involved in different inflammatory conditions such as infectious processes, autoimmune diseases, and cancer. The aim of this review is to provide a comprehensive overview of generation, phenotypes, and biological functions of the MDSCs in oral inflammatory diseases. Also, it is addressed the biological aspects of MDSCs in presence of major oral pathogens. MDSCs have been mainly analyzed in periodontal disease and Sjögren's syndrome and could be involved in the outcome of these diseases. Studies including the participation of MDSCs in other important oral diseases are very scarce. Major oral bacterial and fungal pathogens can modulate expansion, subpopulations, recruitment, metabolism, immunosuppressive activity and osteoclastogenic potential of MDSCs. Moreover, MDSC plasticity is exhibited in presence of oral inflammatory diseases/oral pathogens and appears to be relevant in the disease progression and potentially useful in the searching of possible treatments. Further analyses of MDSCs in oral cavity context could allow to understand the contribution of these cells in the fine-tuned balance between host immune system and microorganism of the oral biofilm, as well as their involvement in the development of oral diseases when this balance is altered.

In Vitro Assessment of Antifungal and Antibiofilm Efficacy of Commercial Mouthwashes against Candida albicans

Candida albicans is the most critical fungus causing oral mycosis. Many mouthwashes contain antimicrobial substances, including antifungal agents. This study aimed to investigate the in vitro activity of 15 commercial mouthwashes against 12 strains of C. albicans. The minimal inhibitory concentrations (MICs), minimal fungicidal concentrations (MFCs), and anti-biofilm activity were studied. MICs were determined by the micro-dilution method using 96-well plates, and MFCs were determined by culturing MIC suspensions on Sabouraud dextrose agar. Anti-biofilm activity was evaluated using the crystal violet method. The mouthwashes containing octenidine dihydrochloride (OCT; mean MICs 0.09-0.1%), chlorhexidine digluconate (CHX; MIC 0.12%), and CHX with cetylpyridinium chloride (CPC; MIC 0.13%) exhibited the best activity against C. albicans. The active compound antifungal concentrations were 0.5-0.9 µg/mL for OCT products and 1.1-2.4 µg/mL for CHX rinses. For mouthwashes with CHX + CPC, concentrations were 1.56 µg/mL and 0.65 µg/mL, respectively. Products with polyaminopropyl biguanide (polyhexanide, PHMB; MIC 1.89%) or benzalkonium chloride (BAC; MIC 6.38%) also showed good anti-Candida action. In biofilm reduction studies, mouthwashes with OCT demonstrated the most substantial effect (47-51.1%). Products with CHX (32.1-41.7%), PHMB (38.6%), BAC (35.7%), Scutellaria extract (35.6%), and fluorides + essential oils (33.2%) exhibited moderate antibiofilm activity. The paper also provides an overview of the side effects of CHX, CPC, and OCT. Considering the in vitro activity against Candida albicans, it can be inferred that, clinically, mouthwashes containing OCT are likely to offer the highest effectiveness. Meanwhile, products containing CHX, PHMB, or BAC can be considered as promising alternatives.

Genotypes and virulence-related activities of Candida albicans derived from oral cavity of patients in Hokkaido

OBJECTIVE

This study aimed to elucidate the difference in virulence of Candida albicans derived from oral candidiasis and non-oral candidiasis patients, and its genotype differences in Hokkaido to obtain a clue of a platform to develop new approaches for diagnosis and treatment.

DESIGN

C. albicans strains were collected from patients who visited the Hokkaido University Hospital Dental Center. Each strain was examined to i) identify the Candida albicans genotype by PCR, ii) measure the strain's extracellular secretory enzyme activity, iii) determine the strain's ability to induce the production of interleukin-8, and iv) determine the strain's ability to induce cell death.

RESULTS

Certain virulence-related protease activities and cytotoxicity were higher in strains derived from patients with oral candidiasis compared with strains derived from patients without oral candidiasis. This is the first report on genotypes and the virulence-related activities, such as some protease secretion, IL-8 induction and cytotoxicity of C. albicans in Hokkaido.

CONCLUSIONS

The virulence-related activities of the fungal strain may influence the pathogenesis of oral candidiasis, such as production of secreted aspartyl protease and cytotoxicity. In addition, C. albicans genotype C may be important for pathogenicity in Hokkaido, because the ratio of genotype C was increased in strains derived from oral candidiasis patients.

Current Drug Delivery Strategies for Buccal Cavity Ailments using Mouth Dissolving Wafer Technology: A Comprehensive Review on the Present State of the Art

BACKGROUND

Mouth-dissolving wafer is polymer-based matrice that incorporates various pharmaceutical agents for oral drug delivery. This polymeric wafer is ingenious in the way that it needs not be administered with water, like in conventional tablet dosage form. It has better compliance among the pediatric and geriatric groups owing to its ease of administration.

OBJECTIVE

The polymeric wafer dissolves quickly in the oral cavity and is highly effective for a targeted local effect in buccal-specific ailments. It is a safe, effective, and versatile drug delivery carrier for a range of drugs used to treat a plethora of oral cavity-specific ailments that inflict common people, like thrush, canker sores, periodontal disease, benign oral cavity tumors, buccal neoplasm, and malignancies. This review paper focuses thoroughly on the present state of the art in mouth-dissolving wafer technology for buccal drug delivery and targeting. Moreover, we have also addressed present-time limitations associated with wafer technology to aid researchers in future developments in the arena of buccal drug delivery.

CONCLUSION

This dynamic novel formulation has tremendous future implications for designing drug delivery systems to target pernicious ailments and diseases specific to the buccal mucosa. In a nutshell, this review paper aims to summarize the present state of the art in buccal targeted drug delivery.

Complex magnetic fields represent an eco-sustainable technology to counteract the resistant Candida albicans growth without affecting the human gingival fibroblasts

Novel technologies such as complex magnetic fields-CMFs represent an eco-sustainable proposal to counteract the infection associated to resistant microorganisms. The aim of this study was to evaluate the effect of two CMF programs (STRESS, ANTIBACTERIAL) against clinical antifungal resistant C. albicans also evaluating their uneffectiveness on gingival fibroblasts (hGFs). The STRESS program was more efficacious on C. albicans biofilm with up to 64.37% ± 10.80 of biomass and up to 99.19% ± 0.06 CFU/ml reductions in respect to the control also inducing an alteration of lipidic structure of the membrane. The MTT assay showed no CMFs negative effects on the viability of hGFs with a major ROS production with the ANTIBACTERIAL program at 3 and 24 h. For the wound healing assay, STRESS program showed the best effect in terms of the rate migration at 24 h, showing statistical significance of p < 0.0001. The toluidine-blue staining observations showed the typical morphology of cells and the presence of elongated and spindle-shaped with cytoplasmic extensions and lamellipodia was observed by SEM. The ANTIBACTERIAL program statistically increased the production of collagen with respect to control and STRESS program (p < 0.0001). CMFs showed a relevant anti-virulence action against C. albicans, no cytotoxicity effects and a high hGFs migration rate. The results of this study suggest that CMFs could represent a novel eco-sustainable strategy to counteract the resistant yeast biofilm infections.

A Membrane-Targeted Photosensitizer Prevents Drug Resistance and Induces Immune Response in Treating Candidiasis

Candida albicans (C. albicans), a ubiquitous polymorphic fungus in humans, causes different types of candidiasis, including oral candidiasis (OC) and vulvovaginal candidiasis (VVC), which are physically and mentally concerning and financially costly. Thus, developing alternative antifungals that prevent drug resistance and induce immunity to eliminate Candida biofilms is crucial. Herein, a novel membrane-targeted aggregation-induced emission (AIE) photosensitizer (PS), TBTCP-QY, is developed for highly efficient photodynamic therapy (PDT) of candidiasis. TBTCP-QY has a high molar absorption coefficient and an excellent ability to generate 1 O2 and •OH, entering the interior of biofilms due to its high permeability. Furthermore, TBTCP-QY can efficiently inhibit biofilm formation by suppressing the expression of genes related to the adhesion (ALS3, EAP1, and HWP1), invasion (SAP1 and SAP2), and drug resistance (MDR1) of C. albicans, which is also advantageous for eliminating potential fungal resistance to treat clinical infectious diseases. TBTCP-QY-mediated PDT efficiently targets OC and VVC in vivo in a mouse model, induces immune response, relieves inflammation, and accelerates the healing of mucosal defects to combat infections caused by clinically isolated fluconazole-resistant strains. Moreover, TBTCP-QY demonstrates excellent biocompatibility, suggesting its potential applications in the clinical treatment of OC and VVC.

Derivative of 7-hydroxycoumarin has antifungal potential against Candida species and low cytotoxicity against human cells: In silico studies and biological evaluation

This study investigates the antifungal and cytotoxic properties of 7-(pentyloxy)-2H-chromen-2-one. Through molecular docking and dynamics simulations, we explored the compound's interactions with fungal cell protein targets. Notably, it exhibited strong affinities for 1,3β-glucan synthase, squalene epoxidase, δ-14-sterol reductase, 14-α-demethylase, and thymidylate synthase, with binding energies ranging from -100.39 to -73.15 kcal/mol. Molecular dynamics simulations confirmed its stable binding at active targets. The MIC and MFC values ranged from 67.16 μM (15.6 μg/mL) to 537.28 μM (125.0 μg/mL). The compound displayed promising antifungal effects, inhibiting fungal growth for at least 24 hours. Fungal plasma membrane function alteration likely contributed to these antifungal mechanisms. Additionally, the combination of the compound with nystatin, fluconazole, and caspofungin showed indifferent effects on antifungal activity. Cytotoxicity assessment in human keratinocyte cells (HaCaT) revealed an IC50 of 100 μM, which was approximately 1.5 times higher than the MIC for C. krusei. Thus, the compound exhibited strongly in silico and in vitro antifungal activity with low cytotoxicity in HaCaT cells. These findings support its potential as a candidate for further development as an antifungal compound.

Antimicrobial photodynamic therapy in the treatment of oral erythematous candidiasis: a controlled and randomized clinical trial

OBJECTIVE

To analyze the clinical and microbiological efficacy of antimicrobial photodynamic therapy (aPDT) in patients with erythematous candidiasis (EC).

METHODS

This study was a controlled and randomized clinical trial in patients diagnosed with EC, who were allocated into a control group (CG) and experimental group (EG) treated with nystatin oral suspension and aPDT with methylene blue 0.1%, respectively. A clinical index was used to classify the EC lesions from mild to severe and assess the treatment efficacy. Microbiological samples were collected before and after aPDT session and analyzed by counting colony-forming units (CFUs) of Candida and Staphylococcus sp.

RESULTS

A total of 41 patients (CG (n = 18); EG (n = 23)) were analyzed in our research. Of these, 16 (94.1%) of the CG and 16 (84.2%) of the EG exhibited complete remission of the lesions. Regarding the degree of the lesion, it was observed that the severe lesions were more difficult to present remission, while all the mild and moderate lesions showed complete regression (p = 0.001). The microbiological analysis showed that Candida albicans and Staphylococcus sp. were the most prevalent microorganisms, and the aPDT group showed a decrease in CFUs of these microorganisms after the first aPDT session (p < 0.05).

CONCLUSIONS

aPDT proved to be a clinically and microbiologically effective therapy for treating EC.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov; Set 12th, 2019; No. RBR-8w8599.

CLINICAL RELEVANCE

aPDT is a promising alternative treatment since it presents satisfactory results and does not cause damage to oral tissues or develop resistance to the treatment.

Respiratory infectious burden in a cohort of antibody deficiency patients treated with immunoglobulin replacement therapy: The impact of lung pathology and gastroesophageal reflux disease

Background

Antibody deficiencies result from reduced immunoglobulin levels and function, increasing susceptibility to, primarily, bacterial infection. Primary antibody deficiencies comprise intrinsic defects in B-cell physiology, often due to inherited errors. Hematological malignancies or B-cell suppressive therapy are major causes of secondary antibody deficiency. Although immunoglobulin replacement therapy (IGRT) reduces infectious burden in antibody deficiency patients, respiratory tract infections remain a significant health burden. We hypothesize that lung pathology and gastroesophageal reflux disease (GORD) increase the risk of pneumonia in antibody deficiency patients, as in the general population.

Objective

For our cohort of patients with primary antibody deficiency and secondary antibody deficiency, we reviewed their respiratory infectious burden and the impact of lung pathologies and GORD.

Methods

The medical records of 231 patients on IGRT at a tertiary referral center, from October 26, 2014, to February 19, 2021, were reviewed to determine microbial isolates from sputum samples and prevalence of common lung pathologies and GORD.

Results

Haemophilus and Pseudomonas species represent a large infectious burden, being identified in 30.2% and 21.4% of sputum samples demonstrating growth, respectively; filamentous fungal and mycobacterial infections were rare. Diagnosed lung pathology increased the proportion of patients with Pseudomonas, Klebsiella, Stenotrophomonas, and Candida species isolated in their sputum, and diagnosed GORD increased the proportion with Enterobacter and Candida species isolated.

Conclusions

Bacterial respiratory infectious burden remains in primary antibody deficiency and secondary antibody deficiency despite IGRT. Lung pathologies encourage growth of species less susceptible to IGRT, so specialist respiratory medicine input and additional treatments such as inhaled antibiotics are indicated to optimize respiratory outcomes.

The profile of chronic hyperplastic candidiasis: a clinico-pathological study

The aims of this study were investigation of clinical presentation, systemic factors, and long-term malignant transformation rate in chronic hyperplastic candidiasis versus leukoplakia. This is a retrospective case-controlled study of cases with chronic hyperplastic candidiasis and leukoplakia without dysplasia, diagnosed between 2000 and 2013. A database was created, and all additional biopsies from the same cases were searched up to 2022, for records of oral malignant transformation. Associations between microscopic diagnoses and clinical features of lesions and clinical outcomes of patients were performed. A study database included 116 patients, allocated to the group diagnosed with chronic hyperplastic candidiasis (CHC-group, 62) and to the group of leukoplakia without dysplasia (LKP-group, 54). Tongue and buccal mucosa were most frequently recorded in both groups. In CHC-group, significantly fewer cases presented as white lesions compared to LKP-group (P < 0.001); more were ulcerated or exophytic (P = 0.006 and P = 0.003, respectively). History of head and neck malignancy was significantly more frequent in CHC-group (P = 0.005), as were chemotherapy, (P = 0.019) radiotherapy (P = 0.0265), and immune-related conditions (P = 0.03). Within the follow-up period (2000-2022), in CHC-group, two cases (3.2%) had malignant transformation at the site of original biopsy, one was recurrence of previous carcinoma. In LKP-group, two cases (3.7%) had newly diagnosed carcinoma and one at the site of original biopsy; no significant differences were found between groups. In conclusion, medical background of immune-related conditions, head and neck malignancy, radiotherapy, and chemotherapy may play a role in predisposing for chronic hyperplastic candidiasis. Malignant transformation rate within CHC-group was low, and similar to that within LKP-group, representing a lower transformation rate than expected.

Streptococcus mutans sigX-inducing peptide inhibits the virulence of Candida albicans and oral candidiasis through the Ras1-cAMP-Efg1 pathway

Oral candidiasis is the most common fungal infectious disease in the human oral cavity, and Candida albicans is the major pathogenic agent. Increasing drug resistance and the lack of new types of antifungals greatly increase the challenges for treating fungal infections. Targeting hyphal transition provides a promising strategy to inhibit the virulence of C. albicans and overcome drug resistance. This study aimed to investigate the effects and mechanisms of sigX-inducing peptide (XIP), a quorum-sensing signal peptide secreted by Streptococcus mutans, on C. albicans hyphal development and biofilm formation in vitro and oropharyngeal candidiasis in vivo. XIP significantly inhibited C. albicans yeast-to-hypha transition and biofilm formation in a dose-dependent manner from 0.01 to 0.1 µM. XIP significantly downregulated expression of genes from the Ras1-cAMP-Efg1 pathway (RAS1, CYR1, TPK2, EFG1 and UME6), a key pathway to regulate C. albicans hyphal development. Importantly, XIP reduced the levels of key molecules cAMP and ATP from this pathway, while the addition of exogenous cAMP and overexpression of RAS1 restored the hyphal development inhibited by XIP. XIP also lost its hyphal inhibitory effects on ras1Δ/Δ and efg1Δ/Δ strains. These results further confirmed that XIP inhibited hyphal development through downregulation of the Ras1-cAMP-Efg1 pathway. A murine oropharyngeal candidiasis model was employed to evaluate the therapeutic effects of XIP on oral candidiasis. XIP effectively reduced the infected epithelial area, fungal burden, hyphal invasion and inflammatory infiltrates. These results revealed the antifungal effects of XIP, and highlighted that XIP can be a potential antifungal peptide against C. albicans infection.

A Putative Role of Candida albicans in Promoting Cancer Development: A Current State of Evidence and Proposed Mechanisms

Candida albicans is a commensal fungal species that commonly colonizes the human body, but it is also a pervasive opportunistic pathogen in patients with malignant diseases. A growing body of evidence suggests that this fungus is not only coincidental in oncology patients, but may also play an active role in the development of cancer. More specifically, several studies have investigated the potential association between C. albicans and various types of cancer, including oral, esophageal, and colorectal cancer, with a possible role of this species in skin cancer as well. The proposed mechanisms include the production of carcinogenic metabolites, modulation of the immune response, changes in cell morphology, microbiome alterations, biofilm production, the activation of oncogenic signaling pathways, and the induction of chronic inflammation. These mechanisms may act together or independently to promote cancer development. Although more research is needed to fully grasp the potential role of C. albicans in carcinogenesis, the available evidence suggests that this species may be an active contributor and underscores the importance of considering the impact of the human microbiome on cancer pathogenesis. In this narrative review, we aimed to summarize the current state of evidence and offer some insights into proposed mechanisms.

Identification and susceptibility testing of oral candidiasis in advanced cancer patients

BACKGROUND

Patients with advanced cancer are prone to develop different opportunistic oral infection due to anti-cancer treatment or the malignancies themselves. Studies of oral fungal samples show an increased prevalence of non-Candida albicans species in mixed oral infections with Candida albicans. Non-C. albicans and C. albicans are associated with varying degrees of resistance to azoles, which may have implications for treatment. This study aimed to assess the diversity and antifungal susceptibility of Candida species detected in the oral cavity.

METHODS

An observational study with microbiological analysis was conducted. Clinical fungal isolates were collected from patients in a hospice unit in 2014-2016. Isolates were re-grown on chromID® Candida plates in 2020. Single colony of each species was re-cultivated and prepared for biochemical identification with a VITEK2® system and verified by gene sequencing. Etest was performed on RPMI agar, and the antifungals fluconazole, amphotericin B, anidulafungin and nystatin were applied.

RESULTS

Fifty-six isolates from 45 patients were identified. Seven different Candida species and one Saccharomyces species were detected. The results of biochemical identification were confirmed with sequencing analysis. Thirty-six patients had mono infection, and nine out of 45 patients had 2-3 different species detected. Of C. albicans strains, 39 out of 40 were susceptible to fluconazole. Two non-C. albicans species were resistant to fluconazole, one to amphotericin B and three to anidulafungin.

CONCLUSION

C. albicans was the predominant species, with a high susceptibility to antifungal agents. Different Candida species occur in both mono and mixed infections. Identification and susceptibility testing may therefore lead to more effective treatment and may prevent the development of resistance among patients with advanced cancer.

TRAIL REGISTRATION

The study Oral Health in Advanced Cancer was registered at ClinicalTrials.gov (#NCT02067572) in 20/02/2014.

Oral microbiome and risk of incident head and neck cancer: A nested case-control study

OBJECTIVES

This nested case-control study in the NIH-AARP Diet and Health Study was carried out to prospectively investigate the relationship of oral microbiome with head and neck cancer (HNC).

MATERIALS AND METHODS

56 incident HNC cases were identified, and 112 controls were incidence-density matched to cases. DNA extracted from pre-diagnostic oral wash samples was whole-genome shotgun metagenomic sequenced to measure the overall oral microbiome. ITS2 gene qPCR was used to measure the presence of fungi. ITS2 gene sequencing was performed on ITS2 gene qPCR positive samples. We computed taxonomic and functional alpha-diversity and beta-diversity metrics. The presence and relative abundance of groups of red-complex (e.g., Porphyromonas gingivalis) and/or orange-complex (e.g., Fusobacterium nucleatum) periodontal pathogens were compared between cases and controls using conditional logistic regression models and MiRKAT.

RESULTS

Participants with higher taxonomic microbial alpha-diversity had a non-statistically significant decreased risk of HNC. No case-control differences were found for beta diversity by MiRKAT model (all p > 0.05). A greater relative abundance of red-complex periodontal pathogens (OR = 0.51, 95 % CI = 0.26-1.00), orange-complex (OR = 0.38, 95 % CI = 0.18-0.83), and both complexes' pathogens (OR = 0.32, 95 % CI = 0.14-0.75), were associated with reduced risk of HNC. The presence of oral fungi was also strongly associated with reduced risk of HNC compared with controls (OR = 0.39, 95 % CI = 0.17-0.92).

CONCLUSION

Greater taxonomic alpha-diversity, the presence of oral fungi, and the presence or relative abundance of multiple microbial species, including the red- and orange-complex periodontal pathogens, were associated with reduced risk of HNC. Future studies with larger sample sizes are needed to evaluate these associations.

Candida albicans can foster gut dysbiosis and systemic inflammation during HIV infection

Candida albicans (C. albicans) is a ubiquitous fungal commensal component of the human microbiota, and under certain circumstances, such as during an immunocompromised state, it may initiate different types of infection. Moreover, C. albicans continuously and reciprocally interacts with the host immune system as well as with other elements of the gut microbiota, thus contributing significantly to both gut homeostasis and host immunity. People living with HIV (PLWH), including those receiving antiretroviral therapy, are characterized by a depletion of CD4 + T-cells and dysbiosis in their gut. C. albicans colonization is frequent in PLWH, causing both a high prevalence and high morbidity. Gut barrier damage and elevated levels of microbial translocation are also fairly common in this population. Herein, we take a closer look at the reciprocity among C. albicans, gut microbiota, HIV, and the host immune system, thus throwing some light on this complex interplay.

Postoperative Pain Exacerbation After Adenotonsillectomy Due to Oral Candida Infection?

Post-tonsillectomy complications can include bleeding, dehydration, edema, airway obstruction, and infection. Oral candidiasis or thrush is a rare complication that can occur post-operatively. We describe a case of a 10-year-old female with oral candidiasis as a postoperative complication of bilateral adenotonsillectomy, presenting on postoperative day (POD) 7 for poor oral intake secondary to worsening odynophagia. A physical exam revealed an easily scrapable, white plaque located mainly over her surgical sites, tongue, and hard palate. Microscopic examination of tissue scrapings revealed pseudohyphae confirming the diagnosis of oral candidiasis. She was treated with seven days of topical nystatin therapy, including topical and systemic pain control with significant improvement of symptoms by POD 13 and complete resolution on POD 21.

Synergistic activity of pomegranate rind extract and Zn (II) against Candida albicans under planktonic and biofilm conditions, and a mechanistic insight based upon intracellular ROS induction

Candida albicans (C. albicans) is an opportunistic pathogen, which causes superficial infection and can lead to mortal systemic infections, especially in immunocompromised patients. The incidence of C. albicans infections is increasing and there are a limited number of antifungal drugs used in treatment. Therefore, there is an urgent need for new and alternative antifungal drugs. Pomegranate rind extract (PRE) is known for its broad-spectrum antimicrobial activities, including against C. albicans and recently, PRE and Zn (II) have been shown to induce synergistic antimicrobial activity against various microbes. In this study, the inhibitory activities of PRE, Zn (II) and PRE in combination with Zn (II) were evaluated against C. albicans. Antifungal activities of PRE and Zn (II) were evaluated using conventional microdilution methods and the interaction between these compounds was assessed by in vitro checkerboard and time kill assays in planktonic cultures. The anti-biofilm activities of PRE, Zn (II) and PRE in combination with Zn (II) were assessed using confocal laser scanning microscopy, with quantitative analysis of biofilm biomass and mean thickness analysed using COMSTAT2 analysis. In addition, antimicrobial interactions between PRE and Zn (II) were assayed in terms reactive oxygen species (ROS) production by C. albicans. PRE and Zn (II) showed a potent antifungal activity against C. albicans, with MIC values of 4 mg/mL and 1.8 mg/mL, respectively. PRE and Zn (II) in combination exerted a synergistic antifungal effect, as confirmed by the checkerboard and time kill assays. PRE, Zn (II) and PRE and Zn (II) in combination gave rise to significant reductions in biofilm biomass, although only PRE caused a significant reduction in mean biofilm thickness. The PRE and Zn (II) in combination caused the highest levels of ROS production by C. albicans, in both planktonic and biofilm forms. The induction of excess ROS accumulation in C. albicans may help explain the synergistic activity of PRE and Zn (II) in combination against C. albicans in both planktonic and biofilm forms. Moreover, the data support the potential of the PRE and Zn (II) combination as a novel potential anti-Candida therapeutic system.

Nystatin Effectiveness in Oral Candidiasis Treatment: A Systematic Review & Meta-Analysis of Clinical Trials

Oral candidiasis is the most common opportunistic fungal infection caused by commensal Candida species. Since there are various local and systemic predisposing factors for the disease, the treatment also varies from topical to systemic antifungal agents. Nystatin is a common antifungal agent used topically. The aim of this systematic review was to evaluate and compare the efficacy of different antifungal agents and the safety of nystatin in the treatment of oral candidiasis. Three electronic databases were searched for randomized controlled trials comparing nystatin with other anti-fungal therapies or placebo. Clinical and/or mycological cure was the outcome evaluation. A meta-analysis and descriptive study on the efficacy, treatment protocols, and safety of nystatin was also conducted. The meta-analysis included five studies, which compared the efficacy of nystatin suspensions with photodynamic therapy. A significant difference in the colony-forming units per milliliters (CFU/mL) of Candida species was observed at 60 days intervals for both palatal mucosa and denture surfaces, with both groups favoring nystatin with low heterogeneity at a 95% confidence interval. Nystatin and photodynamic therapy were found to be equally effective for the clinical remission of denture stomatitis as well as a significant reduction of CFU/mL of Candida species from dentures and palatal surfaces of the patients.

Oral Chronic Hyperplastic Candidiasis and Its Potential Risk of Malignant Transformation: A Systematic Review and Prevalence Meta-Analysis

Chronic hyperplastic candidiasis (CHC) is a prototypical oral lesion caused by chronic Candida infection. A major controversy surrounding CHC is whether this oral lesion owns malignant transformation (MT) potential. The aim of the present study was to evaluate current evidence on the MT of CHC and to determine the variables which have the greatest influence on cancer development. Bibliographical searches included PubMed, Embase, Web of Science, Scopus and LILACS. The cohort studies and case series used to investigate the MT of CHC were deemed suitable for inclusion. The quality of the enrolled studies was measured by the Joanna Briggs Institute scale. Moreover, we undertook subgroup analyses, assessed small study effects, and conducted sensitivity analyses. From 338 studies, nine were finally included for qualitative/quantitative analysis. The overall MT rate for CHC across all studies was 12.1% (95% confidential interval, 4.1–19.8%). Subgroup analysis showed that the MT rate increased when pooled analysis was restricted to poor quality studies. It remains complex to affirm whether CHC is an individual and oral, potentially malignant disorder according to the retrieved evidence. Prospective cohort studies to define the natural history of CHC and a consensus statement to clarify a proper set of diagnostic criteria are strongly needed. PROSPERO ID: CRD42022319572.

Resistance profiles to antifungal agents in Candida albicans isolated from human oral cavities: systematic review and meta-analysis

Aim

To identify the antifungal susceptibility profile of Candida spp. isolated from the human oral cavity was assessed with meta-analyses of observational studies that collected samples from the oral cavity of human subjects.

Material and methods

Isolated Candida albicans tested by E-test®; disk diffusion test; microdilution and macrodilution; Sensititre YeastOne; and/or FungiTest. Search strategies were conducted on the MEDLINE, Embase, CINAHL, Dentistry, and Oral Sciences, Central, Scopus, and LILACS databases, and gray literature sources. Articles were initially screened by title and then their abstracts. Articles that met the conditions for inclusion were read in full, followed by data extraction. A descriptive analysis was conducted of each study, and the data were tabulated. A first meta-analysis was conducted to assess the resistance of antifungals regardless of systemic comorbidities. An additional stratified analysis was conducted by systemic comorbidity groups for the outcome “resistance” to the antifungals.

Results

When not grouping Candida albicans isolates by systemic conditions, the lowest resistance rates to the antifungals tested were observed for amphotericin B, nystatin, flucytosine, and caspofungin. In contrast, the highest resistance rates were observed for miconazole and econazole. There was a high degree of heterogeneity and low resistance in general in all analyses, except for the “several associated comorbidities” group, which had high resistance rates.

Conclusions

Clinical C. albicans isolates had low antifungal resistance.

Clinical relevance

The presence of concomitant systemic comorbidities appears to be an essential factor that should be considered when evaluating resistance to antifungals for oral isolates.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-022-04716-2.

Antimicrobial Efficacy of Silver Nanoparticles against Candida Albicans

Current treatment protocols for patients diagnosed with denture stomatitis are under scrutiny, and alternative options are being explored by researchers. The aim of this systematic review was to determine if silver nanoparticles inhibit the growth of Candida albicans, and the research question addressed was: In adults, do silver nanoparticles inhibit the growth of Candida albicans in acrylic dentures and denture liners compared to normal treatment options. A systematic review was the chosen methodology, and criteria were formulated to include all types of studies, including clinical and laboratory designs where the aim was tested. Of the 18 included studies, only one was a clinical trial, and 17 were in vitro research. The inhibition of candidal growth was based on the % concentration of AgNPs included within the denture acrylic and denture liner. As the % AgNPs increased, candida growth was reduced. This was reported as a reduction of candidal colony forming units in the studies. The quality of the included studies was mostly acceptable, as seen from the structured and validated assessments completed.

Evaluation of the Distribution of Candida Species in Patients with Dysplastic and Nondysplastic Oral Lichen Planus Lesions

Objectives. This study is aimed at identifying and determining the distribution of isolated Candida species in patients with dysplastic and nondysplastic oral lichen planus (OLP) lesions in comparison with those of healthy controls. Material and Methods. This study includes patients with OLP, aged (more than 18 years old), who have had informed consent. Samples of the oral, tongue, and buccal mucus by rubbing with a sterile swab and sterilely next to the lamp flame. Demographic information was obtained using patient records to determine the species of Candida in both groups, and two tests of fertile tube production by Candida albicans and dye production in the dye medium were used. A biopsy from OLP lesions has been taken from each patient after swab sampling and was sent to the pathology department for further histopathological analysis. In the end $p$ value, less than 0/05 was considered significant. Result. In this study, 40 lichen planus patients were compared with 32 control patients. The female/male ratio in OLP and healthy groups was 22/18 and 17/15, respectively. Among the OLP patients, 23 cases (56%) were dysplastic, and the other 17 (44%) patients were nondysplastic. The mean (±standard deviation (SD)) age of patients was 48.83 (±9.34) years, and the mean age of the control group was 40.21 (±10.32). There were no significant differences based on age ( $p>0.05$ ). The highest frequency was related to tongue in both groups (22 (55%)) and buccal mucosa was the least common. There was a significant relationship between the location of the lesion and OLP ( $p=0.05$ ). 18 (45%) were erosive, and 22 (55%) were nonerosive. However, no significant difference was observed between erosive and nonerosive types in the OLP group ( $p=0/07$ ). Regarding the type of Candida, all cases in the patient’s group were related to Candida albicans [40 (100%)], and the correlation was not found in this regard ( $p>0/05$ ). About colony count, the mean for the case and control groups was 26.68 and 23.25, respectively. Also, no significant relationship was found between colony count and groups in this study ( $p=0.3$ ). There was no significant difference between gender and dysplastic or nondysplastic ( $p>0.05$ ). Conclusion. According to the statistical studies performed in this study, the presence of Candida in patients with dysplastic and nondysplastic lichen planus is not significantly different, and this rate is not higher than healthy individuals and in cases where the results are positive. The predominant species of Candida is the Candida albicans. In this study, the highest frequency was related to tongue in both groups. There was only a significant relationship between the location of the lesion and OLP.

B-Cell Epitope Mapping from Eight Antigens of Candida albicans to Design a Novel Diagnostic Kit: An Immunoinformatics Approach

Invasive candidiasis is an emerging fungal infection and a leading cause of morbidity in health care facilities. Despite advances in antifungal therapy, increased antifungal drug resistance in Candida albicans has enhanced patient fatality. The most common method for Candida albicans diagnosing is blood culture, which has low sensitivity. Therefore, there is an urgent need to establish a valid diagnostic method. Our study aimed to use the bioinformatics approach to design a diagnostic kit for detecting Candida albicans with high sensitivity and specificity. Eight antigenic proteins of Candida albicans (HYR1, HWP1, ECE1, ALS, EAP1, SAP1, BGL2, and MET6) were selected. Next, a construct containing different immunodominant B-cell epitopes was derived from the antigens and connected using a suitable linker. Different properties of the final construct, such as physicochemical properties, were evaluated. Moreover, the designed construct underwent 3D modeling, reverse translation, and codon optimization. The results confirmed that the designed construct could identify Candida albicans with high sensitivity and specificity in serum samples of patients with invasive candidiasis. However, experimental studies are needed for final confirmation.

A New Natural Antimycotic Agent is Effective Against Oropharyngeal Candidiasis: The VIPROCAN Study

Background:

The incidence of community and nosocomial candidiasis has dramatically increased in the last two decades. There are multiple treatments for this infection, but the toxicity of some and the induction of resistant strains require the development of new compounds.

Objectives:

With the aim of reducing the Candida population in the oropharyngeal cavity, we have formulated a toothpaste with VG-01 agent, composed of a mixture of carnosic acid (CA) and propolis (PP).

Methods:

We investigated the ability of VG-01 toothpaste to minimize and stabilize fungal presence in 21 patients diagnosed with clinical oropharyngeal candidiasis.

Results:

Our data indicate that VG-01 toothpaste showed an effect not only against the most frequent species of Candida, C. albicans, but also in the other species analyzed. 82% of patients stated that they would continue using it outside the study.

Conclusion:

Our data demonstrate that VG-01, composed of CA and PP is a potential antimycotic agent effective against the most common species that cause oropharyngeal candidiasis present in clinical practice.

Prevalence and Antifungal Susceptibility Profile of Oral Candida spp. Isolates from a Hospital in Slovakia

Oral fungal infections are a worldwide healthcare problem. Although Candida albicans is still the most common yeast involved in the infections of oral cavity, non-Candida albicans Candida species (NCACs) have been highly related to these infections, particularly in older, immunosuppressed or patients with long exposure to antimicrobial drugs. The goal of this work was to perform a quick epidemiological and mycological study on the oral samples collected from a laboratory of a hospital in Slovakia, for 60 days. The samples’ identification was performed by Germ-tube formation test, CHROMID® Candida, Auxacolor 2, ID 32C automated method, and the antifungal susceptibility testing determined by E-test®. Results confirm that comparing with bacteria, yeasts still occur in the lower number, but there is a high rate of antifungal resistance (81.6%)—to, at least one drug—among the collected samples, particularly to azoles and 5′-FC, which is clinically noteworthy.

COVID-19-Associated Candidiasis: Possible Patho-Mechanism, Predisposing Factors, and Prevention Strategies

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is threatening public health. A large number of affected people need to be hospitalized. Immunocompromised patients and ICU-admitted patients are predisposed to further bacterial and fungal infections, making patient outcomes more critical. Among them, COVID-19-associated candidiasis is becoming more widely recognized as a part of severe COVID-19 sequelae. While the molecular pathophysiology is not fully understood, some factors, including a compromised immune system, iron and zinc deficiencies, and nosocomial and iatrogenic transmissions, predispose COVID-19 patients to candidiasis. In this review, we discuss the existing knowledge of the virulence characteristics of Candida spp. and summarize the key concepts in the possible molecular pathogenesis. We analyze the predisposing factors that make COVID-19 patients more susceptible to candidiasis and the preventive measures which will provide valuable insights to guide the effective prevention of candidiasis in COVID-19 patients.

Antifungal activity of [K3]temporin-SHa against medically relevant yeasts and moulds

Few antifungal agents are currently available for the treatment of fungal infections. Antimicrobial peptides (AMPs), which are natural molecules involved in the innate immune response of many organisms, represent a promising research method because of their broad killing activity. The aim of this study was to assess the activity of a frog AMP, [K³]temporin-SHa, against some species of yeasts and moulds, and to further explore its activity against Candida albicans. MIC determinations were performed according to EUCAST guidelines. Next, the activity of [K³]temporin-SHa against C. albicans was explored using time-killing curve experiments, membrane permeabilization assays, and electron microscopy. Finally, chequerboard assays were performed to evaluate the synergy between [K³]temporin-SHa and amphotericin B or fluconazole. [K³]temporin-SHa was found to be active in vitro against several yeasts with MIC between 5.5 and 45 µM. [K³]temporin-SHa displayed rapid fungicidal activity against C. albicans (inoculum was divided into two in less than an hour and no viable colonies were recovered after 5 h) with a mechanism that could be due to membrane permeabilization. [K³]temporin-SHa was synergistic with amphotericin B against C. albicans (FICI = 0.303). [K³]temporin-SHa could represent an additional tool to treat several Candida species and C. neoformans.

A Practical Guide to the Management of Oral Candidiasis in Patients with Plaque Psoriasis Receiving Treatments That Target Interleukin-17

Plaque psoriasis is an immune-mediated inflammatory skin disease associated with the dysregulation of cytokines, especially those involved in the interleukin (IL)-23/IL-17 pathways. In recent years, there has been growing interest in developing biologic therapies that target these pathways. However, inhibition of the cytokines of the IL-23/IL-17 pathways may increase patients' risk of developing fungal infections, particularly oral candidiasis. Therefore, it is important that dermatology practitioners can effectively diagnose and treat oral candidiasis. In this review, we examine the role of the IL-23/IL-17 pathways in antifungal host defense, and provide a practical guide to the diagnosis and treatment of oral candidiasis in patients with psoriasis. Overall, while treatment with anti-IL-17 medications leads to an increased incidence of oral candidiasis in patients with psoriasis, these cases are typically mild or moderate in severity and can be managed with standard antifungal therapy without discontinuing treatment for psoriasis. If applicable, patients with psoriasis should also be advised to practice good oral hygiene and manage or control co-existing diabetes, and should be provided with information on smoking cessation to prevent oral candidiasis.