Low level of antifungal resistance of Candida glabrata blood isolates in Turkey: Fluconazole minimum inhibitory concentration and FKS mutations can predict therapeutic failure

Amir Arastehfar, Farnaz Daneshnia, Mohammadreza Salehi, Melike Yaşar, Tuğrul Hoşbul, Macit Ilkit, Weihua Pan, Ferry Hagen, Nazlı Arslan, Hatice Türk-Dağı, Süleyha Hilmioğlu-Polat, David S Perlin, Cornelia Lass-Flörl

Research output: Contribution to journal/periodicalArticleScientificpeer-review

Abstract

BACKGROUND: Candida glabrata is the third leading cause of candidaemia in Turkey; however, the data regarding antifungal resistance mechanisms and genotypic diversity in association with their clinical implication are limited.

OBJECTIVES: To assess genotypic diversity, antifungal susceptibility and mechanisms of drug resistance of C glabrata blood isolates and their association with patients' outcome in a retrospective multicentre study.

PATIENTS/METHODS: Isolates from 107 patients were identified by ITS sequencing and analysed by multilocus microsatellite typing, antifungal susceptibility testing, and sequencing of PDR1 and FKS1/2 hotspots (HSs).

RESULTS: Candida glabrata prevalence in Ege University Hospital was twofold higher in 2014-2019 than in 2005-2014. Six of the analysed isolates had fluconazole MICs ≥ 32 µg/mL; of them, five harboured unique PDR1 mutations. Although echinocandin resistance was not detected, three isolates had mutations in HS1-Fks1 (S629T, n = 1) and HS1-Fks2 (S663P, n = 2); one of the latter was also fluconazole-resistant. All patients infected with isolates carrying HS-FKS mutations and/or demonstrating fluconazole MIC ≥ 32 µg/mL (except one without clinical data) showed therapeutic failure (TF) with echinocandin and fluconazole; seven such isolates were collected in Ege (n = 4) and Gulhane (n = 3) hospitals and six detected recently. Among 34 identified genotypes, none were associated with mortality or enriched for fluconazole-resistant isolates.

CONCLUSION: Antifungal susceptibility testing should be supplemented with HS-FKS sequencing to predict TF for echinocandins, whereas fluconazole MIC ≥ 32 µg/mL may predict TF. Recent emergence of C glabrata isolates associated with antifungal TF warrants future comprehensive prospective studies in Turkey.

Original languageEnglish
Pages (from-to)911-920
Number of pages10
JournalMycoses
Volume63
Issue number9
DOIs
Publication statusPublished - Sep 2020

Fingerprint

Dive into the research topics of 'Low level of antifungal resistance of Candida glabrata blood isolates in Turkey: Fluconazole minimum inhibitory concentration and FKS mutations can predict therapeutic failure'. Together they form a unique fingerprint.

Cite this