The expression of genes related to azole resistance and biofilm in Candida albicans

doi:10.3969/j.issn.1673-8640.2014.06.005

Abstract

Abstract:

Objective To investigate the expression of genes related to azole resistance and biofilm formation capability in clinical isolates of Candida albicans. Methods In this study, 104 Candida albicans were isolated from blood, sterile sites and mucosal lesions of 92 infectious disease patients [viral hepatitis, tuberculosis and acquired immune deficiency syndrome (AIDS) in Shanghai Public Health Clinical Center from 2006 to 2011. The minimum inhibitory concentrations (MICs) of fluconazole, itraconazole and voriconazole were determined by ATB FUNGUS3. The gene expression of efflux pump genes (CDR1, CDR2 and MDR1) and azole antifungal target gene ERG11 were determined by semi-quantitative reverse transcription polymerase chain reaction (PCR), and the azole susceptibe and susceptible dose dependent (S-DD) states were analyzed. 2,3-bis-(2-methoxy-4-nitro-5-sulphenyl)-2H-tetrazolium- 5-carboxanilide (XTT) test was used to screen the high biofilm formation capability isolates (HBPs). The expressions of ALS3 and HWP1 in low biofilm formation capability isolates (LBPs) were analyzed. Results Among 104 isolates of Candida albicans, 16 isolates were tested resistant to at least one azole, 6 isolates were S-DD to at least one azole.There were statistical significance among resistant, S-DD and susceptible isolates in azole antifungal target gene ERG11 (P=0.007 8), and significant difference was found when comparing susceptible isolates with resistant and S-DD ones (P<0.05). No significant difference was found in the expression levels of efflux pump genes, CDR1, CDR2 and MDR1. The expression levels of HWP1 in HBFs were higher than those in LBFswith statistical significance (P=0.007 9), whereas ALS3 showed nostatistical significance. Conclusions The overexpression levels of ERG11 gene may primarily account for resistance to azole in Candida albicans. High expression of hyphal wall protein HWP1 gene is associated to biofilm formation capability in Candida albicans.

Key words: Efflux pump, ERG11, Biofilm, Candida albicans

CLC Number:

R446.5

HU Lüyin, ZAI Shubei, JIN Xin, CAI Jinfeng, CAO Yushuo, HU Xiangnan, DU Xin, LI Tianming, LI Min. The expression of genes related to azole resistance and biofilm in Candida albicans[J]. , 2014, 29(6): 597-602.

References

[1] Kim J, Sudbery P. Candida albicans, a major human fungal pathogen[J] . J Microbiol,2011,49(2):171-177.
[2] Guo F, Yang Y, Kang Y, et al. Invasive candidiasis in intensive care units in China: a multicentre prospective observational study[J] . J Antimicrob Chemother,2013,68(7):1660-1668.
[3] Rosenblatt HM, Byrne W, Ament ME, et al. Successful treatment of chronic mucocutaneous candidiasis with ketoconazole[J] . J Pediatr,1980,97(4):657-660.
[4] Kontoyiannis DP, Lewis RE. Antifungal drug resistance of pathogenic fungi[J] . Lancet,2002,359(9312):1135-1144.
[5] Sanglard D, Kuchler K, Ischer F, et al. Mechanisms of resistance to azole antifungal agents in Candida albicans isolates from AIDS patients involve specific multidrug transporters[J] . Antimicrob Agents Chemother,1995,39(11):2378-2386.
[6] Sanglard D, Odds FC. Resistance of Candida species to antifungal agents: molecular mechanisms and clinical consequences[J] . Lancet Infect Dis,2002,2(2):73-85.
[7] Xiang MJ, Liu JY, Ni PH, et al. Erg11 mutations associated with azole resistance in clinical isolates of Candida albicans[J] . FEMS Yeast Res,2013,13(4):386-393.
[8] 项明洁,倪培华,刘锦燕,等. ERG11基因突变与白念珠菌对氟康唑耐药性的初步研究[J] . 检验医学,2009,24(12):856-860.
[9] D′Enfert C. Biofilms and their role in the resistance of pathogenic Candida to antifungal agents[J] . Curr Drug Targets,2006,7(4):465-470.
[10] Seneviratne CJ, Jin LJ, Samaranayake YH, et al. Cell density and cell aging as factors modulating antifungal resistance of Candida albicans biofilms[J] . Antimicrob Agents Chemother,2008,52(9):3259-3266.
[11] Perea S. Azole resistance in Candida albicans[J] . Rev Esp Quimioter,2000,13(3):314-317.
[12] Basso LJ Jr, Gast CE, Mao Y, et al. Fluconazole transport into Candida albicans secretory vesicles by the membrane proteins Cdr1p, Cdr2p, and Mdr1p[J] . Eukaryot Cell,2010,9(6):960-970.
[13] 江岑,董丹凤,俞焙秦,等. 3种念珠菌对氟康唑耐药的易感性及耐药机制比较[J] . 中国感染与化疗杂志,2013, 13(4):296-301.
[14] Nailis H, Vandenbroucke R, Tilleman K, et al. Monitoring ALS1 and ALS3 gene expression during in vitro Candida albicans biofilm formation under continuous flow conditions[J] . Mycopathologia,2009,167(1):9-17.
[15] Nobile CJ, Nett JE, Andes DR, et al. Function of Candida albicans adhesin Hwp1 in biofilm formation[J] . Eukaryot Cell,2006,5(10):1604-1610.