Exploring the Antibacterial Effects of Indium and Myrrh against Clinical Bacterial Isolates

Abstract Background and Objective: Treatment of bacterial infections is becoming challenging due to the increased rate of multidrug-resistant (MDR) bacteria. MDR organisms exhibit high resistance to the available antibiotics. Searching for alternative antibacterial agents is very urgent. Natural compounds possess antibacterial activity and may be utilized to kill MDR bacteria. The aim of the current study is to investigate the antimicrobial activity of Myrrh extract and indium against several Gram-positive and Gram-negative bacteria. Materials and Methods: The zone of inhibition assay (ZOI) was utilized to determine the killing activity of either myrrh or indium against 6 bacterial isolates. Micro-dilution method was then used to determine the MIC of indium. Results: Indium showed potent antibacterial activity against Salmonella spp., Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus saprophyticus, Escherichia coli, and Mycobacterium smegmatis. Myrrh extract exhibits toxic activity against only S. aureus. The rest of the tested isolates was resistant to myrrh extract. Using the broth micro-dilution method, the minimum inhibitory concentration of indium was then determined for all the tested strains. Conclusions: Based on the results obtained from the present study, indium and myrrh extract possess potent antibacterial activities against several Gram-positive and negative bacteria. Those two compounds have the potential to serve as alternatives to antibiotics.