title: Histoplasma capsulatum variety duboisii isolated in Japan from an HIV-infected Ugandan patient.
abstract: A strain of Histoplasma capsulatum var. duboisii (deposited as IFM 50954 in Chiba University) was isolated from the cerebrospinal fluid of a female Ugandan patient infected with HIV. The isolate had in vitro urease activity on Christensen's urea agar slants, although the common belief is that H. capsulatum var. duboisii is urease negative, and is, considered one of the characteristic markers that distinguishes the three varieties of H. capsulatum. Forty H. capsulatum var. capsulatum, five H. capsulatum var. duboisii, and five H. capsulatum var. farciminosum isolates were evaluated for urease activity on Christensen's urea agar slants and for other qualitative and quantitative urease assays of activity. All 50 isolates of H. capsulatum used in this study were positive for urease activity, suggesting that urease activity may be universal characteristic of H. capsulatum. We also compared the urease activity and pathogenicity of seven H. capsulatum isolates that convert into yeast-form cells. Although isolate IFM 50954 showed moderate virulence in mice and moderate urease activity among tested H. capsulatum isolates, there was no correlation between level of urease activity and pathogenicity. In addition, scanning electron microscopy revealed that some microconidia of isolate IFM 50954 formed "double-cell" configurations that were attached to each other by narrow bases.
authors: Research Center for Pathogenic Fungi and Microbial Toxicoses, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan.
authors: Shahana
authors: S
authors: Sharmin
authors: Akira
authors: A
authors: Ohori
authors: Ayako
authors: A
authors: Sano
authors: Katsuhiko
authors: K
authors: Kamei
authors: Masashi
authors: M
authors: Yamaguchi
authors: Kanji
authors: K
authors: Takeo
authors: Jun
authors: J
authors: Uno
authors: Kazuko
authors: K
authors: Nishimura
authors: Makoto
authors: M
authors: Miyaji
mesh_terms: D000818:Animals; D005260:Female; D015658:HIV Infections / Q000382:microbiology*; D006658:Histoplasma / Q000302:isolation & purification* / Q000472:pathogenicity; D006801:Humans; D007564:Japan; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D014454:Uganda / Q000208:ethnology; D014510:Urease / Q000032:analysis
chemical_list: D014510:Urease