Date of Award


Document Type


Degree Name

Master of Science (MS)



First Advisor

Bhattacharjee Mrinal

Committee Chair and Members

Bhattacharjee Mrinal, Chair

Joseph Morin

Fatma Abo


Actinomycetemcomitans, Aggregatibacter, Antibacterial, Commiphora molmol, Myrrha, Resistance


The exogenous pathogen Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) is most frequently involved in periodontitis and other systemic diseases. The treatment of these infections involves antibiotic therapy with Amoxicillin being the most popular antibiotic against A. actinomycetemcomitans but now, the drug is not 100% effective due to the development of 0-84% antibiotic resistance. The present study aimed to determine antibacterial activity of Commiphora molmol (Myrrha) against the periodontal pathogen, Aggregatibacter actinomycetemcomitans. In detail, the strain LIU1239 of Aggregatibacter actinomycetemcomitans was used where the plasmid pVJT128 is used for transposon mutagenesis and the Escherichia coli strain MV10Nal (stock # LIU4). The slow growing mutant, LIU 1380 strain was obtained by transposon mutagenesis and was confirmed to be slow growing by sequential streaking on AAGM plates for three passages. The experiment was mainly designed to show the antimicrobial activity of 20% Myrrha oil in AAGM and phosphate buffer. In nutrient rich AAGM, the oil took twenty hours to kill most cells of both strains, and at 5 hours, both strains were killed to the same extent. However, in nutrient-free phosphate buffer Myrrha killed the small colony mutant much faster than the wild type cells. For the very first time, the current study reported a marvelous antibacterial activity of Myrrha oil against A. actinomycetemcomitans in the nutrient-free medium. The findings showed that Myrrha oil extract can kill both growing and non-growing bacteria effectively. This antibacterial activity increases with the increasing concentration of oil up to 0.3 % against LIU1142, LIU 1239, and 1380 mutant. The use of Myrrha against A. actinomycetemcomitans could be a promising treatment to combat periodontitis and other bacterial infections.

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