Uncommon opportunistic fungal infections of oral cavity: A review

Alginate Extracted from Azotobacter chroococcum Loaded in Selenium Nanoparticles: Insight on Characterization, Antifungal and Anticancer Activities

Cancer is a threatening disease that needs strong therapy with fewer side effects. A lot of different types of chemotherapy or chemo-drugs are used in cancer treatments but have many side effects. The increasing number of antibiotic-resistant microorganisms requires more study of new antimicrobial compounds and delivery and targeting strategies. This work aims to isolate and identify Azotobacter sp., and extract alginate from Azotobacter sp. As well as fabricating selenium nanoparticles using ascorbic acid as reducing agent (As/Se-NPs), and loading extracted alginate with selenium nanoparticles (Alg-Se-NCMs). The As/Se-NPs and Alg-Se-NCMs were categorized by TEM, EDX, UV-Vis spectrophotometry, FT-IR, and zeta potential. The antifungal activities of both As/Se-NPs and Alg-Se-NCMs were investigated against some human pathogen fungi that cause skin infection such as Aspergillus niger (RCMB 002005), Aspergillus fumigatus (RCMB 002008), Cryptococcus neoformans (RCMB 0049001), Candida albicans (RCMB 005003), and Penicillium marneffei (RCMB 001002). The anticancer activities were determined against HCT-116 colorectal cancer and Hep G2 human liver cancer cells. UV spectra of As/Se-NPs and Alg-Se-NCMs confirmed a surface plasmon resonance at 269 and 296 nm, and zeta potential has negative charges -37.2 and -38.7 mV,. Both As/Se-NPs and Alg-Se-NCMs were hexagonal, size ranging from 16.52 to 97.06 and 17.29 to 44.2. Alg-Se-NCMs had anticancer activities against HCT-116 and HepG2. The Alg-Se-NCMs possessed the highest antifungal activities against Cryptococcus neoformans, followed by Aspergillus niger, but did not possess any activities against Penicillium marneffei. Alginate-capped selenium nanoparticles can be used as antifungal and anticancer treatments.

Comparative Evaluation of Anti-microbial Activity of Herbal, Homeopathic, and Conventional Dentifrices Against Oral Microflora Using the Disc Diffusion Method: An In Vitro Study

Aim To assess the antimicrobial activity of herbal, homeopathic, and conventional dentifrices against oral microorganisms. Methodology Mueller Hilton agar was used to cultivate distinct strains of Streptococcus mutans and Enterococcus faecalis, whereas Candida albicans was cultured on a potato dextrose agar medium. Diffusion ratios of 1:5, 1:10, and 1:15 were obtained by diluting 1 gram of each dentifrice (KP Namboodiri, Homeodent, and Colgate Strong Teeth) in 4 ml, 9 ml, and 14 ml of distilled water, respectively. The culture medium was filled with sterile discs. Twenty μl of each dilution of prepared dentifrice formulations were incorporated using a micropipette. The agar plates were incubated for 24 hours at 37ºC. Result The findings indicate that there was a higher zone of inhibition against Streptococcus mutans with herbal dentifrice at 10 mm, 8 mm, and 6.5 mm, followed by conventional dentifrice at 10 mm, 7.5 mm, and 7 mm, and the lowest with homeopathic dentifrice at 8 mm, 7 mm, and 7 mm at 1:5, 1:10 and 1:15 dilutions, respectively. Conventional dentifrice was found to inhibit Enterococcus faecalis at 9 mm, 8 mm, and 7 mm with 1:5, 1:10, and 1:15 dilutions followed by herbal dentifrice at 9 mm, 7 mm with 1:5, 1:10 dilutions, and no inhibition at 1:15 dilution. In contrast, homeopathic dentifrice displayed no inhibition at 1:5, 1:10, and 1:15 dilutions. Neither homeopathic nor conventional dentifrices inhibited Candida albicans, but herbal dentifrices showed a 10 mm zone of inhibition at 1:10 dilution. Conclusion Conventional and herbal dentifrices were found to be more effective against Streptococcus mutans than the homeopathic dentifrice used in the study, whereas herbal dentifrice was more effective against Candida albicans when compared to conventional and homeopathic dentifrices.

Drug-resistant oral candidiasis in patients with HIV infection: a systematic review and meta-analysis

BACKGROUND

Oral candidiasis (OC) is a prevalent opportunistic infection in patients with human immunodeficiency virus (HIV) infection. The increasing resistance to antifungal agents in HIV-positive individuals suffering from OC raised concerns. Thus, this study aimed to investigate the prevalence of drug-resistant OC in HIV-positive patients.

METHODS

Pubmed, Web of Science, Scopus, and Embase databases were systematically searched for eligible articles up to November 30, 2023. Studies reporting resistance to antifungal agents in Candida species isolated from HIV-positive patients with OC were included. Baseline characteristics, clinical features, isolated Candida species, and antifungal resistance were independently extracted by two reviewers. The pooled prevalence with a 95% confidence interval (CI) was calculated using the random effect model or fixed effect model.

RESULTS

Out of the 1942 records, 25 studies consisting of 2564 Candida species entered the meta-analysis. The pooled prevalence of resistance to the antifungal agents was as follows: ketoconazole (25.5%, 95% CI: 15.1-35.8%), fluconazole (24.8%, 95% CI: 17.4-32.1%), 5-Flucytosine (22.9%, 95% CI: -13.7-59.6%), itraconazole (20.0%, 95% CI: 10.0-26.0%), voriconazole (20.0%, 95% CI: 1.9-38.0%), miconazole (15.0%, 95% CI: 5.1-26.0%), clotrimazole (13.4%, 95% CI: 2.3-24.5%), nystatin (4.9%, 95% CI: -0.05-10.3%), amphotericin B (2.9%, 95% CI: 0.5-5.3%), and caspofungin (0.1%, 95% CI: -0.3-0.6%). Furthermore, there were high heterogeneities among almost all included studies regarding the resistance to different antifungal agents (I2 > 50.00%, P < 0.01), except for caspofungin (I2 = 0.00%, P = 0.65).

CONCLUSIONS

Our research revealed that a significant number of Candida species found in HIV-positive patients with OC were resistant to azoles and 5-fluocytosine. However, most of the isolates were susceptible to nystatin, amphotericin B, and caspofungin. This suggests that initial treatments for OC, such as azoles, may not be effective. In such cases, healthcare providers may need to consider prescribing alternative treatments like polyenes and caspofungin.

REGISTRATION

The study protocol was registered in the International Prospective Register of Systematic Reviews as PROSPERO (Number: CRD42024497963).

Insights into the antioxidant, anti-inflammatory and anti-microbial potential of Nigella sativa essential oil against oral pathogens

Oral disorders can exert systemic ramifications beyond their localized effects on dental tissues, implicating a wide array of physiological conditions. The utilization of essential oils (EOs) for protection of oral health represents a longstanding practice. Consequently, in this investigation, essential oil derived from Nigella sativa seeds (NSEO) underwent isolation via the hydro-distillation process, followed by a comprehensive evaluation of its antioxidant, anti-inflammatory, anti-fungal, antibacterial activities, and cytocompatibility. The isolated NSEO manifested as a pale-yellow substance and was found to harbor a diverse spectrum of bioactive constituents, including steroids, triterpenoids, flavonoids, phenols, proteins, alkaloids, tannin, sesquiterpenoid hydrocarbons, monoterpenoid alcohol, and monoterpenoid ketone (thymoquinone). Notably, the total phenolic content (TPC) and total flavonoid content (TFC) of NSEO were quantified at 641.23 μg GAE/gm and 442.25 μg QE/g, respectively. Furthermore, NSEO exhibited concentration-dependent inhibition of protein denaturation, HRBC membrane stabilization, and hemolysis inhibition. Comparative analysis revealed that NSEO and chlorhexidine (CHX) 0.2% displayed substantial inhibition of hemolysis compared to aspirin. While NSEO and CHX 0.2% demonstrated analogous antibacterial activity against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, NSEO showcased heightened efficacy against Lactobacillus acidophilus and Candida albicans. Additionally, NSEO exhibited pronounced effects against periodontal pathogens such as Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Prevotella intermedia. Importantly, no cytotoxicity was observed on human gingival fibroblast cell lines. These findings underscore the potential of NSEO as a potent antibacterial and antifungal agent in the management of oral microbial pathogens, thereby offering avenues for the development of innovative therapies targeting diverse oral inflammatory conditions. Nevertheless, further investigations are imperative to unlock its full therapeutic repertoire.

Osteomyelitis of Jaw Bone due to Aspergillosis in Post-COVID-19 Patients: An Observational Study

Background

In the second wave of COVID-19 pandemic, there has been an increase in number of cases with Post-COVID-19 fungal osteomyelitis of jaws. Aspergillosis was found to be one of the causes of osteomyelitis of jaw bones in these patients.

Aim

To evaluate the incidence and pattern of osteomyelitis of jaw due to aspergillosis in post-COVID-19 patients and to discuss the management protocol of the same.

Method

Data were obtained at our institution from the period of January 2021 to June 2021. Patients of all age groups with Post-COVID-19 osteomyelitis of jaw due to aspergillosis and those with combined aspergillosis and mucormycosis infection were included. Patients having rhino-orbito-cerebral fungal infection were excluded.

Results

A total of 47 patients reported to our center. Demographically the average age of the patients was 49.11 years with 72% being males. All 47 patients (N = 100%) had received steroids. 21 of them (N = 44.7%) had diabetes mellitus and 14 (N = 29.8%) patients had other comorbidities. Out of 47 patients, 42 (N = 89.7%) patients were diagnosed with aspergillosis and the remaining 5 (N = 10.3%) cases had a mixed fungal infection of mucormycosis and aspergillosis. On fungal culture Aspergillus flavus was the most common species detected followed by Aspergillus niger and Aspergillus fumigatus. All patients were treated with oral Voriconazole and local surgical debridement. Prompt laboratory testing such as a timely KOH mount, galactomannan test, beta-D-glucan test, histopathology of tissue specimens could help to give an early and definitive diagnosis. The mortality rate we encountered in this study was nil.

Conclusions

Early and definitive diagnosis and immediate initiation of antifungal drug therapy and surgical intervention will significantly reduce the rate of morbidity and mortality.

Exploring the diversity of uncommon oral yeast species and associated risk factors among substance abusers in southwestern Iran

Yeast species are a group of coexistent microorganisms in the oral cavity that can cause opportunistic infections in vulnerable individuals, including addicts. This study aimed to identify the yeast species profile responsible for oral yeast colonization (OYC) and the associated risk factors in patients with substance use disorder (SUD) in Ahvaz, Iran. Oral samples were collected from drug users hospitalized in 12 addiction treatment centers, and the related clinical information was mined. Oral yeast species were identified using 21-plex PCR and sequencing of the internal transcribed spacer region (ITS1-5.8S-ITS2). A total of 244 yeast strains were identified from 245 individuals with substance abuse. Candida albicans was the most common species (37.7%) and non-albicans Candida was responsible for 57.7% of OYC, primarily C. dubliniensis (33.2%) and C. glabrata (11.9%). Moreover, uncommon oral yeasts constituted 5.3% of species, including Saccharomyces cerevisiae, Clavispora lusitaniae, Pichia kluyveri, Geotrichum candidum, Magnusiomyces capitatus, Hanseniospora opuntiae, Wickerhamomyces subpelliculosus, Trichosporon asahii, and Aureobasidium pullulans. Importantly, OYC exhibited associations with such factors as duration of drug use, daily drug consumption rate, opioid utilization, oral drug administration, and the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) score. The present study is the pioneering investigation revealing the prevalence and diversity of oral yeast species, along with associated risk factors, in individuals with SUD in southwestern Iran. Furthermore, it underscores the importance of developing efficient and cost-effective diagnostic methods tailored for resource-constrained settings.

Candida lusitaniae, an Emerging Opportunistic Pathogen in Immunocompetent Populations: A Case Report

Candida lusitaniae is an emerging opportunistic pathogen in immunocompromised hosts and hospitalized patients. However, the incidence is low in immunocompetent hosts. Because of their characteristic similarities, C. lusitaniae may be confused with other fungal species, such as Candida tropicalis, Candida parapsilosis, and even Saccharomyces cerevisiae. Recently reported cases of serious infections caused by C. lusitaniae have proven detrimental, and some cases reported amphotericin resistance. Here, we present a case report of empyema caused by C. lusitaniae in an immunocompetent patient who was admitted to the intensive care unit and intubated for acute hypoxic respiratory failure. This case demonstrates the importance of recognizing this organism and initiating early treatment for the prevention of fatal complications.

Phenotypic Characterization of Oral Mucor Species from Eurasian Vultures: Pathogenic Potential and Antimicrobial Ability

Due to poisoning and decline in the food resources of Eurasian vultures, there has been a rise in the number of Griffon (Gyps fulvus) and Cinereous vultures (Aegypius monachus) needing veterinary care. In captivity, vultures often develop oral and other infectious diseases which can affect their survival and the probability of reintroduction in the wild. Therefore, it is important to characterize relevant microbial species present in the oral cavity of vultures, such as Mucor spp. In this work, seven Mucor spp. isolates previously obtained from Gyps fulvus and Aegypius monachus oral swabs collected at two rehabilitation centers in Portugal were characterized regarding their pathogenic enzymatic profile and antimicrobial activity. Isolates were identified by macro and microscopic observation, and PCR and ITS sequencing. Their antimicrobial activity was determined using a collection of pathogenic bacteria and two yeast species. Results showed that 86% of the isolates produced α-hemolysis, 71% expressed DNase, 57% produce lecithinase and lipase, 29% expressed gelatinase, and 29% were biofilm producers. Four isolates showed inhibitory activity against relevant human and veterinary clinical isolates, including Escherichia coli, Enterococcus faecium, Neisseria zoodegmatis, and Staphylococcus aureus. In conclusion, accurate management programs should consider the benefits and disadvantages of Mucor spp. presence in the oral mucosa.

Altered oral microbiome in Sudanese Toombak smokeless tobacco users carries a newly emerging risk of squamous cell carcinoma development and progression

There are an estimated 6-10 million smokeless tobacco (Toombak) users in Sudan, the majority being males. Toombak is known to be a carcinogenic product that is likely to modify the oral microbiome spatiality into a high-risk potential for the development and progression of oral cancer, but previous studies are lacking in this field. Here, we endeavour for the first time the exploration of the oral microbiome in key mucosal areas of the oral cavity and assess the microbiome variations in premalignant and oral squamous cell carcinoma (OSCC) samples from both users and non-users of Toombak. 16S rRNA sequencing was performed on DNA obtained from pooled saliva, oral mucosa and supragingival plaque from 78 Sudanese users and non-users of Toombak, aged between 20 and 70 years. In 32 of the pooled saliva samples, the mycobiome (fungal) environment was analysed through ITS sequencing. Then, 46 formalin-fixed paraffin-embedded samples of premalignant and OSCC samples were collected, and their associated microbiomes sequenced. The oral Sudanese microbiome was found to be enriched in Streptococcaceae, but Staphylococcaceae were significantly more abundant amongst Toombak users. Genera enriched in the oral cavity of Toombak users included Corynebacterium_1 and Cardiobacterium while in non-users, Prevotella, Lactobacillus and Bifidobacterium were prominent. Aspergillus was the most abundant fungus in the mouths of Toombak users with a marked loss of Candida. The genus Corynebacterium_1 was abundant in the buccal, floor of the mouth and saliva microbiomes as well as in oral cancer samples from Toombak users indicating a possible role for this genus in the early stages of oral cancer development. An oral cancer microbiome that favours poor survival and metastasis in those who use Toombak also emerged that includes the genera Stenotrophomonas and Schlegelella. Those utilising Toombak carry an altered oral microbiome that may be an additional risk factor for this products carcinogenicity to the oral structures. These significant microbiome modulations are a newly emerging key driving factor in oral cancer development and progression in Toombak users while it is also shown that Toombak users carry an oral cancer microbiome that may increase the potential for a poorer prognosis.

An Unconventional Oral Candidiasis in an Immunocompetent Patient

Oral candidiasis (OC) is an opportunistic fungal infection of the oral mucosae, sustained by Candida albicans or other non-albican Candida species (NAC), usually eradicated by conventional antifungals of the classes of azoles, polyenes, or derivative from echinocandins. OC usually occurs under predisposing local or systemic factors. C. lusitaniae is an opportunistic strain that is rarely responsible for human infection and occurs mainly in severe immunocompromised states. The present work reported an unconventional case of OC in an otherwise healthy immunocompetent woman sustained by C. lusitaniae and a multi-resistant strain of C. albicans.

A retrospective analysis for the management of oromaxillofacial invasive mucormycosis and systematic literature review

PURPOSE

Mucormycosis is a type of fatal infectious disease, rarely involved in the oromaxillofacial region. This study aimed to describe a series of 7 cases with oromaxillofacial mucormycosis and to discuss the epidemiology, clinical features, and treatment algorithm thereof.

METHODOLOGY

Seven patients in the author's affiliation have been treated. They were assessed and presented as per their diagnostic criteria, surgical approach, and mortality rates. Reported cases of mucormycosis originally happened in craniomaxillofacial region were synthesized through a systematic review so as to better discuss its pathogenesis, epidemiology, and management.

RESULTS

Six patients had a primary metabolic disorder, and one immunocompromised patient had a history of aplastic anemia. The criteria for a positive diagnosis of invasive mucormycosis were based on clinical presentation of signs and symptoms, and a biopsy for microbiological culture and histopathologic analysis. Each patient used antifungal drugs and five of them also underwent surgical resection at the same time. Four patients died due to the unregulated spread of mucormycosis, and one patient died owing to her main disease.

CONCLUSIONS

Although uncommon in clinical practice setting, mucormycosis should be of great concern in oral and maxillofacial surgery, due to the life-threatening possibility of this disease. The knowledge of early diagnosis and prompt treatment is of utmost importance for saving lives.

Prophylaxis of Antifungal Drugs against Systemic Fungemia induced by Oral Candidiasis in Mice

Oral mucositis is highly prevalent among the elderly, for whom oral care is often difficult. Oral mucositis, such as candidiasis, can induce systemic fungemia. Antifungal prophylaxis may be useful in such cases to prevent systemic fungemia; however, studies on this are limited. The objective of this study was to demonstrate the effectiveness of antifungal prophylaxis to prevent systemic Candida dissemination compared to oral care using a mice model. Oral candidiasis was induced using chemotherapy and inoculation with C. albicans in 8-week-old male mice. Group A was given oral care, Group B was orally administered an antifungal drug, Group C was intravenously administered an antifungal drug, and Group D was used as the negative control group. Macroscopic features of the tongue surface, colony forming units (CFU) on the tongue, and blood culture for C. albicans were evaluated. CFU was significantly higher in Group A than in Groups B and C. The oral care group, but not the groups administered antifungal agents, showed significantly higher positive numbers of animals with C. albicans in the blood as compared to the control group, indicating the effectiveness of antifungal prophylaxis over oral care. Antifungal prophylaxis may be an option for the prevention of systemic fungemia in individuals with difficulty in oral care.

Non-radiation and non-drug-induced maxillary osteomyelitis: Study of underlying risk factors, presentation, management and treatment outcomes

Background

Osteomyelitis of the jawbone is mostly secondary to radiation exposure or bone remodelling drugs, with the mandible being commonly involved. Maxillary osteomyelitis risk is low owing to its high vascularity. This study was undertaken to evaluate risk factors, presentation, management and outcomes of maxillary osteomyelitis caused due to reasons other than irradiation and bone remodelling drugs.

Methods

Patient records diagnosed with maxillary osteomyelitis were evaluated for demographic details, risk factors, clinical presentation, radiological features, treatment performed and outcomes.

Results

In 38 patients with non-irradiated and non-drug-induced osteomyelitis, 13 involved the maxilla, seven were localized to the posterior maxilla and 10 showed paranasal sinus involvement. Dissemination to the cavernous sinus and cerebral spread was seen in one. Clinical findings included oroantral communication, pain and draining sinus. Imaging showed diffuse bone destruction areas with or without evidence of bony sequestrum. The most common systemic risk factor was diabetes mellitus. Maxillary osteomyelitis was associated with tooth extraction in eight cases. Surgical management included debridement, sequestrectomy, functional endoscopic sinus surgery, maxillectomy and reconstruction of soft tissue defect with local and regional flaps. Complete recovery was seen in 11 patients. Mortality was seen in two patients with mucormycosis having disseminated infection.

Conclusion

Compared with previous literature, a relatively higher ratio of maxillary involvement was reported. Diabetes mellitus was the most common risk factor, followed by osteopetrosis and tooth extraction. Osteomyelitis secondary to mucormycosis in immunocompetent patients was relatively localized and gave favourable response to management compared with patients with diabetes mellitus.

Evaluation of Candidiasis in Upper-Aerodigestive Squamous Cell Carcinoma Patients—A Clinico-Mycological Aspect

Candida is a commensal yeast. It can be infective when the host’s defense mechanism is weakened, as in the case of squamous cell carcinoma patients. We aimed to evaluate the prevalence and clinical mycological manifestation of candidiasis in 150 cancer cases comprised of preoperative and post-operative (with or without radiotherapy) upper aerodigestive squamous cell carcinoma. A total of 150 patients suffering from squamous cell carcinoma of the Upper Aero-Digestive Tract (UADT) were divided into preoperative (n = 48), post-operative without radiotherapy (n = 29) and post-operative with radiotherapy (n = 73). Samples were collected using cotton swabs and cultured. Candida species were identified according to color pigmentation on Candida Differential Agar (CDA) plate. The clinico-mycological association of patients was evaluated by the chi-square test, and 98 out of 150 patients showed the presence of various Candida species. The major species isolated was Candida albicans (53%), followed by Candida tropicalis (16%). There was a significant statistical difference between patients who showed mycological associations and patients who did not have any such association (p = 0.0008). The prevalence of oral candidiasis was found to be 65.33% among total cases of upper aero-digestive squamous cell carcinoma. Chronic erythematous cases of candidiasis were mainly seen in preoperative squamous cell carcinoma cases, whereas the acute erythematous type of candidiasis was mainly seen in post-operative cases who received radiotherapy. The clinicomycological assessment can help to correlate the signs and symptoms with the presence of candidiasis in upper aerodigestive squamous cell carcinoma patients. Meticulous testing and examination can help in the early detection of candidiasis. Future studies are needed to develop advance scientific preventive strategies for high-risk cases.

Aspergillosis by cryptic Aspergillus species: A case series and review of the literature

BACKGROUND

The cryptic Aspegillus species are rare, these microorganisms are usually more resistant to common antifungal therapies. Therefore, a correct identification is important when evaluating the impact of such species in aspergillosis.

AIMS

We aimed to describe the frequency, clinical and microbiological characteristics, and the outcomes of those cases of aspergillosis caused by cryptic species in a tertiary hospital.

METHODS

We retrospectively identified all microbiologically documented cases of aspergillosis between January 2013 and December 2018. Definitive species identification of clinically significant isolates was achieved via sequencing methods. The polymerase chain reaction (PCR) products were sequenced, and the results obtained were compared to sequences deposited in GenBank. Antifungal susceptibility testing was performed using the Sensititre® YeastOne® panel.

RESULTS

A total of 679 Aspergillus isolates were recovered from 489 patients, of which 109 were clinically relevant. Ten (9.2%) isolates were identified as cryptic species: Aspergillus arcoverdensis (2), Aspergillus lentulus (2), Aspergillus ellipticus (2), Aspergillus alliaceus (1), Aspergillus nomius (1), Aspergillus tubingensis (1) and Aspergillus montevidensis (1). Most patients already suffered some type of immunosuppression. Half of these patients had required intensive care before the infection showed up, and most of them had a pulmonary infection. Mortality at the 100-day follow-up was 40%. Antifungal susceptibility testing was performed on three of the isolates (A. arcoverdensis, A. tubingensis and A. nomius), which showed high minimum inhibitory concentrations (MIC) for azoles and amphotericin B.

CONCLUSIONS

The frequency of cryptic species in our centre was 9.2%. Most patients had some degree of immunosuppression, and the mortality rate was 40%.

Alternate Special Stains for the Detection of Mycotic Organisms in Oral Cyto-Smears-A Histomorphometric Study

In the wake of the COVID-19 pandemic, fungal infections of the maxillofacial region have become prevalent, making their accurate diagnosis vital. Histopathological staining remains a simple, cost-effective technique for differentiation and diagnosis of the causative fungal organisms. The present study aims to evaluate the staining efficacy of Periodic Acid-Schiff (PAS), Alcian Blue, Safranin-O and Gomori's Methenamine Silver (GMS) on fungal smears. This research work also attempts to study the morphometric characteristics of Candida albicans, Aspergillus flavus, Rhizopus oryzae. Candida albicans, Aspergillus flavus and Rhizopus oryzae, 10 smears each, were stained using PAS, Alcian Blue, Safranin-O and GMS. The morphological characteristics and staining efficacy were examined, and semi-quantitative scoring was performed. Candida albicans, Aspergillus flavus and Rhizopus oryzae were stained for the first time with Safranin-O. The morphometric traits were then analyzed using an image analysis software. Safranin-O provided the most reliable staining efficacy amongst the stains and optimum morphological definition for all three organisms. Safranin-O was found to be superior to PAS and GMS, ensuring detection of even the most minute mycotic colonies. The hyphae of Aspergillus flavus to be the largest, and the spores and fruiting body of Rhizopus oryzae were found to be the largest amongst the three organisms compared. Early and accurate diagnosis of fungal infections can significantly reduce morbidity in orofacial fungal infections.

COVID-19 and Fungal Diseases

Coronavirus Disease-2019 (COVID-19) can cause secondary bacterial and fungal infections by affecting the expression of pro-inflammatory markers, such as tumor necrosis alpha and certain cytokines, as well as the numbers of CD₄ and CD₈ cells. In particular, in the head and neck, various fungal species are naturally present, making it the main route of secondary infection. It is difficult to clearly distinguish whether secondary infection is caused by COVID-19 directly or indirectly as a result of the immunocompromised state induced by drugs used to treat the disease. However, the risk of fungal infection is high in patients with severe COVID-19, and lymphopenia is observed in most patients with the disease. Patients with COVID-19 who are immunosuppressed or have other pre-existing comorbidities are at a significantly higher risk of acquiring invasive fungal infections. In order to reduce morbidity and mortality in these patients, early diagnosis is required, and treatment with systemic antifungal drugs or surgical necrotic tissue resection is essential. Therefore, this review aimed to examine the risk of fungal infection in the head and neck of patients with COVID-19 and provide information that could reduce the risk of mortality.

Mucormycosis in COVID-19 patients: predisposing factors, prevention and management

India is considered the diabetes capital of the world and has the highest burden of mucormycosis. Bacterial, viral and fungal co-infections are increasingly being reported in severe acute respiratory syndrome virus 2 (SARSCoV-2) infected patients. India is one of the worst affected countries during the second wave of the COVID-19 pandemic. This combination of diabetes mellitus, COVID-19 and mucormycosis has led to the drastic upsurge of COVID-19-associated mucormycosis (CAM) in India. Immunosuppression, iron disequilibrium, endothelial injury, ketoacidosis and hypoxia are some of the other COVID-19-related risk factors for CAM. There has been an increase in the proportion of mucormycosis affecting paranasal sinuses and central nervous system (CNS) in CAM compared to pre-COVID-19 literature due to the SARSCoV-2-related pathophysiological mechanisms, complications and treatment strategies. CAM is a medical and surgical emergency, and it can present with non-specific symptoms and signs initially resulting in diagnostic delay. High index of suspicion and regular screening for features of CAM are of paramount importance to prevent lethal consequences. Rapid action with a tripod approach consisting of withdrawal of immunomodulators, early antifungal therapy and extensive surgical debridement is considered the best possible treatment model. We review the published data to give a detailed account of the predisposing factors and their mechanisms, diagnostic work-up, treatment modalities and prevention strategies of CAM with special emphasis on CNS mucormycosis.

First isolation and identification of Cystobasidium calyptogenae from the oral samples of an elderly patient presenting with angular cheilitis

Background

Angular cheilitis, an infection mainly caused by Candida yeasts, is featured by the appearance of inflammatory lesions at the bilateral corners of the mouth, particularly in patients with poor oral hygiene, ill-fitting dentures and old age. The first isolation of an atypical yeast, Cystobasidium calyptogenae, from oral samples of a patient presenting with angular cheilitis is discussed in this study.

Case presentation

Angular cheilitis was diagnosed in a 60-year-old denture-wearing woman who presented with an irritation fibroma on her right lower buccal sulcus over the premolar region. Primary cultures of her oral swab and oral rinse samples grew a pure culture of an uncommon yeast strain resembling Rhodotorula sp. Sequence analysis of the yeast internal transcribed spacer (ITS) gene region and D1D2 domain showed highest similarity (99.6% and 100%, respectively) to C. calyptogenae CBS 9125 type strain. Following 2 weeks of treatment with miconazole/fusidic acid and mouthwash, the oral lesion showed improvement with less erythema. C. calyptogenae was not isolated from the patient’s oral samples upon repeat sampling.

Conclusion

This is the first report on the isolation of C. calyptogenae from human oral samples. The ability of C. calyptogenae to grow at 37 °C and the fact that it was the only yeast species isolated from the patient’s oral samples suggests its pathogenic potential and possible involvement in angular cheilitis. The ubiquitous nature of the Cystobasidium yeast is believed to increase the likelihood of opportunistic infections among immunocompromised individuals. As Cystobasidium is phenotypically indistinguishable from Rhodotorula, an emerging opportunistic pathogen, surveillance using molecular identification in clinical settings is essential in providing accurate diagnosis and treatment of uncommon yeast infections.

Post-COVID-19 maxillary osteonecrosis and floating maxillary teeth due to mucormycosis in two uncontrolled diabetic patients

Mucormycosis is a rare, invasive, quickly progressing fungal infection that generally affects patients who are immunocompromised. If left untreated, the disease is characterized by progressive necrosis and is often fatal. We present two cases of post-COVID-19 mucormycosis with a history of several years of uncontrolled diabetic mellitus.

The mycobiome of the oral cavity in healthy dogs and dogs with periodontal disease

OBJECTIVE

To investigate the mycobiome of the oral cavity in healthy dogs and dogs with various stages of periodontal disease.

ANIMALS

51 dogs without periodontal disease (n = 12) or with mild (10), moderate (19), or severe (10) periodontal disease.

PROCEDURES

The whole maxillary arcade of each dog was sampled with a sterile swab, and swabs were submitted for next-generation DNA sequencing targeting the internal transcribed spacer 2 region with a commercial sequencing platform.

RESULTS

Fungi were detected in all samples, with a total of 320 fungal species from 135 families detected in the data set. No single fungal species was found in all samples. The 3 most frequently found fungal species were Cladosporium sp (46/51 samples), Malassezia restricta (44/51 samples), and Malassezia arunalokei (36/51 samples). Certain fungi, specifically those of the family Didymellaceae, the family Irpicaceae, and the order Pleosporales, were significantly associated with different stages of periodontitis. Mycobial analysis indicated that Cladosporium sp could be considered part of the core oral cavity mycobiome.

CONCLUSIONS AND CLINICAL RELEVANCE

Results highlighted that fungi are present in the oral cavity of dogs and are characterized by substantial species diversity, with different fungal communities associated with various stages of periodontal disease. The next-generation DNA sequencing used in the present study revealed substantially more species of fungi than previous culture-based studies.

The rhinopharyngeal flap for reconstruction of lower clival and craniovertebral junction defects

OBJECTIVE

The endoscopic endonasal approach (EEA) to the lower clivus and craniovertebral junction (CVJ) has been traditionally performed via resection of the nasopharyngeal soft tissues. Alternatively, an inferiorly based rhinopharyngeal (RP) flap (RPF) can be dissected to help reconstruct the postoperative defect and separate it from the oropharynx. To date, there is no evidence regarding the viability and potential clinical impact of the RPF. The aim of this study was to assess RPF viability and its impact on clinical outcome.

METHODS

A retrospective cohort of 60 patients who underwent EEA to the lower clivus and CVJ was studied. The RPF was used in 30 patients (RPF group), and the nasopharyngeal soft tissues were resected in 30 patients (control group).

RESULTS

Chordoma was the most common surgical indication in both groups (47% in the RPF group vs 63% in the control group, p = 0.313), followed by odontoid pannus (20% in the RPF group vs 10%, p = 0.313). The two groups did not significantly differ in terms of extent of tumor (p = 0.271), intraoperative CSF leak (p = 0.438), and skull base reconstruction techniques other than the RPF (nasoseptal flap, p = 0.301; fascia lata, p = 0.791; inlay graft, p = 0.793; and prophylactic lumbar drain, p = 0.781). Postoperative soft-tissue enhancement covering the lower clivus and CVJ observed on MRI was significantly higher in the RPF group (100% vs 26%, p < 0.001). The RPF group had a significantly lower rate of nasoseptal flap necrosis (3% vs 20%, p = 0.044) and surgical site infection (3% vs 27%, p = 0.026) while having similar rates of postoperative CSF leakage (17% in the RPF group vs 20%, p = 0.739) and meningitis (7% in the RPF group vs 17%, p = 0.424). Oropharyngeal bacterial flora dominated the infections in the control group but not those in the RPF group, suggesting that the RPF acted as a barrier between the nasopharynx and oropharynx.

CONCLUSIONS

The RPF provides viable vascularized tissue coverage to the lower clivus and CVJ. Its use was associated with decreased rates of nasoseptal flap necrosis and local infection, likely due to separation from the oropharynx.

Post-COVID fungal infections of maxillofacial region: a systematic review

With the advent of coronavirus disease (COVID-19) pandemic, a wide range of life-threatening maxillofacial fungal coinfections have also been observed in patients. We conducted this systematic review to collate and evaluate the data to enable clinicians to understand the disease pattern and types of mycosis and provide meticulous management of these infections in COVID-19 patients. The review was carried out in accordance with Preferred Reporting Items for Systematic Review and Meta-analysis guidelines. A systematic electronic literature search was conducted on major databases using keywords in combination with Boolean Operators. Manuscripts discussing cases of maxillofacial fungal infections in COVID-19 patients were included. A total of 11 studies were systematically reviewed to assess the fungal coinfections in COVID-19 patients. Twenty-one cases of mucormycosis, 58 of candidiasis, and 1 each of aspergillosis and mixed infection were observed in the region of head and neck. Significant increase in invasive fungal infection is evident in patients suffering from COVID-19 which could be due to immunosuppression and other pre-existing comorbidities. Early diagnosis and intervention like systemic antifungals or surgical debridement is mandatory to reduce morbidity and mortality.

Characterization of Oral Microbiota in Cats: Novel Insights on the Potential Role of Fungi in Feline Chronic Gingivostomatitis

Previous studies have suggested the involvement of viral and bacterial components in the initiation and progression of feline chronic gingivostomatitis (FCGS), but the role of fungi remains entirely unknown. This pilot study aimed to investigate the bacteriome and mycobiome in feline oral health and disease. Physical exams, including oral health assessment, of privately owned, clinically healthy (CH) cats (n = 14) and cats affected by FCGS (n = 14) were performed. Using a sterile swab, oral tissue surfaces of CH and FCGS cats were sampled and submitted for 16S rRNA and ITS-2 next-generation DNA sequencing. A high number of fungal species (n = 186) was detected, with Malassezia restricta, Malassezia arunalokei, Cladosporium penidielloides/salinae, and Aspergillaceae sp. being significantly enriched in FCGS samples, and Saccharomyces cerevisiae in CH samples. The bacteriome was significantly distinct between groups, and significant inter-kingdom interactions were documented. Bergeyella zoohelcum was identified as a potential biomarker of a healthy feline oral microbiome. These data suggest that fungi might play a role in the etiology and pathogenesis of FCGS, and that oral health should not simply be regarded as the absence of microbial infections. Instead, it may be viewed as the biological interactions between bacterial and fungal populations that coexist to preserve a complex equilibrium in the microenvironment of the mouth. Additional investigations are needed to improve our understanding of the feline oral ecosystem and the potential interactions between viruses, bacteria, and fungi in FCGS.

Harmless or Threatening? Interpreting the Results of Molecular Diagnosis in the Context of Virus-Host Relationships

Molecular methods, established in the 1980s, expanded and delivered tools for the detection of vestigial quantities of nucleic acids in biological samples. Nucleotide sequencing of these molecules reveals the identity of the organism it belongs to. However, the implications of such detection are often misinterpreted as pathogenic, even in the absence of corroborating clinical evidence. This is particularly significant in the field of virology where the concepts of commensalism, and other benign or neutral relationships, are still very new. In this manuscript, we review some fundamental microbiological concepts including commensalism, mutualism, pathogenicity, and infection, giving special emphasis to their application in virology, in order to clarify the difference between detection and infection. We also propose a system for the correct attribution of terminology in this context.

Fungal Infections of Oral Cavity: Diagnosis, Management, and Association with COVID-19

The frequency of fungal infections is increasing due to immunodeficiency viruses and immunosuppressive drugs. The most common fungal infection of the oral cavity is candidiasis. The existence of Candida can be a part of normal commensal; hence, the isolation of Candida in the absence of clinical symptoms should exclude candidiasis. The pathogenicity of Candida is witnessed as opportunistic when immune status is compromised. Oral fungal infections are uncommon, but when identified, these infections are associated with greater discomfort and are sometimes destruction of tissues. Cytology and tissue biopsy are helpful in confirming the clinical diagnosis. The management of oral fungal infections must strategically focus on signs, symptoms, and culture reports. This article reviews information on diagnosis and therapeutic management of aspergillosis, cryptococcosis, histoplasmosis, blastomycosis, mucormycosis, and geotrichosis.

Saprochaete clavata Infection in Immunosuppressed Patients: Systematic Review of Cases and Report of the First Oral Manifestation, Focusing on Differential Diagnosis

Background: Saprochaete clavata infection is an emerging issue in immunosuppressed patients, causing fulminant fungaemia. The purpose of this systematic review of cases is to retrieve all cases of S. clavata infection and describe oral lesions as the first manifestation of S. clavata infection. Methods: We report the first case of intraoral S. clavata infection in Acute Myeloid Leukemia (AML) affected subject, presenting as multiple grayish rapidly growing ulcerated swellings, and provide a review of all published cases of infection caused by S. clavata, according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, conducted by searching SCOPUS, Medline, and CENTRAL databases. Only articles in English were considered. Individual patient data were analyzed to identify risk factors for S. clavata infection. Results: Seventeen of 68 retrieved articles were included in the review reporting data on 96 patients (mean age 51.8 years, 57 males and 38 females). Most cases were disseminated (86) with a 60.2% mortality rate. Ninety-five were hematological patients, with AML being the most common (57 cases). Conclusions:S. clavata infection in immunosuppressed patients has a poor prognosis: middle-age patients, male gender and Acute Myeloid Leukemia should be considered risk factors. In immunosuppressed patients, the clinical presentation can be particularly unusual, imposing difficult differential diagnosis, as in the reported case.

Postextraction Mucormycosis in Immunocompromised-Patient Management and Review of Literature

PURPOSE

Mucormycosis is an uncommon aggressive, opportunistic infection that can produce widespread orofacial tissue necrosis. This primarily affects immunocompromised individuals. It is the deadliest and most rapidly progressing type of human-affecting fungal infection. The aim of the study is to investigate the diagnostic criteria and treatment approach in 10 cases of mucormycosis in the author's institute from 2008 to 2019. Moreover, a review of the English literature presents all cases of mucormycosis after tooth extraction.

MATERIALS AND METHODS

Ten patients at our institute have been treated. They were evaluated and discussed as per their diagnostic criteria, surgical treatment, and mortality rates.

RESULTS

All 10 immunocompromised patients had a primary hematologic malignancy. The criteria for a positive diagnosis were clinical symptoms and a biopsy for microbiological culture and histologic analysis. Each patient was subjected to vigorous surgical resection and underwent antifungal treatment. Seven patients died because of their main disease. Owing to the unregulated spread of mucormycosis, 2 patients died. Four cases were diagnosed after maxillary tooth extraction.

CONCLUSIONS

The most important factor for patient survival tends to be the management of the underlying disease with early detection and active surgical and antifungal action. Four of 10 cases diagnosed with mucormycosis appeared after tooth extraction, a relatively high number compared with the literature. Therefore, it is the dental profession's obligation to be familiar with the possibility of the potentially severe and possibly fatal complication.

Dual Fungal Infections (Aspergillosis and Mucormycosis) in a Diabetic Mellitus Patient Leading to Maxillary Sinusitis as a Post-COVID Manifestation: First Case Report

Coronavirus infectious disease-19 caused by Severe acute respiratory distress syndrome-coronavirus-2 has emerged to be an emergency global health crisis for more than a year. And, as the disease has spread, a number of new clinical features have been observed in these patients. Immunosuppression caused by this disease results in an exacerbation of pre-existing infections. While corticosteroids are considered a life-saving therapeutic intervention for this pandemic, they have proved to be a double-edged sword and their indiscriminate use has produced some deleterious results. Recently, in the backdrop of this expression, a notable rise in invasive fungal infections has been identified even in the post-remission phase. Mucormycosis, Aspergillosis, and Candidiasis are the three most common opportunistic fungal infections among those observed. COVID-19 patients with diabetes mellitus are already at a higher risk of developing such secondary infections due to impaired immunity. Here we present a rare case report of a 50-year old male diabetic mellitus patient diagnosed with dual fungal infections (Aspergillosis along with Mucormycosis) leading to maxillary sinusitis as a post-COVID manifestation. To our knowledge, this is the first such case reported till date.

Mucormycosis Following Tooth Extraction in a Diabetic Patient: A Case Report

Mucormycosis is a rare, opportunistic fungal infection, which can progress acutely or subacutely in immunosuppressed patients. It is a devastating disease in patients with poorly controlled diabetes mellitus and immunocompromised conditions. It causes decaying and extensive lesions of the soft tissue caused by fungi belonging to the order of Mucorales and is often fatal. Due to its aggressive nature, early detection and prompt management are of great importance for a good prognosis. We report a case of mucormycosis post-dental extraction in a patient with uncontrolled diabetes mellitus.

Oral Manifestations of Systemic Diseases

Signs and symptoms representative of a systemic condition can manifest in the oral cavity and orofacial region. Such conditions may be previously diagnosed, or the orofacial manifestation may be the presenting sign of an acute or chronic systemic condition not previously diagnosed. Pathologic processes in the mouth, jaws, and contiguous structures could have a direct and indirect impact on the patient's overall systemic condition. Moreover, systemic conditions may result in compromised function of the orofacial region or impact patients' oral health profile. This article reviews selected systemic conditions that present or impact on the oral cavity and orofacial region.

The impact of the oral cavity in febrile neutropenia and infectious complications in patients treated with myelosuppressive chemotherapy

Febrile neutropenia (FN) is an inflammatory response causing fever that may develop during cancer therapy-induced neutropenia. FN may herald life-threatening infectious complications and should therefore be considered a medical emergency. Patients presenting with FN are routinely subjected to careful history taking and physical examination including X-rays and microbiological evaluations. Nevertheless, an infection is documented clinically in only 20-30% of cases, whereas a causative microbial pathogen is not identified in over 70% of FN cases. The oral cavity is generally only visually inspected. Although it is recognized that ulcerative oral mucositis may be involved in the development of FN, the contribution of infections of the periodontium, the dentition, and salivary glands may be underestimated. These infections can be easily overlooked, as symptoms and signs of inflammation may be limited or absent during neutropenia. This narrative review is aimed to inform the clinician on the potential role of the oral cavity as a potential source in the development of FN. Areas for future research directed to advancing optimal management strategies are discussed.

Speciation of Candida using CHROMagar in cases with oral epithelial dysplasia and squamous cell carcinoma

Background

Candida albicans is most frequently isolated from oral cavity but identification of other Candida species such as C. tropicalis, C. krusei, C. glabrata & C. dubliniensis is increasing proportionately. A constant rise in immuno-suppressed patients, widening range of recognized pathogens, and resistance to antifungal drugs are contributing factors which stress the need for species identification of Candida, an opportunistic pathogen. Objectives: 1. To detect the prevalence of Candida albicans and Non albicans Candida albicans (NAC) species in the oral cavity of patients with epithelial dysplasia, Oral squamous cell carcinoma (OSCC) and healthy controls. 2. To identify and differentiate Candidal species using CHROMagar, a differential media.

Material and Methods

The study included smears from 50 patients with histopathological confirmation of epithelial dysplasia & OSCC and 50 normal controls. Candida albicans was identified using Sabouraud dextrose agar media (SDA) as primary culture followed by species identification using CHROMagar on the basis of colony color and morphology.

Results

Non albicans candida predominated (66%) over Candida albicans (34%) in speciation on CHROMagar media in the study group. Non albicans Candida species isolated were C. tropicalis (38%), C. glabrata (24%) and 2 cases showing polyfungal population of C. albicans & C. glabrata.

Conclusions

Species level isolation of Candida helps in early identification of resistant non Candida strains and prompt treatment of the cases there by preventing the dissemination of infection in case of immuno-compromised individuals. The data presented also supports the use of CHROMagar Candida as a pertinent media for the rapid identification of Candida species directly from clinical specimens in resource challenged settings, which could be helpful in developing appropriate therapeutic strategy and management of patients. Key words:Candida, CHROMagar, epithelial dysplasia, oral cancer.

Mucormycosis of maxilla following tooth extraction in immunocompetent patients: Reports and review

Mucormycosis is a rare, fulminant, rapidly spreading fungal infection, which usually affects patient with underlying immune deficiency. If not managed promptly, the disease is characterized by progressive necrosis and is often fatal. A review of English literature shows that only fourteen cases of mucormycosis have been reported after tooth extraction. This paper highlights two cases of mucormycosis subsequent to tooth extraction in healthy adult patients. This first patient presented with an oroantral fistula and extensive maxillary necrosis. Whereas the second case was localized and presented as non-healing extraction socket with alveolar necrosis. This adds two more cases of this rare and serious complication of tooth extraction, to the present literature.

Key words:Fungal, infection, zygomycosis, exodontia, complication, jaw, necrosis.

Primary Oral Mucormycosis Due to Rhizopus microsporus after Allogeneic Stem Cell Transplantation

We herein report a rare case of oral mucormycosis following allogeneic hematopoietic stem cell transplantation. Oral mucormycosis due to Rhizopus microsporus manifested as localized left buccal mucositis with a 1-cm black focus before neutrophil recovery. Combination therapy with liposomal amphotericin B was initiated and surgical debridement was performed; however, the patient died due to progressive generalized mucormycosis. Considerable attention needs to be paid to the diagnosis and management of oral mucormycosis in post-transplant patients, thereby suggesting the importance of fully understanding the risk factors.

Necrotizing fungal gingivitis in a patient with Acute Myelogenous Leukemia: visible yet obscure

Oral fungal infections present with atypical and varied manifestations, and distinguishing them from other entities including leukemic infiltration can be diagnostically challenging. In this report, we describe a 62 year old female with acute myeloid leukemia who presented, towards the end of her second treatment cycle of decitabine in a prolonged neutropenic state, with a month of painful, necrotic-appearing marginal gingival lesions. She was duly initiated on empiric broad spectrum antifungal treatment but did not show a clinical response with the appearance of new skin lesions concerning for progressive fungemia. Concurrent gingival and cutaneous biopsy showed fungal invasion with Fusarium. Despite changing antifungal treatment the lesions progressed, and white blood cell (WBC) transfusions were instituted. The patient had an impressive response with gradual resolution of the skin lesions and regression in gingival lesions over a week of therapy. This case illustrates the highly atypical, confounding appearance of oral fungal infections in immunocompromised hematological malignancy patients. Maxillary and mandibular marginal gingival involvement, although extremely rare, should be recognized as potential sites of fungal involvement. Accurate diagnosis entails a biopsy especially in ambiguous clinical scenarios, as presented here. The role of WBC transfusions in the management of these rare fungal pathogenic infections needs to re-established.

Mixed Infection of Respiratory Tract in a Dog Caused by Rhodotorula mucilaginosa and Trichosporon jirovecii: A Case Report

This report describes the isolation of two environmental fungi: Rhodotorula mucilaginosa and Trichosporon jirovecii accompanied by Pseudomonas aeruginosa and Escherichia coli from a dog with bronchotracheitis. All microorganisms were isolated routinely from a mucopurulent discharge, obtained during bronchoscopy from laryngotracheal area. The initial identification of yeasts was confirmed by API Candida and by molecular analysis of internal transcribed spacer region. Administered antimicrobial treatment with Marbofloxacin and Canizol has brought the improvement in the dogs’ health status. The final results of control mycological culture were negative. Most probably underlying hypothyroidism and the use of steroids were the factors predisposing this patient to opportunistic infection of mixed aetiology. As far as we are concerned, this is the first case of dogs’ respiratory tract infection caused by R. mucilaginosa and T. jirovecii.

The Role of IL-17 in Protection against Mucosal Candida Infections

Interleukin-17 (IL-17) is a proinflammatory cytokine produced by adaptive CD4+ T helper cells and innate lymphocytes, such as γδ-T cells and TCRβ+ "natural" Th17 cells. IL-17 activates signaling through the IL-17 receptor, which induces other proinflammatory cytokines, antimicrobial peptides and neutrophil chemokines that are important for antifungal activity. The importance of IL-17 in protective antifungal immunity is evident in mice and humans, where various genetic defects related to the IL-17-signaling pathway render them highly susceptible to forms of candidiasis such oropharyngeal candidiasis (OPC) or more broadly chronic mucocutaneous candidiasis (CMC), both caused mainly by the opportunistic fungal pathogen Candida albicans. OPC is common in infants and the elderly, HIV/AIDS and patients receiving chemotherapy and/or radiotherapy for head and neck cancers. This review focuses on the role of IL-17 in protection against candidiasis, and includes a brief discussion of non-Candida albicans fungal infections, as well as how therapeutic interventions blocking IL-17-related components can affect antifungal immunity.

Risk of Fungal Infection to Dental Patients

Fungi can cause various diseases, and some pathogenic fungi have been detected in the water of dental equipment. This environment offers suitable conditions for fungal biofilms to emerge, which can facilitate mycological contamination. This study verified whether the water employed in the dental units of two dental clinics at the University of Franca was contaminated with fungi. This study also evaluated the ability of the detected fungi to form biofilms. The high-revving engine contained the largest average amount of fungi, 14.93 ± 18.18 CFU/mL. The main fungal species verified in this equipment belonged to the genera Aspergillus spp., Fusarium spp., Candida spp., and Rhodotorula spp. Among the isolated filamentous fungi, only one fungus of the genus Fusarium spp. did not form biofilms. As for yeasts, all the Candida spp. isolates grew as biofilm, but none of the Rhodotorula spp. isolates demonstrated this ability. Given that professionals and patients are often exposed to water and aerosols generated by the dental procedure, the several fungal species detected herein represent a potential risk especially to immunocompromised patients undergoing dental treatment. Therefore, frequent microbiological monitoring of the water employed in dental equipment is crucial to reduce the presence of contaminants.

Oral mycobiome in community-dwelling elderly and its relation to oral and general health conditions

OBJECTIVE

Oral fungal infection is generally associated with dysbiosis related to antibiotic use, immunodeficiency, or frailty. However, fungal colonization in a typical population without apparent symptoms and its associated conditions are poorly understood. In this study, oral fungal colonization in community-dwelling and independently living elderly populations was evaluated and factors affecting fungal colonization were analyzed.

SUBJECTS AND METHODS

The subjects (410; 181 males and 229 females) were 75-99 years of age; those under prior antibiotic use were excluded. Fungal populations in the saliva were evaluated by PCR-based molecular techniques. Body mass index (BMI), smoking habits, and oral health conditions were examined.

RESULTS

Salivary fungal amounts exceeded 10⁴  CFU/ml in 63 (15.4%) of 410 subjects. Candida albicans was most frequently detected (98.4%), followed by Candida glabrata (54.0%), and Candida dubliniensis (38.1%) in those subjects with fungi at 10⁴  CFU/ml or over. Fungi at 10⁴  CFU/ml or over in the presence of C. glabrata or C. dubliniensis was significantly associated with low BMI.

CONCLUSIONS

Candida albicans, C. glabrata, and C. dubliniensis dominated the oral mycobiome in Japanese community-dwelling elderly. Lower BMI might signify compromised health status and thus could result in susceptibility to specific candidiasis by C. glabrata and C. dubliniensis.