By Stephen Combs, Rebecca Cherian, Natalie Fox

Faculty Mentor: Swati Agrawal

Abstract

EXPLORING SYNERGISTIC PHAGE-ANTIBIOTIC COMBINATION THERAPIES FOR THE TREATMENT OF ANTIMICROBIAL RESISTANCE IN BACILLUS PATHOGENS. Michael Combs, Rebecca Cherian, & Natalie Fox University of Mary Washington. The increased use of antibiotics has contributed to the rise of antimicrobial resistance, which has become a leading public health threat. Bacteriophages, specialized viruses that selectively infect specific bacterial strains, emerge as a valuable alternative amidst the waning availability of effective antibiotics. This research focuses on the pathogenic species of the Bacillus genus, specifically B. cereus (a common source of food poisoning) and Bacillus anthracis (causing anthrax). The phages Jabberwock and JackRabbit, discovered at UMW and initially isolated on the non-pathogenic species Bacillus thuringiensis, possess a broad host range and were found to infect both Bacillus cereus and Bacillus anthracis, the pathogenic species mentioned earlier. We’re investigating the synergistic effects of combining Vancomycin and Oxacillin antibiotics (both targeting the cell wall synthesis of bacteria) with phage cocktails on three isolates of B. cereus with varying degrees of resistance to the aforementioned drugs. We have experimentally determined the Minimum Inhibitory Concentration (MIC) for each of the isolates with and without phage combinations. Our preliminary data demonstrate a promising reduction of MIC in the combined treatments of phages and antibiotics, indicating a positive synergy between the two therapies. Author Contact: scombs3@mail.umw.edu