Staphylococcus epidermidis high persister isolates exhibit increased tolerance within a Drosophila melanogaster sepsis infection 3020

Abstract Description Staphylococcus epidermidis is a common skin bacterium that can cause opportunistic infections, particularly in immunocompromised individuals and those with indwelling medical devices. These infections are often persistent due to biofilm formation and the presence of persister cells, a subpopulation of dormant bacteria that are tolerant to antibiotics. Recently, we demonstrated S. aureus persister cells have increased tolerance to the antimicrobial peptides, LL-37 and human β-defensin 3, thus we hypothesized high persister staphylococcal clinical isolates would have a survival advantage to other components of innate immunity. High persister (hip) isolates were identified through vancomycin time-dependent kill assays with hip isolates exhibiting less than 1-log of killing following 120 hours of antibiotic challenge. To explore the relationship between persisters and innate immunity, a Drosophila melanogaster sepsis infection was utilized. D. melanogaster infected with low persister isolates exhibit increased survival compared to flies infected with high persister isolates following a 14-day survival study. Additionally, preliminary results indicate flies infected with low persister isolates have lower bacterial burden compared to those infected with high persister staphylococcal isolates. These findings suggest S. epidermidis clinical isolates frequently exhibit a hip phenotype and persister formation is advantageous when challenged by the innate immune system. Funding Sources Supported by the National Institute of General Medical Science of the National Institutes of Health (NIH) under award number GM103427. Topic Categories Microbial, Parasitic, and Fungal Immunology (MPF)