The isolation,identification and molecular analysis of Candida spp. isolated from the oral cavities of patients with diabetes mellitus

Previous studies have shown a high incidence (77%) of isolation of Candida spp. from the oral cavities of patients with type 1 diabetes mellitus. The aim of the present study was to assess the prevalence of yeast in the oral cavities of patients suffering from type 1 and type 2 diabetes mellitus. The patients were classified according to the level of diabetic control (HbA1_c), and further stratified on the presence or absence of dental prosthesis. Oral rinse samples were assessed for the growth of yeast and the degree of colonization. Oral isolates were defined to the species level by both phenotypic and novel molecular methods. The overall proportion (60%) of diabetic patients who had Candida spp. isolated from the oral cavity was similar to that previously reported. Local oral factors, such as the presence of dentures, seemed to have a greater influence than diabetic status on the amount and species of Candida isolated from the oral cavities of diabetic patients. Diabetic patients with dentures had more non‐albicans Candida isolated from their mouths than dentate diabetic patients. Candida dubliniensis was isolated from diabetic patients and may have a predilection for dentate patients.     

In vitro antifungal susceptibility to six antifungal agents of 229 Candida isolates from patients with diabetes mellitus

The most common antifungal drugs in current clinical use for the treatment of oral candidosis are polyenes and azoles, mainly used topically. Poor glycaemic control in association with other local factors, such as the presence of oral dental prostheses, salivary pH, salivary flow rate and tobacco habits, may lead to the development of oral candidosis. Topical antifungal agents are frequently used to prevent the development of candidal infections in patients with poor metabolic control, particularly in the elderly wearing dentures. The aim of this study was to assess the antifungal susceptibility of Candida isolates to six antifungal agents using a commercially available kit, Fungitest. The isolated were collected from patients affected by diabetes mellitus from two different geographic localities (London, UK, and Parma, Italy) and from a group of healthy non-diabetic subjects. No differences in antifungal susceptibility to the six agents tested were observed between Candida isolates from diabetic and non-diabetic subjects. However, differences were observed between the two geographically different diabetes mellitus populations. Oral yeast isolates from diabetes mellitus patients in the UK more often displayed resistance or intermediate resistance to fluconazole (P=0.02), miconazole (P<0.0001), and ketoconazole (P=0.01) than did isolates from diabetes mellitus patients in Italy. In addition, more C. albicans isolates were found in diabetic and non-diabetic subjects that were susceptible to fluconazole (P=0.0008 and P=0.01, respectively) than non-albicans isolates. The difference in the antifungal resistance of isolates from the two populations of diabetes mellitus patients may be related to differences in the therapeutic management of candidal infections between the two centres.     

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.     

健康老年人口腔念珠菌与义齿修复的相关研究

目的 研究健康老年人群中口腔念珠菌的定植状况,分析义齿修复对老年人口腔念珠菌定植的影响。方法 212例健康老年人分为4组：A1组（男性,有义齿）,B1组（男性,无义齿）,A2组（女性,有义齿）和B2组（女性,无义齿）。标准含潄法取样,样本接种于沙堡琼脂培养基培养念珠菌,CHROMagar CandidaTM鉴定培养基鉴定白色念珠菌,碳水化合物同化反应鉴定体系鉴定念珠菌菌种。培养基中念珠菌菌落计数为每个样本的念珠菌检出强度。比较4组健康老年人念珠菌检出率和检出强度有无统计学差异。结果 212例老年人中116例检出念珠菌,检出率为54.72％。检出念珠菌包括白色念珠菌、近平滑念珠菌、克柔念珠菌、热带念珠菌等10个菌种。A1、B1、A2和B2组念珠菌检出率分别为66.67%,36.07%,64.15%和56.00%;白色念珠菌检出率分别为56.25%,21.31%,56.60%和38.00%。A1组念珠菌、白色念珠菌检出率高于B1组（P<0.05）。高念珠菌强度者在A1、A2组所占比例分别较B1、
B2组高（P<0.05）。结论 健康老年人口腔总念珠菌及白色念珠菌检出率和检出强度增高与义齿修复相关。老年人
口腔念珠菌检出率和检出强度的差异主要是白色念珠菌检出率和检出强度的差异所造成。     

Molecular characterization of Candida spp. isolated from the oral cavities of patients from diverse clinical settings

Infections by Candida spp. have increased in medical importance over the past few decades. Our understanding of species identification, commensalisms, pathogenicity, person-to-person spread, and the development of antifungal resistance within specific strains has been greatly enhanced by the utilization of molecular epidemiological methodology. The aim of the current research was to assess the quantity, species and molecular characterization of oral yeast isolates from well-defined cohorts of immunocompetent patients from a diverse range of clinical settings. Oral rinse samples were assessed for the growth of yeast and degree of colonization. Isolates were defined to the species level by both phenotypic and molecular methods and strains were further genotypically subtyped. Significant variation was shown to exist in the number, species and genotypic subgroups of yeast isolated from the oral cavity in different patient groups. This variation could be attributed to the local oral conditions unique to these patient groups.     

Isolation of Candida species from the oral cavity and fingertips of complete denture wearers.

STATEMENT OF PROBLEM: Candida species usually colonize in the oral cavity of denture wearers and may also colonize on their fingers because of frequent manual manipulation of the dentures. PURPOSE: This study investigated the association between oral and fingertip candidal isolation in a group of denture wearers. MATERIAL AND METHODS: Oral rinse and fingerprints obtained from 25 healthy male complete denture wearers were microbiologically investigated for candidal growth, and isolated Candida species were identified with a germ tube test and a commercially available yeast identification system. Denture cleanliness, hand washing, and denture wearing and handling habits were recorded for each subject. RESULTS: Candida species were isolated from the oral cavity of 15 (60%) and fingertips of 11 (44%) subjects. Ten (66.7%) subjects had concomitant oral and fingertip candidal isolation, whereas 5 (33.3%) subjects had only oral Candida (P=.005). CONCLUSION: The hands of denture wearers who had oral Candida were significantly more colonized with Candida species than oral Candida-free subjects. Further studies identifying Candida species to the strain level and the significance of hand Candida as a source for mouth reinfection are needed.     

In vitro evaluation of virulence attributes of Candida spp. isolated from patients affected by diabetes mellitus

BACKGROUND: Diabetes mellitus is a common disease found worldwide and it has been previously suggested that oral candidal infections may be more frequent or severe in patients with this disease. Systemic and local factors may influence the balance between the host and yeasts, and favour the transformation of Candida isolates from commensal to pathogenic microorganisms. Candida species have developed specific virulence mechanisms that confer the ability to colonise host surfaces, to invade deeper host tissue, or to evade host defences. Few studies have investigated the expression of the virulence attributes of oral Candida isolates in patients with diabetes mellitus. MATERIAL AND METHODS: The in vitro extracellular proteinase production and the in vitro ability to adhere to fibronectin of 229 Candida isolates of two geographic different groups of patients with diabetes mellitus and of healthy subjects were assessed. RESULTS: Candida isolates of patients with diabetes mellitus expressed a higher ability to adhere than those of healthy subjects. Higher levels of adhesion were also recorded in patients with a lower oral Candida colonisation. No differences were observed in the in vitro expression of extracellular proteinase of Candida isolates of patients with diabetes mellitus and those of non-diabetic subjects. Isolates of patients with type 2 diabetes mellitus expressed greater levels of proteinase than isolates of type 1 diabetes mellitus. CONCLUSIONS: Diabetes mellitus could be considered as an additional variable that may influence not only oral Candida carriage but also the ability of isolates to enhance the expression of virulence attributes.     

Initial Tolerance and Tissue Response to Complete Dentures by Diabetic Patients

Purpose The oral effects of diabetes in dentate patients have been studied extensively, but little clinical data has been collected with regards to edentulous patients who have diabetes. The purpose of this study was to investigate whether there are differences between diabetic and nondiabetic patients in initial patient tolerance and tissue response to complete dentures. Materials and Methods Complete dentures were constructed for 62 diabetic and 56 nondiabetic patients. Treatment followed accepted prosthodontic principles recommended for diabetic patients. Twenty-four hour and 1 week post-placement appointments consisted of a patient questionnaire, intraoral examinations and indicated adjustments. The variables studied were the differences between responses to the questionnaire and the frequency of type, location, and size of clinically visible areas of mucosal irritation reported on standardized tissue evaluation forms. Results Analysis of the responses to the questionnaire indicated diabetic patients reported xerostomia more often than nondiabetics. There were no statistically significant differences in initial tissue response to new complete dentures between the diabetic and nondiabetic patients. A statistically significant difference in tissue response was reported within the diabetic group, significantly fewer diabetic patients exhibited oral irritations at the second examination than at the first examination. Conclusions The results of the present study indicate that when prosthodontic principles recommended for diabetic complete denture patients are followed, there are no clinically significant differences between diabetic and nondiabetic patients in initial patient tolerance and tissue response to complete dentures.     

Analysis of the strain relatedness of oral Candida albicans in patients with diabetes mellitus using polymerase chain reaction-fingerprinting

To increase our understanding of Candida pathogenicity, the identification of those strains most frequently associated with infections is of paramount importance. Polymerase chain reaction (PCR)-based methods are extremely effective in differentiating and determining reproducibility, they require minimum starting material and are rapid and simple to perform. In this study, the genetic relatedness of Candida albicans was assessed for two geographically different patient groups (London, UK and Parma, Italy) affected by diabetes mellitus. C. albicans samples from the oral cavities of non-diabetic healthy subjects were also examined by PCR fingerprinting to evaluate the possible genetic differences among endogenous strains in individuals with and without diabetes mellitus. PCR fingerprinting, with subsequent phylogenetic analysis of C. albicans isolates from the diabetic patients from London and Italy and from the non-diabetic subjects, revealed that there were significant differences (P < 0.0001) between C. albicans isolates indicative of the distinct ecological niches that occur in the oral cavities of these patient cohorts. The most diverse group comprised the isolates from the diabetic patients in the UK, possibly reflecting the antifungal treatment that these patients had received. Further studies that include isolates from patient cohorts with systemic diseases other than diabetes mellitus, and from more diverse geographic localities are required to explain the relatedness of C. albicans isolates in the mouth.     

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.     

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.     

68株临床分离口腔念珠菌对4种抗真菌药的体外药敏实验结果分析

目的：评价临床致病性口腔念珠菌感染的种类及对氟康唑、两性霉素B、5-氟胞嘧啶和伊曲康唑的药物敏感性,比较各种口腔黏膜病中的感染菌株的种类和耐药比例,为临床用药提供指导。方法：收集临床菌株,经YBC Test Kit鉴定其念珠菌种类;根据NCCLS的M27-A2标准方案测定3组（口腔念珠菌病、口腔扁平苔藓合并口腔念珠菌感染、头颈部放化疗患者合并口腔念珠菌感染）菌株对4种抗真菌药物的最低抑菌浓度,并比较不同口腔黏膜病合并念珠菌感染菌株的耐药状况。结果：68株临床分离株对5-氟胞嘧啶全部敏感,91．2％对两性霉素B敏感,氟康唑和伊曲康唑的耐药比例分别为13．2％和22．1％,放化疗组的非白色念株菌比例及耐药比例明显高于口腔念珠菌病组和扁平苔藓组。结论：口腔念珠菌感染菌株对氟康唑和伊曲康唑存在较高耐药比例和交叉耐药比例,头颈部肿瘤放疗或化疗患者口腔念珠菌感染菌株的非白色念株菌比例及耐药比例明显高于口腔念珠菌病和扁平苔藓合并口腔念珠菌感染菌株。     

Close association between oral Candida species and oral mucosal disorders in patients with xerostomia

Oral Diseases (2012) 18, 667-672 Objective: Heightened interest in oral health has lead to an increase in patients complaining of xerostomia, which is associated with various oral mucosal disorders. In this study, we investigated the relationship between Candida species and oral mucosal disorders in patients with xerostomia. Subjects and Methods: We evaluated whole salivary flow rate and presence of oral mucosal disorders in 48 patients with xerostomia and 15 healthy controls. The number of Candida species was measured as colony-forming units after propagation on selective medium. Identification of Candida at the species level was carried out by polymerase chain reaction and restriction fragment length polymorphism analysis. We then examined the relationship between Candida species and oral mucosal symptoms. Results: Compared with controls, patients with xerostomia exhibited significantly decreased whole salivary flow rate, increased rate of oral mucosal symptoms, and higher numbers of Candida. Salivary flow rate negatively correlated with the number Candida. Among patients with oral candidiasis, Candida albicanswas isolated from the tongue mucosa and Candida glabratawas isolated from the angle of the mouth. Conclusion: These results suggest that particular Candida species are involved in the pathogenesis of oral mucosal disorders in patients with xerostomia.     

HIV感染者口腔念珠菌负荷及生物型研究

目的调查人类免疫缺陷病毒（human immunodeficiency virus，HIV）感染者口腔中念珠菌负荷状况、生物分型及与口腔念珠菌病临床表现的关系。方法采取漱口法对64例HIV感染者和42名健康对照者进行口腔念珠菌的定量分离培养，并综合利用革兰染色、厚壁孢子生成实验、CHROMagar显色培养和API 20C AUX酵母菌鉴定系统对分离株进行生物型鉴定。结果64例HIV感染者中，52例中可分离出念珠菌74株，阳性分离率为81．3％，而42名健康对照者口腔念珠菌阳性分离率仅为16．7％（P〈0．001）。通过对74株念珠菌的生物型进行鉴定，发现有39株白色念珠菌，15株热带念珠菌及其他6个生物型20株。健康对照组中，分离出5株白色念珠菌和其他裂2株。结论HIV感染者口腔念珠菌感染率明显增加，其口腔念珠菌的检出率和负荷量亦明显增加，白色念珠菌和热带念珠菌为其主要分离菌；与健康对照组相比，HIV感染者的口腔念珠菌分离株生物类型旱现多样化。     

Insulin-dependent diabetes mellitus and oral soft tissue pathologies: II. Prevalence and characteristics of Candida and Candidal lesions

OBJECTIVE: To assess the prevalence of Candida albicans and oral infection with Candida in patients with insulin-dependent diabetes mellitus (IDDM).Study Design: This cross-sectional study compared the prevalence of candidiasis in 405 subjects with IDDM and 268 nondiabetic control subjects. Assessments included evidence of clinical manifestations of candidiasis and a quantitative measure of Candida pseudohyphae in a cytologic smear from the midline posterior dorsal tongue. RESULTS: More subjects with IDDM than control subjects without IDDM (15.1% vs 3.0%) were found to have clinical manifestations of candidiasis, including median rhomboid glossitis, denture stomatitis, and angular cheilitis. IDDM subjects were also more likely to have any Candida pseudohyphae in their cytologic smears (23.0% vs 5.7%; P <.0001), as well as pseudohyphae counts of >10/cm(2) (7.1% vs 0.8%; P <.0001). Diabetic subjects with median rhomboid glossitis were more likely to have a longer duration of IDDM and complications of nephropathy and retinopathy. Denture stomatitis was associated with smoking, retinopathy, higher Candida counts, poor glycemic control, and longer duration of IDDM. A multivariate regression analysis found 3 factors to be significantly associated with the presence of Candida pseudohyphae in the subjects with IDDM: current use of cigarettes (odds ratio, 2:4), use of dentures (odds ratio, 2:3), and elevated levels of glycosylated hemoglobin (odds ratio, 1:9). The use of antimicrobials, immunosuppressants, or drugs with xerostomic side effects was not related to the presence of Candida. CONCLUSIONS: Candida pseudohyphae and oral soft tissue manifestations of candidiasis were more prevalent in subjects with IDDM than in control subjects without diabetes. The presence of Candida pseudohyphae was significantly associated with cigarette smoking, use of dentures, and poor glycemic control.     

Analysis of the strain relatedness of oral Candida albicans in patients with diabetes mellitus using polymerase chain reaction‐fingerprinting

To increase our understanding of Candida pathogenicity, the identification of those strains most frequently associated with infections is of paramount importance. Polymerase chain reaction (PCR)‐based methods are extremely effective in differentiating and determining reproducibility, they require minimum starting material and are rapid and simple to perform. In this study, the genetic relatedness of Candida albicans was assessed for two geographically different patient groups (London, UK and Parma, Italy) affected by diabetes mellitus. C. albicans samples from the oral cavities of non‐diabetic healthy subjects were also examined by PCR fingerprinting to evaluate the possible genetic differences among endogenous strains in individuals with and without diabetes mellitus. PCR fingerprinting, with subsequent phylogenetic analysis of C. albicans isolates from the diabetic patients from London and Italy and from the non‐diabetic subjects, revealed that there were significant differences (P < 0.0001) between C. albicans isolates indicative of the distinct ecological niches that occur in the oral cavities of these patient cohorts. The most diverse group comprised the isolates from the diabetic patients in the UK, possibly reflecting the antifungal treatment that these patients had received. Further studies that include isolates from patient cohorts with systemic diseases other than diabetes mellitus, and from more diverse geographic localities are required to explain the relatedness of C. albicans isolates in the mouth.     

Oral geotrichosis: report of 12 cases

Oral geotrichosis is an uncommon opportunistic infection caused by Geotrichum candidum, a habitual contaminant and component of the flora of various parts of the body. This communication reports both a 20-year retrospective study of clinically and mycologically proven cases of oral geotrichosis, and a prospective study of fungal oral flora in 200 individuals divided into two groups: normal individuals and individuals with associated conditions. Twelve patients with proven oral geotrichosis were included: 9 females and 3 males, with a mean age of 48.5 years; the associated conditions were diabetes mellitus (66.6%), leukemia, Hodgkin's lymphoma and HIV/AIDS infection. The oral geotrichoses showed three clinical varieties: pseudomembranous (75%), hyperplastic, and palatine ulcer. G. candidum was isolated in 11 cases and G. capitatum in one. Positive fungal cultures were obtained from the two groups, and 48% and 78% of cultures were positive, respectively, for Candida spp. In 2.8% and 6.33% of the cases, G. candidum was isolated, respectively, together with one strain of G. capitatum. Oral geotrichosis is an exceptional infection that clinically presents, and is treated, as oral candidiasis. G. candidum may be isolated from the oral flora of a small proportion of patients, either normal individuals or those with associated conditions.     

Type 1 diabetes mellitus and oral health: assessment of coronal and root caries

OBJECTIVES: The oral health of a large cohort of adult insulin-dependent diabetic patients (Type 1), diagnosed 24 years previously with juvenile onset, was comprehensively assessed. This paper describes the prevalence of coronal and root caries in this adult Type 1 diabetic population and evaluates demographic, dietary, behavioral, physiologic, salivary and medical variables associated with decayed and filled surfaces in the crown (DFS) or root (RDFS). METHODS: Type 1 diabetes mellitus subjects participating in this oral health evaluation had been monitored for 6-8 years as participants in the University of Pittsburgh, Department of Epidemiology, longitudinal study of medical complications associated with diabetes. Four hundred and six diabetic subjects received a comprehensive oral health examination during one of their regularly scheduled medical visits. Oral assessments included coronal and root caries, missing teeth, edentulism, periodontal status, soft tissue pathologies, salivary function and health behaviors. Sixteen diabetic subjects and one control subject were edentulous. Coronal and root caries data from the remaining 390 dentate diabetic subjects were compared with 202 dentate nondiabetic control subjects. RESULTS: The adult Type 1 diabetic subjects were not found to have significantly higher DFS rates as compared with our control subjects or published age-adjusted NHANES III findings. Both control and diabetic subjects had low decayed to filled tooth surface ratios. A linear regression model evaluated possible associations with coronal decayed and filled tooth surfaces (DFS) within the diabetic population. Significant factors included older age, women, fewer missing teeth, more frequent use of dental floss, more frequent visits to the dentist during the last 12 months, and diabetic nephropathy. The prevalence of RDFS was higher in the diabetic subjects as compared to recruited control subjects. Neither dietary behaviors nor glycemic control were found to contribute to coronal or root caries. CONCLUSIONS: Factors associated with presence of coronal and root caries and fillings are discussed. Possible causes and implications for the association between DFS and diabetic nephropathy are provided.