Antibacterial effect of essential oils of rosemary and basil on major bovine mastitis bacteria
reza rahchamani
1
(
Assistant professor, Department of Animal Science, Faculty of Agriculture and Natural Resources, University of Gonbad Kavous, Gonbad Kavous, Iran
)
saman zaroni
2
(
M.Sc. graduate of Department of Animal Science, Faculty of Agriculture and Natural Resources, University of Gonbad Kavous, Gonbad Kavous, Iran
)
farzad ghanbari
3
(
Assistant professor, Department of Animal Science, Faculty of Agriculture and Natural Resources, University of Gonbad Kavous, Gonbad Kavous, Iran
)
Keywords: Antibacterial effect, rosemary, basil, mastitis,
Abstract :
According to the side effects of antibiotics, there is need to new and natural antibacterial agents for treatment of bacterial diseases. Essential oils (EOs) are good alternatives. So, this study investigated antibacterial activity of Rosmarinus officinalis (rosemary) and Ocimum basilicum (basil) EOs in comparison with gentamicin and amoxicillin/clavulanate antibiotics on Escherichia coli, Streptococcus agalactiae, and Staphylococcus aureus. Analysis of EOs was done with GC/MS. The minimum bactericide concentration (MBC) and minimum inhibitory concentration (MIC) were obtained with macrodilution method and the antibacterial effects of EOs in comparison with antibiotics were done by disk diffusion method. The effects of EOs on growth curve were investigated at 0, 6, 10 and 24 h. Major components of rosemary EO were carene (45.11%), eucalyptol (1,8- cineol) (20.62%), and those of basil were estragol (70.42%), carene (17.99%). MIC and MBC were in rosemary 0.078-0.312% and 0.312-0.625% and in basil 0.039-0.312% and 0.078-0.625%, respectively. In disk diffusion, the effect of two EOs on Staphylococcus aureus and Streptococcus agalactiae did not significantly differ from gentamicin but the effect of two EOs on Escherichia was significantly lower than gentamicin (p<0.05). At 24 hour, two EOs significantly decreased the count of Staphylococcus aureus and Escherichia coli and basil significantly decreased the Streptococcus agalactiae count (p<0.05). Generally, the EOs of rosemary and basil had antibacterial effects and the effect on Staphylococcus aureus and Streptococcus agalactiae was not significantly different with gentamicin. Clinical studies about therapeutic effect of these EOs in treatment of various diseases including mastitis are indicated.