Host-pathogen interactions upon infection: fungal behaviour and immune response in .

has globally emerged as a multidrug-resistant fungus linked to healthcare-associated outbreaks. There is still limited evidence on its virulence, pathogenicity determinants, and complex host-pathogen interactions. This study analyzes the fungal behaviour, immune response, and host-pathogen interactions upon infection compared to and in This was performed by immunolabelling fungal structures and larval plasmatocytes and using a quantitative approach incorporating bioinformatic morphometric techniques into the study of microbial pathogenesis. presents a remarkably higher immunogenic activity than expected at its moderate degree of tissue invasion. It induces a greater inflammatory response than and at the expense of plasmatocyte nodule formation, especially in non-aggregative strains. It specifically invades the larval respiratory system, in a pattern not previously observed in other species, and presents inter-phenotypic tissue tropism differences. filaments less frequently than or mostly through pseudohyphal growth. Filamentation might not be a major pathogenic determinant in as less virulent aggregative phenotypes form pseudohyphae to a greater extent. has important both interspecific and intraspecific virulence and phenotype heterogeneity, with aggregative phenotypes of sharing characteristics with low pathogenic species such as Our work suggests that owns an important morphogenetic plasticity that distinguishes it from other yeasts of the genus. Routine phenotypic identification of aggregative or non-aggregative phenotypes should be performed in the clinical setting as it may impact patient management.