**12. Conclusion**

Recently, Salmonella strains resistant to a range of antibiotics, including major therapeutic agents in human medicine have emerged and are threatening to cause serious public health problems.

This resistance results from the use of antibiotics; this situation is getting worse year by year due to misuse or inappropriate use of antibiotics to treat any disease;, hence the importance of direct research into plants that have always been a source of inspiration for new drugs. Thus, the essential oils have a lot of interest as a potential source of bioactive natural molecules which extracts have a strong antimicrobial potency.

The use of essential oils is a serious substitute to treatment with antibiotics in infectious diseases because of their interference with bacteria vital functions. The alteration of the cell membrane including permeability may result in abnormal losses of ions or macromolecules.

Several authors have put the relationship between the antibacterial activity of essential oils with their chemical composition; specially

 phenolic and terpenic compounds but some studies have shown that the antimicrobial activity, antiviral, insecticidal, larvicidal and ovicidal essential oils are superior to those of its majority compounds tested separately.
