title: Resistance of Aspergillus fumigatus to Micafungin is Increased by Exogenous β-glucan.
abstract: Aspergillus species are ubiquitous in the environment and Aspergillus fumigatus can cause life-threatening infections in immunocompromised patients. β-1,3-/1,6-glucan is a major fungal cell wall polysaccharide that has various biological effects on the infected host, but little is known about the influence of β-glucan on the fungus itself. In a previous study, we demonstrated that the cell wall β-glucan content could be increased in Aspergillus spp. by addition of β-glucan to the culture medium. In this study, we investigated the influence of β-glucan on the susceptibility of A. fumigatus to antifungal agents. A. fumigatus was cultured in the presence or absence of β-glucan for antifungal susceptibility testing based on changes of the growth rate and morphology. Susceptibility to micafungin, a β-glucan synthase inhibitor, was about 10-fold lower when β-glucan was added to the culture medium. On the other hand, susceptibility to amphotericin B and voriconazole was similar in either the presence or absence of β-glucan. These results strongly suggest that β-glucan has an important physiological role in Aspergillus spp.
authors.affiliation: Laboratory for Immunopharmacology of Microbial Products, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences.
authors.forename: Takashi
authors.initials: T
authors.lastname: Toyoshima
authors.forename: Ken-Ichi
authors.initials: KI
authors.lastname: Ishibashi
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yamanaka
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Adachi
authors.forename: Naohito
authors.initials: N
authors.lastname: Ohno
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D001232:Aspergillus fumigatus / Q000187:drug effects* / Q000378:metabolism; D025141:Drug Resistance, Fungal / Q000187:drug effects*; D054714:Echinocandins / Q000494:pharmacology*; D006801:Humans; D055666:Lipopeptides / Q000494:pharmacology*; D000077551:Micafungin; D047071:beta-Glucans / Q000378:metabolism* / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D054714:Echinocandins; D055666:Lipopeptides; D047071:beta-Glucans; C064197:beta-1,6-glucan; C033363:beta-1,3-glucan; D000077551:Micafungin