PL EN


Preferences help
enabled [disable] Abstract
Number of results
2013 | 60 | 4 | 547-552
Article title

Nucleotide substitutions in the Candida albicans ERG11 gene of azole-susceptible and azole-resistant clinical isolates

Content
Title variants
Languages of publication
EN
Abstracts
EN
One of the mechanisms of Candida albicans resistance to azole drugs used in antifungal therapy relies on increased expression and presence of point mutations in the ERG11 gene that encodes sterol 14α demethylase (14DM), an enzyme which is the primary target for the azole class of antifungals. The aim of the study was to analyze nucleotide substitutions in the Candida albicans ERG11 gene of azole-susceptible and azole-resistant clinical isolates. The Candida albicans isolates represented a collection of 122 strains selected from 658 strains isolated from different biological materials. Samples were obtained from hospitalized patients. Fluconazole susceptibility was tested in vitro using a microdilution assay. Candida albicans strains used in this study consisted of two groups: 61 of the isolates were susceptible to azoles and the 61 were resistant to azoles. Four overlapping regions of the ERG11 gene of the isolates of Candida albicans strains were amplified and sequenced. The MSSCP (multitemperature single strand conformation polymorphism) method was performed to select Candida albicans samples presenting genetic differences in the ERG11 gene fragments for subsequent sequence analysis. Based on the sequencing results we managed to detect 19 substitutions of nucleotides in the ERG11 gene fragments. Sequencing revealed 4 different alterations: T495A, A530C, G622A and A945C leading to changes in the corresponding amino acid sequence: D116E, K128T, V159I and E266D. The single nucleotide changes in the ERG11 gene did not affect the sensitivity of Candida albicans strains, whereas multiple nucleotide substitutions in the ERG11 gene fragments indicated a possible relation with the increase in resistance to azole drugs.
Year
Volume
60
Issue
4
Pages
547-552
Physical description
Dates
published
2013
received
2012-10-05
revised
2013-06-25
accepted
2013-11-25
(unknown)
2013-12-16
References
  • Akins RA (2005) An update on antifungal targets and mechanisms of resistance in Candida albicans. Med Mycol 43: 285-318.
  • Chau AS et al. (2004) Application of real-time quantitative PCR to molecular analysis of Candida albicans strains exhibiting reduced susceptibility to azoles. Antimicrob Agents Chemother 48: 2124-2131.
  • Chen LM et al. (2010) Overexpression of CDR1 and CDR2 genes plays an important role in fluconazole resistance in Candida albicans with G487T and T916C mutations. J Int Med Res 38: 536-45.
  • Favre B, Didmon M, Ryder NS (1999) Multiple amino acid substitutions in lanosterol 14alpha-demethylase contribute to azole resistance in Candida albicans. Microbiology 145: 2715-2725.
  • Franz R et al. (1998) Multiple molecular mechanisms contribute to a stepwise development of fluconazole resistance in clinical Candida albicans strains. Antimicrob Agents Chemother 42: 3065-3072.
  • Goldman GH et al. (2004) Evaluation of fluconazole resistance mechanisms in Candida albicans clinical isolates from HIV-infected patients in Brazil. Diagn Microbiol Infect Dis 50: 25-32.
  • Kamai Y et al. (2004) Characterization of mechanisms of fluconazole resistance in a Candida albicans isolate from a Japanese patient with chronic mucocutaneous candidiasis. Microbiol Immunol 48: 937-943.
  • Lee MK et al. (2004) Drug resistance genes and trailing growth in Candida albicans isolates. J Antimicrob Chemother 53: 217-224.
  • Lupetti A et al. (2002) Molecular basis of resistance to azole antifungals. Trends Mol Med 8: 76-81.
  • MacCallum DM et al. (2010) Genetic dissection of azole resistance mechanisms in Candida albicans and their validation in a mouse model of disseminated infection. Antimicrob Agents Chemother 54: 1476-83.
  • Maebashi K et al. (2003) Proliferation of intracellular structure corresponding to reduced affinity of fluconazole for cytochrome P-450 in two low-susceptibility strains of Candida albicans isolated from a Japanese AIDS patient. Microbiol Immunol 47: 117-124.
  • Marichal P et al. (1999) Contribution of mutations in the cytochrome P450 14α-demethylase (Erg11p, Cyp51p) to azole resistance in Candida albicans. Microbiology 145: 2701-2713.
  • Marr KA et al. (1998) Rapid, transient fluconazole resistance in Candida albicans is associated with increased mRNA levels of CDR. Antimicrob Agents Chemother 42: 2584-2587.
  • Martinez M et al. (2002) Heterogeneous mechanisms of azole resistance in Candida albicans clinical isolates from an HIV-infected patient on continuous fluconazole therapy for oropharyngeal candidosis. J Antimicrob Chemother 49: 515-524.
  • Morio F et al. (2010) Screening for amino acid substitutions in the Candida albicans Erg11 protein of azole-susceptible and azole-resistant clinical isolates: new substitutions and a review of the literature. Diagn Microbiol Infect Dis 66: 373-84.
  • Morschhäuser J (2002) The genetic basis of fluconazole resistance development in Candida albicans. Biochim Biophys Acta 1587: 240-248.
  • Owen LE et al. (2000) Evolution of drug resistance in experimential populations of Candida albicans. J Bacteriol 182: 1515-1522.
  • Perea S et al. (2001) Prevalence of molecular mechanisms of resistance to azole antifungal agents in Candida albicans strains displaying high-level fluconazole resistance isolated from human human immunodeficiency virus-infected patients. Antimicrob Agents Chemother 45: 2676-2684.
  • Prasad R, Kapoor K (2005) Multidrug resistance in yeast Candida. Int Rev Cytol 242: 215-248.
  • Rex JH, Rinaldi MG, Pfaller MA (1995) Resistance of Candida species to fluconazole. Antimicrob Agents Chemother 39: 1-8.
  • Sanglard D et al. (1998) Amino acid substitutions in the cytochrome P-450 lanosterol 14α-demethylase (CYP51A1) from azole-resistant Candida albicans clinical isolates contribute to resistance to azole antifungal agents. Antimicrob Agents Chemother 42: 241-253.
  • Sanglard D, Odds FC (2002) Resistance of Candida species to antifungal agents: molecular mechanisms and clinical consequences. Lancet Infect Dis 2: 73-85.
  • Sanglard D et al. (2003) Candida albicans mutations in the ergosterol biosynthetic pathway and resistance to several antifungal agents. Antimicrob Agents Chemother 47: 2404-2412.
  • Sasse C, Dunkel N, Schäfer T, Schneider S, Dierolf F, Ohlsen K, Morschhäuser J (2012) The stepwise acquisition of fluconazole resistance mutations causes a gradual loss of fitness in Candida albicans. Mol Microbiol 86: 539-56.
  • Slemp-Migiel A et al. (2009) MSSCP technology as a tool for the detection of genetic differences in ERG11 gene in Candida albicans sensitive and resistant to azoles. Med Mycol 16: 5-9.
  • Wang H (2009) Rapid detection of ERG11 gene mutations in clinical Candida albicans isolates with reduced susceptibility to fluconazole by rolling circle amplification and DNA sequencing. BMC Microbiol 9: 167-178.
  • White TC, Marr KA, Bowden RA (1998) Clinical, cellular, and molecular factors that contribute to antifungal drug resistance. Clin Microbiol Rev 11: 382-402.
  • White TC et al. (2002) Resistance mechanisms in clinical isolates of Candida albicans. Antimicrob Agents Chemother 46: 1704-1713.
  • Xu Y, Chen L, Li C (2008) Susceptibility of clinical isolates of Candida species to fluconazole and detection of Candida albicans ERG11 mutations. J Antimicrob Chemother 61: 798-804.
Document Type
Publication order reference
YADDA identifier
bwmeta1.element.bwnjournal-article-abpv60p547kz
Identifiers
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.