Antibiotic resistance is becoming a global health crisis due to microbes quickly adapting to antibiotics used to treat bacterial infections. The overuse and misuse of antibiotics in healthcare perpetuates this problem, creating the ESKAPE pathogens – Enterococcus species, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species – which cause severe, sometimes lethal infections in hospitalized patients.

 Many known antibiotics come from soil: a microbe-rich environment. Resource limitations in soils naturally drive microbes to create their own antibiotics to kill competitor bacteria, making soil a promising site to discover new, potentially effective antimicrobial substances to use against infectious diseases in humans. 

The Tiny Earth program allowed students to conduct real, hands-on research by culturing and characterizing antibiotic producing bacteria from soil that could be effective against one or several of the ESKAPE pathogens. We isolated numerous pure cultures and screened them against the 6 most common ESKAPEs. When we observed clearing zones, we further characterized the candidate isolate and the putative antimicrobial substance it produced. 

This poster presents the discovery of strain MT-14-25, a Gram-negative bacterium with the ability to inhibit E. faecalis, S. aureus, A. baumannii, and P. aeruginosa. MT-14-25 was grown on Potato Dextrose Agar at 30° C and identified as an aerobic, rod-shaped bacterium capable of degrading casease, casein, starches, and hydrogen peroxide. With numerous strains found from this project alone, antibiotic-producing microbes are prevalent in soils and utilizing their abilities more in healthcare could be one step in combatting the antibiotic resistance crisis.