Antigenic similarity betweenCeratocystisspecies andSporothrix schenckiias observed by immunofluorescence

Abstract

Antigenic properties of Sporothrix schenckii and 2 species of Ceratocystis (C. stenoceras and C. ulmi) were compared by indirect immunofluoreseent staining technique. Both species of Ceratocystis and 2 strains of S. schenckii reacted equally well with the unabsorbed antisera against 2 strains ofS. schenckii, indicating that these three species share common antigen. Tile absorption experiments showed that only S. schenekii human strain demonstrated a unique antigen. These results support the hypothesis of Ceratocystis-Sporothrix complex in the point that both species have one major common antigen.Mariat (1971) proposed that a particular Ceratocystis species (ascomycetes), C. stenoceras, might be the perfect form of Sporothrix schenckii, based upon the similarity of the morphological characteristics of both species and the mode of experimental infection into hamster. Very recently, Mariat and co-worker gave additional findings in favour of this hypothesis by the ecological study (Mariat, 1975) and the analysis of lipids compositions (De Bieuvre & Mariat, 1975).To obtain further evidence for the hypothesis of Ceratocystis-Sporothrix complex, antigenic properties of S. schenckii and 2 Ceratocystis species, namely C. stenoceras and C. ulmi were compared serologically by indirect immunofluorescent staining technique in the present study. Antisera against 2 strains of S. schenckii isolated from different sources and the absorbed antiserum which was found to react with some of the clinical isolates (Nishikawa et al., 1975), were employed to clarify the serologic relationship between strains of Ceratocystis species and S. schenckii. MATERIALS AND METHODS MicroorganismsSporothrix schenckii KO 4606 was isolated from a patient with cutaneous lymphatic sporotrichosis and has been maintained in our laboratory. S. schenckii Kurume No. 23 was isolated from the soil in Ohmuta City, Kyushu and was kindly supplied from the Department of Dermatology, Kurume University School of Medicine. C. stenoceras Duke No. 922 and C. ulmi Duke No. 948 were kindly supplied by Professor R. Fukushiro of Kanazawa University. Preparation of antiseraHeat killed yeast cells of S. schenckii prepared from KO 4606 and Kurume No. 23 were used for the preparation of antisera. Immunisation procedure was described in detail in our previous paper (Nishikawa et al., 1975). Yeast cells of the above strains were obtained by culturing the fungi on BHI agar slant containing 1 ~o Dextrose, 0.5 ~ Yeast extract (Difco, Detroit, Mich.) for several days at 35 °C. Absorption of antiseraAntisera to strains Kurume No. 23 and KO 4606 were absorbed reciprocally with each heterologous strain as described elsewhere (Nishikawa et al., 1975). The anti-

Exoantigen Studies of Sporothrix schenckii, Ceratocystis minor, and Graphium penicilliodes cultures

“…Mariat (10) suggested that once S. schenckii enters a host, it loses its ability to form perithecia, thus explaining the failure to have human isolates form perithecia. The perithecia of C. stenoceras grown on corn meal agar do not fluoresce either with adsorbed or with Harada's unadsorbed anti-S. schenckii antiserum (6).…”