Impact of Cinnamomum verum against different Escherichia coli strains isolated from drinking water sources of rural areas in Riyadh, Saudi Arabia

Objectives: The present study was aimed to evaluate the antimicrobial activity of aqueous, methanolic and essential oil extracts of Cinnamomum verum (cinnamon) against two waterborne pathogenic strains isolated from bottled, tap and wells' water from the rural areas of Riyadh, Saudi Arabia. Methods: The water samples were drawn from different sources and two strains of Escherichia coli were isolated, purified and confirmed using the MALI-TOF-MS technique. The C. verum extraction was carried out using different solvents and essential oil by hydrodistillation according to the standard methods. The antimicrobial potential was evaluated using a well-diffusion assay and percentage inhibition was calculated. Results: The two isolates were identified as Escherichia coli DSM 1103 QC DSM and E. coli MB 11,464 1 CHB by MALDI-TOF-MS. Aqueous, methanolic and oil extracts of cinnamon were tested for their inhibitory activity against the selected strains using the well diffusion method. E. coli strains were more sensitive towards the essential oil extract with the inhibitory zone of 4.5-5.2 cm rather than the aqueous and methanolic extracts. Analysis of cinnamon essential oil by GCMS showed the presence of Cinnamic acid, Cinnamaldehyde and 3-Allyl-6-methoxyphenol in the essential oil. Conclusion: The results indicated the possible potential of Cinnamomum verum essential oil and extracts in the management of E. coli from different water sources. Possibly, the bioactive compounds including cinnamic acid derivatives may responsible for the bioactivities of the plant. (c) 2021 The Author. Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).