International Journal of Homeopathy & Natural Medicines 2022; 8(2): 14-28 http://www.sciencepublishinggroup.com/j/ijhnm doi: 10.11648/j.ijhnm.20220802.11 ISSN: 2472-2308 (Print); ISSN: 2472-2316 (Online) In vitro Antibacterial Activity of Terminalia avicennioides Extracts Against Multidrug Resistant Staphylococcus aureus Strains Danjuma Lawal 1, * , Bobai Mathew 2 , Sani Muhammad Nura 1 1 Department of Microbiology and Biotechnology, Federal University Dutse, Jigawa, Nigeria 2 Department of Microbiology, Faculty of Science, Kaduna State University, Kaduna, Nigeria Email address: * Corresponding author To cite this article: Danjuma Lawal, Bobai Mathew, Sani Muhammad Nura. In vitro Antibacterial Activity of Terminalia avicennioides Extracts Against Multidrug Resistant Staphylococcus aureus Strains. International Journal of Homeopathy & Natural Medicines. Vol. 8, No. 2, 2022, pp. 14-28. doi: 10.11648/j.ijhnm.20220802.11 Received: June 11, 2022; Accepted: June 29, 2022; Published: August 17, 2022 Abstract: Infections caused by multidrug resistance bacteria are now alarming globally, and the increasing rates of antimicrobial resistance are resulting in fewer treatment options. The search for new phytochemicals that could be developed as useful drugs for treatment of infectious diseases consequently increased with medicinal plants extracts receiving greater attention. This study was carried out to determine in vitro antimicrobial activity of Terminalia avicennioides extracts against multidrug resistant Staphylococcus aureus strains isolated from wound infections. Wound swab samples were collected from patients attending Barau Dikko Teaching Hospital Kaduna, Nigeria. Isolation and characterization of Staphylococcus aureus was carried out using standard phenotypic and genotypic identification methods. Antimicrobial susceptibility profile of Staphylococcus aureus isolates was carried out using standard procedures. Also, Terminalia avicennioides extracts were prepared and their in vitro antimicrobial activities tested against multidrug resistant Staphylococcus aureus using standard procedures. The results of the susceptibility profile showed Staphylococcus aureus isolates to be resistant to a ranged of 8.18% to 100% conventional antibiotics used. However, the isolates were 100% sensitive to imipenem. Qualitative and quantitative phytochemical analysis of the extracts revealed the presence of tannin, alkaloids, flavonoids, cardiac glycoside, phenols, saponins and terpenoids and absent of anthraquinones in all extracts. Antimicrobial activity of Terminalia avicennioides extracts against multidrug resistant Staphylococcus aureus isolates showed zones of growth inhibition ranged from 16.28±10.45 – 23.81±6.69 mm and showed significant difference (P < 0.05). Minimum inhibitory concentration (MIC) of the extracts ranged from 56.2500 ± 29.1241 – 31.2500 + 22.16013 gm/ml and showed no significant difference (p > 0.05). The minimum bactericidal concentration (MBC) of the extracts ranged from 175.000 ± 64.2910 – 68.7500 ± 45.8063 mg/ml and showed no significant difference (p > 0.05). Remarkably, the antimicrobial activity of the Terminalia avicennioides extracts exhibit higher inhibitory effects against the multidrug resistant Staphylococcus aureus strains, hence, can further be study and developed for wound infection therapeutic purpose. Keywords: Staphylococcus aureus, Multidrug Resistance, Wound, Antibacterial Terminalia avicennioides 1. Introduction Staphylococcus aureus is known to acquire resistance to new drugs and continues to defy attempts to control it. Infections caused by antibiotic resistant strains of Staphylococcus aureus have reached epidemic proportions globally and the increasing rates of antimicrobial resistance are resulting in fewer treatment options [1]. The economic and health impact of multidrug resistant (MDR) infections on a global scale is enormous and dreadful and recently, it has been underestimated that worldwide, about 700,000 lives are lost annually due to antimicrobial-resistant infections [2-4]. The impact of MDR infections is worse in developing nations, including Nigeria, with unaccounted cost of