Composition and properties of a group A streptococcal teichoic acid

Area of Science:

• Microbiology
• Immunochemistry
• Biochemistry

Background:

• Streptococci possess cell wall components that can elicit immune responses.
• Teichoic acids are cell wall polymers found in Gram-positive bacteria, including streptococci.
• Specific teichoic acids may serve as serological markers for bacterial identification and classification.

Purpose of the Study:

• To characterize the teichoic acid-like material from various streptococcal groups.
• To determine the chemical composition and antigenic properties of group A streptococcal teichoic acid.
• To investigate the prevalence of specific teichoic acid structures among streptococci.

Main Methods:

• Extraction of teichoic acid-like material using cold trichloroacetic acid.
• Precipitin reactions with group-specific antisera.
• Purification of group A teichoic acid via Sephadex column chromatography.
• Analysis of chemical composition using alkaline hydrolysis and enzyme assays.
• Inhibition assays with specific sugars and amino acid derivatives.

Main Results:

• Teichoic acid-like material from streptococci groups A, D, E, O, and T reacted positively with group antisera, while other groups did not.
• Purified group A teichoic acid consisted of glycerol, phosphate, alanine, and glucosamine, with ester linkages.
• N-acetylglucosamine and specific alanine esters inhibited precipitin reactions, indicating their antigenic importance.
• Antibodies in antisera were specific for alanine and glucosamine linkages in group A streptococcal teichoic acid.

Conclusions:

• Group A streptococcal teichoic acid is a polymer of glycerol phosphate with N-acetylglucosamine and alanine.
• Antisera to streptococci contain antibodies recognizing alanine and glucosamine linkages.
• This type of teichoic acid is prevalent across a wide range of streptococcal groups.