title: Candida parapsilosis, Candida orthopsilosis, and Candida metapsilosis virulence in the non-conventional host Galleria mellonella.
abstract: The incidence of fungal infections due to C. parapsilosis and closely related cryptic species (-psilosis complex) has increased in the last few years, but differences in virulence among these species have not been widely studied. Fifteen clinical isolates of C. parapsilosis, C. orthopsilosis, and C. metapsilosis, including the type strains, were used to evaluate their virulence in Galleria mellonella larvae. Fluctuations in the hemocyte density and in the phagocytic activity were also tested. Differences in the median survival for these species were demonstrated at 37 °C (2.6 ± 1.02, 2.3 ± 0.92, and 4.53 ± 1.65 d for C. parapsilosis, C. orthopsilosis, and C. metapsilosis, respectively). Galleria mellonella hemocytes phagocytosed C. metapsilosis strains more effectively than did for C. orthopsilosis and C. parapsilosis (P<0.05). The phagocytosis rate was lower for C. parapsilosis than for C. orthopsilosis (P<0.05). The hemocyte density was increased in larvae infected with C. metapsilosis compared with those infected with C. parapsilosis or C. orthopsilosis (P<0.05). Moreover, in vitro studies of virulence factors such as pseudohyphae production and hydrolytic enzyme secretion showed that the capability of C. metapsilosis strains to produce those virulence factors was reduced. Infections due to -psilosis complex species produced tissue damage in G. mellonella and pseudohyphae could be also observed during infection with C. parapsilosis.
authors.affiliation: Mycology Reference Laboratory; Centro Nacional de Microbiologia; Instituto de Salud Carlos III; Madrid, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Gago
authors.affiliation: Mycology Reference Laboratory; Centro Nacional de Microbiologia; Instituto de Salud Carlos III; Madrid, Spain.
authors.forename: Rocío
authors.initials: R
authors.lastname: García-Rodas
authors.affiliation: Bioinformatic Unit; Centro Nacional de Microbiología; Instituto de Salud Carlos III; Madrid, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Cuesta
authors.affiliation: Mycology Reference Laboratory; Centro Nacional de Microbiologia; Instituto de Salud Carlos III; Madrid, Spain.
authors.forename: Emilia
authors.initials: E
authors.lastname: Mellado
authors.affiliation: Mycology Reference Laboratory; Centro Nacional de Microbiologia; Instituto de Salud Carlos III; Madrid, Spain; Spanish Network for the Research in Infectious Diseases (REIPI RD12/0015); Instituto de Salud Carlos III; Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Alastruey-Izquierdo
mesh_terms: D000818:Animals; D002175:Candida / Q000254:growth & development / Q000302:isolation & purification / Q000472:pathogenicity*; D002177:Candidiasis / Q000382:microbiology; D006801:Humans; D007915:Lepidoptera / Q000382:microbiology*; D014774:Virulence
keywords: Candida metapsilosis; Candida orthopsilosis; Candida parapsilosis; Galleria mellonella; virulence