33 Antibacterial Effect of Gongronema latifolium Leaf Extract on Staphylococcus aureus Isolates from Skin of Human Subjects in Lafia Metropolis Ifeanyi Francis Merenini 1 *, Peter Uteh Upla 1 , Ephraim Ibeabuchi Ezaka 2 , JohnPaul Otuomasirichi Egbobe 3 , Bashiru Eya Sani 1 , Kweku Adobor Yayra 3 , Stephen Baffour Gyawu 4 , Angana Chatterjee 4 & Joseph Fuh Nfongeh 1 1 Department of Microbiology, Federal University of Lafia, Nasarawa State, Nigeria 2 Department of Medical Laboratory Science, College of Health Technology, Adamawa State, Nigeria 3 School of Public Health, Nanjing Medical University, Jiangsu Province, China 4 School of Basic Medical Sciences, Nanjing Medical University, Jiangsu Province, China Abstract Article History Submitted October 11, 2024 Revised December 17, 2024 First Published Online December 30, 2024 *Corresponding author I. F. Merenini  mereniniifeanyi@gmail.com doi.org/10.62050/ljsir2025.v3n1.367 Antibiotics have been critical in the fight against infectious diseases. However, plants have also been used to treat diseases due to the presence of some chemical compounds (active ingredients) that possess medicinal properties. This study investigated the antibacterial effect of Gongronema latifolium (amaranth globe) leaf extract on Staphylococcus aureus isolates from the skin of human subjects in Lafia metropolis, Nasarawa State, Nigeria. Aqueous and ethanol leaf extracts of G. latifolium were screened for antibacterial activity against S. aureus isolates using the agar disk diffusion method. A total of forty (40) specimens were collected and S. aureus was isolated using standard biochemical methods. Hospital isolates had the highest lowest percentage sensitivities of 85.71 and 0.00% from 300 mg/mL ethanol and 200 mg/mL aqueous extracts, respectively. Also, restaurant isolates had the highest percentage and lowest sensitivities of 83.33 and 0.00% from 300 mg/mL ethanol and 200 mg/mL aqueous extracts, respectively. Both extracts showed significant differences observed in their concentration effects against S. aureus isolates from restaurant subjects (p<0.05). MIC was 75 mg/mL for the aqueous extract against isolates obtained from both sources and that for the concentration ranges of 300-9.375 and 200-6.25 mg/mL ethanol extract was observed to be 37.5 and 50 mg/mL, respectively. The result of the study showed that both extracts of G. latifolium have an inhibitory effect proportional to concentration on the test organism S. aureus isolates obtained from both subjects. Hence, ethanol extract of G. latifolium may potentially control skin respiratory and enteric infections caused by S. aureus. Keywords: Antimicrobial, ethanol, Gongronema latifolium, leaf extracts, Nigeria, Staphylococcus aureus Introduction Antibiotics have been critical in the fight against infectious diseases such as boils (abscesses), impetigo, and cellulitis caused by bacteria and other microorganisms particularly methicillin-resistant S. aureus (MRSA) has long been observed among hospitalized patients since 1960 [1]. These microbial infections, if not properly treated as a result of overuse or misuse of drugs or their components, could result in the development of resistant strains by the microorganisms that could pose a threat to society and are predicted to cause about 10 million deaths by 2050 [2, 3]. Plants can fight against diseases due to the presence of some chemical compounds (active ingredients) that give plants their medicinal properties and thus, maintain one's state of good health since they nourish and supply the body with important nutrients in cases of nutrient deficiencies or by attacking the causative organisms themselves [4]. Medicinal plants otherwise known as traditional medicine (TM) have been applied traditionally in the treatment of certain health problems in every community and have been handed down from generation to generation its inception can be traced as far back as the origin of humankind [5, 6]. In developing countries including Nigeria, infectious diseases described as a product of host-parasite interaction from the ecological point of view, account for a high rate of health-related issues induced by pathogenic microorganisms [7]. Staphylococcus aureus, a gram-positive bacterium of clinical significance, constitutes a major public health threat, being one of the most common causes of hospital and community-acquired infections implicated with skin, respiratory tract, and gastrointestinal infections [8, 9]. The organism is frequently resistant to a wide variety of antibiotics. Infections caused by methicillin-resistant S. aureus (MRSA) and Vancomycin-resistant S. aureus (VRSA), leading strains of hospital-associated and community- associated microbial pathogens are associated with Lafia Journal of Scientific & Industrial Research (LJSIR), Vol. 3(1), 2025 p-ISSN: 3026 – 9288 e-ISSN: 3027 – 1800 pages: 33 – 39 https://lafiascijournals.org.ng/index.php/ljsir/index  Published by the Faculty of Science, Federal University of Lafia, Nasarawa State, Nigeria