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.

Oral Candidal Infection Misdiagnosed as a Tumour

A case report on a 70-year-old male patient with atypical candidal infection on the palate that was misdiagnosed for a tumour based on clinical examination. The lesion was an accidental finding when the patient was at a registered dentist for a preventive check-up.

Oral Candidosis: Pathophysiology and Best Practice for Diagnosis, Classification, and Successful Management

Oral candidosis is the most common fungal infection that frequently occurs in patients debilitated by other diseases or conditions. No candidosis happens without a cause; hence oral candidosis has been branded as a disease of the diseased. Prior research has identified oral candidosis as a mark of systemic diseases, such as hematinic deficiency, diabetes mellitus, leukopenia, HIV/AIDS, malignancies, and carbohydrate-rich diet, drugs, or immunosuppressive conditions. An array of interaction between Candida and the host is dynamic and complex. Candida exhibits multifaceted strategies for growth, proliferation, evasion of host defenses, and survival within the host to induce fungal infection. Oral candidosis presents a variety of clinical forms, including pseudomembranous candidosis, erythematous candidosis, angular cheilitis, median rhomboid glossitis, cheilocandidosis, juxtavermillion candidosis, mucocutaneous candidosis, hyperplastic candidosis, oropharyngeal candidosis, and rare suppurative candidosis. The prognosis is usually favorable, but treatment failure or recurrence is common due to either incorrect diagnosis, missing other pathology, inability to address underlying risk factors, or inaccurate prescription of antifungal agents. In immunocompromised patients, oropharyngeal candidosis can spread to the bloodstream or upper gastrointestinal tract, leading to potentially lethal systemic candidosis. This review therefore describes oral candidosis with regard to its pathophysiology and best practice for diagnosis, practical classification, and successful management.

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.

Perception of iron deficiency from oral mucosa alterations that show a high prevalence of Candida infection

BACKGROUND/PURPOSE

Iron deficiency (ID) is the most common cause of anemia. The aim of this study was to investigate patients with oral mucosa alterations as the initial manifestation of ID or ID anemia (IDA).

METHODS

Sixty-four patients (50 IDA and 14 ID) with a wide range of sore mouth were diagnosed and treated. The oral and physical manifestations as well as iron studies and anemia classification based on the mean and heterogeneity of red cell size were assessed.

RESULTS

ID predisposed 64 patients to a high incidence of Candida infection (85%) and showed a variety of oral manifestations including angular cheilitis (63%), atrophic glossitis (AG; 59%), pseudomembranous candidosis (44%), erythematous candidosis (41%), median rhomboid glossitis (5%), chronic mucocutaneous candidosis (5%), papillary hyperplastic candidosis (3%), and cheilocandidosis (3%). Others included pale oral mucosa (31%), burning mouth (28%), and recurrent oral ulcers (6%). Colorectal cancers in two patients were diagnosed. The values of hemoglobin (Hb) in 64 ID patients varied from normal to life-threatening levels, but none had developed advanced systemic symptoms except fatigue. All had low serum iron and ferritin. Sixty (94%) patients had transferrin saturation < 16%; however, 19 (30%) patients remained normocytic and 14 (22%) patients were nonanemic.

CONCLUSION

The study demonstrates that oral mucosa alterations accompanying oral candidosis are a sensitive indicator of ID. All oral changes can be successfully ameliorated by iron therapy plus antifungals when candidosis exists. Investigating the origin of IDA is necessary, because it may be the first sign of a more serious disease, particularly malignancy.

Sensitivity of clinical isolates of Candida to essential oils from Burseraceae family

The aim of this study was to investigate the chemical composition and antifungal activity of four commercial essential oils from the Burseraceae family - two Boswellia carterii Flueck oils, Canarium luzonicum (Blume) A. Gray oil, and Commiphora myrrha (Nees) Engl oil, against most common Candida spp. recovered from the human oral cavity. The essential oil samples were analyzed by GC-FID and GC/MS. The analysis showed that major essential oils' components were α-pinene (23.04 % and 31.84 %), limonene (45.62 %) and curzerene (34.65 %), respectively. Minimum inhibitory (MIC) and minimum fungicidal (MFC) concentrations were determined using a microdilution standardized technique. All tested Candida spp. clinical isolates and ATCC strains showed susceptibility to tested essential oils in a dose dependent manner. The strongest antifungal activity was shown by essential oil of B. carterii, sample 2; the average MIC values ranged from 1.25 to 1.34 mg/ml, and MFC values ranged from 2.50 to 3.75 mg/ml, depending on the fungus. This study supports the possible use of essential oils from the Bursecaceae family in reduction and elimination of Candida spp. populations in patients with oral cavity fungal infections.

Clinical Appearance of Oral Candida Infection and Therapeutic Strategies

Candida species present both as commensals and opportunistic pathogens of the oral cavity. For decades, it has enthralled the clinicians to investigate its pathogenicity and to improvise newer therapeutic regimens based on the updated molecular research. Candida is readily isolated from the oral cavity, but simple carriage does not predictably result in development of an infection. Whether it remains as a commensal, or transmutes into a pathogen, is usually determined by pre-existing or associated variations in the host immune system. The candida infections may range from non-life threatening superficial mucocutaneous disorders to invasive disseminated disease involving multiple organs. In fact, with the increase in number of AIDS cases, there is a resurgence of less common forms of oral candida infections. The treatment after confirmation of the diagnosis should include recognizing and eliminating the underlying causes such as ill-fitting oral appliances, history of medications (antibiotics, corticosteroids, etc.), immunological and endocrine disorders, nutritional deficiency states and prolonged hospitalization. Treatment with appropriate topical antifungal agents such as amphotericin, nystatin, or miconazole usually resolves the symptoms of superficial infection. Occasionally, administration of systemic antifungal agents may be necessary in immunocompromised patients, the selection of which should be based upon history of recent azole exposure, a history of intolerance to an antifungal agent, the dominant Candida species and current susceptibility data.

Impact of brief and sequential exposure to nystatin, amphotericin B, ketoconazole, and fluconazole in modulating adhesion traits of oral Candida dubliniensis isolates

AIM

Candida adherence is implicated in the pathogenesis of oral candidosis. Adhesion to buccal epithelial cells (BEC), germ tube (GT) formation, and relative cell surface hydrophobicity (CSH) are colonization attributes of candidal pathogenicity. Candida dubliniensis (C. dubliniensis) is allied with recurrent oral candidosis, which can be treated with nystatin, amphotericin B, ketoconazole, and fluconazole. Due to the diluent effect of saliva and the cleansing effect of the oral musculature in the oral cavity C. dubliniensis isolates undergo brief and sequential exposure to antifungal agents during therapy. Thus, in the present study, we evaluated the adhesion to BEC, GT formation, and the CSH of oral isolates of C. dubliniensis following brief and sequential exposure to nystatin, amphotericin B, ketoconazole, and fluconazole.

METHODS

After determining the minimum inhibitory concentration (MIC) of the aforementioned drugs, 20 oral isolates of C. dubliniensis were briefly (1 h), and sequentially (10 days) exposed to subcidal concentrations of these drugs. Following drug removal, adhesion to BEC, GT formation, and CSH of these isolates were determined.

RESULTS

The percentage reduction of adhesion to BEC, GT formation, and CSH of the isolates following exposure to antifungal agents were as follows: nystatin: 53.55%, 33.98%, and 29.83% (P < 0.001); amphotericin B: 53.84%, 36.23%, and 28.97% (P < 0.001); ketoconazole: 37.43%, 20.51%, and 16.49% (P < 0.001); and fluconazole: 8.93% (P < 0.001), 1.6%, and 0.63% (P > 0.05).

CONCLUSIONS

Brief and sequential exposure of C. dubliniensis to antifungal agents would continue to wield an antifungal effect by altering its adhesion attributes, and elucidate possible pharmacodynamics by which antifungal agents might operate in modulating candidal adherence.

Fermentative 2-carbon metabolism produces carcinogenic levels of acetaldehyde in Candida albicans

Acetaldehyde is a carcinogenic product of alcohol fermentation and metabolism in microbes associated with cancers of the upper digestive tract. In yeast acetaldehyde is a by-product of the pyruvate bypass that converts pyruvate into acetyl-Coenzyme A (CoA) during fermentation.

THE AIMS OF OUR STUDY WERE

(i) to determine the levels of acetaldehyde produced by Candida albicans in the presence of glucose in low oxygen tension in vitro; (ii) to analyse the expression levels of genes involved in the pyruvate-bypass and acetaldehyde production; and (iii) to analyse whether any correlations exist between acetaldehyde levels, alcohol dehydrogenase enzyme activity or expression of the genes involved in the pyruvate-bypass. Candida albicans strains were isolated from patients with oral squamous cell carcinoma (n = 5), autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) patients with chronic oral candidosis (n = 5), and control patients (n = 5). The acetaldehyde and ethanol production by these isolates grown under low oxygen tension in the presence of glucose was determined, and the expression of alcohol dehydrogenase (ADH1 and ADH2), pyruvate decarboxylase (PDC11), aldehyde dehydrogenase (ALD6) and acetyl-CoA synthetase (ACS1 and ACS2) and Adh enzyme activity were analysed. The C. albicans isolates produced high levels of acetaldehyde from glucose under low oxygen tension. The acetaldehyde levels did not correlate with the expression of ADH1, ADH2 or PDC11 but correlated with the expression of down-stream genes ALD6 and ACS1. Significant differences in the gene expressions were measured between strains isolated from different patient groups. Under low oxygen tension ALD6 and ACS1, instead of ADH1 or ADH2, appear the most reliable indicators of candidal acetaldehyde production from glucose.

Oropharyngeal candidosis relative frequency in radiotherapy patient for head and neck cancer

Background:

Radiation given during treatment of oral and pharyngeal malignancy frequently causes alteration of the oral environment predisposing to the colonization of the oral mucosa by yeast species most frequently Candida.

Objective:

Thus, this study was undertaken in 107 patients to find out association between radiation therapy and frequency of oropharyngeal candidosis, to quantitate colony forming units (CFUs) to identify Candida at species level and to check the incidence of serotype A and B in C. albicans.

Materials and Methods:

The study was done on patients suffering from oropharyngeal cancer who were advised radiotherapy. The oral rinse collection method was used to collect the sample. Sabourauds Dextrose Agar (SDA) was used as primary culture media and subsequently speciation was done using standard techniques. The strains of C. albicans were serotyped employing the method described by Hansclever and Mitchell (1961, J Bacteriol 1961;82:570-3).

Results:

26.16% patients were mycologically positive for candida before radiotherapy with CFUs 100. 14 ± 59.11 that increased to 60.74% patients during radiotherapy with an increase in CFUs to 490.15 ± 207.97. Clinically, grading of mucositis was done and also individual signs and symptoms were noted in each patient. The occurrence of erythmatous lesions, ulceration, and xerostomia were found to be statistically significant (P<0.05). C. albicans was the most frequently encountered species with higher prevalence of serotype A suggesting higher virulent species.

Conclusion:

It is proposed that in such patients taking radiotherapy prophylactic antifungal treatment should be given specially in patients showing development of oral mucosal lesions such as erythmatous lesions, ulcerations, and complaining about dryness of mouth, that is, xerostomia irrespective of presence or absence of clinical oral candidosis.

Antifungal, cytotoxic, and immunomodulatory properties of tea tree oil and its derivative components: potential role in management of oral candidosis in cancer patients

Candida albicans forms oral biofilms that cause disease and are difficult to treat with conventional antifungal agents. Tea tree oil (TTO) is a natural compound with reported antimicrobial and immunomodulatory activities. The aims of the study were to evaluate the antifungal efficacy of TTO and key derivatives against C. albicans biofilms, to assess the toxicological effects of TTO on a clinically relevant oral cell line, and to investigate its impact on inflammation. TTO and its derivatives were examined against 100 clinical strains of C. albicans. Planktonic minimum inhibitory concentrations (MICs) were determined using the CLSI M-27A broth microdilution method. Sessile MICs were determined using an XTT reduction assay. Inhibition, time-kill, and mode of action studies were performed. OKF6-TERT2 epithelial cells were used for cytotoxicity and cytokine expression assays. Planktonic C. albicans isolates were susceptible to TTO, terpinen-4-ol (T-4-ol), and α-terpineol, with an MIC₅₀ of 0.5, 0.25, and 0.25%, respectively. These three compounds also displayed potent activity against the 69 biofilm-forming strains, of which T-4-ol and α-terpineol displayed rapid kill kinetics. For all three compounds, 1 × MIC₅₀ effectively inhibited biofilm growth when C. albicans were treated at 0, 1, and 2 h post adhesion. By scanning electron microscopy analysis and PI uptake, TTO and derivative components were shown to be cell membrane active. TTO and T-4-ol were cytotoxic at 1 × MIC₅₀, whereas at 0.5 × MIC₅₀ T-4-ol displayed no significant toxicity. Transcript and protein analysis showed a reduction of IL-8 when treated with TTO and T-4-ol. These data provide further in vitro evidence that TTO and its derivative components, specifically T-4-ol, exhibit strong antimicrobial properties against fungal biofilms. T-4-ol has safety advantages over the complete essential oil and may be suitable for prophylaxis and treatment of established oropharyngeal candidosis. A clinical trial of T-4-ol is worthy of consideration.

Pathogenesis and treatment of oral candidosis

Oral infections caused by yeast of the genus Candida and particularly Candida albicans (oral candidoses) have been recognised throughout recorded history. However, since the 1980s a clear surge of interest and associated research into these infections have occurred. This has largely been due to an increased incidence of oral candidosis over this period, primarily because of the escalation in HIV-infection and the AIDS epidemic. In addition, changes in medical practice leading to a greater use of invasive clinical procedures and a more widespread use of immunosuppressive therapies have also contributed to the problem. Whilst oral candidosis has previously been considered to be a disease mainly of the elderly and very young, its occurrence throughout the general population is now recognised. Candida are true ‘opportunistic pathogens’ and only instigate oral infection when there is an underlying predisposing condition in the host. Treatment of these infections has continued (and in some regards continues) to be problematic because of the potential toxicity of traditional antifungal agents against host cells. The problem has been compounded by the emergence of Candida species other than C. albicans that have inherent resistance against traditional antifungals. The aim of this review is to give the reader a contemporary overview of oral candidosis, the organisms involved, and the management strategies that are currently employed or could be utilised in the future.

Double-layered mucoadhesive tablets containing nystatin

The objective of this work was to design a mucoadhesive tablet with a potential use in the treatment of oral candidosis. A 2-layered tablet containing nystatin was formulated. Lactose CD (direct compression), carbomer (CB), and hydroxypropylmethylcellulose (HPMC) were used as excipients. Tablets were obtained through direct compression. Properties such as in vitro mucoadhesion, water uptake, front movements, and drug release were evaluated. The immediate release layer was made of lactose CD (100 mg) and nystatin (30 mg). The CB:HPMC 9:1 mixture showed the best mucoadhesion properties and was selected as excipient for the mucoadhesive polymeric layer (200 mg). The incorporation of nystatin (33.3 mg) in this layer affected the water uptake, which, in turn, modified the erosion front behavior. Nystatin showed a first-order release. The polymeric layer presented an anomalous kinetic (n = 0.82) when this layer was individually evaluated. The mucoadhesive tablet formulated in this work releases nystatin quickly from the lactose layer and then in a sustained way, during approximately 6 hours, from the polymeric layer. The mixture CB:HPMC 9:1 showed good in vitro mucoadhesion. A swelling-diffusion process modulates the release of nystatin from this layer. A non-Fickian (anomalous) kinetic was observed.