Chemical composition and antimicrobial activity of Artemisia annua (L.) essential oil against different fish pathogens

In the present study, the composition of the essential oil and antimicrobial activity from aerial parts of Artemisia annua growing wild in north of Iran was investigated. The major ingredients of the essential oil of A. annua were camphor (29.2%), 1.8-cineole (13.3%), tetradecanol (6.16%), β-selinene (5.82%) and pinocarvone (3.86%). In the current study, the antimicrobial activity of A. annua was tested against 4 fish pathogenic bacteria including: Streptococcus iniae, Yersinia ruckeri, Aeromonas hydrophila and Lactococcus garvieae and 3 fish pathogenic fungi namely Saprolegnia sp., Fusarium solani and Aspergillus flavus. Based on the results, Y. ruckeri, A. hydrophila and Saprolegnia sp. showed higher sensitivity to the essential oil of A. annua L. than to control antibiotic (ciprofloxacin, 0.3% w/v). Maximum antibacterial and antifungal activity was observed against Y. ruckeri (22.6±0.6 mm) and Saprolegnia sp. (18.7±0.8 mm) respectively, while S. iniae (10.2±1.2 mm) and A. flavus (12.9±0.82 mm) showed the least sensitivity. In addition, the minimum inhibitory concentration (MIC) test showed that concentrations of the essential oil within the range between 3.2 to 25 μg/L were able to inhibit the growth of the selected bacterial and fungal pathogens. According to the results, that the essential oil of A. annua could be a potential new and more effective antibacterial component for the aquaculture industry.