title: Detection and quantitation of the glucuronoxylomannan-like polysaccharide antigen from clinical and nonclinical isolates of Trichosporon beigelii and implications for pathogenicity.
abstract: Sera from patients with systemic infections caused by the opportunistic fungus Trichosporon beigelii have been shown to cross-react with anticryptococcal antibodies. We quantitatively compared the amounts of antigen produced and examined the expression of O-acetyl epitopes from 35 strains of T. beigelii isolated from deep and superficial infections. By counterimmunoelectrophoresis, 10 of 10 isolates from deep infections were positive for polysaccharide, compared with 7 of 13 isolates from superficial infections (P = 0.02). All 23 strains tested were positive for polysaccharide when screened by immunodot. By enzyme immunoassay, the cross-reactive antigen produced by deep isolates (n = 9) had a mean titer of 1:5,500. In contrast, superficial isolates (n = 22) produced significantly less antigen than the deep isolates (P < 0.001), with a mean titer of 1:700. Isolates from environmental sources (n = 3) were similar to the superficial isolates, with a mean titer of 1:600. The mean concentrations +/- standard errors of cross-reactive polysaccharide released by deep isolates and superficial isolates were 3.09 +/- 0.44 and 1.74 +/- 0.30 micrograms/ml, respectively, when measured by rocket immunoelectrophoresis (P = 0.02). O-Acetyl epitopes were detected on polysaccharide from 8 of 9 strains of T. beigelii isolated from deep sources, while only 2 of 12 superficial isolates expressed detectable O-acetyl epitopes (P = 0.01). Thus, while all isolates of T. beigelii tested were capable of producing glucuronoxylomannan-like cross-reactive antigen, pathogenic isolates produced significantly more antigen than superficial or environmental isolates. Furthermore, significantly more pathogenic isolates than superficial or environmental isolates expressed antigen that was O acetylated.
authors.affiliation: Pediatric Branch, National Cancer Institute, Bethesda, Maryland.
authors.forename: C A
authors.initials: CA
authors.lastname: Lyman
authors.forename: S J
authors.initials: SJ
authors.lastname: Devi
authors.forename: J
authors.initials: J
authors.lastname: Nathanson
authors.forename: C E
authors.initials: CE
authors.lastname: Frasch
authors.forename: P A
authors.initials: PA
authors.lastname: Pizzo
authors.forename: T J
authors.initials: TJ
authors.lastname: Walsh
mesh_terms: D000107:Acetylation; D000942:Antigens, Bacterial / Q000276:immunology* / Q000302:isolation & purification; D001769:Blood / Q000382:microbiology; D003429:Cross Reactions; D003454:Cryptococcus / Q000276:immunology; D000939:Epitopes; D006801:Humans; D007122:Immunoelectrophoresis; D007124:Immunoenzyme Techniques; D009181:Mycoses / Q000382:microbiology*; D011134:Polysaccharides / Q000276:immunology* / Q000302:isolation & purification; D011135:Polysaccharides, Bacterial / Q000276:immunology* / Q000302:isolation & purification; D012867:Skin / Q000382:microbiology; D013183:Sputum / Q000382:microbiology; D014250:Trichosporon / Q000276:immunology* / Q000472:pathogenicity
chemical_list: D000942:Antigens, Bacterial; D000939:Epitopes; D011134:Polysaccharides; D011135:Polysaccharides, Bacterial; C027478:glucuronoxylomannan