2F3 Monoclonal Antibody Recognizes the O26 O-Antigen Moiety of the Lipopolysaccharide of Enterohemorrhagic Escherichia coli Strain 4276

Abstract

Enterohemorrhagic Escherichia coli (EHEC) and enteropathogenic E. coli (EPEC) organisms are groups of pathogenic strains whose infections are characterized by a typical lesion of enterocyte attachment and effacement. They are involved in enteric diseases both in humans and in animals, and EHEC strains can be responsible for hemolytic uremic syndrome in humans. Previously, it was shown that the 2F3 monoclonal antibody (MAb) is specific for the O26 EHEC and EPEC strains (P. Enterohemorrhagic Escherichia coli (EHEC) strains are an important class of pathogens for humans and animals. The term EHEC denotes E. coli strains that cause attaching and effacing lesions on epithelial cells, express Shiga toxin-encoding genes, possess a 60-MDa virulence plasmid, and produce hemorrhagic colitis and/or hemolytic uremic syndrome (17,18).KerrBesides those of the O157:H7 and O157:H Ϫ serotypes, EHEC strains of serogroup O26 are the most common strains found in human infections (4, 17). In addition, O26 EHEC strains are an important cause of enteritis in calves (12). One of the most important steps in the pathogenic mechanism of enteric bacteria is the initial adhesion of the bacteria to the intestinal wall. Several stages of colonization have been recognized in attaching and effacing E. coli pathogenesis, some of which await characterization. Some level of host specificity is shown by EHEC strains, but the role in host specificity of the recognized virulence factors, such as Shiga toxin 1 (Stx1) and/or Stx2 and the intimin protein (a protein that is encoded by the eae gene and necessary for the production of the attaching and effacing lesion), is unknown (8, 19). The bovine host specificity shown by O26 EHEC and enteropathogenic E. coli (EPEC) strains could be based on the production of a colonization factor, such as an adhesin, that is specific for cattle; such a colonization factor has been demonstrated to be the basis of the host specificity of classical human EPEC strains. Such an adhesin is likely to be a specific immunogen exposed at the bacterial cell surface (3,13,15,17,23,24).A monoclonal antibody (MAb), 2F3, was derived against a surface antigen extracted from the bovine O26 EHEC strain 4276; it tested positive in an enzyme-linked immunosorbent assay (ELISA) with all of the O26 and half of the O111 bovine and human EHEC and EPEC strains (9). Recent reexamination of six of the O111 EHEC and EPEC strains that tested positive revealed a contamination by O26 EHEC or EPEC strains. Purification of the strains in the mixed culture demonstrated that the O111 strains were 2F3 negative and the O26 strains were 2F3 positive (J. McCappin and H. Ball, unpublished data).Since the 2F3 MAb is specific for the O26 EHEC and EPEC strains, it may not only represent a diagnostic tool of these confirmed pathogens but also recognize a factor involved in the production of the attaching and effacing lesion. In view of these results, this study was initiated (i) to characterize the antigen recognized by the 2F3 MAb and its genetic determinant an...

Putative Adhesins of Enteropathogenic and EnterohemorrhagicEscherichia coliof Serogroup O26 Isolated from Humans and Cattle

“…Forty-four strains were isolated from the feces or intestines of young calves (1 non-EPEC/non-EHEC, 18 EPEC, and 25 EHEC strains), and 33 strains were isolated from humans (4 non-EPEC/non-EHEC, 10 EPEC, and 19 EHEC strains). Most of the strains had been described previously (37), but their pathotype (EPEC or EHEC) and serotype O26:H11 status were confirmed by PCR for the stx 1 , stx 2 , eae, EHEC hlyA, wzx-wzy O26 , and fliC H11 genes (Table 1) (10,13,15).…”

Comparison of a monoclonal antibody-based capture/enrichment sandwich enzyme linked immunosorbent assay with immunomagnetic bead separation for the detection of attachment effacement Escherichia coli O26 strains from cattle faeces

“…Recent work with Mab 2F3 has demonstrated that its target antigen was in the lipopolysaccharide domain, and that it was nonreactive to a small collection of non‐AEEC O26 strains from human (4), pig (1), poultry (1) and cattle (1) (Szalo et al. 2004).…”

“…Recent work with Mab 2F3 has demonstrated that its target antigen was in the lipopolysaccharide domain, and that it was nonreactive to a small collection of non-AEEC O26 strains from human (4), pig (1), poultry (1) and cattle (1) (Szalo et al 2004). Although Mab 2F3 reactive non-AEEC O26 isolates were not detected in a previous examination of the use of the capture/enrichment sELISA Rhamnose + antibiotics* eae +ve/VT +ve 9 9 2 3 0 0 eae +ve/VT )ve 11 10 7 10 10 8 (3 · NG ) eae )ve/VT )ve 10 9 2 0 5 2 (7 · NG) Total 30 28 11 13 15 10 (10 · NG) *Rhamnose agar containing cefixime (0AE05 mg l )1 ) and potassium tellurite (2AE5 mg l )1 ).…”

Study of polymorphisms in tir, eae and tccP2 genes in enterohaemorrhagic and enteropathogenic Escherichia coli of serogroup O26

“…Most of the strains had been described previously [37,38] and their pathotype (EPEC or EHEC) and serotype O26:H11 had been confirmed by PCR for stx1, stx2, eae, wzx-wzy O26 and fliC H11 genes [39-41]. …”