title: Paracoccidioides brasiliensis isolated from armadillos is virulent to Syrian hamsters.
abstract: Isolates of Paracoccidioides brasiliensis may vary in virulence according to time of in vitro subcultivation. The present study compared the morphology and pathogenicity to hamsters of two P. brasiliensis isolates: one obtained from human lesions and maintained in the laboratory for several years (Pb-18) and the other isolate recovered from hamsters inoculated with organ homogenates from armadillos (Pb-T). The microscopic morphology of Pb-18 and Pb-T showed yeast cells with similar diameter. However, Pb-T produced a significantly higher number of buds per mother cell than Pb-18. Besides, the mycelial form of Pb-T developed abundant sporulation during 8 weeks of culture which was absent in the Pb-18 isolate. Virulence studies demonstrated that mortality rates, antibody levels, fungal load and extent of lesions in the organs were significantly higher in animals infected with Pb-T. The results demonstrated that Pb-T recently isolated from an animal was more virulent than Pb-18. These differences between the two P. brasiliensis isolates may be indicators of virulence attenuation in this fungal species.
authors.affiliation: Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil. peracoli@ibb.unesp.br
authors.forename: M T
authors.initials: MT
authors.lastname: Peraçoli
authors.forename: M F
authors.initials: MF
authors.lastname: Sugizaki
authors.forename: R P
authors.initials: RP
authors.lastname: Mendes
authors.forename: R
authors.initials: R
authors.lastname: Naiff
authors.forename: M R
authors.initials: MR
authors.lastname: Montenegro
mesh_terms: D000818:Animals; D000908:Antibodies, Fungal / Q000097:blood; D001135:Armadillos / Q000382:microbiology*; D006224:Cricetinae; D005260:Female; D006801:Humans; D008168:Lung / Q000382:microbiology; D008297:Male; D008647:Mesocricetus / Q000382:microbiology*; D010228:Paracoccidioides / Q000276:immunology / Q000472:pathogenicity*; D010229:Paracoccidioidomycosis / Q000382:microbiology*; D014774:Virulence
chemical_list: D000908:Antibodies, Fungal