Screening and Characterization of Streptomyces spp. Isolated from Soil Producing a Potential Inhibitors of the Proteus mirabilis

Proteus mirabilis is a common cause of urinary tract infections and other nosocomial infections that can lead to severe health consequences. Despite the availability of various antibiotics, the increasing prevalence of multidrug-resistant (MDR) strains of Proteus mirabilis has necessitated the development of novel therapeutic compounds. The ability of species to produce a wide variety of secondary metabolites, such as antibiotics Streptomyces, immunosuppressants, and antivirals, is well known. In this study, a Streptomyces strain was isolated from soil near saltwater bodies, and its secondary metabolic extract was evaluated for its antimicrobial activity against Proteus mirabilis. The Streptomyces isolate demonstrated significant antimicrobial activity for Proteus mirabilis, with a minimum inhibitory concentration (MIC) of 34 µg/mL. The antimicrobial potential of the extract was confirmed through additional examination of the metabolite extract using deterministic assays, such as nucleic acid and protein release and time-kill curve assay. Molecular identification of the Streptomyces strain showed similarity with Streptomyces triticirhizae. GC-MS analysis of the extract revealed the presence of compounds such as Octadecanoic acid and n-Hexadecanoic acid, which are frequently associated with potent antimicrobial activity. HR-LCMS analysis revealed the presence of compounds such as Neomycin, Polymyxin B, and Maculosin, which also have potent antimicrobial activity. These findings strongly indicate the potential of the Streptomyces metabolite extracts as a novel therapeutic compound against Proteus mirabilis.