Comparative preparation methods of sialylated capsule antigen from Streptococcus suis type 2 with type specific antigenicity.
The capsular polysaccharide (CPS) of Streptococcus (S.) suis type 2 was isolated from a type strain of S. suis NCTC 10234 by three different preparative methods: (A) lysozyme treatment method, (B) autoclave extraction method, and (C) HCl-extraction method. The structural characteristics of the three CPS (CPS-A, B and C) were examined by gel permeation chromatography, reactivity against rabbit antiserum and proton-nuclear magnetic resonance (1H-NMR). N-Acetylneuraminic acid (NeuAc) residues as sialic acid in CPS-C were partially dissociated or degraded during preparation with a remarkable decrease in the molecular mass and the antigen activity. Although both methods A and B produced intact CPS without releasing NeuAc residues, method B was considered to be a more suitable procedure for preparing the CPS antigen because of time-saving and safety factors. Sugar analysis by high performance liquid chromatography and gas liquid chromatography showed that CPS-B consisted of five kinds of sugars: Rhamnose (Rha), Glucose (Glc). Galactose (Gal), N-acetylglucosamine (GlcNAc) and NeuAc, in a molar ratio of 1.00:0.95:3.68:0.80:1.31. After complete removal of NeuAc residues by mild acid hydrolysis of CPS-B, the reactivity with anti-type 2 serum was not detected. The NeuAc residue in CPS of S. suis type 2 strain was thought to be the antigen epitope portion.
Sendai Meat Inspection Center, Miyagi, Japan.
M
M
Katsumi
T
T
Saito
Y
Y
Kataoka
T
T
Itoh
N
N
Kikuchi
T
T
Hiramune
D000942:Antigens, Bacterial / Q000276:immunology*; D016667:Bacterial Capsules / Q000276:immunology*; D002849:Chromatography, Gas; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003429:Cross Reactions; D000939:Epitopes / Q000276:immunology; D009682:Magnetic Resonance Spectroscopy; D019158:N-Acetylneuraminic Acid; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D017011:Streptococcus suis / Q000276:immunology*
D000942:Antigens, Bacterial; D000939:Epitopes; D011135:Polysaccharides, Bacterial; C028096:capsular polysaccharide, Streptococcus suis type 2; D019158:N-Acetylneuraminic Acid