Fluconazole Resistance in Candida albicans: basal ERG11, MDR1 and CDR1 gene expression of Clinical Isolates in Ecuador

Abstract

Candida albicans is one of the most frequently reported opportunistic pathogens that cause life-threatening conditions with high mortality rates. Azoles are the first line of treatment for 3 3 this fungus, but resistance to these drugs has increasingly been reported worldwide. Azoles resistance has been associated with various molecular mechanisms such as overexpression and mutations of ERG11, MDR1 and CDR1 genes. Adequate surveillance of resistance mechanisms would allow better treatment strategies. The aim of this study was to determine the basal expression of genes related to the azole resistance (MDR1, CDR1 and ERG11) by qPCR in 53 C. albicans clinical isolates in Ecuador. The results showed that most samples (75,47%) expressed the three genes, with ERG11 being the most frequently expressed (94,34%). However, the CDR1 gene had the highest expression level (9,37E+04) among the three evaluated genes. Remarkably, only one sample presented no expression of these genes. Although correlation analyses do not show a relationship between the origin of the sample and the expression levels of the genes, most isolates with high expression of these azoles resistant genes come from urine samples. To the author's knowledge, this is the first study that analyzes the basal expression of genes related to azole resistance in Candida albicans and highlights the importance of epidemiological surveillance of this pathogen in the country's health system.