Specific and Rapid Identification of Medically Important Fungi by Exoantigen Detection

Abstract

Within a decade of its introduction, the exoantigen technique has won general acceptance for accurate and rapid identification of fungal pathogens. This acceptance is emphasized by the fact that positive exoantigen results obtained with the dimorphic pathogenic fungi B. dermatitidis, C. immitis, H. capsulatum varieties capsulatum, duboisii, and farciminosum, and P. brasiliensis are no longer considered presumptive evidence but are considered definitive data for species identification. Technical problems associated with poor sensitivity and false-positives in some of the early tests have been resolved. The test expands the diagnostic capabilities of the laboratory. We encourage the establishment of libraries of antisera for species identification and, where appropriate, for serotyping. Since the test is simple and reagents for many of the pathogens are commercially available, the test can be performed in most laboratories. As highly defined antigens are produced, more standardized and specific tests will be developed. Hybridoma technology may provide the means for producing specific antibodies without the need for highly purified antigens, which have been difficult to produce. The identification of numerous fungi could be facilitated by application of exoantigen techniques. Specific antisera should be developed to achieve this goal and to obtain antigenic data useful for elucidating taxonomic relationships. Some fungi cannot be classified on the basis of morphologic and biochemical qualities alone. Supplementary data obtained with exoantigen analyses could undoubtedly aid in resolving such problems.

Development of polyclonal antibodies againstFusarium verticillioidesexoantigens

“…Several enzyme linked immunosorbent assays (ELISAs) based on detection of exoantigens have been developed for detecting moulds in grains (Gan et al 1997, Abramson et al 1998, Chen et al 2000, Yong & Cousin 2001. Exoantigens are soluble immunogenic molecules produced by fungi that can be readily detected in culture broths or aqueous extracts of slant cultures (Kaufman & Standard 1987). Many fungi produce exoantigens that are unique to a specific genus and/or species, therefore these can be used in identification (Kaufman & Standard 1987).…”

“…Exoantigens are soluble immunogenic molecules produced by fungi that can be readily detected in culture broths or aqueous extracts of slant cultures (Kaufman & Standard 1987). Many fungi produce exoantigens that are unique to a specific genus and/or species, therefore these can be used in identification (Kaufman & Standard 1987).…”

Imunoensaios: uma alternativa para a detecção de fungos toxigênicos em alimentos

“…Muitos fungos produzem antígenos que são específicos para um gênero e/ou espécie, portanto podem ser utilizados para identificação, apresentando grande aplicabilidade na imunoidentificação de fungos patogênicos e na resolução de problemas taxonômicos (KAUFMANN; STANDARD, 1987).…”

Produção e caracterização de exoantígenos de Fusarium verticillioides

“…Estes apresentam grande valor, seja na imunoidentificação de fungos patogênicos ou na resolução de problemas taxonômicos, uma vez que a maioria dos fungos produz exoantígenos espécie-específicos (KAUFFMAN; STANDARD, 1987). Devido à termoestabilidade, os exoantígenos são detectados por ELISA mesmo após o processamento térmico, fornecendo inclusive informações sobre possíveis contaminações fúngicas de alimentos processados (NOTERMANS et al, 1986).…”