Date of Completion


Document Type

Honors College Thesis


Department of Animal and Veterinary Sciences

Thesis Type

Honors College

First Advisor

John Barlow


Cinnamon bark oil, non-aureus staphylococci, bovine mastitis, antimicrobial susceptibility testing, essential oils



The aims of this study were to develop a method for antimicrobial susceptibility testing (AST) with cinnamon bark oil (CBO) by broth microdilution, to determine the minimum inhibitory concentration (MIC) of CBO for several non-aureus staphylococci isolates, and to determine whether there is a correlation between penicillin MIC and CBO MIC for these isolates.

Methods and Results:

AST for both CBO and penicillin was performed on four isolates of S. chromogenes, three isolates of S. equorum, and three isolates of S. xylosus.


All isolates had a CBO MIC within the tested range of CBO concentrations. No correlation was found between penicillin MIC and CBO MIC for all isolates.

Significance and Impacts:

These findings demonstrate that CBO has antimicrobial activity against several species of non-aureusstaphylococci, including two bovine-mastitis-causing pathogens, supporting the possibility that it could be used in the dairy industry in the prevention and treatment of mastitis. The lack of correlation between CBO MIC and penicillin MIC suggests that CBO may be effective even against penicillin-resistant strains. Furthermore, a method was developed for performing AST with CBO by broth microdilution, which could be used in future work.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

Available for download on Friday, May 19, 2023