Characterization of Antibioticproducing Bacterium Isolated From Anthill Sediment With Activity Against ESKAPE Pathogens

Healthcare institutions have seen an increase in infections caused by antibiotic-resistant ESKAPE pathogens. Current antibiotics have become less potent against pathogenic bacteria due to their overuse and misuse. In recent years, scientists have revisited local environments in search of novel antibioticproducing microbes to address the increasing threat of resistance. One species of bacteria was isolated from anthill sediment in coastal North Carolina. This environment was selected for its abiotic properties, including organic substrates, moisture saturation and aeration. Anthill isolate A2, inhibited various Grampositive and negative ESKAPE pathogens or their surrogates, including Staphylococcus aureus, Klebsiella pneumoniae, and Acinetobacter calcoaceticus, in crossstreak tests. 16S rRNA sequencing identified isolate A2 as Pseudomonas koreensis. Mass spectrometry and small-molecule analysis performed on ethyl-acetate extracts of culture supernatant were used to evaluate bioactivity and identify the probable structure of one potential antimicrobial compound, monolauryl maleate. Discovery of novel antimicrobial compounds to replace overused antibiotics may help reduce the impact of antibiotic-resistant pathogens.