Relationship of Colominic Acid (Poly N-Acetylneuraminic Acid) to Bacteria which Contain Neuraminic Acid

Abstract

SUMMARY: The bacteriocinic strain of Escherichia coli known as K235L+OC+ which elaborates colominic acid (poly N-acetylneuraminic acid) possesses a K antigen and has the serotype E. coli O1:K1:HNM in accordance with the Kauffmann-White classification scheme of the enterobacteriaceae. Strains of E. coli with O1:K1:HNM or O2:K1:HNM serotype elaborate a similarly constituted colominic acid. Chemical analysis has revealed that all E. coli with a K1 serotype contain neuraminic acid, but that strains which have other K serotypes do not contain significant amounts of this substance. The nature of the O serotype and the ability to produce haemolysins or bacteriocines are unrelated to the presence of neuraminic acid in the various strains analysed. Thus, the close association between a K1 serotype and colominic acid in E. coli suggests that all strains of this serotype produce colominic acid. Salmonella dahlem, S. djkarta, E. coli O1O:K5:HNM, Group C Neisseria meningitidis 1908 and 1935, and Citrobacter freundii O5:H30 (E. coli 5396/38) contain neuraminic acid as shown by chemical tests. However, the neuraminic acid is firmly bound and polysaccharides containing this material are not readily elaborated. As no serological relationship exists between these strains and strains of E. coli having a K1 serotype, it is concluded that they are non-producers of colominic acid. Thus, bacteria of various genera which contain neuraminic acid have this substance in different chemical combinations.