Cariogenicity of Candida albicans of distinct genotypes among 3-5-year-old Uygur children in Kashgar, China- a case-control study

BACKGROUND: In recent years, the opportunistic fungus C.albicans has been linked to ECC.It is important to investigate the relationship between the distribution of C.albicans and early childhood caries (ECC) in 3–5-year-old Uygur and Han children in Kashgar, and the role of C.albicans of distinct genotypes in caries. METHODS: Two hundred fifty-six Uygur and 141 Han children were enrolled in the study. The identified C.albicans isolates were genotyped based on 25S rDNA Polymerase Chain Reaction(PCR) amplification, and their acidogenicity, aciduricity, and adhesiveness were examined. Moreover, secreted aspartic protease (Sap) activity and SAP1–5 transcriptional levels were compared in the ECC and caries-free (CF) groups of Uygur children. RESULTS: C.albicans detection rate was significantly higher in Uygur children than in Han children (44. 5% vs. 31. 2%; χ2= 6.739, P = 0.009);the A genotype was dominant in Uygur and Han children with ECC, the C genotype was dominant in Uygur CF children(P = 0.022). C.albicans acidogenicity and growth were more pronounced in the Uygur ECC group than in CF group, especially at pH 4.0 and 4. 5(pH 4.0, P = 0.012; pH 4. 5, P = 0.029); the average ratios of glass-wall adhesion and the Sap activity was higher in ECC group than in CF group(P < 0.01), and SAP2(P < 0.001) and SAP5(P = 0.001) were expressed more robustly in ECC group. CONCLUSIONS: The strong acidogenicity and aciduricity, Sap activity, and high SAP2 and SAP5 expression might be closely associated with ECC. C.albicans potentially plays a key role in the progression of caries, which most readily affects genotype A carriers and could be attributed to person-to-person environmental variation.