Oral fungal infections

Mechanisms underlying sex bias in oral immune-mediated conditions, an insight

The predilection for women in systemic autoimmune diseases is well established. However, this sex bias in oral autoimmune diseases has been classically reported from an epidemiological perspective without any elaborate attempts to unveil the underlying mechanisms. The unique nature of the oral environment is likely to impose a combination of systemic and local factors that ultimately result in the sex bias in autoimmune diseases of the oral cavity. Variations of immune responses, target organ vulnerability, endocrine and genetic factors, sex chromosomes and modes of parental inheritance are potential systemic factors, while the oral microbiome, oral tolerance, saliva, and oral epithelial stem cells may account for local contributing factors. This review will discuss the preponderance of women in oral immune-mediated diseases, the potential systemic and local mechanisms underlying this predominance and highlight the crucial need for further research in this area.

The Spectrum of Infections in Patients with Lung Cancer

Although diagnostic and therapeutic advances in lung cancer (LC) have increased the survival of patients, infection and its complications are still among the most important causes of mortality. The disruption of tissue caused by tumor mass, management of cancer therapy and alteration in the humoral/cellular immune systems due to both cancer itself and therapy considerably increase susceptibility to infection in cancer patients. Particularly, opportunistic microorganisms should be considered, then applying rapid and sensitive diagnostic methods for them. Thus, cancer patients who are already exposed to difficult, long-term and expensive treatments can be prevented from dying from complications related to infections.

Antifungal Activity of Commercial Essential Oils and Biocides against Candida Albicans

Management of oral candidosis, most frequently caused by Candida albicans, is limited due to the relatively low number of antifungal drugs and the emergence of antifungal tolerance. In this study, the antifungal activity of a range of commercial essential oils, two terpenes, chlorhexidine and triclosan was evaluated against C. albicans in planktonic and biofilm form. In addition, cytotoxicity of the most promising compounds was assessed using murine fibroblasts and expressed as half maximal inhibitory concentrations (IC50). Antifungal activity was determined using a broth microdilution assay. The minimum inhibitory concentration (MIC) was established against planktonic cells cultured in a range of concentrations of the test agents. The minimal biofilm eradication concentration (MBEC) was determined by measuring re-growth of cells after pre-formed biofilm was treated for 24 h with the test agents. All tested commercial essential oils demonstrated anticandidal activity (MICs from 0.06% (v/v) to 0.4% (v/v)) against planktonic cultures, with a noticeable increase in resistance exhibited by biofilms (MBECs > 1.5% (v/v)). The IC50s of the commercial essential oils were lower than the MICs, while a one hour application of chlorhexidine was not cytotoxic at concentrations lower than the MIC. In conclusion, the tested commercial essential oils exhibit potential as therapeutic agents against C. albicans, although host cell cytotoxicity is a consideration when developing these new treatments.

Cancer risk in patients with candidiasis: a nationwide population-based cohort study

BACKGROUND

Candidiasis and certain types of cancer are related to immunocompromised status. This study aimed to evaluate whether Candida infection (CI) is associated with subsequent cancer risk in Taiwan.

METHODS

Data from the National Health Insurance system of Taiwan were used to evaluate the association between CI and cancer risk. The CI cohort comprised 34,829 patients. Each patient was randomly frequency matched with one person from the general population without CI on the basis of age, sex, year of index date of CI diagnosis, and other characteristics to generate the control group. We used Cox's proportional hazard regression analysis to estimate the effects of CI on subsequent cancer risk.

RESULTS

Compared with the control group, patients with CI had a significantly higher risk of overall cancer (adjusted hazard ratio = 1.19, 95% confidence interval = 1.09-1.30). For subsite analysis, the risks of hematologic malignancy and head and neck, pancreatic, skin, and thyroid cancers were significantly higher in the CI group. Stratified analyses by sex, age, and follow-up time revealed different patterns.

CONCLUSION

Our study suggested that CI can significantly increase overall and some individual cancer risks, which is partially compatible with previous findings.

Spectrum of Lip Lesions in a Tertiary Care Hospital: An Epidemiological Study of 3009 Indian Patients

Aim:

Large-scale population-based screening studies have identified lip lesions to be the most common oral mucosal lesions; however, few studies have been carried out to estimate the prevalence of lip lesions exclusively. The aim of present study is to highlight the diversity of lip lesions and determine their prevalence in an unbiased Indian population.

Materials and Methods:

Lip lesions were selected from 3009 patients who visited the department over a period of 3 years (January 2012 to December 2014). Age, sex, location of lip lesions, a detailed family and medical history, along with the history of any associated habit was recorded. Biopsy was carried out in necessary cases to reach a final diagnosis. The pathologies of the lip were classified based on the etiology.

Results:

Among 3009 patients, 495 (16.5%) had lip lesions ranging from 4 years to 85 years with a mean age of 39.7 years. There were 309 (62.4%) males and 185 (31.9%) females. Lower lip was the most affected region (54.1%) followed by the corner of the mouth (30.9%) and upper lip (11.7%). In 3.2% of the cases, both the lips were involved. Of the 495 lip lesions, the most common were Potentially Malignant Disorders (PMDs) (37.4%), herpes labialis (33.7%), mucocele (6.7%), angular cheilitis (6.1%), and allergic and immunologic lesions (5.7%).

Conclusion:

Lip lesions may act as an indicator for the presence of an underlying systemic disease. PMDs and infections were the most common lip lesions in the present study.

An In Vitro Model for Oral Mixed Biofilms of Candida albicans and Streptococcus gordonii in Synthetic Saliva

As a member of the normal human oral microbiota, the fungus Candida albicans is often found in association with Streptococcus gordonii, a member of dental plaque forming bacteria. Evidence suggests that S. gordonii serves as a facilitator of C. albicans adherence to dental tissues, which represents a clinically relevant problem, particularly for immunocompromised individuals that could subsequently develop fungal infections. In this study we describe the development of a relatively simple and economical in vitro model that allows for the growth of mixed bacterial/fungal biofilms in 96-well microtiter plates. We have applied this method to test and compare the growth characteristics of single and dual species biofilms in traditional microbiological media versus a synthetic saliva medium (basal medium mucin, BMM) that more closely resembles physiological conditions within the oral cavity. Results indicated a synergistic effect for the formation of biofilms when both microorganisms were seeded together under all conditions tested. The structural and architectural features of the resulting biofilms were further characterized using scanning electron microscopy and confocal scanning laser microscopy. We also performed drug susceptibility assays against single and mixed species biofilms using commonly used antifungals and antibacterial antibiotics, both in monotherapy and in combination therapy, for a direct comparison of resistance against antimicrobial treatment. As expected, mixed species biofilms displayed higher levels of resistance to antimicrobial treatment at every dose tested in both traditional media and BMM synthetic saliva, as compared to single-species biofilms.

Invitro Antifungal Evaluation of Denture Soft Liner Incorporated with Tea Tree Oil: A New Therapeutic Approach Towards Denture Stomatitis

AIM

Adherence and colonization of candida on denture soft liners is the most important contributing factor in development of denture stomatitis. This invitro study is undertaken to investigate whether the incorporation of tea tree oil into denture soft liners would inhibit the growth of candida albicans.

MATERIALS AND METHODS

Each 10 specimen disks incorporated with tea tree oil into soft liners (St) and without tea tree oil (S) were prepared. Both the tea tree oil daily. These disks were inoculated with candida albicans suspension for assessment of fungal growth and were rinsed with sterile water to remove loosely attached surface organisms. The attached yeasts were measured by inoculating them on saboraud's agar. Treated and control disks were stored in distilled water for 1, 30, 60 days and washed daily with wet cotton. Data between treated and control disks were compared by applying t-test.

RESULTS

The mean colony forming units (CFU) per mm(2) for specimens without tea tree oil after water storage and wash with wet cotton for 1, 30 and 60 days was 7.1 × 10(6), 6.5 × 10(6), 6.8 × 10(6), respectively and for specimens with tea tree oil CFU decreased significantly to 2.1 × 10(6), 2.8 × 10(6), 3.1 × 10(6) after 1, 30 and 60 days. Treated disks were effective in controlling the growth of C.albicans for two months following water storage.

CONCLUSION

Addition of tea tree oil to denture soft liner significantly reduced growth of C.albicans suggesting a new form of intra oral effective antifungal management for denture stomatitis.

The effect of antifungal agents on surface properties of poly(methyl methacrylate) and its relation to adherence of Candida albicans

PURPOSE

Candida-associated denture stomatitis is the most prevalent form of oral candidosis affecting 65% of denture wearers. Failure of therapy and recurrence of infection are not uncommon and the continuous use of antifungal agents may affect the surface properties of the denture material and may contribute to Candida adhesion. This study aimed to investigate surface properties of poly(methyl methacrylate) PMMA denture material before and after exposure to antifungal agents and its relation to in vitro adhesion of Candida albicans.

METHODS

Four groups of acrylic specimens (20 mm × 20 mm × 2.5mm) were prepared (25 specimens in each group). Specimens were immersed in nystatin (group 1), fluconazole (group 2), distilled water (group 3) and group 4 was not exposed. Specimens were tested for surface roughness, contact angle, surface hardness and in vitro Candida adherence to PMMA.

RESULTS

The results showed that nystatin had no statistically significant effect on surface hardness (P>0.05), but had a statistically significant effect on surface roughness, contact angle, and Candida adhesion to PMMA (P<0.05). On the other hand, fluconazole had no statistically significant effect on surface hardness or roughness (P>0.05), but had a statistically significant effect on contact angle, and Candida adhesion to PMMA (P<0.05). Distilled water had no statistically significant effect on surface hardness, roughness, contact angle, or Candida adhesion to PMMA (P>0.05).

CONCLUSIONS

Exposure of PMMA to nystatin may induce changes in roughness, wettability while exposure to fluconazole may affect surface free energy and therefore may increase Candida adhesion to it.

Epithelial GM-CSF induction by Candida glabrata

The main cytokine induced by the interaction of oral epithelial cells with C. glabrata is granulocyte monocyte colony-stimulating factor (GM-CSF); however, the mechanisms regulating this response are unknown. Based on previously published information on the interactions of C. albicans with oral epithelial cells, we hypothesized that interaction with viable C. glabrata triggers GM-CSF synthesis via NF-kappaB activation. We found that C. glabrata-induced GM-CSF synthesis was adhesion-dependent, enhanced by endocytosis, and required fungal viability. NF-kappaB activation was noted during interaction of epithelial cells with C. glabrata, and pre-treatment with an NF-kappaB inhibitor partly inhibited GM-CSF synthesis. Blocking TLR4 with anti-TLR4 antibody did not inhibit GM-CSF production. In contrast, an anti-CDw17 antibody triggered significant inhibition of NF-kappaB activation and GM-CSF synthesis. beta-glucans did not stimulate GM-CSF synthesis, suggesting that the CDw17/NF-kappaB/GM-CSF pathway may be beta-glucan-independent. This study provides new insights into the mechanism of GM-CSF induction by C. glabrata.

Molecular typing of clinical Candida strains using random amplified polymorphic DNA and contour-clamped homogenous electric fields electrophoresis

AIMS

This report describes an investigation into the genetic profiles of 38 Candida albicans and 19 Candida glabrata strains collected from a dental hospital of Monastir (Tunisia) and the Laboratory of Parasitology, Farhat Hached Hospital of Sousse (Tunisia), using two typing methods: random amplified polymorphic DNA (RAPD) and contour-clamped homogenous electric fields (CHEF).

METHODS AND RESULTS

The two methods (RAPD and CHEF electrophoresis) were able to identify clonal-related isolates from different patients. RAPD method using two primers (CA1 and CA2) exhibited the highest discriminatory power by discriminating 22 genotypes for C. albicans with CA1 oligonucleotides and 19 genotypes with CA2 primer. For C. glabrata, 17 genotypes were obtained when both primers CA1 and CA2 were combined. The CHEF karyotyping of C. albicans has discriminated only 17 different karyotypes.

CONCLUSION

The genotype of each isolate and genotypic difference among C. albicans and C. glabrata isolates were patient specific and not associated with the site of infection, geographic origin or date of isolation.

SIGNIFICANCE AND IMPACT OF THE STUDY

Identification of relatedness between Candida species using molecular approaches with high discriminatory power is important in determining adequate measures for interruption of transmission of this yeast.

Mucocutaneous Splendore-Hoeppli phenomenon

Splendore-Hoeppli phenomenon (asteroid bodies) is the in vivo formation of intensely eosinophilic material (radiate, star-like, asteroid or club-shaped configurations) around microorganisms (fungi, bacteria and parasites) or biologically inert substances. This study presents a literature review concerning Splendore-Hoeppli reaction in the mucocutaneous diseases. It examines the histopathological features, nature and differential diagnosis of this reaction. It also discusses the mucocutaneous infections and the non-infective diseases associated with it. Available studies indicate that several mucocutaneous infections can generate Splendore-Hoeppli reaction. The fungal infections include sporotrichosis, pityrosporum folliculitis, zygomycosis, candidiasis, aspergillosis and blastomycosis. The bacterial infections include botryomycosis, nocardiosis and actinomycosis. The parasitic conditions include orbital pythiosis, strongyloidiasis, schistosomiasis and cutaneous larva migrans. In addition, Splendore-Hoeppli reaction may be seen with non-infective pathology such as hypereosinophilic syndrome and allergic conjunctival granulomas. The Splendore-Hoeppli reaction material comprises antigen-antibody complex, tissue debris and fibrin. Although the exact nature of this reaction is unknown, it is thought to be a localized immunological response to an antigen-antibody precipitate related to fungi, parasites, bacteria or inert materials. The characteristic formation of the peribacterial or perifungal Splendore-Hoeppli reaction probably prevents phagocytosis and intracellular killing of the insulting agent leading to chronicity of infection. To conclude, Splendore-Hoeppli reaction is a tell tale of a spectrum of infections and reactive conditions. The molecular pathways involved in the development of this reaction are open for future investigations.

Reduced biocide susceptibility in Candida albicans biofilms

Candida biofilm formation is common during infection and environmental growth. We tested the impacts of three biocides (ethanol [EtOH], H(2)O(2), and sodium dodecyl sulfate) on Candida albicans, C. parapsilosis, and C. glabrata biofilms. Higher concentrations of the biocides were required for efficacy against biofilms than for efficacy against planktonic controls. A combination study with two biocides (EtOH and H(2)O(2)) and fluconazole demonstrated that the combination had enhanced efficacy.

Candida glabrata: an emerging oral opportunistic pathogen

Following the widespread use of immunosuppressive therapy and broad-spectrum antimycotic prophylaxis, C. glabrata has emerged as an important opportunistic pathogen in the oral mucosa. In the past, studies on the virulence factors and host-pathogen interactions of this organism were scarce, but continued to rise in recent years. Denture-wearing, immunosuppression, antibiotic therapy, and aging are risk factors for oral colonization or infection with C. glabrata. Compared with C. albicans, C. glabrata exhibits lower oral keratinocyte-adherence capacity, but higher denture-surface-adherence ability. The role of extracellular hydrolase production in the virulence of this organism does not appear to be as important as it is in C. albicans pathogenesis. Although traditionally thought of as a non-transforming yeast organism, both phenotypic switching and pseudohyphal formation have recently been identified in C. glabrata, but their role in pathogenesis is not known. With the exception of granulocyte monocyte colony-stimulating factor, C. glabrata triggers a lower proinflammatory cytokine response in oral epithelial cells than does C. albicans, in a strain-dependent manner. C. glabrata is less susceptible to killing by human beta-defensins than is C. albicans and exhibits various degrees of resistance to the antifungal activity of salivary histatins and mucins. In addition, C. glabrata possesses both innate and acquired resistance against antifungal drugs, due to its ability to modify ergosterol biosynthesis, mitochondrial function, or antifungal efflux. This resistance allows for its relative overgrowth over other susceptible species and may contribute to the recent emergence of C. glabrata infections in chronically immunocompromised populations. Further investigations on the virulence and host-pathogen interactions of C. glabrata are needed to better define the pathogenesis of oral C. glabrata infection in susceptible hosts.

Effect of a novel phyto-compound on mucosal candidiasis: further evidence from an ex vivo study

OBJECTIVE

To isolate, identify and determine the prevalence of yeasts in the oral cavity of individuals and to test the minimum inhibitory dilution (MID) of Kolorex against the yeasts isolated.

METHODS

Twenty-nine individuals of both sexes aged on average 61.3 years were evaluated at the dental clinic in order to isolate and identify yeasts from their oral cavity, with and without lesions, and to determine the MID of the commercial phyto-product Kolorex against the strains isolated. The antifungal activity of the product tested was determined by the technique of dilution on a solid medium. Monocyte chemoattractant protein 1 (MCP-1) was measured by biotinylated antibody assay by an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Yeasts of the genus Candida were detected in the saliva of 45.4% of the 11 individuals with a clinically healthy mouth and in 88.2% of 17 individuals with oral lesions. In the group with oral candidiasis we isolated in tongue and lesion, respectively, for each species: C. tropicalis (5.8% and 11.7%), C. glabrata (5.8% and 5.8%) and C. parapsilosis (0% and 5.8%), in addition to C. albicans as the only species or in association with others, respectively (64.7% and 70.5%). The total clonal formation unit (CFU) (counts/mL) in the saliva showed a higher mean value in the group with oral candidiasis (158.3x10(3)) than in the control group (64.6x10(3)). Most of the 70 test strains (95.7%) were sensitive to Kolorex by presenting a MID of 1:20. Sixty percent of strains from the 70 healthy sites showed results similar to those obtained with strains from oral lesions. Different results were mainly observed among different species. Patients with oral lesions showed a significant time-course increase of the level of monocyte chemoattractant protein 1 (MCP 1) as compared to those without lesions or to healthy people in whom Candida has not been detected (P<0.05). Co-culture with Kolorex using aliquots from the same patients with oral lesions inhibited such event (P<0.05).

CONCLUSION

Although this study was focused on oral cavity candidiasis, the results indicate the possibility of a broader use of the antifungal Kolorex in the prevention and treatment of mucosal candidiasis located elsewhere.

Pharmaceutical prescribing for children. Part 4. Antifungal and antiviral therapy

This is the fourth paper in a series on the prescribing of medicines for children by dentists working in primary dental care. It deals with the prescription of antifungals and antivirals for children.

Salivary gland function in HIV-infected patients treated with highly active antiretroviral therapy (HAART)

OBJECTIVE

This study was undertaken to determine if HAART alters salivary oral host defense in HIV(+) men.

STUDY DESIGN

Whole, parotid, and submandibular/sublingual saliva was collected from 39 healthy men and 147 HIV(+) patients with mild to moderate immune dysfunction (69 treated with HAART [HAART(+)]; 78 not treated [HAART(-)]). Salivary flow rates, anticandidal activities, electrolytes, and antimicrobial/antifungal proteins were determined.

RESULTS

While CD4(+) cell counts were not different between the HIV(+) groups, the median viral load for HAART(-) was 15 times greater than HAART(+). For both HAART groups, salivary yeast carriage rates and concentration were comparable and both showed similar reductions in salivary flow rates. Salivary anticandidal activities were not altered. Saliva composition of both HIV(+) groups was different from control, but only uric acid in parotid saliva of HAART(+) differed from HAART(-).

CONCLUSIONS

HAART does not adversely affect inherent salivary oral host defense in HIV(+) patients with mild to moderate immune dysfunction.