The Study of Protective Extracellular Proteome Staphylococcus aureus № 6

Abstract

In recent years, there is a persistent increase in the spread of community-acquired infections and medical care associated infections, the cause of which is S. aureus. Previously using liquid chromatography in combination with mass spectrometry (LC-MS) analysis, spectrum of having protective activity S. aureus № 6 proteins with a molecular weight of 30 - 50 kDa, secreted into the culture medium at the end of the exponential growth phase, was investigated. 11 proteins were identified from indicated peptides and preliminary results of the protective activity of the secreted protein-based substances (SPS), marked as «initial», were obtained. While its fractionation with ion exchange chromatography on DEAE-Sepharose, the protective fraction - II SPS - was obtained. Its hypodermic immunization leads to reduction of kidney inoculation, and to kidney abscess formation, compared to the control, during the generalized infection of mice BALB/c, developing as a result of retro-orbital injection of sublethal dose S. aureus. Aim. investigation the protective extracellular proteome II SPS S. aureus № 6. Material and methods. LC-MS analysis of the received data was carried out by comparing the detected mass-spectrum protein IISPS with the results of proteomic study of the virulent strain of S. aureus Newman widely used in researches. More than 100 interacting protein clusters were identified for certain using various databases. Results. During analysis main attention was paid to 46 identified proteins involved in various biological processes. Thus, the largest group (19 proteins) is composed of carbohydrate metabolism enzymes, eight of which are involved in key stages of glycolysis; 6 proteins are related to pathogenicity factors (including clamping factors A and B, gaptoglobin-adhesive surface protein) and 4 proteins are related to stress ones. The remaining 17 proteins represent a large group of proteins involved in various metabolic and biosynthetic processes. Conclusion. The received results confirmed the data of other researchers on the identification of a large number of secreted proteins of S. aureus and on their low coincidence with secreted from clinical isolates. This demonstrates the validity of the postulate of the plasticity of the S. aureus genome affecting the exoproteome profile that largely determines the difficulties in creation of effective anti-staphylococcal vaccines.