Effect of the association of experimental compounds and antifungal in the expression of Candida albicans genes in stress response metabolic pathways associated with tolerance and resistance to antifungal drugs

Abstract

Many microorganisms in the medical and dental fields show tolerance or resistance to antibiotics/antimicrobial drugs. Thus, alternative compounds are sought that would not elicit tolerance/resistance and could be used concomitantly with drugs in clinical use to increase their efficacy. In 2022, WHO classified fungal pathogens into critical, high and moderate priorities and included Candida albicans in the critical list. This species is commensal and an opportunistic pathogen when host conditions are conducive for it to exert its pathogenesis. It contributes to the construction of biofilms associated with the development of caries lesions and causes several infections, from lesions in the oral mucosa to candidemia (fungus in the bloodstream) that can lead to death. Thus, the objective is to investigate how experimental compounds (which showed antimicrobial activity against cells grown in planktonic cultures and in biofilms) combined with antifungal drugs affect the expression of C. albicans genes linked to stress response metabolic pathways, as these genes are associated with tolerance and resistance. For this purpose, cultures of the SC5314 strain will be treated with the compounds tt-farnesol (terpenoid), hydroxychalcone'4 (metabolic intermediate for the synthesis of flavonoids) and myricetin (flavonoid) and with the antifungal drugs fluconazole, echinocandin and amphotericin B. Afterwards, RNA will be isolated, followed by cDNA synthesis and qPCR analysis with specific primers for the genes PKC1 (key kinase of the protein kinase C pathway of cell wall integrity), MKC1 (via MAPK), CNA1 (calcineurin pathway), HSP90 (chaperone), CDR1 (drug tolerance), ERG11 (ergosterol synthesis), SOD1 (oxidative stress) and FKS1 (cell wall). Quantitative data will be analyzed via descriptive and inferential statistics (±=0.05).