Lack of association of Escherichia coli exhibiting both mannose-resistant haemagglutination and diffuse adherence to HEp-2 cells with acute diarrhoea in children.

Stool specimens from 631 children with acute diarrhoea and from 277 healthy controls were tested for the presence of non-enteropathogenic, non-enterotoxigenic Escherichia coli strains which mediated mannose-resistant haemagglutination of human erythrocytes (MRHA+). Fifty-nine (34.9%) of 169 isolated MRHA+ strains but none of 210 MRHA- strains exhibited diffuse adherence (DA+) to HEp-2 cells. DA+ strains were found in 37 (5.9%) children with diarrhoea and in 22 (7.9%) controls. MRHA+/DA+ strains in comparison to MRHA+/DA- strains significantly less frequently expressed P fimbriae (10.7 vs. 73.6%), haemolysin production (12.5 vs. 63.2%), and MRHA of other species erythrocytes (21.4 vs. 84%). These data demonstrate that E. coli which exhibit the diffuse pattern of adherence to HEp-2 cells also cause MRHA of human erythrocytes. Since these strains were found with similar frequencies in children with and without diarrhoea it seems that DA is not a marker of enteropathogenicity of E. coli.