Oral Candida species and betel quid-associated oral lesions in Padaung women of Northern Thailand

Presence of Candida and its associated factors in participants attending oral cancer screening in the lower northeastern area of Thailand

BACKGROUND

Certain evidence indicated high prevalence of Candida in oral potentially malignant disorders (OPMDs) and oral cancer (OC). This study was aimed to investigate the presence of Candida and its associated factors in participants who attended the oral cancer screening program in the lower northeastern districts of Thailand.

METHODS

Convenient participants residing in the lower northeastern districts of Thailand who attended the oral cancer screening were enrolled. A questionnaire retrieving demographic characteristics, risk factors of oral cancer, and risk of having Candida was completed. Oral examination was performed by oral medicine specialists or oral surgeons. The participants were categorized into 4 groups according to their clinical diagnosis, namely normal oral mucosa (NOM), OPMDs/OC, non-OPMDs/OC and clinically suspected oral candidiasis (CSOC). Stimulated saliva flow rate was measured. Dip-slide test was performed in each participant to evaluate the presence of Candida. The levels of Candida were categorized into high and low levels according to the score received from the dip-slide test. Factors associated with high levels of Candida were identified using multivariate logistic regression analysis.

RESULTS

A total of 577 participants were recruited. High levels of Candida were found in 31.3%, 24.7%, 25.9% and 18.1% in the OPMDs/OC, the non-OPMDs/OC, the CSOC and the NOM groups, respectively. According to multivariate logistic regression analysis, age above 60 years, female gender, betel quid chewing habit, use of denture, hyposalivation, and being in the CSOC group were found to be significantly associated with high levels of Candida.

CONCLUSION

Higher number of participants in the OPMDs/OC group was found to have high levels of Candida. Increasing age, female gender, betel quid chewing habit, use of denture, hyposalivation and having CSOC lesions were associated with high levels of Candida.

Which Factors, Smoking, Drinking Alcohol, Betel Quid Chewing, or Underlying Diseases, Are More Likely to Influence the Severity of COVID-19?

The global outbreak of the coronavirus disease 2019 (COVID-19) pandemic occurred in late 2019 and early 2020. The factors that influence disease severity should be of clinical concern. Existing findings on the effects of smoking on COVID-19 are also controversial and need to be confirmed by further research. In addition, the effects of alcohol consumption and betel quid (BQ) chewing on COVID-19 are unclear. The aim of this study was to examine the demographic characteristics of COVID-19 patients and the effects of smoking, drinking, BQ chewing, and underlying diseases on the severity of COVID-19. A retrospective study was conducted on 91 patients with confirmed cases of COVID-19 hospitalized in Yueyang, Hunan Province, China from 21 January to 8 March, 2020. Patient demographic data, and information on smoking, drinking and BQ chewing, and underlying diseases were extracted from the patient electronic medical records (EMR) and telephone interviews. The chi-square test was used to conduct a univariate analysis of the factors influencing the severity of COVID-19, and ordinal logistic regression analysis was used to identify the factors related to the severity of COVID-19. The results showed that the rates of smoking, drinking and BQ chewing were 15.4, 26.4, and 7.1%, respectively, there was no significant relationship between these lifestyle factors and the severity of COVID-19 (P > 0.05). However, underlying diseases such as diabetes [odds ratio (OR) = 7.740, 95% confidence interval (CI):1.000-60.740, P = 0.050], source of infection (OR = 0.180, 95% CI: 0.030-0.980, P = 0.049), and employment status (retired/unemployed vs. employed: OR = 29.430, 95% CI, 1.050 - 822.330, P = 0.047) were significant independent predictors of severe COVID-19 infection. These individuals should be informed of methods to increase personal protection, and doctors should prevent these individuals from developing serious diseases. It is important to pay attention to the source of infection and timely medical treatment. This study showed that the clinical classification of COVID-19 was associated with patients with diabetes, source of infection, and retired/unemployed. Therefore in the clinical practice of COVID-19 should be more concern these factors. Although no statistical significance was found in smoking, drinking alcohol, BQ chewing, and severity of COVID-19 patients, more studies have confirmed that are harmful and risk factors for underlying diseases in the population. Health authorities should formulate policies to publicize the harmful effects of smoking, drinking, and betel nut chewing and promote a healthy lifestyle.

Type 2 diabetes mellitus and oral Candida colonization: Analysis of risk factors in a Sri Lankan cohort

Aims: Oral candidiasis is a major oral manifestation of uncontrolled diabetes mellitus, and a number of cofactors are associated with the pathogenesis of this infection. Here, we describe the prevalence of oral Candida in a Sri Lankan cohort of type 2 diabetes mellitus and risk factors that predispose them to this common fungal infection. Methods: A case-control study was conducted in 250 diabetics with type 2 diabetes and 81 nondiabetic controls. Clinical and demographic data were collected using an interviewer administered questionnaire, and patient records. Oral rinse samples were collected to determine the candidal carriage, and the resultant yeast growth was quantified and speciated using multiplex-PCR and phenotypic analyses. Chi-square test (χ² test) and Fisher exact test were used for the determination of the significant relationships between risk factors and oral candidiasis. Results: The oral prevalence of Candida species among both groups was similar (81%) although a significantly higher proportion of diabetics (32.8%) yielded >2000 CFU/mL of yeasts compared with only 12.3% of the healthy controls (p < .05). Significant associations were noted between oral candidal carriage amongst diabetics, and (i) denture wearing, (ii) female gender and (iii) cigarette smoking (all, p < .05). Amongst both groups, C.albicans was the most common Candida species isolated followed by C. parapsilosis, C. tropicalis and C. glabrata. Conclusions: The oral infestation of Candida in our Sri Lankan cohort of diabetics is significantly higher than their healthy counterparts, and co-carriage of multiple yeast species is a common finding in the study population. As there are no previous such reports of the latter phenomenon particularly from the Asian region it is noteworthy, mainly in view of the recent data on the emergence of drug-resistant yeast species the world over.

Comparison of oral Candida carriage in waterpipe smokers, cigarette smokers, and non-smokers

The aim of the present cohort study was to compare oral carriage of Candida in waterpipe smokers (WS), cigarette smokers (CS), and non-smokers (NS). A total of 141 individuals (46 WS, 45 CS, and 50 NS) were included. A questionnaire was used to gather demographic information and data on the daily frequency and duration of smoking habits, the reasons for smoking, and daily oral hygiene maintenance habits. Oral Candida (C.) samples were cultured and yeast species were identified using polymerase chain reaction. Unstimulated whole salivary flow rate (UWSFR) was also recorded. The numbers of missing teeth (MT) were counted and tongue lesions were clinically identified. C. albicans was the most prevalent yeast species isolated from all groups. Oral C. albicans carriage was higher among WS (P < 0.05) and CS (P < 0.05) than among NS. Oral C. tropicalis carriage, age, UWSFR and the number of MT were comparable among the groups. Oral Candida carriage was significantly higher among WS and CS than among NS. Therefore it appears that WS and CS are at an increased risk of developing oral candida infections.

Candida albicans Inhibits Pseudomonas aeruginosa Virulence through Suppression of Pyochelin and Pyoverdine Biosynthesis

Bacterial-fungal interactions have important physiologic and medical ramifications, but the mechanisms of these interactions are poorly understood. The gut is host to trillions of microorganisms, and bacterial-fungal interactions are likely to be important. Using a neutropenic mouse model of microbial gastrointestinal colonization and dissemination, we show that the fungus Candida albicans inhibits the virulence of the bacterium Pseudomonas aeruginosa by inhibiting P. aeruginosa pyochelin and pyoverdine gene expression, which plays a critical role in iron acquisition and virulence. Accordingly, deletion of both P. aeruginosa pyochelin and pyoverdine genes attenuates P. aeruginosa virulence. Heat-killed C. albicans has no effect on P. aeruginosa, whereas C. albicans secreted proteins directly suppress P. aeruginosa pyoverdine and pyochelin expression and inhibit P. aeruginosa virulence in mice. Interestingly, suppression or deletion of pyochelin and pyoverdine genes has no effect on P. aeruginosa’s ability to colonize the GI tract but does decrease P. aeruginosa’s cytotoxic effect on cultured colonocytes. Finally, oral iron supplementation restores P. aeruginosa virulence in P. aeruginosa and C. albicans colonized mice. Together, our findings provide insight into how a bacterial-fungal interaction can modulate bacterial virulence in the intestine. Previously described bacterial-fungal antagonistic interactions have focused on growth inhibition or colonization inhibition/modulation, yet here we describe a novel observation of fungal-inhibition of bacterial effectors critical for virulence but not important for colonization. These findings validate the use of a mammalian model system to explore the complexities of polymicrobial, polykingdom infections in order to identify new therapeutic targets for preventing microbial disease.

Pseudomonas aeruginosa and Candida albicans are two medically important human pathogens that often co-infect or co-colonize the same human niches, such as the gut. In a normal healthy host, P. aeruginosa and C. albicans can colonize the gut without any significant pathologic sequelae. But in immunocompromised hosts, both pathogens can escape the gut and cause life-threatening disseminated infections. Yet the mechanisms and pathogenic consequences of interactions between these two pathogens within a living mammalian host are not well understood. Here, we use a mouse model of P. aeruginosa and C. albicans gut co-infection to better understand the mechanisms by which C. albicans inhibits P. aeruginosa infection. C. albicans inhibits the expression of P. aeruginosa genes that are vital for iron acquisition. Accordingly, deleting these iron acquisition genes in P. aeruginosa prevents infection. Understanding how microbes interact and antagonize each other may help us identify new potential therapeutic targets for preventing or treating infections.

Activation of HIF-1α and LL-37 by commensal bacteria inhibits Candida albicans colonization

Candida albicans colonization is required for invasive disease^1-3. Unlike humans, adult mice with mature intact gut microbiota are resistant to C. albicans gastrointestinal (GI) colonization^2,4. But the factors that promote C. albicans colonization resistance are unknown. Here we demonstrate that commensal anaerobic bacteria – specifically Clostridial Firmicutes (Clusters IV and XIVa) and Bacteroidetes – are critical for maintaining C. albicans colonization resistance in mice. Using Bacteroides thetaiotamicron as a model organism, we find that HIF-1α, a transcription factor important for activating innate immune effectors, and the antimicrobial peptide LL37-CRAMP are key determinants of C. albicans colonization resistance. While antibiotic treatment enables C. albicans colonization, pharmacologic activation of colonic Hif1a induces CRAMP expression and results in a significant reduction of C. albicans GI colonization and a 50% decrease in mortality from invasive disease. In the setting of antibiotics, Hif1a and Cramp are required for B. thetaiotamicron-induced protection against CA colonization of the gut. Thus, C. albicans GI colonization modulation by activation of gut mucosal immune effectors may represent a novel therapeutic approach for preventing invasive fungal disease in humans.

Correlation of presence of Candida and epithelial dysplasia in oral mucosal lesions

BACKGROUND

Candida and epithelial dysplasia have long been associated with oro-mucosal lesions.

AIM AND OBJECTIVE

The present study was designed to evaluate the correlation between presence of Candida organisms and epithelial dysplasia in various oral mucosal lesions associated with areca nut and tobacco use.

MATERIALS AND METHODS

A total of 50 individuals were selected, between age range of 19-70 y. Three separate cytosmears were prepared for each participant. All the slides were stained with PAS stain and the best slide was viewed for candidal organisms.

STATISTICAL TESTS

The data was analysed using the SPSS version16. Chi square test was performed.

RESULTS

Out of these, samples of 26 participants displayed presence of Candida. It was further observed that all the samples that were positive for presence of Candida displayed the organism in hyphal form. Out of 50 biopsy specimens stained for presence of Candida using PAS stain, samples of only 2 participants demonstrated presence of Candida in hyphal form, whereas the biopsy specimens stained for demonstrating dysplastic changes using H&E stain displayed various levels of cellular atypia in samples of 16 participants. Out of these 12 were mild, 3 were moderate & 1 displayed severe dysplastic changes.

CONCLUSION

The study revealed a statistically non significant correlation between the presence of Candida and epithelial dysplasia in oral mucosal lesions.

Oral Candida carriage and prevalence of Candida species among Maras powder users and non-users

INTRODUCTION

The aim of this study was to investigate Candida carriage and species in Maras powder users and non-users.

MATERIAL AND METHODS

This study included 100 volunteering men in 12 cafés in the city of Kahramanmaras, Turkey. A questionnaire composed of questions about socio-demographic features and Maras powder use was filled in by the participants. Culture specimens were obtained from bilateral buccal mucosa and dorsum of the tongue with a sterile cotton-tipped swap. The specimens were inoculated in Sabouraud Dextrose Agar (SDA).

RESULTS

The mean age of the participants was 48.0 ± 12.5 years (min = 20, max = 70). Fifty-four percent of the Maras powder users and 22% of the non-users were Candida carriers. The difference between the groups was significant (P = 0.001). The most frequently isolated species was Candida albicans at a rate of 44% in the Maras powder users and at a rate of 18% in the non-users. Other frequent species were Candida glabrata at a rate of 6% in the Maras powder users and 2% in the control group and Candida tropicalis at a rate of 4% in the Maras powder users and 2% in the nonusers.

CONCLUSION

We found that a significantly high rate of the Maras powder users was Candida carriers. It should be kept in mind that opportunistic infections may be caused by Candida species in Maras powder users especially with immunosuppressive conditions since Candida species are likely to lead to such infections in cases of immunosuppressive diseases.

Oral Candida carriage and species prevalence amongst habitual gutka-chewers and non-chewers

Oral Candida colonisation is higher in tobacco smokers as compared to non-smokers; however, it remains unknown whether smokeless tobacco chewers are susceptible to increased oral Candida colonisation. The aim was to determine the oral Candida carriage and species prevalence amongst habitual gutka-chewers and non-chewers in a cohort from Karachi, Pakistan. Forty-five gutka-chewers and 45 non-chewers were included. Information regarding age, sex, duration of gutka-chewing habit, daily frequency of gutka consumption, duration of holding gutka in the mouth, daily frequency of tooth-brushing and tongue brushing was collected using a questionnaire. Oral yeast samples were collected by scraping the dorsum of the tongue and bilateral buccal mucosa with a sterile cotton swab. Identification of yeast species was performed using standard techniques. Tongue lesions were identified and recorded. Unstimulated whole salivary flow rate (UWSFR) was also measured. There was no significant difference in the mean age, UWSFR and oral Candida carriage among gutka-chewers and non-chewers. Individuals were chewing gutka since 4·4 years and were consuming five gutka sachets daily. Candida albicans (C. albicans) was the most common yeast species isolated from 57·8% gutka-chewers and 64.4% non-chewers. In 24.4% gutka-chewers and 22·2% non-chewers, two candidal strains (C. albicans and Candida tropicalis) were isolated. In conclusion, the present results indicated no significant difference in oral Candida carriage in habitual gutka-chewers and non-chewers.

Oral Candida carriage, quantification, and species characterization in oral submucous fibrosis patients and healthy individuals

AIM

  To determine the prevalence of oral Candida carriage, candidal quantification, and various subtypes of Candida species in oral submucous fibrosis patients and healthy individuals.

METHODS

  The study comprised 30 clinically-diagnosed and -staged oral submucous fibrosis patients aged 20-40 years, and 20 age- and sex-matched controls. Buccal mucosa was sampled by sterile swab technique. Each sample was inoculated on Sabouraud's dextrose agar and CHROMagar culture media. Candida species identification was done using the KB006 Candida identification kit.

RESULTS

  Eleven (36.67%) cases in the study group, and two (10%) cases in the control group, yielded Candida on culture. The value of CFU/mL increased with an increased duration of betel quid chewing habit. All Candida-positive oral submucous fibrosis patients complained of a burning sensation. Candida albicans and Candida tropicalis were the most common species in the oral submucous fibrosis cases. Candida dubliniensis was isolated in both the study and control groups.

CONCLUSIONS

  Our observations in this study affirm that oral submucous fibrosis favors the colonization of Candida. Mucosal alterations due to the underlying disease process or betel quid chewing, coupled with other factors, might lead to candidal colonization, even in the absence of clinically-related mycotic manifestations.

Characteristics of dual species Candida biofilms on denture acrylic surfaces

Biofilms contribute to the pathogenesis of oral candidiasis, some 15% of which may be due to dual Candida species. Despite extensive studies on monospecies biofilms (MSB) on denture acrylic surfaces, few have investigated the characteristics of dual species Candida biofilms (DSB).

OBJECTIVES

To examine interactions of DSB of Candida albicans and Candida krusei on denture acrylic surfaces.

METHODS

Two isolates each of C. albicans (Ca) and C. krusei (Ck), with high (Ca(h), Ck(h)) and low (Ca(l), Ck(l)) biofilm-forming ability were used. The biofilms were developed on acrylic surfaces aerobically at 37 degrees C in yeast nitrogen base (YNB) medium, and growth quantified by colony-forming unit (CFU) assay. We determined: (i) the population profiles of DSB comprising each pair of Candida species, of a total of four combination pairs, after 12 h, (ii) the effect of a constant concentration of Ca(h) (10(7)cells/ml) on varying concentrations of Ck(h) (10(3)-10(7)cells/ml) on DSB development and (iii) the effect of saliva on the growth of DSB.

RESULTS

(i) DSB exhibited a lower cell population after 9 or 12 h in comparison to MSB (P<0.05), (ii) C. albicans (10(7)cells/ml) co-cultured with varying initial concentrations of C. krusei was inhibited at high concentrations of the latter (10(6)-10(7)cells/ml) (P<0.05) and (iii) only the MSB development of C. krusei was affected by saliva (P<0.05).

CONCLUSION

Our data suggest that the competitive interactions of fungal species are likely to be important in biofilm formation on acrylic surfaces and human saliva may further modulate this process.

Oral submucous fibrosis and oral yeast carriage - a case control study in Sri Lankan patients

Oral submucous fibrosis (OSMF) is a well-known precancerous condition. Epithelial atrophy is one of the key features in OSMF. Presence of Candida in the mouth together with epithelial changes may predispose to candidal infection. Candidal infection together with other co-factors may also induce epithelial atypia and dysplasia leading to malignant change. The purpose of this study was to determine the prevalence of oral yeast carriage in patients with OSMF and to compare the carriage with the normal individuals. Thirty patients with histologically proven OSMF and healthy subjects were used as the test and control respectively. Oral rinse samples were collected from all the subjects and cultured on Sabouraud's agar. Species were identified using API 32C AUX identification kits. Nineteen (63.6%) of the test group and 15 (50%) of the control group had yeast isolated from their mouth. The carriage of yeast in the OSMF group was not statistically significant compared with the control group. We isolated C. dubliniensis in Sri Lanka for the first time and interestingly from the oral cavities of both OSMF patients and healthy individuals.