Fungal antigens as a source of sensitization and respiratory disease in Scottish maltworkers

Abstract

SummaryMycological and serological studies were carried out as part of a survey of respiratory disease in Scottish maltworkers. 70% of stained sputum smears from 574 workers showed the presence of higher plant cells and/or mycelia, and the spores of common environmental fungi. Penicillium spp. (90/%), Rhizopus stolonifer (48%) and yeasts (53%) were the dominant fungi in 699 sputum cultures, and showed a similar proportional distribution in 327 samples of grain, malt, culms and dusts from fifty‐six makings.57% of 711 men were serologically positive for fungi, 22% for Aspergillus fumigatus, 20% for A. clavatus, 10% for A. niger, 16% for Cladosporium herbarum and over 3% for Rhizopus stolonifer. 6% of 132 men were positive for Penicillium cyclopium. No precipitating antibodies to antigens from Alternaria tenuis, Aureobasidium pullulans, Candida albicans, Geotrichum candidum, Rhodotorula glutinis or Trichoderma viride were detected in tests of forty sera.Sera from the 5.2% of men with symptoms of extrinsic allergic alveolitis showed increased reactivity to mycelial antigens from Aspergillus clavatus. The fungus was cultured from 21 % of maltings, 7% of all environmental samples and from the sputa of 8% of maltworkers.

Genomic sequence of the pathogenic and allergenic filamentous fungus Aspergillus fumigatus

“…N. fennelliae is not known to be pathogenic to humans and possesses a sexual cycle. Another closely related species is Aspergillus clavatus, a mycotoxin producer that has been implicated in neurotoxicosis in beef cattle as well as respiratory disease in maltworkers 28 . We have used genomic DNA from N. fischeri, N. fennelliae and A. clavatus as well as from two additional strains of A. fumigatus, Af294 and Af71, to perform comparative genomic hybridization (CGH) with our Af293 polymerase chain reaction (PCR) amplicon coding sequence (CDS) microarray.…”

Comparative Genomics and the Evolution of Pathogenicity in Human Pathogenic Fungi

“…Subsequent analyses applied CGA to two of the species most closely related to A. fumigatus, namely, Neosartorya fischeri and Aspergillus clavatus (18). The former is a species that has only very rarely been associated with infection, while A. clavatus, which is known to produce allergens and mycotoxins, is a rare cause of alveolar inflammation, particularly in malt workers (6,10). At a gross level, significant differences in genome size were observed, which may be explained by the greater number of transposable elements in the N. fischeri genome.…”

Mutagenic and tumourigenic properties of the spores of Aspergillus clavatus

“…Sources of Aspergillus clavatus.-During a survey of respiratory disease in Scottish maltworkers (Blyth et al, 1977) Some cultures were also grown in 11 Roux bottles on Czapek Dox/Casein hydrolysate medium supplemented with 2% Davis agar and were kept in darkness at 26°C for 10-14 days. Spores were harvested into sterile PBS by rubbing with a smoothed glass rod and the saline suspension was filtered through sterile gauze to remove fragments of mycelium and conidiophores.…”

“…If these conclusions are accepted, the apparently mutagenic and tumorigenic properties of the spores of A. clavatus would give additional emphasis to the necessity, already acknowledged because of the known role of the fungus in extrinsic allergic alveolitis, to avoid inhalation. The isolate of the fungus used in the experiments was cultured from the sputum of a maltworker during a survey of respiratory disease in Scottish maltworkers (Blyth et al, 1977). A. clavatus was cultured from the environments of 12 of the 56 maltings investigated and from the sputa of 57 of 699 men.…”

“…Aspergillus clavatus is an allergenic and mycotoxic fungus, which, when inhaled as air-borne conidia (spores) released from contaminated barley malt is known to cause extrinsic allergic alveolitis in maltworkers (Riddle et al, 1968;Channell et al, 1969;Grant et al, 1976;Blyth et al, 1977). The disease can be induced experimentally in non-sensitized, sensitized precipitin-negative and sensitized precipitinpositive mice (Blyth, 1978).…”