RESUMEN
INTRODUCTION: Candida dubliniensis was reclassified from the C. albicans genotype D, and reports show its frequent detection in HIV-positive individuals and easy acquisition of antifungal drug resistance. However, the oral carriage rate in healthy people and contribution to candidiasis in Japan is unclear. METHODS: We conducted a cross-sectional survey of the C. dubliniensis carriage rate, performed genotyping and tested antifungal drug susceptibility and protease productivity. Specimens from 2432 Japanese subjects in six regions (1902 healthy individuals, 423 with candidiasis individuals, 107 HIV-positive individuals) were cultured using CHROMagarTMCandida, and the species was confirmed via 25S rDNA amplification and ITS sequences analyzed for genotyping. RESULTS: The C. dubliniensis carriage rate in healthy Japanese was low in the central mainland (0-15%) but high in the most northerly and southerly areas (30-40%). The distribution of these frequencies did not differ depending on age or disease (HIV-infection, candidiasis). Genotype I, previously identified in other countries, was most frequent in Japan, but novel genotypes were also observed. Six antifungal drugs showed higher susceptibility against C. albicans, but protease productivity was low. CONCLUSIONS: Oral C. dubliniensis has low pathogenicity with distribution properties attributed to geography and not dependent on age or disease status.
RESUMEN
Caries sensitivity varies between the two strains of inbred mice, BALB/cA has high sensitivity and C3H/HeN has low sensitivity. One potential reason seems to be a difference in pellicle-forming saliva protein composition. Here, we performed a proteomic analysis in order to identify differences of hydroxyapatite (HAP) adsorbed saliva proteins between these two mouse strains. HAP column chromatography revealed twice the quantity of high-affinity saliva proteins in C3H/HeN compared to BALB/cA. One- and two-dimensional electrophoresis showed 2 bands/spots with deviating migration. They were identified as murine carbonic anhydrase VI (CAVI) by peptide mass fingerprinting and confirmed with western blotting using a specific polyclonal antibody. Total RNA from the salivary glands of both mouse strains, PCR amplification of cDNA with a CAVI specific primer, and sequence analysis revealed one different base in codon 96, resulting in one different amino acid. Glyco-chains of CAVI deviate in one N-glycan, confirmed by mass analysis. CAVI activity was estimated from distinct circular dichroism spectra of the molecules and found higher in C3H/HeN mice. In summary, the CAVI composition of BALB/cA and C3H/HeN differs in one amino acid and a glyco-chain modification. Further, saliva from caries resistant C3H/HeN mice displayed higher CAVI activity and also overall hydroxyapatite adsorption, suggesting a relationship with caries susceptibility.