Comparison of the sialic acid binding activity of transmissible gastroenteritis coronavirus and E-coli K99

Transmissible gastroenteritis coronavirus (TGEV) and Escherichia coli K99 a re both enteropathogenic for pigs with infections bring most severe in neon ate animals. For both microorganisms, a sialic acid binding activity has be en shown to be an essential pathogenicity factor. Here we demonstrate with haemagglutination and haemagglutination-inhibition assays that TGEV and E. coli K99 differ in their sialic acid binding activities with respect to the type and amount of sialic acid residues required on the erythrocytes surfa ce as well as with respect to the type of sialoglycoconjugate preferentiall y recognized. Intestinal mucins from piglets (12-14 days old) and adult ani mals were shown to inhibit TGEV to the same extent. From our results we con clude that E. coli K99 and TGEV interact with different sialoglycoconjugate s to establish an intestinal infection. The implications for the enteropath ogenicity of TGEV are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.