Oral candidal infections and antimycotics

Antimicrobial Activity of Crataegi fructus Extract Used for Potential Application in the Prevention and Treatment of Oral Diseases

Background and Objectives: This study evaluated the antimicrobial effect and cytotoxic potential of the natural Crataegi fructus extract against Streptococcus mutans (S. mutans), the causative agent of dental caries, which is a typical oral disease, and Candida albicans (C. albicans), which causes oral candidiasis. Materials and Methods: Crataegi fructus was shaken in 70% ethanol for 12 h to obtain samples through enrichment and lyophilization. Then, 1, 5, 10, 20, 30, and 40 mg/mL of the Crataegi fructus extract were applied to S. mutans and C. albicans to demonstrate its antimicrobial effect after 24 h. The stability of Crataegi fructus extract on the survival rate of human keratinocytes (HaCaT) was confirmed using water-soluble tetrazolium salt (WST-1) analysis. A one-way ANOVA determined the difference between each group. A Tukey HSD test was performed as a post-hoc analysis at the 0.05 significance level. Results: Crataegi fructus extract showed antimicrobial effects against S. mutans and C. albicans that increased in a concentration-dependent manner. However, high concentrations affected cell growth and lowered cell survival. The half maximal inhibitory concentration (IC50 value) of Crataegi fructus extract showed a survival rate of 53.04% at a concentration of 30 mg/mL, which was found to be applicable. Conclusions: Thus, Crataegi fructus extract may be used as a natural material for the prevention and treatment of oral diseases. Crataegi fructus demonstrates optimal antimicrobial effects without affecting cell proliferation and growth at 30 mg/mL concentration.

Evaluation of the Antifungal Effect of Rhus verniciflua Stokes Extract for Oral Application Potential

Background and Objectives: This study confirms the possibility of using Rhus verniciflua Stokes (RVS) extract as a natural treatment for oral candidiasis. Materials and Methods: RVS was extracted with 70% ethanol to examine the antioxidant activity through polyphenol, flavonoid content, and DPPH (1,1-diphenyl-2-picrylhydrazyl). To evaluate the antifungal effect against Candida albicans (C. albicans; KCTC 7965/ATCC 10231) and evaluate the stability of RVS, a water-soluble tetrazolium salt (WST-1) assay was performed in human keratinocytes (HaCaT). Results: The findings revealed that RVS extract has fairly high antioxidant activity. The clear zones of the RVS extract against C. albicans increased in diameter due to the inhibition of fungal growth at higher concentrations. Treatment with the 1.25 mg/mL RVS extract had a more than 99% antifungal effect against C. albicans, and the 20 mg/mL RVS extract had a 100% antifungal effect. The WST-1 assay showed that the RVS extract induced low cell viability in the HaCaT cells, which inhibited their proliferation, and the RVS extract is also toxic to normal cells. Conclusions: Although the RVS extract with high antioxidant activity showed clear antifungal activity against C. albicans, it exhibited a low survival rate. Therefore, the development of a safe natural antibiotic is necessary.

Antifungal Susceptibility of Oral Candida Isolates from Mother-Infant Dyads to Nystatin, Fluconazole, and Caspofungin

The carriage of Candida albicans in children's oral cavities is associated with a higher risk for early childhood caries, so controlling this fungus in early life is essential for preventing caries. In a prospective cohort of 41 mothers and their children from 0 to 2 years of age, this study addressed four main objectives: (1) Evaluate in vitro the antifungal agent susceptibility of oral Candida isolates from the mother-child cohort; (2) compare Candida susceptibility between isolates from the mothers and children; (3) assess longitudinal changes in the susceptibility of the isolates collected between 0 and 2 years; and (4) detect mutations in C. albicans antifungal resistance genes. Susceptibility to antifungal medications was tested by in vitro broth microdilution and expressed as the minimal inhibitory concentration (MIC). C. albicans clinical isolates were sequenced by whole genome sequencing, and the genes related to antifungal resistance, ERG3, ERG11, CDR1, CDR2, MDR1, and FKS1, were assessed. Four Candida spp. (n = 126) were isolated: C. albicans, C. parapsilosis, C. dubliniensis, and C. lusitaniae. Caspofungin was the most active drug for oral Candida, followed by fluconazole and nystatin. Two missense mutations in the CDR2 gene were shared among C. albicans isolates resistant to nystatin. Most of the children's C. albicans isolates had MIC values similar to those from their mothers, and 70% remained stable on antifungal medications from 0 to 2 years. For caspofungin, 29% of the children's isolates showed an increase in MIC values from 0 to 2 years. Results of the longitudinal cohort indicated that clinically used oral nystatin was ineffective in reducing the carriage of C. albicans in children; novel antifungal regimens in infants are needed for better oral yeast control.

Clinical atrophy patterns of filiform papillae of the tongue and their relationship with the serum levels of iron, vitamin B12 and folic acid in patients with systemic diseases

BACKGROUND

The purpose of the study was to evaluate the clinical patterns of atrophy of the filiform papillae (FP) of the tongue and their relationship with the serum levels of iron and vitamin B₁₂ among patients with systemic diseases, in a tertiary care center.

METHODS

A cross-sectional, analytical, research study was designed. A systematic tongue examination was performed to evaluate the presence and clinical patterns of FP atrophy. We collected epidemiologic, clinical, and laboratory data. Statistical analysis included χ² test, Fisher's exact test, Kruskal-Wallis test, and a logistic regression analysis.

RESULTS

A total of 87 patients (83.9% females) were included [median age = 55 (range 20-89) years]. Endocrinopathy (60.9%) was the most frequent comorbidity. We found atrophy of the FP in 90.8% of the patients; the atrophy was mild in 83.5% of the cases, and severe in 16.5%. The most common atrophic patterns were as follows: focalized in 64 (73.6%) cases, "U"-shaped pattern in 60 (69%), and generalized in 30 (34.5%). Geographic tongue and median rhomboid glossitis were observed in 12 (13.8%) and 11 (12.6%) subjects, respectively. Lower titers of serum iron were detected in cases with focal (median = 71 vs. 110 mcg/dl) and generalized (median = 55 vs. 78 mcg/dl) FP atrophy (P = 0.03 and P = 0.009, respectively), than their counterparts. The presence of symptomatology was related to the focal pattern of atrophy (P = 0.038).

CONCLUSIONS

A high frequency of filiform papillary atrophy of the tongue was observed in patients with comorbidities. Some atrophic patterns of the tongue were significantly associated with certain medical conditions.

Antimicrobial effects of nano titanium dioxide and disinfectants on maxillofacial silicones

STATEMENT OF PROBLEM

Deficient hygiene of maxillofacial prostheses can be a source of infection, and various disinfectants, including nano-oxides, have been suggested for the disinfection of silicone prostheses. While maxillofacial silicones involving nano-oxides at different sizes and concentrations have been evaluated in terms of their mechanical and physical properties, reports are lacking on the antimicrobial effect of nano titanium dioxide (TiO₂) incorporated into maxillofacial silicones contaminated by different biofilms.

PURPOSE

The purpose of this in vitro study was to evaluate the antimicrobial effects of 6 different disinfectants and nano TiO₂ incorporation into maxillofacial silicone contaminated with Staphylococcus aureus, Escherichia coli, and Candida albicans biofilms.

MATERIAL AND METHODS

A total of 258 silicone specimens (129 pure silicones and 129 nano TiO₂-incorporated silicones) were fabricated. Specimens in each silicone group (with or without nano TiO₂) were divided into 7 disinfectant groups (control, 0.2% chlorhexidine gluconate, 4% chlorhexidine gluconate, 1% sodium hypochlorite, neutral soap, 100% white vinegar, and effervescent) in each biofilm group. Contaminated specimens were disinfected, and the suspension of each specimen was incubated at 37 °C for 24 hours. Proliferated colonies were recorded in colony-forming units per mL (CFU/mL). The differences in microbial levels among specimens were evaluated to test the effect of the type of silicone and the disinfectant (α=.05).

RESULTS

Significant difference was found among disinfectants regardless of the silicone type (P<.05). Nano TiO₂ incorporation showed an antimicrobial effect on S aureus, E coli, and C albicans biofilms. Nano TiO₂ incorporated silicone cleaned with 4% chlorhexidine gluconate had statistically less C albicans than pure silicone. Using white vinegar or 4% chlorhexidine gluconate led to no E coli on either silicone. Nano TiO₂ incorporated silicone cleaned with effervescent had fewer S aureus or C albicans biofilms.

CONCLUSIONS

The tested disinfectants and nano TiO₂ incorporation into silicone were effective against most of the microorganisms used in this study.

A Current Overview of Cyclodextrin-Based Nanocarriers for Enhanced Antifungal Delivery

Fungal infections are an extremely serious health problem, particularly in patients with compromised immune systems. Most antifungal agents have low aqueous solubility, which may hamper their bioavailability. Their complexation with cyclodextrins (CDs) could increase the solubility of antifungals, facilitating their antifungal efficacy. Nanoparticulate systems are promising carriers for antifungal delivery due to their ability to overcome the drawbacks of conventional dosage forms. CD-based nanocarriers could form beneficial combinations of CDs and nanoparticulate platforms. These systems have synergistic or additive effects regarding improved drug loading, enhanced chemical stability, and enhanced drug permeation through membranes, thereby increasing the bioavailability of drugs. Here, an application of CD in antifungal drug formulations is reviewed. CD-based nanocarriers, such as nanoparticles, liposomes, nanoemulsions, nanofibers, and in situ gels, enhancing antifungal activity in a controlled-release manner and possessing good toxicological profiles, are described. Additionally, the examples of current, updated CD-based nanocarriers loaded with antifungal drugs for delivery by various routes of administration are discussed and summarized.

Oro-facial mucocutaneous manifestations of Coronavirus Disease-2019 (COVID-19): A systematic review

We reviewed the prevalence, the likely aetiopathogenesis, and the management of oro-facial mucocutaneous manifestations of Coronavirus Disease-2019 (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus -2 (SARS-CoV-2). English language manuscripts searched using standard databases yielded 26 articles that met the inclusion criteria. In total, 169 cases (75 females; 94 males) from 15 countries with a spectrum of COVID-19 severities were reviewed. Gustatory perturbations were prevalent in over 70%. Mucocutaneous manifestations were reported predominantly on the tongue, palate, buccal mucosa, gingivae, and lips and included ulcers, blisters, erosions, papillary hyperplasia, macules, glossitis, and mucositis. Ulcerative lesions, present in over 50 percent, were the most common oral manifestation. Lesions resembling candidal infections, with burning mouth, were prevalent in 19%. Petechiae and angina bullosa were generally seen, subsequent to COVID-19 therapies, in 11%. Ulcerated, necrotic gingivae were documented in severely ill with poor oral hygiene. These manifestations, present across the COVID-19 disease spectrum, were commonly associated with the immunosuppressed state and/ or the concurrent antimicrobial/steroidal therapies. In summary, a wide variety of orofacial mucocutaneous lesions manifest in COVID-19. They are likely to be secondary to the disease-associated immune impairment and/or pharmaco-therapy rather than a direct result of SARS-CoV-2 infection per se.

Antioxidant and Antimicrobial Activities of Chemically-Characterized Essential Oil from Artemisia aragonensis Lam. against Drug-Resistant Microbes

This study investigated the chemical composition, antioxidant and antimicrobial activity of essential oil extracted from Artemisia aragonensis Lam. (EOA). Hydrodistillation was employed to extract EOA. Gas chromatography with flame ionization detection (GC-FID) and gas chromatography-mass spectrometry analyses (GC-MS) were used to determine the phytochemical composition of EOA. Antioxidant potential was examined in vitro by use of three tests: 2.2-diphenyl-1-picrilhidrazil (DPPH), ferric reducing activity power (FRAP) and total antioxidant capacity assay (TAC). Agar diffusion and microdilution bioassays were used to assess antimicrobial activity. GC/MS and GC-FID detected 34 constituents in the studied EOA. The major component was Camphor (24.97%) followed by Borneol (13.20%), 1,8 Cineol (10.88%), and Artemisia alcohol (10.20%). EOA exhibited significant antioxidant activity as measured by DPPH and FRAP assays, with IC50 and EC50 values of 0.034 ± 0.004 and 0.118 ± 0.008 mg/mL, respectively. EOA exhibited total antioxidant capacity of 7.299 ± 1.774 mg EAA/g. EOA exhibited potent antibacterial activity as judged by the low minimum inhibitory concentration (MIC) values against selected clinically-important pathogenic bacteria. MIC values of 6.568 ± 1.033, 5.971 ± 1.033, 7.164 ± 0.0 and 5.375 ± 0.0 μg/mL were observed against S. aureus, B. subtills, E. coli 97 and E. coli 57, respectively. EOA displayed significant antifungal activity against four strains of fungi: F. oxysporum, C. albicans, A. flavus and A. niger with values of 21.50 ± 0.43, 5.31 ± 0.10, 21.50 ± 0.46 and 5.30 ± 0.036 μg/mL, respectively. The results of the current study highlight the importance of EOA as an alternative source of natural antioxidant and antibacterial drugs to combat antibiotic-resistant microbes and free radicals implicated in the inflammatory responses accompanying microbial infection.

Evaluation of Antimicrobial Activity of Conyza bonariensis Leaf Extracts against Clinically Isolated Fungi Causing Superficial Infection

Plants have been used since long time ago to treat infectious diseases and are considered as important sources of new antimicrobial agents. In this study, crude extracts from leaves of Conyza bonariensis were prepared using methanol, ethyl acetate, hexane, and chloroform. Antimicrobial activity of the extracts was evaluated against pathogenic fungi causing superficial infection (Candida albicans, Malassezia globosa, and Malassezia furfur). Results demonstrated that all extracts had different effects against all the tested fungi with the exception of crude extract using hexane which did not show any effect against M. furfur. A strong effect was observed with chloroform and hexane extracts on C. albicans (32.60 ± 4.69 mm and 27.00 ± 1.00 mm), respectively. While, ethyl acetate and methanol extracts showed the best effect against M. furfur (30.80 ± 1.71 mm and 27.00 ± 1.00 mm), respectively. Moreover, the ethyl acetate showed a considerable effect on M. globosa (25.03 ± 1.05 mm). Minimum inhibitory concentration (MIC) of the fractions was also determined by the microbroth dilution method. The results recorded as the MIC values of the tested extracts against fungi varied from 0.19 ± 0.00 to 66.66 ± 2.86 mg/mL. Ethyl acetate was the best and powerful extract with the lowest MIC value of 0.190.19 ± 0.00 mg/mL for all tested fungi followed by chloroform and methanol extracts with the MIC values ranging from 0.19 ± 0.00 to 0.78 ± 0.00 mg/mL and 0.84 ± 0.68 to 1.56 mg/mL, respectively. Concerning minimum bactericidal concentration (MFC), ethyl acetate was the most potent extract with a MFC value of 0.190.19 ± 0.00 mg/mL for C. albicans and M. furfur. Higher (0.39 mg/mL) MFC was recorded against M. globosa by this extract. In conclusion, solvent extracts of some C. bonariensis can be used to treat infections with pathogenic fungi such as C. albicans, M. furfur, and M. globosa. Further studies should consider this plant as one of the best candidates for the discovery of potent antimicrobial compounds that treat superficial infections.

Oral microbial diversity analysis among atrophic glossitis patients and healthy individuals

Atrophic glossitis is a common disease in oral mucosal diseases. The Current studies have found the human oral cavity contains numerous and diverse microorganisms, their composition and diversity can be changed by various oral diseases. To understand the composition and diversity of oral microbiome in atrophic glossitis is better to explore the cause and mechanism of atrophic glossitis. The salivary microbiome is comprised of indigenous oral microorganisms that are specific to each person, exhibits long-term stability. We used llumina MiSeq high-throughput sequencing based on the V3-V4 region of the bacterial 16S rRNA gene and the internal transcribed spacer (ITS) region of fungal rRNA genes from saliva in atrophic glossitis patients and healthy individuals to explore the composition and diversity of oral microbiome. In our reports, it showed a lower diversity of bacteria and fungi in atrophic glossitis patients than in healthy individuals. The data further suggests that Lactobacillus and Saccharomycetales were potential indicators for the initiation and development of atrophic glossitis. Moreover, we also discuss the relationship between the oral microbial ecology and atrophic glossitis.

Striking Back against Fungal Infections: The Utilization of Nanosystems for Antifungal Strategies

Fungal infections have become a major health concern, given that invasive infections by Candida, Cryptococcus, and Aspergillus species have led to millions of mortalities. Conventional antifungal drugs including polyenes, echinocandins, azoles, allylamins, and antimetabolites have been used for decades, but their limitations include off-target toxicity, drug-resistance, poor water solubility, low bioavailability, and weak tissue penetration, which cannot be ignored. These drawbacks have led to the emergence of novel antifungal therapies. In this review, we discuss the nanosystems that are currently utilized for drug delivery and the application of antifungal therapies.

Development of purified cashew gum mucoadhesive buccal tablets containing nystatin for treatment of oral candidiasis

OBJECTIVE

The objective of this work was to prepare mucoadhesive buccal tablets containing nystatin and purified cashew gum for the treatment of oral candidiasis.

SIGNIFICANCE

Mucoadhesive buccal tablets containing the drug nystatin are an alternative to oral suspensions, which cause low therapeutic adherence to the treatment of oral candidiasis. Purified cashew gum has been studied as a diluent and mucoadhesive agent in tablets.

METHODS

Two batches of mucoadhesive tablets were produced, MT1 and MT 2, containing purified cashew gum, nystatin (500,000 IU), flavoring agent and with or without the presence of lubricant agent. The average weight, mechanical properties, dose uniformity, drug release profile, mucoadhesive properties and antimicrobial activity against Candida albicans were evaluated.

RESULTS

Tablets presented average weight of 329.1 ± 3.1 mg (MT1) and 334.6 ± 1.5 mg (MT2), hardness of 9.8 ± 0.8 KgF (MT1) and 8.3 ± 0.4 KgF (MT2), friability of 0.2% (MT1 and MT2), and dose uniformity of 102.20 ± 1.17% (MT1) and 99.06 ± 7.40% (MT2). MT1 and MT2 were able to swell, erode, release the drug and remain adhered to the pig's cheek up to 3 h for batch MT1 and 4 h for batch MT2, and the amount of nystatin released since the beginning of the test in both batches was sufficient to inhibit the growth of the fungus.

CONCLUSIONS

Therefore, the proposed formulation proved to be very promising and met all the studied criteria, showing to be ideal for the treatment of oral candidiasis.

Fibrin Biopolymer Incorporated with Antimicrobial Agents: A Proposal for Coating Denture Bases

The characteristics of the denture base surface, in combination with the oral environment, promote the colonization and development of Candida albicans biofilm, which is the main cause of denture stomatitis. This study evaluated the effectiveness of fibrin biopolymer with digluconate chlorhexidine or Punica granatum alcoholic extract to prevent C. albicans biofilm. Conventional heat polymerized and pre-polymerized poly(methyl methacrylate) (PMMA) circular specimens (10 × 2 mm) were fabricated (n = 504) and randomly divided into groups: no treatment (control—CT), fibrin biopolymer coating (FB), fibrin biopolymer with P. granatum (FBPg), or digluconate of chlorhexidine (FBCh) coating. The specimens were inoculated with C. albicans SC5314 (1 × 10⁷ cells/mL) and incubated for 24, 48, and 72 h. Crystal violet and colony-forming unit assays were used to quantify the total biofilm biomass and biofilm-living cells. A qualitative analysis was performed using confocal laser scanning microscopy. Data obtained are expressed as means and standard deviations and were statistically analyzed using a three-way analysis of variance (α = 0.05). The FBPg and FBCh groups inhibited the growth of C. albicans biofilm in both PMMA materials analyzed, with FBCh performing better in all periods evaluated (p < 0.0001). The colony forming unit (CFU) assay showed that the FB group favored the C. albicans biofilm growth at 24 h and 48 h (p < 0.0001), with no differences with CT group at 72 h (p = 0.790). All groups showed an enhancement in biofilm development up to 72 h (p < 0.0001), except the FBCh group (p = 0.100). No statistical differences were found between the PMMA base materials (p > 0.050), except in the FB group (p < 0.0001). Fibrin biopolymer, albeit a scaffold for the growth of C. albicans, when combined with chlorhexidine digluconate or P. granatum, demonstrated excellent performance as a drug delivery system, preventing and controlling the formation of denture biofilm.

Hydrogel-Based Active Substance Release Systems for Cosmetology and Dermatology Application: A Review

Hydrogels are playing an increasingly important role in medicine and pharmacy. Due to their favorable physicochemical properties, biocompatibility, and designed interaction with living surroundings, they seem to be one of the most promising groups of biomaterials. Hydrogel formulations from natural, semi, or synthetic polymeric materials have gained great attention in recent years for treating various dermatology maladies and for cosmetology procedures. The purpose of this review is to present a brief review on the basic concept of hydrogels, synthesis methods, relevant mechanisms, and applications in dermatology or cosmetology. This review discusses transdermal therapies and the recent advances that have occurred in the field.

Impact of Cigarette Smoke Condensate on Adhesion-Related Traits and Hemolysin Production of Oral Candida dubliniensis Isolates

BACKGROUND

Cigarette smoke is associated with higher oral Candida carriage and possible predisposition and increased susceptibility to oral candidal infection. Candida dubliniensis is associated with oral candidosis. Candidal adherence to buccal epithelial cells (BEC) and denture acrylic surfaces (DAS), germ tube (GT) formation, cell surface hydrophobicity (CSH) and hemolysin production are pathogenic traits of Candida.

OBJECTIVES

The impact of exposure to cigarette smoke on the aforementioned pathogenic attributes of oral C. dubliniensis has not been studied. Hence, the impact of cigarette smoke condensate (CSC) on adhesion to BEC and DAS, GT formation, CSH and hemolysin production of 20 oral C. dubliniensis isolates after exposure to CSC for 24, 48 and 72 h was ascertained.

METHODS

After preparation of the CSC, using an in-house smoking device, the Candida isolates were exposed to the CSC for 24, 48 and 72 h, by a previously described in vitro method. Thereafter, the adhesion to BEC and DAS, GT formation, CSH and hemolysin production of C. dubliniensis isolates was investigated by hitherto described in vitro assays.

RESULTS

Exposure to CSC significantly increased the ability of C. dubliniensis oral isolates to adhere to BEC, DAS, GT formation, CSH and produce hemolysin following 24-h, 48-h and 72-h exposure periods to CSC (P < 0.001 for all attributes tested).

CONCLUSIONS

Exposure of oral C. dubliniensis isolates to CSC may significantly promote in vitro adhesion traits and hemolysin production of these isolates, thereby augmenting its pathogenicity in vitro in the presence of cigarette smoke.

Effects of Streptococcus salivarius K12 with nystatin on oral candidiasis-RCT

OBJECTIVE

To evaluate the efficacy and safety of Streptococcus salivarius K12 as an adjuvant in treating oral candidiasis.

METHODS

A total of 56 patients were participated in the randomized, double-blinded, placebo-controlled clinical trial. The S. salivarius K12 or placebo lozenges plus nystatin tablets were given for up to 4 weeks at 1-week interval and then followed up for 1 week thereafter. We collected and analyzed the mycological and clinical data, treatment course, and safety data.

RESULTS

At the end of the treatment, significant differences were found in the mycological cure rates between K12 group and control group (90.48% and 55.56%, respectively, p = 0.008). Survival analysis demonstrated no statistical difference in overall cure rates comprehensively considering mycological cure, clinical improvement, and recurrence (p = 0.078), while statistical difference was found in mycological cure (p = 0.013) between the two groups. The median treatment courses of K12 group and control group were 3 weeks and 4 weeks, respectively. No severe events were reported during the study.

CONCLUSION

Streptococcus salivarius K12 exhibited potential efficacy and safety as an adjuvant in treating oral candidiasis by enhancing mycological cure and shortening the treatment course of conventional antifungal therapy in this randomized, double-blinded, placebo-controlled clinical trial. Further large-scale clinical studies are desired to accumulate more evidence for its clinical applications.

Whole Genome Analysis of Lactobacillus plantarum Strains Isolated From Kimchi and Determination of Probiotic Properties to Treat Mucosal Infections by Candida albicans and Gardnerella vaginalis

Three Lactobacillus plantarum strains ATG-K2, ATG-K6, and ATG-K8 were isolated from Kimchi, a Korean traditional fermented food, and their probiotic potentials were examined. All three strains were free of antibiotic resistance, hemolysis, and biogenic amine production and therefore assumed to be safe, as supported by whole genome analyses. These strains demonstrated several basic probiotic functions including a wide range of antibacterial activity, bile salt hydrolase activity, hydrogen peroxide production, and heat resistance at 70°C for 60 s. Further studies of antimicrobial activities against Candida albicans and Gardnerella vaginalis revealed growth inhibitory effects from culture supernatants, coaggregation effects, and killing effects of the three probiotic strains, with better efficacy toward C. albicans. In vitro treatment of bacterial lysates of the probiotic strains to the RAW264.7 murine macrophage cell line resulted in innate immunity enhancement via IL-6 and TNF-α production without lipopolysaccharide (LPS) treatment and anti-inflammatory effects via significantly increased production of IL-10 when co-treated with LPS. However, the degree of probiotic effect was different for each strain as the highest TNF-α and the lowest IL-10 production by the RAW264.7 cell were observed in the K8 lysate treated group compared to the K2 and K6 lysate treated groups, which may be related to genomic differences such as chromosome size (K2: 3,034,884 bp, K6: 3,205,672 bp, K8: 3,221,272 bp), plasmid numbers (K2: 3, K6 and K8: 1), or total gene numbers (K2: 3,114, K6: 3,178, K8: 3,186). Although more correlative inspections to connect genomic information and biological functions are needed, genomic analyses of the three strains revealed distinct genomic compositions of each strain. Also, this finding suggests genome level analysis may be required to accurately identify microorganisms. Nevertheless, L. plantarum ATG-K2, ATG-K6, and ATG-K8 demonstrated their potential as probiotics for mucosal health improvement in both microbial and immunological contexts.

Influence of subinhibitory antifungal concentrations on extracellular hydrolases and biofilm production by Candida albicans recovered from Egyptian patients

BACKGROUND

Extracellular hydrolases (phospholipase, aspartyl protease and haemolysin) and biofilm production are considered as major virulence factors of the opportunistic pathogenic fungus Candida albicans. However, the impact of antifungal therapy on such virulence attributes is not well investigated. The common antifungal agents may disturb the production of secreted hydrolases as well as biofilm formation. Accordingly, this study addressed the effect of subinhibitory concentrations (sub-MICs) of selected antifungal agents on some virulence factors of C. albicans clinical isolates.

METHODS

C. albicans isolates (n = 32) were recovered from different clinical samples and their identification was confirmed to the species level. Antifungal susceptibility profiles of isolates were determined against (nystatin, fluconazole and micafungin) and minimum inhibitory concentrations (MICs) were interpreted according to Clinical and Laboratory Standards Institute guidelines. Virulence determinants comprising secreted hydrolases (phospholipase, aspartyl protease and haemolysin) and biofilm formation were investigated in the presence of the sub-MICs of the tested antifungal agents.

RESULTS

Treatment of clinical C. albicans isolates with subinhibitory nystatin, fluconazole and micafungin concentrations significantly decreased production of extracellular hydrolases. Nystatin had the greatest inhibitory effect on phospholipase and aspartyl protease production. However, micafungin showed the highest reducing effect on the hemolytic activity of the treated clinical isolates. Moreover, nystatin and micafungin, but not fluconazole, had a noticeable significant impact on inhibiting biofilm formation of C. albicans clinical isolates.

CONCLUSION

Our findings highlighted the significant influences of commonly prescribed antifungal agents on some virulence factors of C. albicans. Accordingly, antifungal therapy may modulate key virulence attributes of C. albicans.

In vitro Post-Antifungal Effect of Posaconazole and Its Impact on Adhesion-Related Traits and Hemolysin Production of Oral Candida dubliniensis Isolates

OBJECTIVE

Candidal adherence to denture acrylic surfaces (DAS) and oral buccal epithelial cells (BEC), formation of candidal germ tubes (GT), candidal cell surface hydrophobicity (CSH), and hemolysin production are important pathogenic traits of Candida. The antifungal drug-induced post-antifungal effect (PAFE) also impacts the virulence of Candida. Candida dubliniensis isolates are associated with the causation of oral candidiasis which could be managed with posaconazole. Thus far there is no evidence on posaconazole-induced PAFE and its impact on adhesion-related attributes and production of hemolysin by C. dubliniensis isolates. Hence, the PAFE, adhesion to DAS and BEC, formation of GT, CSH, and hemolysin production of 20 oral C. dubliniensis isolates after brief exposure to posaconazole was ascertained.

MATERIALS AND METHODS

The PAFE, adherence to DAS and BEC, formation of GT, candidal CSH, and hemolysin production were investigated by hitherto described in vitro assays.

RESULTS

The mean PAFE (h) induced by posaconazole on C. dubliniensis isolates was 1.66. Exposure to posaconazole suppressed the ability of C. dubliniensis to adhere to DAS, BEC, formation of candidal GT, candidal CSH and to produce hemolysin by a reduction of 44, 33, 34, 36, and 15% (p < 0.005 to p < 0.001), respectively.

CONCLUSION

Exposure of C. dubliniensis isolates to posaconazole for a brief period induced an antimycotic impact by subduing its growth in addition to suppressing pathogenic adherence-associated attributes, as well as production of hemolysin.

Clotrimazole is effective for the regression of endometriotic implants in a Wistar rat experimental model of endometriosis

The present work aimed to evaluate molecular, angiogenic and inflammatory changes induced by clotrimazole (CTZ) on endometriosis lesions. For this, thirty female Wistar rats with surgically implanted autologous endometrium were treated with CTZ or vehicle (200 mg/kg) via esophageal gavage for 15 consecutive days. CTZ treatment significantly decreased the growth and the size of the implants, and histological examination indicated regression and atrophy, with no toxicity to the animals. The levels of the angiogenic markers VEGF and VEGFR-2 were significantly decreased in CTZ group. The treatment also promotes a reduction on PGE₂ and TNF-α levels. All these effects involve the amelioration of ERK1/2, Akt, AMPK and PERK signaling upon CTZ treatment. In conclusion, CTZ promoted an overall amelioration of endometriosis in a rat model due to the anti-angiogenic properties of the drug. Therefore, our results support the proposal of a clinical trial using CTZ for the treatment of endometriosis.

Antifungal effect of Satureja khuzestanica Jamzad essential oil on oral candidiasis in immunosuppressed rats

Introduction: The antimicrobial, antibacterial, antioxidant, antihyperlipidaemic, antidiabetic, anti-inflammatory and analgesic effects of Satureja khuzestanica (Lamiaceae) have been investigated in numerous studies.

Objective: The antifungal effects of S. khuzestanica essential oil (SKJO) in immunosuppressed rats suffering from oral candidiasis were investigated.

Methods: A fungal suspension with a density of 3×108 CFU/ml was taken from the isolate of a case with acute vaginitis. In order to achieve a medicinal formulation, accurate twice the minimum inhibitory concentration (MIC) of SKJO and 10 times MIC of nystatin was used with 0.8% agar as a base material. In this study, 35 rats divided into 5 groups each of 7 were used. The assessment of level of infection and specification of the effects of treatment were performed using microbiological and histopathological methods as well as clinical examinations.

Results: Our results show that carvacrol is the main compound of SKJ essential oil. Lesions completely disappeared in both treatment groups (SKJO and nystatin) after 8 days of treatment. Furthermore, in groups treated with SKJO and nystatin, the quantities of mean logarithm of colony forming unit (CFU) were 85.62% and 90.62%, respectively, in comparison with placebo group. Also, histopathological properties suggested no infection in groups who had clean and normal dorsal tongue mucosa.

Conclusions: Using SKJO with twice accuracy it was concluded that MIC in immunosuppressed rats was quite successful in a time of a week and equal with that of a nystatin treatment with an accuracy of 10 times the MIC.

Therapy of Skin, Hair and Nail Fungal Infections

Treatment of superficial fungal infections has come a long way. This has, in part, been through the development and evaluation of new drugs. However, utilising new strategies, such as identifying variation between different species in responsiveness, e.g., in tinea capitis, as well as seeking better ways of ensuring adequate concentrations of drug in the skin or nail, and combining different treatment methods, have played equally important roles in ensuring steady improvements in the results of treatment. Yet there are still areas where we look for improvement, such as better remission and cure rates in fungal nail disease, and the development of effective community treatment programmes to address endemic scalp ringworm.

Virulence factors and determination of antifungal susceptibilities of Candida species isolated from palm wine and sorghum beer

Since it has been considered that Candida species in food or drinks may, following ingestion, enter the bloodstream and cause fungaemia, the presence of these yeast species in traditional alcoholic beverages may be of some clinical significance. Thus we attempted to assess virulence factors and antifungal susceptibility profile of Candida strains and other potential pathogenic yeasts isolated from palm wine and sorghum beer (tchapalo). Of the 23 yeast isolates from palm wine, phospholipase, esterase and haemolysin production was revealed amongst 69.6%, 65.2% and 100% isolates respectively with high activity belonging to Candida tropicalis strains. All the isolates were biofilm producers at variable degree but none showed proteinase activity. When the isolates were tested for their susceptibility to five antifungal agents, we found that ketoconazole (91.3%) followed by fluconazole (78.3%) and amphotericin B (73.9%) were the most potent agents. Of the 14 isolates from tchapalo, 57.1%, 87.5% and 57.1% exhibited phospholipase, haemolysin and esterase activity respectively. They did not also show proteinase activity while 87.5% produced biofilm. The majority of the isolates were susceptible to azoles (92.7%) and amphotericin B (85.3%) but they were 5-flucytosine resistant like palm wine strains.

Chemical hygiene protocols for complete dentures: A crossover randomized clinical trial

STATEMENT OF PROBLEM

Clinical evidence on the best chemical protocol for the disinfection and removal of biofilm from complete dentures is lacking.

PURPOSE

The purpose of this crossover randomized clinical trial was to assess the effectiveness of various chemical hygiene clinical protocols in reducing the microbial viability of biofilm formed on complete dentures.

MATERIAL AND METHODS

In this triple-blind (participants, dentist, and outcome evaluator) study, complete denture wearers without candidiasis were randomly divided into 4 groups (n=40) according to the chemical hygiene protocol: water (placebo), 0.5% sodium hypochlorite solution, 0.12% chlorhexidine gluconate solution, and 5% sodium bicarbonate solution. The biofilm formed on the palate intaglio and denture teeth was collected and assessed in each experimental phase for quantitative microbial viability at the seventh and 14th day after using the chemical protocol.

RESULTS

Two participants were lost. Data were analyzed by MANOVA and Tukey HSD tests. Soaking dentures was not effective in decreasing Candida albicans, C. non-albicans, and lactobacillus counts. The use of sodium hypochlorite and chlorhexidine decreased total microorganisms and Streptococcus mutans counts for both palate and teeth compared with water and sodium bicarbonate. The intaglio of the dentures always presented higher microbial counts than did the denture teeth.

CONCLUSIONS

The use of sodium hypochlorite and chlorhexidine and mechanical cleansing with a toothbrush decreased microbial viability in healthy complete denture wearers.

Randomized pilot study on probiotic effects on recurrent candidiasis in oral lichen planus patients

Some patients with oral lichen planus (OLP) experience recurrent oral candidiasis(OC). Probiotic bacteria have shown to reduce the oral Candida count in vivo.

OBJECTIVE

To study whether probiotic intervention reduces recurrent OC in patients with OLP.

MATERIAL AND METHODS

Twenty-two patients with symptomatic OLP were enrolled in the double-blinded, randomized, placebo-controlled intervention study. Lozenges containing Lactobacilli reuteri (DSM 17938 and ATCC PTA 5289) or placebo were dissolved intra-orally three times daily for 16 weeks, after which patients were followed up for 36 weeks. Mucosal symptoms, VAS pain, OLP severity score, plaque index (PI) and gingival index (GI), Candida count/carriage, and OC and/or need for symptomatic treatment were registered. Statistical significance was set at p < .05.

RESULTS

No difference was observed between the groups during the intervention or follow-up in terms of recurrent OC (p = .966) or need for symptomatic treatment (p = 1.000). There was no difference in terms of Candida count (p = .96) or carriage over time (p = .511). GI decreased in the probiotic group and increased in the placebo group (p = .046). OLP severity score decreased in both groups during the study period (p = .039). Across the entire study period, the placebo group had higher VAS pain score (p = .037).

CONCLUSIONS

Probiotic intervention did not reduce recurrent OC or Candida count/carriage, but the study experienced recruitment problems, which may have influenced results.

Antimicrobial and cytotoxic effects of denture base acrylic resin impregnated with cleaning agents after long-term immersion

The coadjutant method for denture cleansing most used by denture wearers is immersion in chemical agents, which are toxic when in direct contact with cells. However, clinically, the contact between these chemical agents and prosthetic tissues does not occur directly, but rather with what remained impregnated into acrylic bases, even after rinsing the disinfected dentures. This study evaluated the antimicrobial and cytotoxic effects of a denture acrylic resin after successive cycles of daily overnight immersion in 1% sodium hypochlorite (1%NaClO) and 2% chlorhexidine digluconate (2%CHX), simulating the periods of 9 months or 1.5 year. Microbiological and cytotoxic assays were performed, respectively, by broth microdilution method (Candida albicans or Staphylococcus aureus) and MTT assay. Chemical residues of 2%CHX impregnated into the denture acrylic resin had an antimicrobial effect on both immersion periods, which was not observed with those of 1%NaClO. However, residues of 2%CHX were severely cytotoxic to human gingival fibroblasts compared to those of 1%NaClO and acrylic resin (not submitted to the denture cleansers), which were slightly cytotoxic. Even at low concentrations recommended for overnight soaking of removable dentures, the chemical residues of CHX may result in some degree of toxicity to the denture-bearing mucosa after long-term daily immersion.

1,4-Naphthoquinone derivatives potently suppress Candida albicans growth, inhibit formation of hyphae and show no toxicity toward zebrafish embryos

PURPOSE

In this study, we applied various assays to find new activities of 1,4-naphthoquinone derivatives for potential anti-Candida albicans applications.

METHODOLOGY

These assays determined (a) the antimicrobial effect on growth/cell multiplication in fungal cultures, (b) the effect on formation of hyphae and biofilm, (c) the influence on cell membrane integrity, (d) the effect on cell morphology using atomic force microscopy, and (e) toxicity against zebrafish embryos. We have demonstrated the activity of these compounds against different Candida species and clinical isolates of C. albicans.

KEY FINDINGS

1,4-Naphthoquinones significantly affected fungal strains at 8-250 mg l^-1 of MIC. Interestingly, at concentrations below MICs, the chemicals showed effectiveness in inhibition of hyphal formation and cell aggregation in Candida. Of note, atomic force microscopy (AFM) analysis revealed an influence of the compounds on cell morphological properties. However, at low concentrations (0.8-31.2 mg l^-1), it did not exert any evident toxic effects on zebrafish embryos.

CONCLUSIONS

Our research has evidenced the effectiveness of 1,4-naphthoquinones as potential anti-Candida agents.

Impact of Brief Exposure to Drugs with Antifungal Properties on the Susceptibility of Oral Candida dubliniensis Isolates to Lysozyme and Lactoferrin

OBJECTIVE

Lysozyme and lactoferrin have anti-candidal activity. Candida dubliniensis is associated with oral candidiasis. Candida infections are managed with nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine. Candida species undergo a brief exposure to therapeutic agents in the mouth. There is no data on the influence of limited exposure to antimycotics on the sensitivity of C. dubliniensis to lactoferrin and lysozyme. Hence, this study observed the changes in the sensitivity of C. dubliniensis to anti-candidal action of lactoferrin and lysozyme after transitory exposure to sub-lethal concentrations of antifungals.

MATERIALS AND METHODS

After determination of the minimum inhibitory concentration (MIC), 20 C. dubliniensis isolates were exposed to twice the concentration of MIC of nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine for 1 h. Drugs were removed by dilution and thereafter the susceptibility of these isolates to lysozyme and lactoferrin was determined by colony-forming unit quantification assay.

RESULTS

Exposure of C. dubliniensis to nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine resulted in an increase in susceptibility to lysozyme by 9.45, 30.82, 30.04, 50.64, 55.60, and 50.18%, respectively (p < 0.05 to p < 0.001). Exposure of C. dubliniensis to nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine resulted in an increase in susceptibility to lactoferrin by 13.54, 16.43, 17.58, 19.60, 21.32, and 18.73, respectively (p < 0.05 to p < 0.001).

CONCLUSION

Brief exposure to nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine enhances the antifungal effect of lysozyme and lactoferrin on C. dubliniensis isolates in vitro.

The Candida species that are important for the development of atrophic glossitis in xerostomia patients

Background

The purpose of this study was to clarify the species of Candida that are important for the development of atrophic glossitis in xerostomia patients.

Methods

A total of 231 patients with subjective dry mouth were enrolled in the present study. Logistic regression analysis was performed to clarify the contribution of each Candida species and other variables to the development of atrophic glossitis. The dependent variable was the absence/presence of atrophic glossitis. The Candida colony-forming units (CFU) of C. albicans, C. glabrata, C. tropicalis, and C. krusei, as well as age, gender, resting (RSFR) and stimulated (SSFR) whole salivary flow rate, and denture-wearing status, were treated as explanatory variables.

Results

Logistic regression analysis showed that two factors were closely associated with the presence of atrophic glossitis: an increase in C. albicans CFU and a decrease in the SSFR.

Conclusions

C. albicans, but not non-albicans Candida, was associated with atrophic glossitis in xerostomia patients who had no systemic predisposing factors, indicating that C. albicans remains a treatment target for Candida-related atrophic glossitis.

Synthesis, Antifungal Activity, and Biocompatibility of Novel 1,4-Diazabicyclo[2.2.2]Octane (DABCO) Compounds and DABCO-Containing Denture Base Resins

The fungal pathogen Candida albicans causes a variety of oral infections, including denture stomatitis, which is characterized by inflammation of the oral mucosa in direct contact with dentures and affects a significant number of otherwise healthy denture wearers. While antifungal treatment reduces symptoms, infections are often recurrent. One strategy to address this problem is to incorporate compounds with fungicidal activities into denture materials to prevent colonization. Our laboratory synthesized novel derivatives of 1,4-diazabicyclo[2.2.2]octane (DABCO), which is an organic compound typically used as a catalyst in polymerization reactions. DABCO derivatives with different aliphatic chain lengths (DC16, DC16F, DC18, and C6DC16), as well as methacrylate monomers conjugated to DABCO compounds (DC11MAF and C2DC11MAF), were synthesized and tested for antimicrobial activity. All the compounds exhibited fungicidal activity against several Candida species at concentrations ranging between 2 and 4 μg/ml. Moreover, acrylic denture base resins fabricated to contain 1, 2, or 4 wt% DABCO compounds inhibited surface C. albicans biofilm formation, as well as fungal growth, in disc diffusion assays. Remarkably, discs (4 wt%) aged for 2 months also exhibited approximately 100% growth-inhibitory activity. While some DABCO compounds exerted intermediate to high cytotoxicity against mammalian oral cell types, DC11MAF and denture base resin discs containing 2 or 4 wt% C2DC11MAF exhibited relatively low cytotoxicity against periodontal ligament (PDL) cell and gingival fibroblast (GF) lines, as well as primary oral epithelial cells. These studies demonstrate that DABCO derivatives can be incorporated into denture materials and exert fungicidal activity with minimal cytotoxicity to mammalian cells. DC11MAF and C2DC11MAF are considered strong candidates as therapeutic or preventive alternatives against Candida-associated denture stomatitis.

Antifungal response of oral-associated candidal reference strains (American Type Culture Collection) by supercritical fluid extract of nutmeg seeds for geriatric denture wearers: An in vitro screening study

OBJECTIVES

Since time immemorial, plants have continued to play a predominant role in the maintenance of human health as sources of medicinal compounds. Several effective antifungal agents are available for oral Candida infections; the failure is not uncommon because isolates of Candida albicans may exhibit resistance to the drug during therapy. The present study aimed to identify an alternative, inexpensive, simple, and effective method of preventing and controlling the candidal infection.

METHODOLOGY

All the procured and authenticated nutmeg seeds were dried in shade and cleaned by hand sorting. The crushed seeds were passed through mesh no. 40 individually. About 50 g of powdered nutmeg seeds was loaded in the supercritical fluid extractor unit using supercritical CO₂ as extracting solvent in accordance with the methods of Nguyen et al. Supercritical fluid (SFE) extraction was done using CO₂ gas without any cosolvents.

RESULTS

The nutmeg extract displayed antifungal activity with the effective zone of inhibition ranging from 18.0 to 12.0 mm when compared with nystatin as positive control.

CONCLUSION

This paper described the in vitro antibacterial activity, and phytochemical analysis of SFE extract of nutmeg (Myristica fragrans) evaluated against C. albicans (American Type Culture Collection 10231) through agar well diffusion method. SFE of nutmeg seeds can be used as an adjunct to conventional therapy for oral candidiasis.

Impact of short-term exposure of antifungal agents on hemolysin activity of oral Candida dubliniensis isolates from Kuwait and Sri Lanka

OBJECTIVE

Ability to produce hemolysin by Candida species is an important determinant of its pathogenicity. Candida dubliniensis is implicated in the causation of oral candidosis, which can be treated with polyene, echinocandin, and azole groups of antifungal agents as well as chlorhexidine. After oral application, however, the concentrations of these agents tend to decrease quickly to subtherapeutic levels due to the peculiarity of the oral environment. In this study, we have evaluated the effect of short-term exposure of sublethal concentrations of these drugs on hemolysin production by oral C. dubliniensis isolates obtained from two different geographical locale.

MATERIALS AND METHODS

Twenty C. dubliniensis oral isolates obtained from Kuwait and Sri Lanka were exposed to sublethal concentrations of nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine for 1 h. Thereafter, the drugs were removed by dilution and the hemolysin production determined by a previously described plate assay.

RESULTS

Hemolysin production of these isolates was significantly suppressed with a percentage reduction of 17.09, 16.45, 17.09, 11.39, 8.23 and 12.03 following exposure to nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine, respectively.

CONCLUSION

Brief exposure to sublethal concentrations of drugs with antifungal properties appears to reduce the pathogenic potential of C. dubliniensis isolates by suppressing hemolysin production.

IODINE DEFICIENCY AND PATHOLOGY OF THYROID GLAND AS A BACKGROUND STATE OF CANDIDIASIS OF MUCOSA OF THE UPPER PART OF DIGESTIVE TRACT

There were examined 119 patients of gastroenterological profile, who, according to the results of microbiological examination of scraping from tongue and biopsy material of digestive tract and stomach, were divided into three groups: 1 group – patients with oropharyngeal candidiasis and surface candidiasis of mucous tunic, 2 group – patients with invasion of Candida fungi in mucous tunic, 3 group – patients without oropharyngeal candidiasis and without growth of fungi in biopsy material. The status of iodine provision was studied in 78 persons. The results of research revealed that at structural changes of thyroid gland the dominating position in patients with candidiasis of mucous tunic occupies the nodular goiter– 29,31% and 36,36% for 1 and 2 group respectively, whereas in 3 group the frequency of nodular goiter was 11,76%, at that hyperplasia and nodular goiter in patients with fungi invasion in mucous tunic was revealed 2,6 times more often comparing with patients without candidiasis (χ2=4,01; р<0,05). In patients with oropharyngeal and surface candidiasis and invasive candidiasis of mucous tunic of the upper part of digestive tract the hard degree of iodine nutrition deficiency with thyroglobulin level higher than 40 ng/ml was revealed in more than half of cases. At that the frequency of hard iodine deficiency at fungi invasion in mucous tunic 4,2 times higher comparing with patients without candidiasis of mucous tunic (F=0,024; р<0,05). So, the concomitant comorbid state with pathology of thyroid gland and iodine deficiency is an aggravating factor in the course of candida infection that is necessary to be taken into account at clinical monitoring of patients with candidiasis of mucous tunic of the upper part of gastrointestinal tract.

Extracellular phospholipase production of oral Candida albicans isolates from smokers, diabetics, asthmatics, denture wearers and healthy individuals following brief exposure to polyene, echinocandin and azole antimycotics

Objective

Candida albicans is the primary causative agent of oral candidosis, and one of its key virulent attributes is considered to be its ability to produce extracellular phospholipases that facilitate cellular invasion. Oral candidosis can be treated with polyenes, and azoles, and the more recently introduced echinocandins. However, once administered, the intraoral concentration of these drugs tend to be sub-therapeutic and rather transient due to factors such as the diluent effect of saliva and cleansing effect of the oral musculature. Hence, intra-orally, the pathogenic yeasts may undergo a brief exposure to antifungal drugs. We, therefore, evaluated the phospholipase production of oral C. albicans isolates following brief exposure to sub-therapeutic concentrations of the foregoing antifungals.

Materials and methods

Fifty C. albicans oral isolates obtained from smokers, diabetics, asthmatics using steroid inhalers, partial denture wearers and healthy individuals were exposed to sub-therapeutic concentrations of nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole for one hour. Thereafter the drugs were removed and the phospholipase production was determined by a plate assay using an egg yolk-agar medium.

Results

The phospholipase production of these isolates was significantly suppressed with a percentage reduction of 10.65, 12.14, 11.45 and 6.40% following exposure to nystatin, amphotericin B, caspofungin and ketoconazole, respectively. This suppression was not significant following exposure to fluconazole.

Conclusions

Despite the sub-therapeutic, intra oral, bioavailability of polyenes, echinocandins and ketoconazole, they are likely to produce a persistent antifungal effect by suppressing phospholipase production, which is a key virulent attribute of this common pathogenic yeast.

Efficacy of citronella and cinnamon essential oils on Candida albicans biofilms

INTRODUCTION

The discovery of new antimicrobials derived from plants could aid in the management of biofilm-associated infections, including denture-induced stomatitis (DS). DS is an oral infection caused by Candida biofilms on the surfaces of poorly cleansed dentures. Effective treatment of DS requires the use of an appropriate denture cleanser and preferably one that exhibits antimicrobial properties.

OBJECTIVE

This study aimed to evaluate the anti-Candida and anti-biofilm efficacy of two essential plant oils from Cymbopogon winterianus (citronella) and Cinnamon cassia (cinnamon).

MATERIALS AND METHODS

Minimum Inhibitory Concentrations (MICs) and Minimum Fungicidal Concentrations (MFCs) were determined by broth microdilution, whilst anti-biofilm activity was measured against mature (cultured for 72 h) biofilms on acrylic surfaces. Candida cell viability was assessed immediately (0 h) after treatment (T0) and 48 h after biofilm re-growth (T48). Biofilm structure was determined using Scanning Electron Microscopy (SEM) at T0 and T48.

RESULTS

The respective MICs of cinnamon and citronella oils were 65 and 250 μg/ml and these were also the MFC values. For anti-biofilm efficacy, both oils significantly (p < 0.05) reduced the number of viable micro-organisms and accumulation of biofilms at T0. However, at T48, there was no difference between treated and untreated biofilms.

CONCLUSIONS

It is concluded that citronella and cinnamon essential oils have potential for daily anti-candidal denture cleansing.

Impact of brief exposure to antifungal agents on the post-antifungal effect and hemolysin activity of oral Candida albicans

Post-antifungal effect (PAFE) of Candida and its production of hemolysin are determinants of candidal pathogenicity. Candida albicans is the foremost aetiological agent of oral candidosis, which can be treated with polyene, azole, and echinocandin antifungals. However, once administered, the intraoral concentrations of these drugs tend to be subtherapeutic and transient due to the diluent effect of saliva and cleansing effect of the oral musculature. Hence, intra-orally, Candida may undergo a brief exposure to antifungal drugs.

Caspofungin-induced in-vitro post-antifungal effect and its impact on adhesion related traits of oral Candida dubliniensis and Candida albicans isolates

Adhesion to buccal epithelial cells (BEC) and denture acrylic surfaces (DAS), germ tube (GT) formation and cell surface hydrophobicity (CSH) are all virulence traits involved in the pathogenicity of Candida. Post-antifungal effect (PAFE) also have a bearing on pathogenicity and virulence of Candida. Candida dubliniensis is associated with oral and systemic candidosis, which can be managed with caspofungin. There is no published information on caspofungin-induced PAFE and its impact on adhesion traits of C. dubliniensis isolates. Thus, the purpose of this investigation was to determine the in vitro duration of PAFE on 20 C. dubliniensis isolates following transient exposure to caspofungin. Furthermore the impacts of caspofungin-induced PAFE on adhesion to BEC and DAS, GT formation and CSH of these isolates were also determined. After establishing the minimum inhibitory concentration (MIC) of caspofungin, C. dubliniensis isolates were exposed to sub-lethal concentrations (×3 MIC) of caspofungin for 1 hr. Thereafter the duration of PAFE, adhesion to BEC and DAS, GT formation and CSH were determined by previously described in-vitro assays. MIC (μg/mL) of C. dubliniensis isolates to caspofungin ranged from 0.004 to 0.19. Caspofungin-induced mean PAFE on C. dubliniensis isolates was 2.17 hr. Exposure to caspofungin suppressed the ability of C. dubliniensis isolates to adhere to BEC and DAS, form GT and CSH by 69.97%, 71.95%, 90.06% and 32.29% (P < 0.001 for all), respectively. Thus, transient exposure of C. dubliniensis isolates to caspofungin produces an antifungal effect not only by suppressing its growth but also by altering its adhesion traits.

Disinfectants to Fight Oral Candida Biofilms

Oral biofilms, especially those caused by oral mycobiota, which include Candida species, are very difficult to eradicate, due to their complex structure and recalcitrance. Moreover, the mouth is prone to be colonized since it presents different types of surfaces, especially biomaterials and dental implants, often associated with a high rate of infections. Therefore, although disinfection of the oral cavity is of major importance, the number of commercially available disinfectants is not high. However, new solutions, as silver nanoparticles are being developed to help oral biofilms' eradication.

In vitro Impact of Limited Exposure to Subtherapeutic Concentrations of Chlorhexidine Gluconate on the Adhesion-Associated Attributes of Oral Candida Species

OBJECTIVE

Candida albicans and its non-albicans counterparts, such as C. tropicalis, C. krusei, C. glabrata and C. dubliniensis, are the major etiological agents of oral candidosis. Their adherence to buccal epithelial cells (BEC), denture acrylic surfaces (DAS) and cell surface hydrophobicity (CSH) are attributes associated with yeast colonization and infection. Chlorhexidine gluconate (CG) is a widely used antiseptic in dentistry. When administered, the diluent effect of saliva and the cleansing effect of the oral musculature reduce its bioavailability, compromising its efficacy. Hence, intraorally, Candida undergoes a transient exposure to high CG concentrations, and thereafter it is likely to be subtherapeutic. Therefore, the impact of CG on adhesion to BEC, DAS and CSH of different oral Candida species was investigated following brief exposure to three subtherapeutic concentrations of CG.

MATERIALS AND METHODS

Ten oral isolates of each of the above five Candida species obtained in Kuwait from oral rinse samples were exposed to 0.00125, 0.0025 and 0.005% CG for 30 min. Subsequently, the yeast adhesion to BEC, DAS and CSH was determined. The data were analyzed using ANOVA Dunnett's t tests.

RESULTS

Exposure to the lowest dilution (0.00125%) of CG did not elicit a noteworthy collective suppression on all three adhesion traits evaluated. Exposure to 0.0025% CG curtailed the adhesion to BEC, DAS and CSH of Candida species by 50.89, 40.79 and 24.58%, respectively (p < 0.001). Exposure to the highest concentration (0.005%) of CG reduced the adhesion to BEC, DAS and CSH of Candida species by 64.68, 54.59 and 50%, respectively (p < 0.001).

CONCLUSIONS

Brief exposure to subtherapeutic concentrations of CG suppressed the adhesion to BEC, DAS and CSH of oral Candida species, indicating probable pharmacodynamics that may potentiate its antiseptic properties.

Erythematous candidiasis leading to systemic manifestations of human immunodeficiency virus co-infection with secondary syphilis: A diagnostic and therapeutic dilemma

The intensification of human immunodeficiency virus (HIV) and rising frequency of immunocompromised individuals have resulted in a resurgence of opportunistic infections. The most common opportunistic oral fungal infection in HIV-positive individuals is oral candidiasis. The classical presentation is as white scrapable form called as thrush, which is easily diagnosed and treated. The clinician is presented with a diagnostic and management dilemma when these lesions appear in new facades such as erythematous candidiasis, the latter's prevalence with HIV and AIDS being well established. In this case report, we present a case of Erythematous Candidiasis, which was associated with type 1 HIV co-infected with syphilis. We highlight the diagnostic importance of a naive looking manifestation of the tongue which was followed by a series of challenging presentations of secondary syphilis. Since the patient had a negative Veneral Disease Research Laboratory and left us with a management dilemma, the article also features the importance of prozone phenomenon (seen in 2% cases of secondary syphilis), and it's higher association with HIV co-infected individuals. With confusing clinical oral manifestations associated with these diseases, the dentist might be the first person to encounter such lesions, who should be able to recognize erythematous candidiasis and correlate them with the underlying pathology.