Antimicrobial Effects of Arctostaphylos uva ursi Extract against Acinetobacter baumannii. Dicey Stewart*, Elliot Collins*, James Healy*, Caleb Martin*, Francisco Leon#, Joseph Horzempa*. *Department of Natural Sciences and Mathematics, West Liberty University, West Liberty, WV. #Department of BioMolecular Sciences, University of Mississippi School of Pharmacy.

Abstract

Acinetobacter baumannii is a Gram-negative, opportunistic pathogen associated with a high
mortality rate in those infected with this bacterium. There are few classes of antibiotics that can successfully eliminate A. baumannii infections; therefore, it is imperative to find novel therapeutics to reduce the mortality rate of those infected with these drug-resistant bacteria. Preliminary studies from our laboratory have shown that Arctostaphylos uva ursi (kinnikinnick) leaf extracts (AUU) inhibit the growth of A. baumannii. The AUU compounds were separated by chromatography, and the resulting fractions were tested for antimicrobial activity using an agar-based diffusion assay. This indicated that two fractions exhibited substantial antimicrobial activity. These results were verified using a Galleria mellonella larvae infection model. The G. mellonella model also indicated that active fractions were not toxic to these insects. The fraction with the most robust antimicrobial activity was further separated via chromatography and bio-assay guided fractionation (agar-based diffusion assays and G. mellonella infections) was used to identify fractions containing the active compound. Once the active compound has been isolated via a final round of chromatography using a sephadex column, this molecule will be elucidated via NMR and mass spectrometry.

(Supported by NIH Grant P20GM103434 to the West Virginia IDeA Network for Biomedical
Research Excellence and through the WV Research Challenge Fund [HEPC.dsr.14.13])