Antibacterial Activities of Kelussia odoratissima and Echinophora platyloba Extracts and Essential Oils against Waterborne Pathogens

Abstract

Natural antimicrobials, such as plant extracts (Es) and essential oils (EOs), are gaining popularity in food preservation. This study investigated the attendance of waterborne bacterial pathogens in drinking water samples (DWSs) from various urban centers in Shahrekord. It also examined the sensitivity of these bacteria to Es and EOs derived from Kelussia odoratissima Mozaff. (KOME, KOMO) and Echinophora platyloba (EPE, EPO). In 2022, 200 distinct DWSs were gathered from various places in Shahrekord. Escherichia coli, Salmonella typhimurium, and Helicobacter pylori isolates were identified using routine biochemical and PCR tests, respectively. Following the preparation of hydroalcoholic Es and EOs, the chemical compounds were identified using the Folin-Ciocalteu method and gas chromatography-mass spectrometry (GC-MS), respectively. Using agar diffusion and micro-dilution methods, the antibacterial properties of KOME, EPE, KOMO, and EPO were evaluated against the bacterial isolates from drinking water. The overall frequencies of E. coli, S. typhimurium, and H. pylori were 2.5% (n= 5/200), 1% (n= 2/200), and 2% (n= 2/200), respectively. The total phenol content of KOME and EPE was 92.23±4.1 and 243.6±14.3 mg GAE/g, respectively. 5-methylsalicylic acid (40.57%) and cyclopropane (1-methyl-1,2-propadienyl)- (37.28%) were detected as the highest compounds in KOMO and EPO. The MIC and MBC values for the tested bacteria ranged from 250 to 1500 µg/mL and 500 to 2000 µg/mL, respectively. The most significant inhibition zone was observed for KOMO against S. typhimurium (20.03±0.08 mm). KOMO and EPO had more robust antibacterial properties than EPE and KOME. The findings revealed the presence of pathogens in drinking fountains, posing potential health risks. Moreover, the results demonstrated the efficacy of EOs as potent antimicrobial agents, suggesting their promising applications for reducing pathogenic bacteria in the food industry.