الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
This experimental study was conducted during eight month period from November 2015 to July 2016. It included a total of 40 P.aeruginosa and 40 BCC which isolated from clinical samples collected from burn and intensive care units of the Alexandria Main University Hospital, the isolation and also identification done in the microbiology lab of HIPH (by another researcher belonging to the supervisor of the present thesis).
In addition, a total of four herbal plants (clove, cinnamon, thyme and origanum) were subjected to hydrodistillation process in the Pharmacognosy Department in Faculty of Pharmacy, Alexandria University to prepare the EOs of each studied plant. The antibacterial effects of these EOs were tested against the identified strains of P.aeruginosa and BCC.
It aimed at studying the efficacy of essential oils of some herbal plant against multidrug resistant P. aeruginosa and BCC. The study revealed the following results:
In this context a study of antimicrobial activities of clove, cinnamon, thyme and origanum against P. aeruginosa and BCC demonstrated that, the four studied essential oils displayed activities towards all the tested clinical isolates.
from the results of this study the cinnamon essential oil and origanum essential oil gave the best results as they showed MIC and MBC against P. aeruginosa and BCC at concentration 10 -4 μl/ml.
In case of comparing the antimicrobial activity of each pair of the studied essential oils: Thyme essential oil was more active than clove essential oil at conc. 10-3 μl/ml. Regarding cinnamon essential oil, it was more active than both clove and thyme essential oils at conc. 10-4 μl/ml, while cinnamon and origanum essential oils both illustrated the same activity at conc. 10-4 μl/ml. Concerning origanum essential oil it was more active than both clove and thyme essential oils at conc. 10-4 μl/ml.
Cinnamon essential oil is enriched in phenyl propanoids as cinnamaldehyde, cinnamic acid, cinnamyl acetate and eugenol, in addition to the monoterpene hydrocarbons; terpinolene and α-thujene and the 3ry alcohol linalool. On the other hand, origanum essential oil contains many phenyl propanoid compounds as eugenol, carvacol, p-cymene, estragole and thymol. Moreover, it contains monoterpene hydrocarbons; αpinene, myrcene, β-ocimene and α-terpinene. Consequently the higher activities of both cinnamon and origanum essential oils are attributed to the synergism of all their volatile components.
Volatile oil components are reported to exhibit antimicrobial activity via various potential pathways, they induce structural changes in cytoplasmic membrane, affecting its permeability, resulting in release of ATP and interacts with both membrane and intracellular proteins damaging a variety of cellular functions the results of this study, it could be concluded that:
The four EOs (clove, cinnamon, thyme and origanum) had an inhibitory effect with varying degrees on tested P.aeruginosa and BCC isolates.Cinnamon oil and origanum oil had a significantly stronger inhibitory effect on all tested isol