Hyaluronic acid capsule is a virulence factor for mucoid group A streptococci.
- 1 October 1991
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 88 (19), 8317-8321
- https://doi.org/10.1073/pnas.88.19.8317
Abstract
Mucoid strains of group A Streptococcus have been associated with recent outbreaks of acute rheumatic fever. The mucoid colony morphology of these strains is a result of abundant production of capsular polysaccharide, which is composed of hyaluronic acid. To study the role of the hyaluronic acid capsule in virulence, we derived an acapsular mutant from a mucoid strain of group A Streptococcus by transposon mutagenesis. M protein expression was not altered in the mutant strain. The mucoid wild-type strain grew in fresh human blood and was resistant to phagocytic killing in vitro. In contrast, the acapsular mutant failed to grow in fresh human blood and was sensitive to phagocytic killing in vitro. Loss of capsule was associated with a 100-fold reduction in virulence of the organisms in mice. We conclude that the hyaluronic acid capsule protects mucoid group A streptococci from phagocytosis and has an important role in virulence.Keywords
This publication has 20 references indexed in Scilit:
- GENETIC REGULATION OF BACTERIAL VIRULENCEAnnual Review of Genetics, 1989
- Severe Group A Streptococcal Infections Associated with a Toxic Shock-like Syndrome and Scarlet Fever Toxin ANew England Journal of Medicine, 1989
- Group A Streptococcal Serotypes Isolated from Patients and Sibling Contacts During the Resurgence of Rheumatic Fever in the United States in the Mid-1980sThe Journal of Infectious Diseases, 1989
- Identification of a gene that regulates expression of M protein, the major virulence determinant of group A streptococci.Proceedings of the National Academy of Sciences, 1987
- In Vivo Streptococcus pyogenes C5a Peptidase Activity: Analysis Using Transposon- and Nitrosoguanidine-Induced MutantsThe Journal of Infectious Diseases, 1987
- Immunologic and chemical similarities between the streptococcus and human connective tissue.1968
- Current Knowledge of Type-Specific M Antigens of Group A StreptococciThe Journal of Immunology, 1962
- Diffusion-in-gel methods for immunological analysis.1958
- DIFFERENTIATION OF GROUP A STREPTOCOCCI WITH A COMMON R ANTIGEN INTO THREE SEROLOGICAL TYPES, WITH SPECIAL REFERENCE TO THE BACTERICIDAL TESTThe Journal of Experimental Medicine, 1957
- PROTEIN MEASUREMENT WITH THE FOLIN PHENOL REAGENTJournal of Biological Chemistry, 1951