title: Candida metapsilosis as the least virulent member of the 'C. parapsilosis' complex.
abstract: Results of recent molecular studies have provided evidence of three distinct species within the Candida parapsilosis complex, namely Candida parapsilosis, Candida orthopsilosis and Candida metapsilosis. While there are initial data pertaining to the virulence of these Candida species with respect to reconstituted epidermal and oral epithelial tissues, there have been no studies, as of yet, on their interaction with immune cells. Employing an in vitro infection model using microglial cells, we investigated the pathogenetic potential of different isolates of each of these three species. We show that C. metapsilosis isolates are more susceptible to microglia-mediated antifungal activity, as compared with those of C. parapsilosis and C. orthopsilosis. Interestingly, C. metapsilosis isolates are also phagocytosed to a lower extent, but the yeast-containing phagosomes exhibit the highest degree of acidification in comparison with the phagosomes containing C. parapsilosis or C. orthopsilosis. Furthermore, when assessing microglia secretory response to infection, comparable high levels of MIP-1α and little or no TNF-α production are observed with all of these Candida species. Finally, unlike C. metapsilosis infected cells, microglial cells infected with C. parapsilosis and C. orthopsilosis release high and time-dependent levels of lactate dehydrogenase (LDH). Overall, these findings point to C. metapsilosis as the least virulent member of the 'C. parapsilosis' complex.
authors.affiliation: Dipartimento di Scienze di Sanità Pubblica, Università degli Studi di Modena e Reggio Emilia, Modena, Italy.
authors.forename: Carlotta Francesca
authors.initials: CF
authors.lastname: Orsi
authors.forename: Bruna
authors.initials: B
authors.lastname: Colombari
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Blasi
mesh_terms: D000818:Animals; D002175:Candida / Q000276:immunology / Q000472:pathogenicity*; D002478:Cells, Cultured; D054405:Chemokine CCL3 / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D051379:Mice; D017628:Microglia / Q000276:immunology / Q000382:microbiology; D010587:Phagocytosis; D010588:Phagosomes / Q000737:chemistry; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014774:Virulence
chemical_list: D054405:Chemokine CCL3; D014409:Tumor Necrosis Factor-alpha; D007770:L-Lactate Dehydrogenase