An immunofluorescent counting method for tremorgenic penicillia

Abstract

Antibodies produced against tremorgenic strains of Penicillium crustosum and Penicillium janczewskii, conjugated indirectly with fluorescein, were used to stain mycelium of pure cultures of moulds and also hyphae present in natural substrates. There was strong fluorescent staining of strains of nine of 11 Penicillium species known to produce tremorgens and a variable staining reaction of two. Strains of seven of 11 non-tremorgenic Penicillium species did not react, three stained weakly or variably and one stained strongly. None of the isolates of 17 other mould genera examined, including tremorgenic strains of Aspergillus spp., was reactive. Fluorescent hyphae were seen in preparations of soil suspensions and plant washings from which reactive Penicillia were isolated by culture on dilution plates.

Keywords:

• Penicillium crustosum
• P. janczewskii
• ryegrass staggers
• animal diseases
• antibodies
• noxious fungi
• cultures
• tremorgens
• disease detection
• Moniliales
• Fungi imperfecti