Mass Spectrometry-Based Proteomic Profiling of Sonicate Fluid DifferentiatesStaphylococcus aureusPeriprosthetic Joint Infection from Non-Infectious Failure: A pilot study

Abstract

ABSTRACTPurposeThis study aims to use proteomic profiling of sonicate fluid samples to compare host response duringStaphylococcus aureus-associated periprosthetic joint infection (PJI) and non-infected arthroplasty failure (NIAF) and investigate novel biomarkers to increase diagnostic accuracy.Experimental DesignIn this pilot study, eight sonicate fluid samples (four from NIAF and four fromStaphylococcus aureusPJI) were studied. Samples were reduced, alkylated and trypsinized overnight, followed by analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) on a high-resolution Orbitrap Eclipse mass spectrometer. MaxQuant software suite was used for protein identification, filtering, and label-free quantitation.ResultsPrincipal component analysis of the identified proteins clearly separatedS. aureusPJI and NIAF samples. Overall, 810 proteins were quantified in any three samples from each group and 35 statistically significant differentially abundant proteins (DAPs) were found (2-sample t-test p-values ≤0.05 and log2fold-change values ≥2 or ≤-2). Gene ontology pathway analysis found that microbial defense responses, specifically those related to neutrophil activation, were increased inS. aureusPJI compared to NIAF samples.Conclusion and Clinical RelevanceProteomic profiling of sonicate fluid using LC-MS/MS, alone or in combination with complementary protein analyses, differentiatedS. aureusPJI and NIAF in this pilot study.