ABSTRACT
Streptococcus gordonii alpha-phosphoglucomutase, which converts glucose 6-phosphate to glucose 1-phosphate, is encoded by pgm. The pgm transcript is monocistronic and is initiated from a sigma(A)-like promoter. Mutants with a gene disruption in pgm exhibited an altered cell wall muropeptide pattern and a lower teichoic acid content, and had reduced fitness both in vitro and in vivo. In vitro, the reduced fitness included reduced growth, reduced viability in the stationary phase and increased autolytic activity. In vivo, the pgm-deficient strain had a lower virulence in a rat model of experimental endocarditis.
Subject(s)
Cell Wall/chemistry , Gene Deletion , Phosphoglucomutase/genetics , Streptococcus/enzymology , Base Sequence , Cell Wall/metabolism , Endocarditis, Bacterial/microbiology , Endocarditis, Bacterial/physiopathology , Gene Expression Regulation, Bacterial , Molecular Sequence Data , Phosphoglucomutase/chemistry , Phosphoglucomutase/metabolism , Sequence Analysis, DNA , Streptococcal Infections/microbiology , Streptococcal Infections/physiopathology , Streptococcus/genetics , Streptococcus/growth & development , Streptococcus/pathogenicity , VirulenceABSTRACT
The ability to induce experimental endocarditis of biofilm-deficient mutants of Streptococcus gordonii was studied in an isogenic background. Strains were inactivated in either comD, fruK or pbp2b genes, which are involved in biofilm formation. These strains were clearly impaired (>75% reduction) in biofilm production in vitro. However, this did not result in a decreased severity of infection in vivo.
