DIVERSITY IN AMINOGLYCOSIDE ANTIBIOTIC-RESISTANCE OF ACTINOMYCETES AND ITS EXPLOITATION IN THE SEARCH FOR NOVEL ANTIBIOTICS

Wide varieties of multiple aminoglycoside antibiotic (AG) resistance t hat are not found in known Streptomyces cultures were found among acti nomycetes isolated as AG-resistant. Screening of about 170 AG-resistan t isolates demonstrated their high probability (63%) of antibiotic pro duction including the production of eight different AGs. We found spec ific AG-resistance patterns correlating to the productivity of specifi c AGs and established an AG-targeted assay system using AG producers a s test organisms. Consequently, AG-directed screening totally on the b asis of multiple AG-resistance was established. Necessity of biochemic al and genetic studies on primary metabolism in order to find a new ba sis to search for novel metabolites is also discussed.