The influence of hay-packing techniques on the presence of saccharopolyspora rectivirgula.

Environmental factors influencing the growth, distribution and viability of thermophilic actinomycetes, especially Saccharopolyspora rectivirgula as an agent of extrinsic allergic alveolitis in farms workers, were studied. Total microbial count, eumycetes and thermophilic actinomycetes were determined on 96 hay samples, randomly collected, from small prismatic and large cylindrical bales, 30 air samples before and after animal feeding, and various surfaces in two farms located in the province of Reggio Emilia, Italy. The number of thermophilic actinomycetes (potentially responsible for hypersensitivity pneumonitis) was higher in hay samples from large cylindrical bales than in those from small prismatic bales. The structural characteristics of the buildings (barns with stalls, poor ventilation) and the feeding practices (manual handling of hay, constant presence of hay in feedings corridors) contributed to the dispersion of high levels of thermophilic actinomycetes spores (potentially responsible for extrinsic allergic alveolitis). The ventilation system proved to be inadequate in reducing the number of microorganisms present.