Evaluation of Antibacterial Activity of Commercial Lemon, Geranium, and Thistle Oils Against Pseudomonas Species

<span style="color: rgb(17, 17, 17); font-family: Poppins; font-size: 14px;">Increasing antibiotic resistance is increasingly affecting human and animal health. Pseudomonas spp. are opportunistic pathogens resistant to multiple antibiotics. <i>Pseudomonas</i> spp. can be found in various environmental sources, including surface water, wastewater, food, and soil, and can cause hospital-associated infections. Therefore, due to the increasing resistance to antibiotics, plants and their extracts are being investigated as alternative natural sources of antibiotics. Thus, in this study, the antibacterial activities of commercially available thistle (<i>Silybum marianum</i>) fixed oil, lemon (<i>Citrus limon</i>), and geranium (<i>Pelargonium graveolens</i>) essential oils against <i>Pseudomonas aeruginosa</i>, <i>Pseudomonas putida</i>, and <i>Pseudomonas monteilii</i> isolated from used makeup sponges, as well as <i>Pseudomonas aeruginosa</i> ATCC 27853 and ATCC 10145, were evaluated in vitro using agar well diffusion and microdilution methods. It was determined that thistle fixed oil, lemon, and geranium essential oils did not give an inhibition zone against the tested <i>Pseudomonas</i> species, and their MIC values were greater than 80 μg/mL.</span>