OCCURRENCE OF THERMOPHILIC ACTINOMYCETES IN NATURAL SUBSTRATES IN NIGERIA

Thermophilic actinomycetes were isolated from 163 (48.95%) of 333 samp les of vegetable substrates and soil from different sites in Anambra a nd Enugu States in Nigeria. Thermoactinomyces (Tha.) vulgaris was the most common, occurring in 32.4% of samples while Tha. thalpophilus was isolated from 20.1%. Tha. sacchari, Saccharomonospora (Sam.) viridis and Saccharopolyspora (Sap.) rectivirgula were isolated from 3-10.5% o f the samples examined. Streptomyces (Stm.) thermovulgaris occurred in 2.7% and Thermomonospora spp. in 0.6% of samples. Except for Stm. the rmovulgaris and, perhaps, Thermomonospora spp., all the species isolat ed are known to be allergenic in man. The five known allergenic specie s were abundant in hay and maize silage. T. vulgaris and T. thalpophil us were also frequently isolated from rice straw. Tha. vulgaris, Tha. thalpophilus and Sap. rectivirgula were all most numerous in hay while Tha. sacchari was most numerous in maize silage. The widespread occur rence of thermophilic actinomycetes in Nigeria emphasizes the need for investigation of their role in allergic respiratory disorders.