Metabolic profiling and antibacterial activity of secondary metabolites extracted from the endophytic bacteria of Combretum erythrophyllum.

Antibiotic resistance continues to pose a significant global challenge associated with increased rates of illness and death. The emergence of multidrug resistance patterns in pathogenic bacteria poses a challenge in their treatment, rendering them unmanageable with traditional antibiotics in the foreseeable future. Thus, prioritising innovative pharmaceuticals for therapy and exploring alternate approaches to combat antimicrobial resistance is of utmost importance. Endophytic bacteria derived from medicinal plants are reservoirs of active therapeutic compounds, offering a promising alternative for discovering novel and therapeutically bioactive compounds. This work involved the isolation and identification of four endophytic bacteria from Combretum erythrophyllum. The antibacterial activity and metabolic profiling of the secondary metabolite extract were assessed via the microdilution technique and gas chromatography data analysis, respectively. The assessed extract showed wide-ranging effectiveness against Gram-positive and Gram-negative bacteria, with a particular preference for Klebsiella aerogenes (ATCC 27853) at a minimum inhibitory concentration of 125 µg/mL. The analysed secondary metabolites revealed phytochemicals, namely terpenoids, ketones, phytosterols, phenols, alkanes, and fatty acid methyl esters (FAME) as the bioactive constituents. In conclusion, this study underscores the importance of the endophytic bacteria of C. erythrophyllum as a potential source of active natural bioactive compounds for antibiotic therapy.