Role of mutation and over-expression of ERG11 gene inCandida albicans in cross-resistance to azoles

OBJECTIVE To preliminarily explore the role of the mutation and over-expression of ERG11 gene in Candida albicans in cross-resistant to azoles so as to provide theoretical basis for reasonable clinical use of antibiotics.METHODS The in vitro drug susceptibility testing was performed for 43 clinical C.albicansisolates that were collected from Sep 2014 to Oct 2015,then the ERG11 gene was amplified by using polymerase-chain-reaction（PCR）and was sequenced,the mutation of the ERG11 gene was analyzed,and the level of expression of mRNA of the ERG11 gene was detected with the use of real-time fluorescence quantitative PCR（RT-PCR）.RESULTS Of the43 experimental strains,15 were drug-susceptible,13 were single drug-resistant,and 15 were cross-resistant;five missense mutations,including T123 I,Y132H,E174 A,G450Eand G464 S,were identified in 9cross-resistant strains.The rate of the ERG11 gene mutation in the cross-resistant strains was significantly higher than that in the drug-susceptible strains and single drug-resistant strains（P＜0.05）.The expression level of mRNA of ERG11 gene was（4.00±2.06）in the cross-resistant strains,significantly higher than（0.93±0.21）in the drug-susceptible strains,however,there was no significant difference between the cross-resistant strains and the single drug-resistant strains（3.92±1.01）.CONCLUSION Both the mutation and over-expression of the ERG11 gene are the drug resistance mechanisms of the C.albicans,the cross-resistance is associated with the gene mutation,however,the correlation with the over-expression needs to be further studied.