Antibacterial Activity of Streptomyces Strains Isolated from Different Regions of Jordan

Members of the genus Streptomyces produce more than 70% of antibiotics. The rise in antibiotic resistance globally enhanced the search for novel species with the ability to produce new bioactive compounds. This study was initiated to investigate different regions in Jordan for previously uncultured and rare Streptomyces species capable of producing novel antimicrobial compounds especially active against bacteria resistant to antibiotics. A total of 191 Streptomyces strains were isolated from 26 soil samples collected from different geographic regions in Jordan. Isolates were characterized based on colony and cellular morphology as well as using 16S rRNA gene sequencing. These isolates were screened for their ability to produce antibiotics by the perpendicular-cross streak method, and then tested by well diffusion method against tested pathogens. Fifty-four isolates showed potential to produce antimicrobial products especially active against resistant bacteria, 20.1% of the isolates showed inhibitory effect against Staphylococcus aureus, 16.9% against clinical MSSA strains, and 18.0% against MRSA: whereas only 4.2% against Esherichia coli, 3.2% against Klebsiella pneumonia, 2.7% against Pseudomonas aeruginosa, and 10.0% against clinical Candida albicans. Three isolates were selected for further identification due to their antibacterial activity against S. aureus, MRSA, and MSSA. These isolates were identified as follows; Streptomyces aburaviensis DSa3, Streptomyces alboniger SAb7 and Streptomyces misionensis ZAb2, based on cultural, biochemical characteristics and molecular analysis of the 16S rRNA. KCI Citation Count: 0