Antigenic relations between pathogenic Paecilomyces lilacinus and P. variotii and other hyalohyphomycotic agents

AbstractObjective: The antigenic relations between Paecilomyces variotii and Paecilomyces lilacinus were studied by comparison of their exoantigens.Methods: Forty-one isolates of hyalohyphomycosis-causing fungi including P. lilacinus (n = 15) and P. variotii (n = 12), one isolate each of Paecilomyces inflatus, Paecilomyces marquandii, and Paecilomyces carneus, Fusarium species (n = 3), Neosartorya pseudofischeri (n = 5), and Penicillium species (n = 3), were studied using the exo-antigen test. Ten-day-old extracts derived from Sabouraud's dextrose agar slants were concentrated (25x), and reacted against rabbit anti-P. lilacinus and anti-P. variotii sera in the presence of partially purified homologous antigens (20x) prepared from 5-week-old shaken cultures. Extracts of isolates of P. lilacinus and P. variotii produced one to three lines of identity against the reference homologous antisera. No cross-reactivity or bands of non-identity were observed with other Paecilomyces isolates, N. pseudofischeri, Fusarium species, and Penicillium species isolates.Conclusion: The results of this investigation indicate that P. lilacinus and P. variotii are antigenically distinct and that they can be identified rapidly and accurately by their exoantigens. Exoantigen extracts of morphologically similar fungi and other species of Paecilomyces isolates studied did not possess antigens common to P. lilacinus and P. variotii