Open AccessDegradation and utilisation of chondroitin sulphate by Streptococcus intermedius
Author(s) -
H. Shain,
Karen A. Homer,
David Beighton
Publication year - 1996
Publication title -
journal of medical microbiology/journal of medical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 117
eISSN - 1473-5644
pISSN - 0022-2615
DOI - 10.1099/00222615-44-5-372
Subject(s) - streptococcus intermedius , biochemistry , uronic acid , chemistry , galactose , streptococcus , disaccharide , microbiology and biotechnology , stereochemistry , polysaccharide , bacteria , biology , genetics
Streptococcus intermedius, part of the 'Streptococcus milleri group', has the ability to produce glycosaminoglycan depolymerising enzymes (hyaluronidase and chrondroitin sulphate depolymerase) which is unique amongst the viridans streptococci and may contribute to their virulence in brain and liver abscesses. The growth of S. intermedius strain UNS 35 was studied in basal medium supplemented with chondroitin sulphate A (CS-A, sulphated at position 4 of the N-acetylgalactosamine moiety) or chondroitin sulphate C (CS-C, sulphated at position 6 of the N-acetylgalactosamine moiety) as the major carbohydrate source. CS-A but not CS-C supported the growth of S. intermedius. Extracellular degradation of CS-A resulted in the initial accumulation of 2-acetamido-2-deoxy-3-O-(beta-D-gluco-4-delta-enepyranosyluronic acid)-D-galactose (deltaUA GalNAc-0S), and low levels of 2-acetamido-2-deoxy-3-O-(beta-D-gluco-4-delta-enepyranosyl uronic acid)-4-O-sulpho-D-galactose (deltaUA GalNAc-4S) in the medium with GalNAc-0S being subsequently utilised during bacterial growth. Metabolic end-products included formate and ethanol but not lactate, indicating that growth was probably carbon-limited. The CS-A contained 30% CS-C, which was also depolymerised resulting in the formation of 2-acetamido-2-deoxy-3-O-(beta-D-gluco-4-delta-enepyranosyluronic acid)-6-O-sulpho-D-galactose (deltaUA GalNAc-6S) in the culture supernate, but this unsaturated disaccharide was apparently not utilised during growth. The results indicate that S. intermedius produced CS-AC depolymerase, which was inducible and extracellular, and sulphatase activity. Experiments with authentic deltaUA GalNAc-4S and deltaUA GalNAc-6S demonstrated that deltaUA GalNAc4S rather than deltaUA GalNAc-6S was the preferred substrate for the sulphatase. Therefore, it is suggested that the CS-AC depolymerase of S. intermedius may play a role in the destruction of CS in host tissues, facilitating bacterial spread, and also in bacterial nutrition by the liberation of nutrients at the site of infection.