Poster abstracts
Poster number 148 submitted by Annie Witzky
Elongation Factor P is required for antibiotic resistance in β-lactam resistant Escherichia coli
Kelsey Shaffer (Ohio University Heritage College of Osteopathic Medicine), Tiffany Kelley (Ohio University Heritage College of Osteopathic Medicine), Annie Witzky (Department of Biological and Environmental Sciences, Capital University)
Abstract:
The rise of antibiotic resistant bacteria has been identified as a global health crisis. The CDC has specifically identified carbapenem resistant and extended-spectrum beta-lactamase producing Enterobacterales as urgent and serious threats respectively. Combatting these threats will rely on better understanding the mechanisms that Enterobacterales use to maintain resistance. Elongation factor P (EF-P) is a translation factor that influences antibiotic sensitivity in many bacterial species. EF-P assists the ribosome in translation of polyproline motifs by entering the ribosome through the E-site and stimulating peptide bond formation. Though the functional role of EF-P in translation has been established, the significance it may have in antibiotic resistant bacteria has not been characterized. Here, we aimed to assess the role of EF-P in β-lactam resistant Escherichia coli. Initial disc diffusion results confirmed that loss of EF-P activity in E. coli resulted in increased susceptibility to ampicillin, penicillin, meropenem, and carbapenem. When this experiment was repeated in E. coli that harbored plasmids conferring resistance, loss of EF-P resulted in hypersensitivity to meropenem and carbapenem, but not ampicillin or amoxicillin. To assess the genetic basis for the role of EF-P in β-lactam resistance, a suppressor screen was used to identify Δefp mutants that had suppressed antibiotic hypersensitivity. Initial screening resulted in identification of an Δefp suppressor mutant with restored resistance to multiple antibiotics. Together, these results indicate that EF-P is required for antibiotic resistance in β-lactam resistant E. coli, and this requirement can be by-passed through a suppressor mutation. Future work will center on identification and characterization of the suppressor mutation as well as further screening for additional mutants.
Keywords: Elongation Factor P, Antibiotic Resistance, Translation