Studies on K Antigens of Vibrio parahaemolyticus

Abstract

In the previous paper, it was reported that the purified K antigens of Vibrio parahaemolyticus strains O2:K3 and O2:K28 had been shown to have antigenic specificity by the Ouchterlony method, and that analysis had clarified that these antigens were mainly composed of acidic polysaccharide. The present paper deals with the immunochemical characteristics of the remaining 43 of the 46 types of purified K antigens of the organism.The results obtained are summarized as follows.1) All the K antigens, except K 27 and K 16 which failed to release any K antigenic substance by the phenol water extraction method, were proved to be substances mainly composed of acidic polysaccharide.2) Thirty-nine of the 43 types of purified K antigens showed antigenic specificity against homologous anti-KO serum by the Ouchterlony gel-diffusion method.3) It was proved serologically that O3:K30 and O5:K14 had exactly the same K antigen, although they had different O antigens.4) The pilot strain of the organism, O11:K35, which has lately been added as a new serotype, gave completely the same results with the pre-existing O5:K15 pilot strain.5) Chemical analysis of the purified K antigens revealed that the sugar composition varied with the type of K antigens, except O2:K3 and O2:K28. The sugar detected were glucose, galactose, mannose, fucose, rhamnose, ribose, glucosamine, galactosamine, uronic acid, sialic acid, and several unknown kinds. Uronic acid or sialic acid was detected from 18 of the 43 K antigens tested.