Isolation of soil Streptomyces as source antibiotics active against antibiotic-resistant bacteria

Abstract

The focus of this study was the in vitro antimicrobial activities of Streptomycetes, bacteria commonly found in soil and known antibiotic-producers. Streptomycete isolates obtained from different fields in Muðla, Turkey were evaluated for their inhibitory activities on seven microorganisms including multiple antibiotic resistant Staphylococcus aureus and Stenotrophomonas maltophilia. Fifteen Streptomycete isolates which exhibited antimicrobial activity against at least two of the test organisms were characterized by conventional methods. The results indicated that five isolates were highly active against S. aureus strains including meticillin resistant Staphylococcus aureus (MRSA). Twelve Streptomycete isolates showed anticandidal activity against Candida albicans. Ten isolates were highly active with an inhibition zone more than 30 mm in diameter. Most of the isolates inhibited growth of the Gram negative bacteria tested. Eight isolates showed antibacterial activity on S. maltophilia MU64. The inhibition zones of two were higher than 30 mm for S. maltophilia.