THE DISTRIBUTION OF ANTIBIOTIC-RESISTANCE PATTERNS WITHIN STREPTOMYCETES AND THEIR USE IN SECONDARY METABOLITE SCREENING

A collection of 169 streptomycetes representing natural isolates and type strains were examined for resistance phenotypes to 11 antibiotics. A total of 84 profiles were obtained with 18 patterns being repeated in two or more strains. The most common pattern was resistance to penicillin in an otherwise sensitive phenotype and accounted for 51 strains. This data was used to cluster the strains and groups defined were examined for correlation with bioactivity. Antibiotic producers were found in clusters 1, 2, 4 and 5-10. Certain strains in these areas were highly bioactive and typically had multiple resistances. Almost half of the collection of strains examined grouped in cluster 3, and were characterized as having a sensitive phenotype and virtually no biological activity in agrochemical screens.