P048 Antifungal susceptibility and mechanism of azole resistance in Candida albicans clinical isolates from oropharyngeal candidiasis patients in Iran

Abstract

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PM ObjectivesOropharyngeal candidiasis (OPC) is the most frequent opportunistic fungal infection in head and neck cancer patients. This study was done to investigate the azole susceptibility of Candida albicans (C. albicans) from oropharyngeal candidiasis (OPC) patients and to determine the relationship between ERG11 gene mutations in these isolates and azole resistance.MethodsA total of 324 clinical isolates of Candida species were collected. Identification of the oral clinical samples was determined by culturing on CHROMagar, carbohydrate assimilation and ITS sequencing methods. Azole susceptibility was tested in vitro in microdilution studies. The ERG11 genes of 42 isolates of C. albicans were amplified and sequenced.ResultsOf the 324 isolates collected, 44.75% (145 isolates) were C. albicans. ERG11 gene was sequenced in 42 isolates. In total, 14 missense mutations were detected in ERG11 genes from 42 isolates. Among them, A945C and T495A substitutions were most prevalent and were known to cause fluconazole resistance.ConclusionsA total of 14 mutations in the ERG11 gene were identified in azole-resistant C. albicans isolates, which indicated a possible relation with the increase in resistance to azole drugs and the recurrence of oropharyngeal candidiasis. Finding more mutations and relevance requires studies with a higher number of samples.