OBJECTIVETo observe the drug resistance and drug efflux pumps gene mRNA of Saccharomyces albicans, including CDR1 gene and MDR1 gene, at different stage of biofilm formation in chemostat, furthermore to analysis the relationship between the drug efflux pump gene expression and the biofilm related drug resistance.

METHODSTo form the mature biofilm in vitro in chemostat, then collect the biofilm strains at different development stages (2, 12, 24, 48 h) to semi-quantified mRNA amount of CDR1 gene and MDR1 gene by one step RT-PCR method. Using XTT reduction method to test the dynamic change of Saccharomyces albicans drug resistance in biofilm.

RESULTSAntifungal resistance of biofilm-grown cells increased conjunction with the biofilm maturation. Compared with earth stage of biofiom strains, the amount of CDR1 mRNA gene in mature biofilm strains increased, while MDR1 gene did not.

CONCLUSIONThere is positive correlation between drug resistance and biofilm maturation of Saccharomyces albicans. Biofilm related drug resistance appears to be partially associated with the upregulation of drug efflux pumps, although the variation is not shown coincidence. During the biofilm formation, CDR1 gene expression is actively up-regulated, but MDR1 gene expression is stable.