Surface-shaving of Staphylococcus aureus strains using Lipid-based Protein Immobilization (LPI) and quantitative proteomic analysis reveal differences in protein expression levels of the surfaceome

ABSTRACT: Staphylococcus aureus is a pathogen which can cause a wide range of infections. To find new targets for diagnostics and treatment as well as understanding host-pathogen interactions, many studies have focused on the bacterial surface proteins. In the study presented here, bacterial cell surface-shaving, using Lipid-based Protein Immobilization (LPI), followed by tandem mass tag (TMT) protocols for performing relative quantitative mass spectrometry proteomics, was performed to examine the surface proteome (surfaceome) of selected strains of S. aureus. The study included analyses of surface protein-deficient mutants compared to the wildtype S. aureus strain Newman, as well strain isolates of different clinical associations. Quantitative proteomics were applied in the analysis of the surface proteome of Staphylococcus aureus. In study 1, the differential abundance of proteins in the mutant strains ΔClfA, ΔSrtAΔSrtB and ΔSpa was compared to those in the Newman parental strain. All together 7880 peptides were identified in Study 1 corresponding to 1290 proteins, and the results clearly showed that the mutant strains were deficient in the knocked-out genes. The Clinical strains study (Study 2) included the Newman strain, the reference strains LS-1 and SH1000 and three clinical isolates, two from invasive infections and one from mild skin infection. A total of 4949 peptides were identified in Study 2 corresponding to 919 proteins. For each strain, approximately 20 proteins showed higher or lower abundance (fold changes) when compared to the Newman strain. The results indicate that surface shaving of intact bacteria by LPI in combination with protocols for performing quantitative proteomics makes it possible to distinguish differences in protein abundance of the surfaceome, including virulence factors, between S. aureus strains.

INSTRUMENT(S): Orbitrap Fusion, Q Exactive

ORGANISM(S): Staphylococcus Aureus

TISSUE(S): Cell Culture

SUBMITTER: Proteomics Core Facility  

LAB HEAD: Roger Karlsson

PROVIDER: PXD025436 | Pride | 2024-10-17

REPOSITORIES: Pride