In a previous paper (6) the preparation and immunochemical properties of undigested aell walls of the Staph. aureus strains Cowan I and 1503 were studied. The precipitinogens, agglutinogens and sensitizing antigens found in whole bacteria were also demonstrated in the cell wall preparations. Except for polysaccharide A precipitins and most of the type agglutinins, the cell wall antisera contained antibodies to all antigens demon8trated.In addition to thc components regularly found in Staph. aureus cell walls our preparations contained 6 more amino acids: aspartic acid, serine, thrconine, groline, valine, and leucine. Since isolated teichoic acid has been shown to contain ester-linked alanine and the rigid mucopeptide (glycopeptide) contains 4 amino acids only (lysine, glycine, glutamic acid and alanine), it was assumed that our wall preparations contain additional structures. This assumption was supported by the various antigenic activities demonstrated.In the present work teichoic acid has been extracted and chemical and serological examinations have been made of the extracted and the unextractable material.
M A T E R I A L S A N D M E T H O D SPreparations: The preparations employed in the present investigation, i.e. cell wall of Staph. aureus type strain Cowan I, protein A, and polysaccharide A are the same as in the previous experiments (6).Antisera: The rabbit antisera described in (6) were used. Eztraction of teichoric acid: Incubation of polysaccharide A with 5 per cent trichloro-acetic acid for 15 mins a t 90" C ( 7 ) resulted in almost complete loss of serological activity by ring test. Since incuhation of polysaccharide A with phenylhydrazine hydrochloride (pH 7.0) at 80" C for 30 mins was shown not to reduce the ring test titre, this method of extraction was preferred.The cell wall preparation was extracted with phenylhydrazine according to the description of Archibald & Baddilelj ( 1 ) . The extraction process was controlled by agar gel diffusion with polysaccharide A (teichoic acid) as indicator. The combined supernatants, containing teichoic acid, and the unextractable residue were dialysed and freeze-dried. 27 ACTA PATH. 71;3