Diversity in aminoglycoside antibiotic resistance of actinomycetes and its exploitation in the search for novel antibiotics

Abstract

Wide varieties of multiple aminoglycoside antibiotic (AG) resistance that are not found in knownStreptomyces cultures were found among actinomycetes isolated as AG-resistant. Screening of about 170 AG-resistant isolates demonstrated their high probability (63%) of antibiotic production including the production of eight different AGs. We found specific AG-resistance patterns correlating to the productivity of specific AGs and established an AG-targeted assay system using AG producers as test organisms. Consequently, AG-directed screening totally on the basis of multiple AG-resistance was established. Necessity of biochemical and genetic studies on primary metabolism in order to find a new basis to search for novel metabolites is also discussed.