The Antibiotic Resistance Phenomenon: Use of Minimal Inhibitory Concentration (MIC) Determination for Inquiry Based Experimentation

 

Tested Studies in Laboratory Teaching, 2008, Volume 29

Paula B. Lessem

Abstract

The antibiotic resistance phenomenon in bacteria is reported regularly in the popular press and is a well recognized problem. This mini-workshop presents a multi-week module that provides a hands-on opportunity for students to investigate this problem. It introduces the students to Minimal Inhibitory Concentration (MIC) determination, use of sub-MIC levels to induce bacteria, and the possible development of cross resistance; that is resistance to an antibiotic different from the inducing antibiotic. Macrolide antibiotics (particularly tylosin, erythromycin, azithromycin, and roxithromycin) will be used in this study. Tylosin, an antibiotic with widespread use in veterinary medicine, will be used as the inducing antibiotic. Students will investigate whether increased resistance to tylosin will result in increased resistance to other macrolides. This is significant as other macrolides, particularly erythromycin and azithromycin, have widespread use in medicine. Inherent in this module is flexibility for student design to select: (1) sub-MIC [tylosin], (2) use two drugs together, or (3 ask a related question. The students can discuss the implications of the data collected probing the effect of antibiotic usage in veterinary medicine. This workshop will provide protocols needed for introductory experiments (serial dilutions), the MIC and the induction study. Participants will have the opportunity to perform MIC simulations to understand the techniques necessary to successfully complete this investigation. Finally, group discussions will explore the utility of the module and how it can be adapted for different levels of college undergraduates. Development for this course was made possible by funds from the Associated Colleges of the South Keck Science Reform Mini-grant program.

Keywords:  microbiology, microbiological techniques, antibiotic

University of Kentucky (2007)