Open Access Thesis
Date of Award
Nutrition and Food Science
SCREENING OF NATURAL ANTIMICROBIAL AGENTS AND ANTIMICROBIAL - RESISTANT BACTERIA USING A SOLERIS SYSTEM
Advisor: Dr. Yifan Zhang
Major: Food Science and Nutrition
Degree: Master of Science
Traditional broth micro-dilution method is a common assay of measuring Minimum Inhibitory Concentration (MIC) to determine the antimicrobial activity of an antimicrobial agent. However, this method is generally time-consuming and labor intensive. Alternatively, an automated optical method using the Soleris system was applied in this study. The system was compared to the traditional broth micro-dilution 96-well assay to test the antimicrobial activity of 11 essential oils and 2 plant-derived compounds against Escherichia coli and Staphylococcus aureus. We also used the system to differentiate antimicrobial-resistant and -susceptible bacteria based on their antimicrobial resistance phenotypes. MIC values of cefoxitin against 5 strains of methicillin-resistant S. aureus (MRSA) and 8 strains of methicillin-susceptible S. aureus (MSSA) were tested. MIC values were also determined on cefoxitin, ampicilin and tetracycline against 11 ß-lactam-resistant E. coli and 3 susceptible E. coli. Most of the selected essential oils revealed strong antimicrobial effects against the tested microorganisms. Cinnamon oil and carvacrol compound were found to be more active against the test strains than any other selected antimicrobial agents. MICs obtained by Soleris system were comparable to those determined by standard micro-dilution method with respect to susceptibility testing of antimicrobial agents. The advantage of the Soleris system is its time efficiency and ease to perform. It provides a rapid and cost-efficient alternative for screening antimicrobial agents and antimicrobial-resistant bacteria.
Huang, Mingyang, "Screening Of Natural Antimicrobial Agents And Antimicrobial-Resistant Bacteria Using A Soleris System" (2014). Wayne State University Theses. 303.