Dataset Information

Quantitation of ergosterol content and gene expression profile of ERG11 gene in fluconazole-resistant Candida albicans.

ABSTRACT: Background and Purpose:The frequency of opportunistic fungal infections in immunocompromised patients, especially by Candida species, has sharply increased in the last few decades. The objective of this study was to analyse the ergosterol content and gene expression profiling of clinical isolates of fluconazole-resistant Candida albicans. Materials and Methods:Sixty clinical samples were identified and collected from immunocompromised patients, namely recurrent oral, vaginal, and cutaneous candidiasis, during 2015-16. Antifungal susceptibility testing of fluconazole against clinical Candida species was performed according to Clinical and Laboratory Standards Institute guidelines. Ergosterol content and gene expression profiling of sterol 14?-demethylase (ERG11) gene in fluconazole-susceptible and -resistant C. albicans were investigated. Results:The specimens consisted of C. albicans (46.67%), Candida krusei (41.67%), and Candida tropicalis (11.67%). All the isolates were resistant to fluconazole. No significant reduction was noted in total cellular ergosterol content in comparison with untreated controls in terms of fluconazole-resistant C. albicans. The expressionlevel of ERG11 gene was down-regulated in fluconazole-susceptible C. albicans. Eventually, the expression pattern of ERG11 gene revealed no significant changes in fluconazole-resistant isolates compared to untreated controls. The results revealed no significant differences between fluconazole-susceptible and -resistant C. albicans sequences by comparison with ERG11 reference sequence. Conclusion:Our findings provide an insight into the mechanism of fluconazole resistance in C. albicans. The mechanisms proposed for clinical isolates of fluconazole-resistant C. albicans are alteration in sterol biosynthesis, analysis of expression level of ERG11 gene, and analysis of gene sequences. Nonetheless, further studies are imperative to find molecular mechanisms that could be targeted to control fluconazole resistance.

SUBMITTER: Alizadeh F

PROVIDER: S-EPMC5747584 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature

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Quantitation of ergosterol content and gene expression profile of <i>ERG11</i> gene in fluconazole-resistant <i>Candida albicans</i>.

Alizadeh F F Khodavandi A A Zalakian S S

Current medical mycology 20170301 1

<h4>Background and purpose</h4>The frequency of opportunistic fungal infections in immunocompromised patients<i>, </i>especially by <i>Candida</i> species<i>,</i> has sharply increased in the last few decades. The objective of this study was to analyse the ergosterol content and gene expression profiling of clinical isolates of fluconazole-resistant <i>Candida albicans.</i><h4>Materials and methods</h4>Sixty clinical samples were identified and collected from immunocompromised patients, namely r ...[more]

PMID: 29302625

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Project description:Background and purposeCandidiasis is referred to a group of superficial and deep-tissue fungal infections often caused by Candida albicans. The superficial infections affect the oral, oropharynx, esophagus, and vaginal mucosa. The treatment of choice for these infections is the use of azoles, such as fluconazole. However, the increased use of these antifungal agents has led to the emergence of azole-resistant isolates of C. albicans. Different mechanisms have been suggested for the development of drug resistance, such as mutations in the encoding gene ERG11. Mutations in ERG11 result in changes in the ERG11p spatial construction and reduce the affinity between the protein and azole. This study aimed to determine the susceptibility profile of C. albicans clinical isolates to fluconazole using microdilution method. The present research was also targeted toward the detection of mutations that might be related to fluconazole resistance by the amplification and sequencing of ERG11 gene.Materials and methodsThis study was conducted on a total of 216 clinical isolates obtained from Mashhad, Isfahan, and Tehran cities in Iran, during 2016-2018. The clinical isolates were identified using molecular techniques. Furthermore, minimum inhibitory concentration (MICs) was determined according to the clinical and laboratory standards institute M27-A3 and M27-S4 documents. The concentration range for fluconazole was obtained as 0.063-64 μg/ml. In the resistant strains, ERG11 genes were amplified by specific primers. Subsequently, cycle sequencing reactions were performed on purified polymerase chain reaction (PCR) products in forward and reverse directions. Finally, the results were analyzed by MEGA (version 7) and Gene Runner software (version 6.5.30).ResultsOut of 216 strains, 100 (46.3%) species were identified as C. albicans. The MIC values for fluconazole had a range of 0.125-16 μg/ml with the MIC50 and MIC90 values of 0.5 and 1 μg/ml, respectively. Totally, 41 nucleotide changes were detected among 4 resistant isolates. In this regard, 4 out of 41 mutations in codons caused changes in ERG11p; however, these mutations did not lead to fluconazole resistance.ConclusionFluconazole resistance among clinical isolates is not merely due to the changes in ERG11p. This resistance may be also related to some other mechanisms, such as the prevention of the intracellular accumulation of the antifungal agent and alteration of the target enzyme to diminish drug binding.

Dataset Information

Quantitation of ergosterol content and gene expression profile of ERG11 gene in fluconazole-resistant Candida albicans.

Publications

Quantitation of ergosterol content and gene expression profile of <i>ERG11</i> gene in fluconazole-resistant <i>Candida albicans</i>.

Similar Datasets

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