FUNGAL COLONIZATION OF AIR FILTERS FROM HOSPITALS

Air fillers of various types, selected on the basis of discoloration, were collected from the primary and secondary filter banks of the heat ing, ventilating, and air-conditioning systems in seven hospitals in t he eastern United States and examined with direct microscopy for funga l colonization. Microscopic observations and culture results showed th at filters from five of the hospitals were colonized with fungi includ ing species of Acremonium, Alternaria, Aspergillus, Cladosporium, Epic occum, Penicillium, and Rhinocladiella, and a Beauveria-like fungus. S everal of these commonly airborne species, e.g., Epicoccum purpurescen s (syn. E. nigrum) and Rhinocladiella sp., had not been previously rep orted to colonize (with conidiogenesis) air filters.