Prevalence of oral Candida species in leprosy patients from Cambodia and Thailand

BACKGROUND: Leprosy is a chronic bacterial infection which may lead to significant orofacial morbidity. However, reports on the oral mycotic flora of leprosy patients are rare. The aim of the current study was to explore the oral yeast carriage in two groups of leprosy patients. METHODS: 40 Cambodian (seven men, 33 women) and 48 Thai (14 men, 34 women) leprosy patients from Leprosy Rehabilitation Centre Khien Kleang, Phnom Penh, Cambodia and McKean Rehabilitation Center, Chiangmai, Thailand were randomly selected and their demographic data and clinical history were recorded. Tongue and palatal swabs of each patient were collected using sterile Fungi-Quick swabs (Hain Diagnostika, Nehren, Germany) and they were cultured aerobically on Sabouraud's dextrose agar and CHROMAgar (CHROMagar, Paris, France). Yeast were identified by germ tube, chlamydospore production, and assimilation tests (API 20C AUX, Bio-Merieux, Marcy l'Etoile, France) and reconfirmed using APILAB Plus system (Bio-Merieux). RESULTS: Two groups (Cambodian and Thai) had median age of 35 and 64 years. They had been with leprosy for median durations of 17.7 and 38.9 years (P<0.05), respectively. Overall yeast carriage in two cohorts were 80% and 93.75%. Candida albicans had highest carriage rate in either group (65.6%, 44.4%). Candida krusei and C. glabrata existed as second-line colonizers after C. albicans. Candida glabrata carriage was significantly higher in Thai patients (P<0.05). Multispecies carriage was seen in three Cambodian (9.4%) and five Thai (11.5%) patients. CONCLUSIONS: This study indicates high oral yeast carriage in leprosy patients. Candida albicans remains predominant while C. krusei and C. glabrata are second-line oral colonizers. Co-inhabitation of multiple yeast species is also noted in these patients' oral mycotic flora.     

Betel quid chewing,oral cancer and other oral mucosal diseases in Vietnam: a review

Background: Betel quid chewing (BQC) in Vietnam is still prevalent, however, no detailed information about its association with oral cancer and pre‐cancer are available in the English literature. Respective online searches (PubMed, Medline) were negative. Methods: Relevant publications in Vietnamese were collected by the authors and translated. Visits to cancer centres and institutes of odontology (Ho Chi Minh City, Hanoi) were made and seminars with respective scientists were held. Field excursions to local markets and interviews with betel quid vendors and individual BQ chewers gave further insights. Results: Generally, BQC is on the decline in Vietnam. 6.7% of the female population still seems to indulge in this habit. In an earlier study, a prevalence of 0.06% of oral cancer was reported. In a study of 1084 cases of oral cancer, the male:female ratio was 1.05:1 (1997). The age group between 60 and 75 years is most often affected by oral cancer. In BQ chewing women, the buccal mucosa (27.9%), tongue (23.1%) and lips (22.4%) are most often affected. Verrucous carcinoma is seen in the age group 70–79 years with women most often being affected (male:female ratio 1:3.4). The most important risk factor for oral cancer in women is BQC compared with men where smoking, alcohol drinking or combined smoking and drinking habits are the most common risk factors. Oral leukoplakia in BQ chewers is observed in 3.8%, oral submucous fibrosis in 13%. Conclusions: BQC in Vietnam is on the decline. Association between BQC and oral cancer in elderly women is still of importance. Eventually, the BQC habit will vanish and only play a role in socio‐ritual contexts.     

Mycological and cytological examination of oral candidal carriage in diabetic patients and non-diabetic control subjects: thorough analysis of local aetiologic and systemic factors

In this study, 55 diabetic patients and 45 non-diabetic control subjects were examined to determine oral candidal carriage state. The influence of some local aetiologic and systemic factors such as: salivary flow rate and pH, heredity, alcohol drinking, smoking habits, antimicrobial therapy, wearing of denture, burning sensation, dry mouth, taste alteration and tooth brushing habit on candidal carriage rate were investigated. Imprint culture, cytological smears and biochemical tests were used. Oral carrier rate and density of Candida species were non-significantly higher in the diabetic patients than in the non-diabetic control subjects. This increase was confirmed cytologically too. In both groups, Candida albicans was found to be a predominant species on tongue dorsum. Cigarette and alcohol habits of men were higher while tooth brushing habit was less than in women in diabetic and control groups. Salivary flow rate and pH values of diabetic patients were significantly lower while serum glucose values were significantly higher than of non-diabetic controls. The rate of diabetic patients suffering from dry mouth and having diabetic heredity in the family were significantly higher than control subjects. The candidal colonization was higher and keratinization was lower while diabetic treatment tended from diet and oral antidiabetic towards insulin. The decrease in salivary pH, the increase in serum glucose and wearing denture were correlated with the increased rate and density of C. albicans in both groups. Keratinization was also accompanied with the increase in leucocytes. In diabetic group, positive correlations were found between antimicrobial therapy and C. glabrata carriage; the increase in leucocytes and C. albicans carriage; the increase in keratinization and alcohol habit; serum glucose and smoking habit; dry mouth complaint and antimicrobial therapy. There was a negative correlation between salivary flow rate and C. albicans carriage. In control group a positive correlation was found between antimicrobial therapy and keratinization.     

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.     

Oral distribution of Candida species and presence of oral lesions in Brazilian leprosy patients under multidrug therapy

Objective:  The aim of this study was to evaluate the prevalence of Candida spp. and presence of oral lesions in Brazilian leprosy patients under multidrug therapy (MDT).
Methods:  Thirty-eight individuals (18 males and 20 females, median age 53 years) clinically and microbiologically diagnosed as leprosy (lepromatous variant), and under MDT for at least 45 days were studied. The control group constituted by 38 healthy individuals (median age 53.5), matched to the test group in relation to age, gender and oral conditions. Oral rinses were collected and the Candida identification was performed by phenotypic tests. The existence of Candida dubliniensis among the isolates was analyzed using a validated multiplex PCR assay. Twenty-nine leprosy patients were examined intra-orally for the presence of lesions. Data were analyzed by z- and Mann–Whitney tests (α = 5%).
Results:  Yeast carriage rate between leprosy patients (65.8%) and controls (47.4%) was similar ( P  = 0.099), and no significant difference between yeast counts was observed ( P  = 0.1004). Candida albicans was the most frequently isolated species in both groups. In the leprosy group, Candida tropicalis and Candida parapsilosis were also identified. In the control group, we additionally identified Candida tropicalis , Candida glabrata and Candida kefyr. Candida dubliniensis was not detected. No leprosy-related oral lesion was registered.
Conclusion:  Within the limits of the study, we concluded that Brazilian leprosy patients under MDT showed similar levels of carriage and Candida species distribution in relation to the controls.     

Oral Candida infection and colonization in solid organ transplant recipients

Introduction:  Oral Candida carriage and infection have been reported to be associated with a greater risk for systemic infection in transplant recipients; however, a systematic analysis of the oral Candida titers and species has not been previously conducted. The objectives of this study were to determine the prevalence of oropharyngeal candidiasis, the oral carrier status, Candida titers and species in this population.
Methods:  Ninety kidney and heart transplant subjects and 72 age-matched healthy controls were included. Swabs from the oral mucosa and a standardized amount of unstimulated saliva were plated on Chromagar™ Candida , and colony-forming units per millilitre were calculated. Initial speciation was based on colony color and was confirmed by standard germ tube, biotyping, or polymerase chain reaction assays.
Results:  Infection with C. albicans was detected in seven transplant subjects and none of the controls. The transplant group had significantly higher oral Candida titers than the control group. There were no statistically significant relationships between the dose or type of immunosuppressants and oral Candida titers or infection. A significantly higher percentage of transplant subjects were colonized by more than one species, compared with control subjects. The most frequent species combination in transplant subjects was C. albicans and C. glabrata . C. glabrata was isolated from 13.5% of transplant carriers and none of the controls.
Conclusions:  Increased oral Candida infection and carriage titers were found in the transplant population. Although the majority of transplant patients were colonized by C. albicans , C. glabrata appears to emerge as the second most prevalent species.     

Carriage of Candida species in the oral cavity in diabetic patients: relationship to glycaemic control

To study the possible relationship between the quality of glycaemic control in diabetes mellitus and the carriage of Candida species, the Candidal carrier status of 412 diabetic patients was examined using an oral rinse technique and correlated with measurements of random blood glucose and total glycosylated haemoglobin. Candida was isolated in 210 diabetics (51%) with 13 patients (6%) carrying more than one species. The positive isolates were: Candida albicans (89%), Candida krusei (2.8%), Candida glabrata (2.8%), Candida tropicalis (6.2%), Candida stellatoidea (2.8%) and Candida parapsilosis (0.5%). No association was identified between carriage rates and the type of treatment of diabetes, or with the quality of glycaemic control. As in non-diabetic subjects, the carriage rates were higher in diabetic patients wearing dentures. Thus, the oral carriage of Candida in diabetic patients was independent of glycaemic control but in certain sub-groups the carriage rates were higher, and involved uncommon candidal species.     

Carriage of Candida species in the oral cavity in diabetic patients: relationship to glycaemic control

To study the possible relationship between the quality of glycaemic control in diabetes mellitus and the carriage of Candida species, the candidal carrier status of 412 diabetic patients was examined using an oral rinse technique and correlated with measurements of random blood glucose and total glycosylated haemoglobin. Candida was isolated in 210 diabetics (51%) with 13 patients (6%) carrying more than one species. The positive isolates were: Candida albicans (89%), Candida krusei (2.8%), Candida glabrata (2.8%), Candida tropicalis (6.2%), Candida stellatoidea (2.8%) and Candida parapsilosis (0.5%). No association was identified between carriage rates and the type of treatment of diabetes, or with the quality of glycaemic control. As in non-diabetic subjects, the carriage rates were higher in diabetic patients wearing dentures. Thus, the oral carriage of Candida in diabetic patients was independent of glycaemic control but in certain sub-groups the carriage rates were higher, and involved uncommon candidal species.     

Candidal carriage in the oral cavity of human immunodeficiency virus-infected subjects

OBJECTIVES. We sought to assess asymptomatic oral carriage of Candida species and relative density in human immunodeficiency virus-infected (HIV+) subjects, as well as to determine whether yeast carriage is associated with CD4+ cell count, HIV-1 RNA quantity, gender, route of HIV transmission, antiretroviral therapy, or smoking. STUDY DESIGN. A cross-sectional analysis of oral rinses from HIV+ and healthy subjects was undertaken. Oral candidal carriage and relative species were investigated in 42 HIV+ and 41 healthy individuals, all of whom were seen at the Palermo University Department of Oral Sciences, Italy. Data were managed and analyzed by means of the computer software package StatView 5.0.1. RESULTS. Carriage rate was 61.9% and 29.3% (P =.003) among HIV+ and healthy subjects, respectively. Similarly, density carriage in the HIV+ group was found to be significantly higher than in the control group (P = .0002). Among HIV+ subjects, Candida carriage was significantly associated with smoking, whereas density was not. Oral candidal carriage and relative density were not significantly associated with the other 4 parameters evaluated. Candida albicans was the most frequently recovered species. CONCLUSIONS. Asymptomatic candidal carriage and relative density were found to be significantly higher in the oral cavity of HIV+ subjects-but not associated with CD4+ counts or HIV-1 RNA quantities.     

Betel chewer's mucosa in elderly Cambodian women

A total of 102 rural Cambodian women with a mean age of 60×8.5 years (range 39 to 80 years) who chewed betel quid were examined for oral mucosal lesions, in particular betel chewer's mucosa. The average duration of betel quid chewing was 15.5 × 12.8 years. The average number of daily betel quids was 5.4 × 2.9. Forty women (39.2%) used betel quids overnight. Thirty-eight (37.3%) did not show any oral mucosal lesion. Sixty-two (60.8%) showed beiel chewer's mucosa. Homogeneous leukoplakia was found in three women (2.9%). Out of 130 sites affected by chewer's mucosa, the buccal mucosa was the most frequently involed ( n = 68). In thirty-two subjects (31.4%) more than one location was affected. The presence of a lesion was significantly associated with the duration of the habit ( P < 0.01) and the number of betel quids per day ( P <0.001). Betel chewing seems to be prevalent in elderly Cambodian women, while younger people do not seem to have taken up this habit. The risk for oral cancer in the Cambodian population is presently unknown.     

The relationship between oral Candida carriage and the secretor status of blood group antigens in saliva

OBJECTIVE: The aim of the study was to investigate the relationship between oral Candida carriage and the secretor status of blood group antigens. STUDY DESIGN: Unstimulated whole saliva and oral rinse samples were obtained from 180 healthy subjects. These samples were plated on Sabouraud's dextrose agar media to determine oral Candida carriage. Sodium dodecylsulfate polyacrylamide gel electrophoresis and immunoblotting were performed on whole saliva samples to determine the secretor status of blood group antigens. RESULTS: The oral Candida carriage rate was found to be 45.0%. The sensitivity of the concentrated rinse culture proved to be superior. Oral Candida carriage was not significantly related to the blood group or secretor status of ABH or Lewis antigens. No significant relationship was found between oral Candida carriage and salivary flow rate. However, smoking affected oral Candida carriage. CONCLUSION: Oral Candida carriage in healthy individuals is not significantly related to blood group or secretor status.     

Yeast species and biotypes associated with oral leukoplakia and lichen planus

Of 36 patients, 17 had oral leukoplakia, including homogeneous and nonhomogeneous types, and 19 had reticular lesions of oral lichen planus. A sample of yeast flora in each patient was taken from the pathologic lesion as well as from normal-appearing mucosa. The isolated yeasts were identified according to species level, and identification was extended beyond the species level for one species, Candida albicans, to reveal the biotype by means of the Odds and Abbott procedure comprising tests for acid and salt tolerance, proteinase production, resistance to 5-fluorocytosine and safranine, and assimilation of urea, sorbose, and citrate. Yeasts were present in the lesions of 82% of leukoplakia patients, compared to 37% of lichen planus patients, a frequency of yeasts corresponding to that in healthy adults. C. albicans was the dominating species in lesions of both diseases, constituting 82% of all yeasts in the leukoplakia lesions. In addition, the following species were identified: Candida tropicalis, Candida pintolopesii, Torulopsis glabrata, and Saccharomyces cerevisiae. Eighteen biotypes of C. albicans were encountered, the most frequently occurring biotypes being 355 and 177. Differences between C. albicans biotypes isolated from pathologic and normal mucosa were encountered in five of eleven leukoplakia patients and in one of three lichen planus patients. This indicates that the oral cavity comprises several ecologic niches for yeasts. As nonhomogeneous leukoplakias are more likely to develop into carcinoma than are homogeneous leukoplakias, it is interesting to note that the C. albicans biotypes isolated from nodular lesions (one type of nonhomogeneous leukoplakia)--biotypes 145, 175, and 575--rarely occur.(ABSTRACT TRUNCATED AT 250 WORDS)     

Oral yeast carriage in patients with advanced cancer

The aim of this study was to investigate oral yeast carriage amongst patients with advanced cancer. Oral rinse samples were obtained from 120 subjects. Yeasts were isolated using Sabouraud's dextrose agar and CHROMagar Candida, and were identified using a combination of the API 20 C AUX yeast identification system, species-specific PCR and 26S rDNA gene sequencing. Oral yeast carriage was present in 66% of subjects. The frequency of isolation of individual species was: Candida albicans, 46%; Candida glabrata, 18%; Candida dubliniensis, 5%; others, < 5%. The increasing isolation of non-Candida albicans species is clinically important, since these species are often more resistant to antifungal drugs. Oral yeast carriage was associated with denture wearing (P = 0.006), and low stimulated whole salivary flow rate (P = 0.009). Identification of these risk factors offers new strategies for the prevention of oral candidosis in this group of patients.     

中老年患者口腔念珠菌携带情况的研究

目的研究口腔修复门诊戴用和不戴可摘义齿中老年患者口腔念珠菌携带情况及常见的念珠菌菌种,并分析相关因素。方法选择不戴可摘义齿患者54人(A组),戴上颌可摘义齿患者84人(B组),年轻学生51人作为对照组(C组)。采集唾液培养并初步鉴定菌种,分析相关因素。结果 A组念珠菌检出率为51.9%,白念珠菌占82.1%。B组念珠菌检出率为82.1%,白念珠菌占73.9%。C组念珠菌检出率为17.6%,白念珠菌占55.6%。A、B、C 3组间及每两组间的念珠菌检出率差异均有统计学意义(P≤0.01)。结论戴用可摘义齿的中老年患者口腔念珠菌检出率显著高于不戴义齿中老年患者;中老年患者口腔念珠菌检出率明显高于年轻对照组。白念珠菌仍是口腔中主要念珠菌种。     

Association of asymptomatic oral candidal carriage, oral candidiasis and CD4 lymphocyte count in HIV-positive patients in China

OBJECTIVES: To compare the prevalence of asymptomatic oral candidal carriage in healthy volunteers with human immunodeficiency virus (HIV)-positive patients in China, as well as to investigate the relationship between CD4+ lymphocyte count and oral candidal colonization or oral candidiasis. METHODS: Oral candidal carriage and oral candidiasis were investigated in 101 patients with HIV-infection seen at Youan Hospital, Beijing, China. Two hundred and seventeen healthy volunteers were involved as a control. Culture from saliva was used to test for the presence of oral Candida. CD4+ lymphocyte count was measured by flow cytometry. All data were analyzed statistically by SAS. RESULTS: Asymptomatic oral candidal carriage rate (28.6%) in HIV-positive group was similar to that in the healthy group (18.0%; P = 0.07). No significant difference in CD4+ lymphocyte count was found between oral Candida carriers and non-carriers among HIV-positive subjects (P = 0.89). However, the frequency of oral candidiasis increased with the decrease in CD4+ lymphocyte count (P < 0.0001), and pseudomembranous candidiasis was predominant in HIV-positive patients with CD4+ <200 cells microl(-1) (66.7%). CONCLUSIONS: In HIV-positive subjects, asymptomatic oral candidal colonization is not related to CD4+ lymphocyte count of blood, and the carriage rate is similar to that in the healthy population. Oral candidiasis is more likely to be observed in HIV-positive patients who have a low CD4+ lymphocyte count.     

Frequency, species and molecular characterization of oral Candida in hosts of different age in China

INTRODUCTION: Research indicates that host age is a determining factor in yeast carriage. From the neonatal period, humans go through several dentition periods, and the emergence and substitution of teeth and changes in living habits greatly change the environment of the oral cavity, and therefore influence colonization by oral commensal organisms, certainly including Candida spp. No previous study of Candida carriage by different age groups divided by dentition has been reported. This study supplies data on the geographical specificity of C. albicans genotypic subgroup distribution. METHODS: All test individuals came from a single geographical locale over a short period. Following mucosal swab sampling, CHROMagar Candida-yeast differential media were used to determine the frequency of carriage and species. All C. albicans strains were confirmed by PCR and PCR using primers reported to span a transposable intron region in the 25S rRNA gene was used to determine genotypic subgroups. RESULTS: The results demonstrate that for the tested population, the frequency of Candida species and the distribution of C. albicans genotypic subgroups varied with age group. With increasing age, the frequency of C. albicans decreases, non-C. albicans yeasts increases; Genotypic subgroup A is the dominating strain in the oral cavities of healthy young individuals. CONCLUSIONS: The influence of dentition substitution on oral yeast carriage was minor.     

化疗患者口腔白假丝酵母菌的分布及基因分组研究

目的研究以白假丝酵母菌（S.albicans）为代表的假丝酵母菌在化疗肿瘤患者口腔中的分布情况,并对检出的白假丝酵母菌进行基因分组。方法从390例接受化疗1年以上的肿瘤患者口腔中取样,采用颊黏膜拭子法,CHROMagar CandidaTM鉴定培养基初步鉴定,根据白假丝酵母菌25S rDNA基因多态性设计引物,根据PCR产物多态性进行基因分组。结果肿瘤患者口腔假丝酵母菌检出率为53.85％（210/390）,白假丝酵母菌的检出率为48.21％（188/390）,其余为光滑假丝酵母菌5.64%（22/390）;白假丝酵母菌基因分组A、B、C组均有检出,其中以B组为主,59.57%（112/188）。结论肿瘤患者口腔的假丝酵母菌以白假丝酵母菌为主,与健康人群的口腔白假丝酵母菌A组占有绝对多数的情况不同,B组白假丝酵母菌在化疗患者口腔中占主导地位。     

Implantation of Candida albicans and other Candida species in the oral cavity of rats

The carriage of five Candida species in the mouths of normal and siaioadenectomised rats was determined for periods up to 30 days after inoculation into the oral cavity. In both test and control animals. Candida albicans was the species recovered in greatest quantities at all periods, followed by C. parapsilosis and C. tropicalis. In contrast. C. gullliermondii and C. krusei were isolatable only in small numbers and only from the 1st up to the 5th day; they were not present thereafter. Sialoadenectomy favoured oral colonisation only by C. albicans ( P <0.05) and did not influence the carriage of the other species.     

Prevalence of oral mucosal lesions among tobacco users

Purpose: To determine the prevalence of oral mucosal lesions associated with tobacco among patients visiting the dental hospital. Materials and Methods: A selection of 1525 patients visiting the Department of Oral Medicine and Radiology were interviewed regarding tobacco habits. Examination of the oral cavity was performed by trained examiners under good illumination using diagnostic instruments. Oral mucosal lesions were diagnosed based on the clinical features. Results: The patients were divided into groups based on their tobacco habits. Out of 1525 patients, 359 patients (23.5%) had the habit and 265 (73.8%) of them had oral mucosal lesions. Leukoedema was the most prevalent lesion. Leukoplakia was found in 3.5% of the patients. Malignancy was found only among chewers. Conclusion: Nearly three-quarters of the patients with the tobacco habit had oral mucosal lesions. This emphasises that routine examination of oral mucosa is important and that the patients must be motivated to quit this harmful habit.     

Candida albicans in leukokeratotic lesions of oral mucosa

The potential presence of Candida albicans in oral leukokeratotic lesions, also entailing the need of additional antimiotic therapy, has been quite extensively discussed in literature. Therefore, the aim of this study was to assess the prevalence of Candida albicans isolates in subjects with oral leukoplakia as well as of candidal leukoplakia according to oral mucosa regions. The study included 60 subjects, mean age 46 years. A study group had 28 subjects with oral leukoplakia, whereas a control group comprised subjects free of any pathological alterations of oral mucosa. In all subjects, a clinical oral examination was performed and material for microbiological analysis taken. Following cultivation and incubation, tests of identification and microbiological analysis were carried out on the material thus grown. Results of the study revealed that Candida albicans was present in 67.9% of subjects with oral leukoplakia, which is the highest percentage reported on so far, and in 28.1% of subjects without any pathologic alterations of oral mucosa. The prevalence of candidal leukoplakia was found to be highest in oral mucosa, followed by lips, tongue and sublingual mucosa. Thus, these findings appear to clearly confirm the need of additional use of antimicotics, along with antikeratotic therapy of leukoplakia.