Plants from Brazilian savannah possessing activity against bacteria causing dermatophilosis in animals

Dermatophilosis, also known as streptothrichosis or "lumpy wool disease" in sheep is a skin disease caused by the Gram-positive bacterium Dermatophilus congolensis. This disease affects many species of animals, such as cattle, sheep, goats, horses, pigs, dogs, domestic cats, and occasionally humans. Dermatophilosis is seen in animals at all ages but is most prevalent in the young, in animals chronically exposed to moisture, and in immunosuppressed hosts. The objective of this study was to test ethanolic extracts from leaves of three plant species of the Brazilian savannah (cerrado), Anacardium humile, Annona crassiflora, Byrsonima crassifolia and Eugenia dysenterica for in vitro antimicrobial activity against Dermatophilus congolensis strains. Plant material was harvested in UPIS, Lagoa Bonita Farm, Planaltina – DF, Brazil. This leaves were dried at 37 °C, transformed into powder by a grinder and macerated with ethanol for five days with stirring, at room temperature. Then the extracts were filtered and concentrated using an evaporator at 50 °C. The microbiological tests were performed according to the Bauer – Kirby method, with modifications. After 24h of incubation zones of inhibitions were seen with extracts of A. humile (29 mm), A. crassiflora (24 mm), B. crassifolia (19 mm) and E. dysenterica (16 mm) at a test concentration of 0,5 mg/mL. These preliminary results suggest that the extracts may be of interest for further investigations.