Isolation and Identification of Streptomyces geysiriensis IN7 from Marine Water and Evaluating the Efficiency of Their Bioactive Compounds against Commonly Exposed Multidrug-Resistant Pathogens

The emergence of multidrug-resistant (MDR) pathogens necessitates exploring novel antimicrobial agents. This study has investigated the potential of actinobacteria isolated from marine sediments as a source of bioactive substances effective against multidrug-resistant bacteria. The study evaluated the effectiveness of different solvents methanol, hexane, and ethyl acetate in extracting bioactive compounds from actinobacteria. SCA (Starch Casein Agar) medium was used for isolation and the spread plate method was employed. IN7 was assigned to the isolates that were chosen. The 16S rRNA gene sequences were analyzed phylogenetically and the results showed that Streptomyces geysiriensis IN7 shared the greatest percentage of similarity (96%). Isolates were fermented for 14 days in a fermentation medium in order to produce antibacterial compounds. The antimicrobial activity of the extracts was then assessed against various MDR pathogens, Proteus vulgaris MTCC 742, Escherichia coli MTCC 442 and Salmonella enterica MTCC 1166. The results demonstrated in 96 well plate method and statistical evaluations were carried out using log 10-transformed data that methanol and ethyl acetate extracts exhibited promising activity against the tested pathogens, while the hexane extract showed minimal effect.