A study on stability of phenotype and genotype of Trichophyton rubrum.

摘要: Objective: To explore the stability of phenotype and genotype in Trichophyton rubrum. Methods: All strains were cultured on Sabouraud’s dextrose agar slopes, identified to species level. Strains isolated recently subcultured Sabouraud slopes four times at an interval 4 weeks. DNA was extracted with CTAB method. A probe consisting 3′ end 18S rDNA, adjacent ITS1, 5.8S rDNA ITS2 regions amplified from template T. rubrum standard strain using fungal universal primers NS5 ITS4, labelled by P32 hybridized EcoR I-digested genomic DNA. Results: (1) Four phenotypes 207 strains, downy type (45.4%) first place, granular not found. After 1 year conservation, 54 showed morphological variations total variation rate 26.1%. (2) Eleven colony morphology or pigment upon subculture. (3) AP-PCR analysis 10 isolates one similar patterns main bands 2.2, 1.7, 1.3, 0.9 0.7 kb. No changes pattern found (4) Hybridization revealed that all 11 presented three into two types (2.4, 3.9, 5.9 kb 2.4, 4.4, 6.5 kb). band Conclusions: Phenotype instable colonial easily changed during conservation subculture, while its relatively stable.