title: Conidial germination in Scedosporium apiospermum, S. aurantiacum, S. minutisporum and Lomentospora prolificans: influence of growth conditions and antifungal susceptibility profiles.
abstract: In the present study, we have investigated some growth conditions capable of inducing the conidial germination in Scedosporium apiospermum, S. aurantiacum, S. minutisporum and Lomentospora prolificans. Germination in Sabouraud medium (pH 7.0, 37ºC, 5% CO2) showed to be a typically time-dependent event, reaching ~75% in S. minutisporum and > 90% in S. apiospermum, S. aurantiacum and L. prolificans after 4 h. Similar germination rate was observed when conidia were incubated under different media and pHs. Contrarily, temperature and CO2 tension modulated the germination. The isotropic conidial growth (swelling) and germ tube-like projection were evidenced by microscopy and cytometry. Morphometric parameters augmented in a time-dependent fashion, evidencing changes in size and granularity of fungal cells compared with dormant 0 h conidia. In parallel, a clear increase in the mitochondrial activity was measured during the transformation of conidia-into-germinated conidia. Susceptibility profiles to itraconazole, fluconazole, voriconazole, amphotericin B and caspofungin varied regarding each morphotype and each fungal species. Overall, the minimal inhibitory concentrations for hyphae were higher than conidia and germinated conidia, except for caspofungin. Collectively, our study add new data about the conidia-into-hyphae transformation in Scedosporium and Lomentospora species, which is a relevant biological process of these molds directly connected to their antifungal resistance and pathogenicity mechanisms.
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Departamento de Microbiologia Geral, Laboratório de Investigação de Peptidases, Rio de Janeiro, RJ, Brasil.
authors.forename: Thaís Pereira de
authors.initials: TP
authors.lastname: Mello
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Departamento de Microbiologia Geral, Laboratório de Investigação de Peptidases, Rio de Janeiro, RJ, Brasil.
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Aor
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Departamento de Microbiologia Geral, Laboratório de Investigação de Peptidases, Rio de Janeiro, RJ, Brasil.
authors.forename: Simone Santiago Carvalho de
authors.initials: SS
authors.lastname: Oliveira
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Departamento de Microbiologia Geral, Laboratório de Investigação de Peptidases, Rio de Janeiro, RJ, Brasil.
authors.forename: Marta Helena
authors.initials: MH
authors.lastname: Branquinha
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Departamento de Microbiologia Geral, Laboratório de Investigação de Peptidases, Rio de Janeiro, RJ, Brasil.
authors.forename: André Luis Souza Dos
authors.initials: AL
authors.lastname: Santos
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D003470:Culture Media / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D021681:Scedosporium / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D013172:Spores, Fungal / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D013997:Time Factors
chemical_list: D000935:Antifungal Agents; D003470:Culture Media