Circulating antibodies against thermophilic actinomycetes in farmers and mushroom workers

Sera from individuals exposed to moldy hay, mushroom compost and unexposed individuals, were studied for antibodies against thermophilic actinomycetes and Aspergillus fumigatus. Antigens extracted from Thermoactinomyces vulgaris strains isolated from China were used in the study along with antigens from standard strains to screen the sera of individuals exposed to farms and unexposed controls from both China and the United States. It was found that very little antibody response to A. fumigatus and F. rectivirgula was demonstrated in the sera of both individuals exposed to farm environments and unexposed controls. On the other hand, antibodies to Thermoactinomyces vulgaris and T. candidus strains were seen in the sera of both exposed and unexposed individuals from China, indicating that these organisms are prevalent in all the environments of China. The results also indicate that antigenicity of the strains vary considerably in their reactivity with sera.