Prevalence of Trichophyton rubrum in Tehran, Isolated from Different Levels of Society and Study of Its Probable Organ Orientation

Abstract

Candidiasis and systemic candidiasis are on the rise in recent years, especially in immunologically challenged persons. Morphology switching in Candida albicans, the most virulent human fungal pathogen, has been identified as one important factor of virulence. Nevertheless, the exact mechanism of this phenomenon has not been fully understood. This has prompted intensive research into the genetic aspects of Candida albicans pathogenicity, albeit the elusive gene(s) causing morphology switching has not been uncovered. In our study, an uncharacterized gene fragment of interest was previously found via differential display reverse transcription-PCR. A1—1 was identified as upregulated in the Candida albicans hyphal forms at 1, 3 and 6 hours after hyphal induction compared to the yeast form. The differential expression of A1—1 in yeast-hyphae switching was then studied in further detail. Candida albicans yeast forms were grown at 25 ◦C in Winge medium. Half of this culture was incubated in hyphal-induction conditions in RPMI-1640 added with penicillin-streptomycin and fetal bovine serum at 37 ◦C with 5% CO2. RNA from the yeast form and hyphal forms at 1, 3, 6, 12 and 24 hour time-points were extracted. All RNA were reverse transcribed into cDNA. A1—1 sequence-specific primers were designed, with betaactin as the housekeeping gene. The Pfaffl mathematical method of relative quantitative real-time PCR using SYBR Green was used to validate the differential expression. A1—1 was found to be upregulated in the hyphal forms of Candida albicans. This gene fragment has presented itself as an interesting target for ongoing further studies to elucidate the function of this potentially novel gene in Candida albicans yeast-hyphae morphology switching.