Evaluation of In vitro Antibacterial Activity of Endophytic Bacteria Isolated from Catharanthus roseus

Abstract

Abstract Background: Research on the antimicrobial potential of endophytic bacteria isolated from Catharanthus roseus has gained significant attention due to the increasing need for novel treatment options. The scientific community has explored a wide range of bioactive metabolites in endophytes, such as antiviral, anticancer, antidiabetic, and antibacterial substances, highlighting their potential therapeutic applications. These endophytes play a crucial role in enhancing host fitness and competitive ability by improving nutritional uptake, seed germination success, tolerance to environmental stresses, and resistance to phytopathogens. India, with its rich biodiversity of medicinal plants, offers a vast resource for antimicrobial agents. Plants such as C. roseus have been traditionally used in various medical systems for their therapeutic properties. C. roseus, belonging to the Apocynaceae family, contains beneficial compounds such as antioxidant-rich phenolic chemicals, which contribute to its medicinal properties. Methods: The main objective of this investigation was to isolate endophytic bacteria from C. roseus, focusing on various colonies isolated from leaf discs. The isolated organisms were identified using Gram staining techniques. Furthermore, the study assessed the in vitro antibacterial activity of the isolated bacteria against selected human pathogens using the well-diffusion method. In addition, the investigation aimed to determine the minimal inhibitory concentration of leaf extract by employing standard antibiotics. Results: The study demonstrated that bacterial isolates from C. roseus exhibited potent antibacterial activity against pathogens such as Staphylococcus and Pseudomonas species. The results indicated that the leaf isolates from C. roseus showed strong inhibitory effects against pathogenic bacteria. The Gram-positive organisms were more susceptible than Gram-negative organisms, reflecting the differences in their cell wall structures. Conclusion: While the antibacterial activity of C. roseus showed promising results, it was not as potent as certain common antibiotics. This study contributes to the understanding of the antibacterial potential of endophytic bacteria from C. roseus and lays the groundwork for further research on their therapeutic applications in combating bacterial infections.