Testing UD Soil Isolates for Antimicrobial Activity


Testing UD Soil Isolates for Antimicrobial Activity



Elizabeth M Collins


This poster reflects research conducted as part of a course project designed to give students experience in the research process.



Antibiotics are important in both the prevention and treatment of bacterial infections. However, there has been an increase in antibiotic resistance. Antibiotic resistance is when a microbe counters the effects of the antibiotic, and continues to reproduce. As the spread of antibiotic-resistant infections grow, the bigger the threat to public and global health. The Small World Initiative and the Tiny Earth Network’s mission is to support student research in antibiotic discovery by isolation of unknown bacteria from soil. Over the past semester, I have been conducting research with the aim to find microbes that produce antimicrobial effects on known ESKAPE pathogens from soil collected outside Roesch Library. A soil sample was collected from the gazebo next to Roesch Library. Bacteria colonies were plated on TSA and TH plates. Eleven colonies from the TSA plate and ten colonies from the TH plate were selected to be tested against the known pathogens of Enterococcus faecium and Klebsiella pneumoniae. These pathogens cause similar infections and are transmitted the same way by direct contact. However, Enterococcus faecium is a gram positive bacterium and Klebsiella pneumoniae is a gram negative bacterium. By choosing two different types of bacterium the goal is to discover if there is a difference in antimicrobial activity based on the type of pathogen. Antimicrobial activity is determined by the presence of a zone of inhibition. For the bacteria that show antimicrobial activity, a series of tests, which include gram staining and biochemical testing, were performed to identify the bacterial isolates. Future implications of this research could help create new antibiotics to fight against human pathogens and further improve the public health of the community.

Publication Date


Project Designation

Course Project

Primary Advisor

Erica Marie Rinehart, Yvonne Y. Sun

Primary Advisor's Department



Stander Symposium project

Testing UD Soil Isolates for Antimicrobial Activity