Immunological fitness of echinocandin-resistant Nakaseomyces glabratus (former Candida glabrata): the impact on the management of candidemia

We here described the immunological fitness of echinocandin-resistant Candida glabrata and the consequence in term of management of candidemia. We used different in vitro model (simple and complex) and multiple microscopical techniques. <em>Nakaseomyces glabratus</em> (formerly <em>Candida glabrata</em>) (<em>N. glabratus</em>) is a commensal yeast that is increasingly associated with invasive candidiasis. The rapid acquisition of echinocandin resistance by <em>N. glabratus </em>has raised public health concerns and led the WHO to classify it as a high-priority fungal pathogen in 2022. However, the impact of antifungal resistance on the host immune response remains poorly understood. Since echinocandin resistance often involves alterations to the fungal cell wall, which is critical for host immune recognition, such mutations may affect fungal fitness and immune evasion. We analyzed the immunological fitness of echinocandin-resistant <em>N. glabratus</em> using clinical isolates from a patient with recurrent bloodstream infections. <em>In vitro</em> yeast-macrophage and yeast-human leukocyte co-culture models were used to evaluate immune responses. Echinocandin-resistant isolates exhibited modified cell wall composition. Compared to susceptible strains, the resistant isolates induced a delayed and reduced pro-inflammatory cytokine response and demonstrated prolonged survival within immune aggregates. These findings suggest that immune evasion and persistence may confer additional fitness advantages to echinocandin-resistant <em>N. glabratus</em>, potentially impacting the pathophysiological interactions between host and pathogen