Antibacterial activity of ajwain essential oil against some zoonotic bacteria

Harmful pathogens such as viruses, bacteria, parasites, and fungi can cause different types of diseases in people and animals, ranging from mild to severe illness and even death. Due to the increasing frequency of antimicrobial resistance among germs causing zoonotic diseases, more studies have focused on the usage of natural agents against them. This study aimed to evaluate the antibacterial effects of ajwain essential oil on some of the most common zoonotic bacteria. Antibacterial activity of ajwain essential oil was screened against Bacillus anthracis, Staphylococcus aureus, Streptococcus pneumonia, Escherichia coli, Listeria monocytogenes, Salmonella Typhimurium, Pseudomonas aeruginosa, and Klebsiella pneumonia using disc diffusion method and broth microdilution assays. Ajwain essential oil exhibited antimicrobial activity against all the tested bacteria with minimal inhibitory concentrations (MIC) at a range of 2.5 to 10 μg/ml for Gram-positives and 40 to 80 μg/ml for Gram-negatives and minimum biocidal concentration (MBC) at a range of 10-40 μg/ml for Gram-positives and 80 μg/ml for Gram-positives. However, Streptococcus pneumoniae, Staphylococcus aureus, and Bacillus anthracis were the most susceptible to this essential oil, respectively. The results suggest that the activity of ajwian essential oil can be mainly attributed to the presence of phenol, benzene methyl, γ-terpinene, and thymol which appears to possess similar activities against all the tested bacteria. In conclusion, this material could be served as an important natural alternative to prevent zoonotic bacterial growth.