New concepts in the pathophysiology of infective endocarditis

Abstract

Endocarditis pathogens colonize valves with pre-existing sterile vegetations or valves with minimal endothelial lesions. Inflamed endothelia produce cytokines, integrins, and tissue factor, which in turn attract fibronectin, monocytes, and platelets. Bacteria attaching to such structures further activate the cascade, becoming embedded and protected from host defenses. Staphylococcus aureus also actively invade the endothelium, causing apoptosis and endothelial damage. Knowledge of this interplay identifies host factors as potential therapeutic targets. Blocking infection by modulating host factors might be opportune because host factors are conserved. In contrast, interfering with bacterial virulence factors might be more complicated because they vary among different bacteria.

Proteomic and Transcriptomic Profiling of Staphylococcus aureus Surface LPXTG-proteins: Correlation with agr Genotypes and Adherence Phenotypes

“…In the same line, a few LPXTGproteins were not detected at all (i.e. Srap and SasC) in S. aureus Newman, although they were detected by LC-MS/MS in recombinant lactococci (35,41). This raises the question of their conditional expression, as observed in the present experiments and by others for isd genes (32,33), or of differential access of trypsin digestion.…”

“…We previously showed that LPXTG-proteins from S. aureus could be heterogeneously expressed in L. lactis and individually detected by LC-MS/MS in the recombinant lactococci (35,41). On this basis we constructed a peptide library specific to each of these LPXTG-proteins.…”

Molecular Characterization of Endocarditis-Associated Staphylococcus aureus

“…Fibronectin-binding protein A and B (FnBPA/FnBPB) and Clumping Factor A (ClfA) are wellcharacterized Microbial Surface Components Recognizing Adhesive Matrix Molecules (MSCRAMMs) that mediate attachment and colonization of S. aureus to the heart endothelium and medical devices (16)(17)(18)(19). The capsular polysaccharide is another important virulence factor expressed by most clinical strains of S. aureus.…”

Infective Endocarditis: Diagnosis, Treatment and Prevention: Review

“…Kapak sklerozu, vaskülit veya direkt bakteri aktivitesi (Staphylococcus aureus gibi) endotel hasarına yol açmaktadır. 7 Fibronektin, stafilokokal "clumping" faktör A ve B gibi adezyon proteinleri bakterilerin yapışmasında önemli bir role sahiptir. 7,8 Bakteri kolonizasyonu, endotel hasarını ve trombüs oluşmasını/büyüme-sini tetiklemektedir.…”

“…7 Fibronektin, stafilokokal "clumping" faktör A ve B gibi adezyon proteinleri bakterilerin yapışmasında önemli bir role sahiptir. 7,8 Bakteri kolonizasyonu, endotel hasarını ve trombüs oluşmasını/büyüme-sini tetiklemektedir. Polisakkarit ve protein matriks içeren çok katmanlı bakteri kümeleri (agregatlar) oluşmaktadır.…”