Citrus Aurantifolia Essential Oil Composition, Bioactivity, and Antibacterial Mode of Action on Salmonella Enterica, a Foodborne Pathogen

Salmonella enterica is a well-known pathogenic bacterium that can cause intracellular illness and food poisoning in humans, especially salmonellosis. In the present study, 20 essential oils of aromatic plants were screened for their antibacterial activity against S. enterica. Among the essential oils screened, Citrus aurantifolia essential oil (CAEO) demonstrated most efficient activity against S. enterica. CAEO had minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 8 and 16 μl/mL, respectively. A significant scavenging of radical cations was observed with CAEO using 2, 2'-diphenyl-1-picryl hydrazyl with an IC50 of 0.2147 mg/mL. Total phenolic content of CAEO was 10.90 mg GAE/100 μL. The treatment of bacterium with CAEO caused the leakage of cellular components, i.e., both nucleic acids and proteins. Furthermore, scanning electron microscopy (SEM) was used to measure the ultrastructure of control and treated bacterium (due to CAEO). The results of SEM reveal a loss of cellular integrity and function of bacterial cell membrane. The GC/GC-MS analysis of CAEO revealed E-citral (67.97%) as a major chemical component. CAEO may be considered as a safe antibacterial agent against foodborne S. enterica. The present study investigated a detailed analysis of antibacterial activity of C. aurantifolia essential oil, which can provide insight for further studies.