Biological Characterstics Of Oral Candida Albicans Of Children

To study the frequency of oral Candida spp.of different age chil dren grouped by dentition,and after genotyped the Candida albicans strai ns by PCR,study the characteristics of genotypic groups including the a bility of biofilms formation,expression of ALS gene family in biofil m condition,and at the same time , altered expression of ALS gene comparing the planktonic cells. By acquired the knowledge of colon ization of Candida albicans and the other species of Candida , and t he molecular characteristics of Candida albicans, we can incubrate the c onstituation and succession of oral normal flora. From the aspect of C andida albicans bioflms in vitro, deeply understand the gene expression of different genotype of Candida albicans, at the same time, find the altered gene expression in biofilm circumstance.Four groups of different age children grouped by dentition, they ar e neonatal group,primary dentition,mixed dentition, secondary dentition, and one control group of adult. By sampling methods of buccal mucosa swabbing with centrifugation, culture and identificationof Candida spp.by CHROMagar Candida?-yeast differential medium, we can get the frequency of Candida spp. and especially Candida al bicans strains. Genotypic grouped the Candida albicnas strain by P CR amplication diversity, the primers designed by a transposable intro n region in the 25S rRNA gene. Compare three kinds of Candida albicans biofilm models in vitro,observe the formation of biofilm by fluore sence microscope and confocal laser scaning microscope(CLSM),XT T reduced method to quantitative study biofilm formation of differen t genotypes, and by RT-PCR observe the ALS gene expression in bio film of different genotypes ,and compare the ALS gene expression in two growth condition of biofilm and planktonic.We can isolated Candida spp. form all groups of different grou ps, the frequency of Candida spp. of neonatal group is low as far as 7. 5%,from group of primary dentition to adults group ,the frequency of C andia albicans decrease, the frequency of Candida spp. not because non-Candida albicans strains increase. We totally found three genoty pic groups of Candida albicans, group A B and C, the group A is th e dominating group in all of the age groups. The Candida albicans biofilms formed by three kinds of model are correlated measured by XTT reduced method and morphologically observed by fluorese nee microscope, the analysis of biofilm formation ability of three genoty pes cannot explain the colonization of different genotype, the expressi on of ALS gene in the biofilm circumstance show great diversity accord ing to strains and ALS gene individuals ; comparing the ALS gene ex pression between biofilm and planktonic condition, the results show th e expreassion surely upregulated in biofilm, but the degree of upregulat ion is different according to strains and ALS gene individuals too.The results demonstrate that for the tested population, the frequen cy of Candida species, and the distribution of Candida albicans genotyp ic 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 yo ung individuals.The expression and upregulation of ALS gene in biofilm show diversity according to differernt strains and ALS gene individuals.