Abstract 1363 Detecting Bacterial Extracellular Vesicles in Human Plasma for Sepsis Diagnosis

Sepsis is a clinical syndrome that occurs when host proinflammatory immune responses become elevated in response to an infection. If untreated, sepsis can result in severe sepsis, causing organ failure or hypotension, known as septic shock. Outer membrane biomolecules LPS, OmpA, and Pal have been implicated in the pathophysiology of Escherichia coli (E. coli) sepsis, specifically, the over-inflammatory response observed in sepsis patients. Notably, all of these proteins are released as a complex inside extracellular vesicles (EVs) from E. coli and other Gram-negative bacteria. We hypothesize that these proteins and EVs themselves may serve as excellent biomarkers for the diagnosis of sepsis. The purpose of this study was to optimize the detection of EVs from complex human biofluids such as plasma and urine. Here, we describe the results of our preliminary study, which demonstrates that we are able to isolate EVs from human plasma and characterize them using immunoblots to E. coli antigens, such as LPS, OmpA, and Pal. This work was supported by NIAID of the National Institutes of Health under award number R21AI163782 to LVM and TG.