Expression Of ALS4 Gene MRNA And ALS9 Gene MRNA Of Candida Albicans In Different Biological Status

Objective To evaluate the role of Candida albicans ALS gene in transformation and biofilm formation, to provide theoretical basis for Candida albicans pathogenesis so that compare the expression of ALS gene mRNA level of Candida albicans between yeast and hyphal, between plantonic and biofilm.Methods Three C.albicans standard and ten clinical strain were induced to form yeast form in the condition cultured in GBS culture medium for 48h at 25℃, at planktonic condition. Germ tubes were induced by cultured in RPMI-1640 medium for 3h at 37℃, pH value at 7.0 with the shake speed of 150rpm. Biofilm models in vitro were formed on 6-well cell culture plate in RPMI-1640 media., after 48h incubation, the biofilm-grown cells were harvest. Liquid nitrogen and Trizol method were performed to isolate total RNA from the four different biological status separately. The purity of RNA was measured by absorption at 260/280nm with spectrophotometer. A semi-quantitative RT-PCR two-step method was developed to determine ALS4 and ALS9 genes against the housekeeping gene ACT 1.The identity of cloned fragments was confirmed with agarose gel electrophoresis. Gene expression leves were assayed by gel documentation system and Quantity One software. The paired test was used to analyze the experimental data.Result The RT-PCR results showed that the expression levels of ALS4 mRNA (P <0.05) and ALS9mRNA (P<0.05) of the standard strains were higher in germ tube compared with yeast form. Expression levels of ALS4 mRNA (P<0.05) and ALS9 mRNA (P<0.05) of the clinical strains were higher in germ tube compared with yeast form. Expression levels of ALS4 mRNA (P<0.05) and ALS9mRNA (P<0.05) of the standard strains in biofilm increased compare with planktonic cells.There were also increases in biofilm cells compared with the planktonic cells in the expression levels of ALS4mRNA(P<0.05) and ALS9mRNA (P<0.05) of the clinical strain.Conclusion The ALS4 and ALS9 gene may play an important role in Candida albicans transformation from yeast to germ tube and in biofilm formation in vitro.