Streptococcus pneumoniae can utilize multiple sources of hyaluronic acid for growth.
The mechanisms by which Streptococcus pneumoniae obtains carbohydrates for growth during airway colonization remain to be elucidated. The low concentration of free carbohydrates in the normal human airway suggests that pneumococci must utilize complex glycan structures for growth. The glycosaminoglycan hyaluronic acid is present on the apical surface of airway epithelial cells. As pneumococci express a hyaluronate lyase (Hyl) that cleaves hyaluronic acid into disaccharides, we hypothesized that during colonization pneumococci utilize the released carbohydrates for growth. Hyaluronic acid supported significant pneumococcal growth in an hyl-dependent manner. A phosphoenolpyruvate-dependent phosphotransferase system (PTS) and an unsaturated glucuronyl hydrolase (Ugl) encoded downstream of hyl are also essential for growth on hyaluronic acid. This genomic arrangement is present in several other organisms, suggesting conservation of the utilization mechanism between species. In vivo experiments support the hypothesis that S. pneumoniae utilizes hyaluronic acid as a carbon source during colonization. We also demonstrate that pneumococci can utilize the hyaluronic acid capsule of other bacterial species for growth, suggesting an alternative carbohydrate source for pneumococcal growth. Together, these data support a novel function for pneumococcal degradation of hyaluronic acid in vivo and provide mechanistic details of growth on this glycosaminoglycan.
Center for Microbial Pathogenesis, The Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, USA.
Carolyn
C
Marion
Jason M
JM
Stewart
Mia F
MF
Tazi
Amanda M
AM
Burnaugh
Caroline M
CM
Linke
Shireen A
SA
Woodiga
Samantha J
SJ
King
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000378:metabolism; D006801:Humans; D006820:Hyaluronic Acid / Q000378:metabolism*; D051379:Mice; D010770:Phosphotransferases / Q000378:metabolism; D011133:Polysaccharide-Lyases / Q000378:metabolism; D013296:Streptococcus pneumoniae / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*
D001426:Bacterial Proteins; D006820:Hyaluronic Acid; D010770:Phosphotransferases; D006026:Glycoside Hydrolases; C120983:unsaturated glucuronyl hydrolase; D011133:Polysaccharide-Lyases; C100002:hyaluronate lyase