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1.
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.  相似文献   

2.
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.  相似文献   

3.
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 (HbA1c), 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.  相似文献   

4.
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 (HbA1c), 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.  相似文献   

5.
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.  相似文献   

6.
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.  相似文献   

7.
OBJECTIVE: This study investigated the influence of nystatin and fluconazole on virulence properties of Candida albicans. STUDY DESIGN: A total of 108 diabetic patients participated in the study. Eighty-eight patients had clinical oral candidosis. Drug therapy was given at 6 hourly intervals for nystatin or daily with fluconazole for a maximum of 2 weeks. Adhesion of C albicans to buccal epithelial cells was determined by using an autologous adhesion assay prospectively over 6 months. Phospholipase production was estimated by using an agar plate method. The data analysis included a paired Student t test and calculation of correlation coefficients. RESULTS: Unlike nystatin, treatment with fluconazole reduced the ability of C albicans to colonize the buccal mucosa for up to 8 weeks after the treatment. Patients without clinical signs of oral candidosis had significantly fewer C albicans isolates producing phospholipase than did patients with oral candidosis. Treatment with fluconazole, but not nystatin, reduced the production of phospholipase from C albicans oral isolates in patients with diabetes mellitus. CONCLUSIONS: In addition to being antifungal, fluconazole alters phospholipase production, modifies buccal epithelial cells, and reduces adhesion of C albicans to human buccal epithelial cells for up to 8 weeks posttreatment in diabetic patients with oral candidosis.  相似文献   

8.
In vitro susceptibility of oral Candida to seven antifungal agents   总被引:3,自引:0,他引:3  
The in vitro susceptibility of 618 Candida isolates to fluconazole, itraconazole, voriconazole, ketoconazole, miconazole, amphotericin B, and nystatin was determined. The isolates were obtained from 559 patients who had attended the UK dental hospital departments in Cardiff, Belfast, Glasgow or London. Antifungal susceptibility was assessed using a broth microdilution method following the National Committee for Clinical Laboratory Standards (NCCLS) M27-A guidelines. The majority of the test strains were C. albicans (n = 521) with few of these being resistant to fluconazole (0.3%). A low incidence of fluconazole resistance (0-6.8%) was similarly evident with all non albicans species (Candida glabrata, 5 of 59 resistant; Candida krusei, 0 of 7 resistant; Candida tropicalis, 0 of 13 resistant; Candida parapsilosis, 0 of 12 resistant; other Candida species, 0 of 6 resistant). Voriconazole, ketoconazole, and miconazole also revealed high activity against both C. albicans and non albicans isolates, and 23.7% of C. glabrata isolates were found to be resistant to itraconazole. There was little difference in the antifungal susceptibilities of Candida isolated from patients who had a history of previous antifungal therapy compared with those who had not received antifungal treatment. In summary, this surveillance study of antifungal susceptibility of oral candidal isolates in the UK, through the collaboration of four dental hospitals, demonstrates that oral Candida species have a high level of susceptibilities to a range of antifungal agents.  相似文献   

9.
BACKGROUND: Yeasts are found in periodontal pockets at a frequency of 15-21%. However, the genetic relatedness of oral yeasts within and between patients with marginal periodontitis is not clear. OBJECTIVES: Assay genetic relatedness of oral yeasts from marginal periodontitis patients and oral health subjects, as well as genetic relatedness of yeasts from different oral sites in these two groups of participants. MATERIAL AND METHODS: Yeast isolates were collected from 23 marginal periodontitis patients and 19 oral health subjects. Random amplified polymorphic DNA (RAPD) fingerprinting and the Dendron computer-assisted program for gel analyses were applied for estimation of genetic relatedness of yeasts. RESULTS: The similarity coefficient (S(AB)) of the marginal periodontitis group ranged from 0.49 to 1.00 with an average of 0.64 +/- 0.11, whereas the S(AB) of the oral health group ranged from 0.62 to 1.00 with an average of 0.72 +/- 0.07. Three genetic clusters and 73 genotypes were obtained from the marginal periodontitis group, whereas three genetic clusters and 55 genotypes were found in the oral health group. In the pooled dendrogram, 57% of the yeast isolates and the type strain of Candida albicans fell in a major cluster V. There were no significant differences between the frequencies of clusters from the different oral sites within the two participant groups. CONCLUSIONS: Genetically heterogeneous yeasts were found in the oral cavities of marginal periodontitis patients and oral health subjects. Similar genetic clustering patterns were obtained from the yeasts of the two groups, with cluster V being most predominant. Yeasts of the marginal periodontitis group were more genetically diverse than yeasts of the oral health group, and some yeasts of the marginal periodontitis group exhibited unique genetic patterns. There was no clear association between yeast genetic clusters and oral sites in the two participant groups.  相似文献   

10.
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.  相似文献   

11.
The effect of 0.2% chlorhexidine gluconate on in vitro adhesion of Candida albicans to buccal epithelial cells (BHC) was studied in 12 healthy subjects and 12 patients with diabetes mellitus. Exposure of BFC for one minute with 0.2% chlorhexidine gluconate in vitro , or by rinsing the mouth in vivo, resulted in a significant reduction in candidal adhesion to BHC in both diabetic and non-diabetic subjects and between both groups. In addition to the known fungicidal effect of chlorhexidine, it also reduces Candida albicans adhesion to oral mucosal cells, a factor of importance in the establishment of candidal infection.  相似文献   

12.
Buccal epithelial cells (BEC) from 12 patients with diabetes mellitus and 12 age-and sex-matched non-diabetic subjects were tested in vitro for adhesion of Candida albicans following exposure to nystatin both in vitro and in vivo. Adhesion was significantly reduced ( P < ss0.002) to cells from both the diabetic and non-diabetic subjects after in vitro exposure to nystatin. but the reduction in adhesion was variable (5.0–50.7%) in control subjects and 0.5-4–8.4% in diabetic subjects) and equivalent between the two groups. In vivo exposure to nystatin produced no overall significant reduction in Candida! adhesion to cells from either diabetic or control subjects.  相似文献   

13.
Introduction:  The aim of this study was to investigate the oral colonization profile of Candida albicans strains isolated from diabetic patients and their non-diabetic consorts. In addition hydrolytic enzyme activity of these isolates was analysed.
Methods:  The genetic diversity of C. albicans oral isolates from 52 couples was established using isoenzyme marker and cluster analysis. Hydrolytic enzyme characteristics, namely secreted aspartyl proteinases (SAPs) and phospholipases (PLs) were also analysed.
Results:  Simultaneous colonization by C. albicans was observed in the consorts of 12 couples (23.1%). Patterns of monoclonal and polyclonal oral colonization by C. albicans strains were identified and the coexistence of identical or highly related strains was observed in both members of eight couples. The genetic diversity observed in the total yeast population revealed four large, genetically distinct groups (A to D) and the coexistence of strains in couples or consorts conjugally unrelated. SAP and PL activity was observed in the majority of C. albicans isolates without any association to particular strain, strain clusters (highly related isolates), or clinical characteristics of the consorts (diabetic, non-diabetic, and gender).
Conclusion:  Possible sources of transmission and oral propagation of groups (clusters) of strains of C. albicans can occur between diabetic and non-diabetic consorts. A conjugal genotypic identity exists in most C. albicans -positive couples, that is, both consorts share identical or highly related strains; however, this identity is not couple-specific as seen by the coexistence of clusters in couples and unrelated consorts.  相似文献   

14.
A total of 4–22 isolates of oral yeasts per subjects from 48 yeast-positive Finnish and American subjects (25 females and 23 males) were phenotyped and genotyped to determine the frequency of simultaneous oral carriage of multiple yeast taxa. An oral sample from either periodontal pockets, oral mucosa or saliva was obtained. All subjects yielded Candida albicans and 3 subjects an additional yeast species ( Candida krusei, Candida glabrata or Saccharomyces cerevisiae ). The API 20C Aux kit distinguished 9 different carbohydrate assimilation profiles among the C. albicans isolates. Thirty-eight of 46 C. albicans biotype I isolates were categorized in a single numerical profile. PCR analysis, using a random primer OPA-03 and a repetitive primer (GACA)4, detected 2 major genotypic groups among the C. albicans isolates; 44 subjects showing isolates with a "typical" PCR-profile and 4 subjects isolates with an "atypical" PCR-profile. The "atypical" PCR-profile was similar to that of Candida dubliniensis. All C. albicans isolates assimilated xylose, except 5, including the 4 with an "atypical" PCR-profile. No difference was found in distribution of oral yeast species, and of C. albicans phenotypes and genotypes between Finnish and American subjects. The present PCR method may offer a rapid and easy means of distinguishing oral Candida species.  相似文献   

15.
BACKGROUND/AIMS: A monoclonal killer anti-idiotypic antibody (mAbK10) and a synthetic killer peptide, acting as internal images of a microbicidal, wide-spectrum yeast killer toxin (KT) have been recently shown to express candidacidal in vitro and an in vivo therapeutic activity against experimental mucosal and systemic candidosis models caused by a reference strain of Candida albicans (10S). MATERIAL AND METHODS: The in vitro candidacidal activity of mAbK10 and synthetic killer peptide was compared using a colony forming unit assay against a large number of isolates of different Candida spp., obtained from oral saliva of adult diabetic (type 1 and 2) and nondiabetic subjects from Parma (Italy) and London (UK). RESULTS: Both the KT-mimics exerted a strong dose-dependent candidacidal activity, probably mediated by the interaction with beta-glucan KT receptors on target yeast cells, against all the tested strains, regardless of their species and pattern of resistance to conventional antifungal agents. CONCLUSIONS: These observations open new perspectives in the design and production of candidacidal compounds whose mechanism reflects that exerted in nature by killer yeasts.  相似文献   

16.
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.  相似文献   

17.
OBJECTIVES: The aim of the study was to determine the recurrence rate of denture stomatitis and persistence of Candida in 22 patients (5 male and 17 female, mean age 71 years) over a 3-year period. STUDY DESIGN: Denture hygiene practice, denture cleanliness, and the presence of palatal erythema were assessed for each patient at the start of the study (baseline). The oral cavity was sampled for yeasts by imprint culture and denture discs. Ten patients received a capsular form of itraconazole (100 mg twice daily for 15 days) and 12 patients were provided with 100 mg of itraconazole in the form of a mouthwash (10 mL twice daily), which was then swallowed. No further antifungal treatment was administered to any of the patients. Clinical and microbiological assessments were repeated for each patient at 6 months and 3 years after the original appointment. Yeasts were identified by colony color on CHROMagar Candida, germ-tube formation, and API-32C profiling. Selected isolates were then typed by inter-repeat polymerase chain reaction (IR PCR). RESULTS: Candida albicans was isolated at baseline from all patients either alone (12 patients) or in combination with another species (10 patients). Other yeast species recovered were C glabrata (5 patients), C tropicalis (1 patient), C guilliermondii (1 patient), C krusei (1 patient), C parapsilosis (1 patient), C kefyr (1 patient), and Saccharomyces cerevisiae (2 patients). Candida albicans and/or C glabrata were recovered from 11 of the 22 patients after 6 months or 3 years. A complete and consistent change of yeast species from baseline was observed in 6 patients after 6 months and at 3 years. The remaining 5 patients were yeast-free at the follow-up assessments. PCR fingerprinting of C albicans and C glabrata indicated strain persistence over 6 months in 10 patients and in 4 patients after 3 years. A switch in strain type occurred for 1 patient after 6 months and for 3 patients after 3 years. CONCLUSIONS: The recurrence of denture stomatitis in patients who maintained a high standard of denture cleanliness was low. Although itraconazole was beneficial in reducing the fungal load, there may be strain persistence or subsequent recolonization of the oral cavity by a broader range of potentially less sensitive yeast species.  相似文献   

18.
目的:研究口腔粘膜癌前损害和口腔鳞癌患者以及正常人的口腔白色念珠菌分离株的磷脂酶活性。方法: 应用蛋黄培养基沉淀环面积测量法,研究来自于口腔粘膜癌前损害(21株)、口腔鳞癌(15株)患者以及正常人(19 株)共55株白色念珠菌的磷脂酶活性大小。结果:虽然口腔癌前损害组的沉淀环面积平均值较正常对照组为高, 但却无统计学差异;而口腔鳞癌组白色念珠菌的值较口腔癌前损害及正常对照组均小(P<0105),说明口腔鳞癌组分离株的磷脂酶活性较口腔癌前损害组及正常对照组高。结论:在口腔癌前损害和鳞癌患者口腔中的白色念珠菌分离株具有不同的毒力学特点,提示白色念珠菌在这两种具有关联性的疾病中所起的作用可能具有差异。  相似文献   

19.
HIV感染者及艾滋病患者口腔白色念珠菌毒性的体外研究   总被引:4,自引:0,他引:4  
目的从白色念珠菌本身毒性变化的角度探讨人类免疫缺陷病毒(HIV)感染者易感染口腔念珠菌病的原因。方法通过体外试验从天冬氨酸蛋白酶活性、对颊黏膜上皮细胞的黏附性两方面比较HIV阳性与阴性宿主口腔内白色念珠菌的致病能力。结果在天冬氨酸蛋白酶活性和黏附性方面,HIV阳性口腔念珠菌病致病菌的毒性显著低于HIV阴性口腔念珠菌病致病菌(P<0.01);寄生菌间差异无统计学意义;HIV阳性宿主中,口腔念珠菌病致病菌与寄生菌间差异无统计学意义;而HIV阴性宿主中,口腔念珠菌病致病菌毒性显著高于寄生菌(P<0.01)。结论HIV感染者口腔念珠菌病与某些占主导优势的高毒性菌株无关,而HIV阴性的普通宿主则可能与其选择毒性更强的菌株有关。  相似文献   

20.
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.  相似文献   

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