Streptococcus mutans autolysin AtlA is a fibronectin-binding protein and contributes to bacterial survival in the bloodstream and virulence for infective endocarditis
Journal
Molecular microbiology
Journal Volume
74
Journal Issue
4
Pages
888
Date Issued
2009-11
Author(s)
Abstract
Streptococcus mutans, a commensal of the human oral cavity, can survive in the bloodstream and cause infective endocarditis (IE). However, the virulence factors associated with this manifestation of disease are not known. Here, we demonstrate that AtlA, an autolysin of S. mutans is a newly identified fibronectin (Fn) binding protein and contributes to bacterial resistance to phagocytosis and survival in the bloodstream. Interestingly, prior exposure to plasma at low concentrations was sufficient to enhance bacterial survival in the circulation. Calcium ions at physiological plasma concentrations induced maturation of AtlA from the 104-90 kDa isoform resulting in increased Fn binding and resistance to phagocytosis. An isogenic mutant strain defective in AtlA expression exhibited reduced survival and virulence when tested in a rat model of IE compared with the wild-type and complemented strains. The data presented suggest that plasma components utilized by S. mutans enhanced survival in the circulation and AtlA is a virulence factor associated with infective endocarditis.
SDGs
Other Subjects
autolysin A; calcium ion; fibronectin binding protein; isoprotein; plasma protein; unclassified drug; virulence factor; amino terminal sequence; animal experiment; animal model; article; bacterial cell; bacterial colonization; bacterial endocarditis; bacterial survival; bacterial virulence; bactericidal activity; calcium blood level; circulation; controlled study; heart valve; human; human cell; immunofluorescence; mutant; nonhuman; phagocytosis; polymorphonuclear cell; priority journal; protein binding; protein cleavage; protein expression; protein isolation; protein processing; proteomics; rat; solubility; strain difference; Streptococcus mutans; wild type; Adhesins, Bacterial; Animals; Blood; Blood Bactericidal Activity; Colony Count, Microbial; Endocarditis; Gene Deletion; Humans; Microbial Viability; Models, Biological; Molecular Weight; N-Acetylmuramoyl-L-alanine Amidase; Phagocytosis; Protein Processing, Post-Translational; Rats; Rats, Wistar; Streptococcus mutans; Virulence; Bacteria (microorganisms); Rattus; Streptococcus mutans
Publisher
WILEY
Type
journal article