Homologous and Heterologous Antibody Responses to Lipopolysaccharide after Enterohemorrhagic Escherichia coli Infection

Abstract

To evaluate antibody responses against lipopolysaccharide (LPS: O157, O26, and O111) in enterohemorrhagic Escherichia coli (EHEC) infection, sera of 24 schoolchildren associated with the Morioka outbreak in 1997 and of 74 sporadic patients suspected of having EHEC infection were examined. Using a positive standard serum, quantitative evaluation of LPS antibodies by an enzyme‐linked immunosorbent assay (ELISA) was established. High levels of specific IgM and IgA antibodies against homologous E. coli LPS were present in the acute period and are characteristic of EHEC. This could be used for the serological diagnosis of EHEC infection, except for early infants and the elderly. In addition to the specific homologous response, multiple antibody responses against different serotypes other than those isolated were demonstrated in many cases by qualitative analysis using Western blotting.

Acquisition of Serum Antibodies Reactive With Enterohemorrhagic Escherichia coli Virulence-Associated Factors by Healthy Brazilian Children and Adults

“…Paired acute and convalescent sera from patients infected with E. coli O157 exhibited strong responses to homologous and heterologous LPS O157, LPS O111, and LPS O26, although sera from healthy subjects were not tested. 22 IB assays performed with OMP were consistent with an immunologic memory for the bacterial proteins, but not indicative of acute infection, as it was observed as a strong recognition of several antigenic fractions by IgG antibodies, including intimin, and a weaker reaction by IgM antibodies. Interestingly, serum sample 2 from a 4-month-old child showed strong recognition of several EHEC antigens by IgG antibodies (probably acquired through placental transfer) but not by IgM antibodies.…”

“…In the Brazilian population, the total IgM concentrations equivalent to adults are reached by 12 months of age; adult IgG values, with some variations in the different subclasses, are reached at 24 months, whereas IgA levels equivalent to the adult values are only reached by the beginning of the adolescence. 20 Anti-LPS antibody values in healthy populations tend to increase with age in children 21 and adults, 22 or with contact with cattle. 23 This increased immunity may be related to environmental exposure to the pathogen or to cross-reactive antigens, leading to background immunity as well as to a decreased risk of severe STEC disease.…”

Surveillance of Hemolytic Uremic Syndrome in Children Less Than 15 Years of Age, a System to Monitor O157 and Non-O157 Shiga Toxin-Producing Escherichia coli Infections in France, 1996–2006

“…In our surveillance system, serology was selected as the principle method for STEC confirmation, because various studies demonstrated that STEC is rarely excreted in stools after the first week of illness when HUS typically begins 30,34 -36 and that serologic tests for antibodies to LPS of STEC are very sensitive. [37][38][39] It is possible that some of the HUS cases with no evidence of STEC infection were infected by STEC not recognized by our diagnostic methods. This could be the case if the STEC serogroup was not included in the LPS panel used by our reference laboratories, or if the sensitivity of the serologic test for a specific serogroup was particularly low.…”

“…This difference in serology positivity rates according to age could be explained by the immunologic immaturity of younger children and a less effective antibody response to LPS of STEC. 38 It could also be caused by the combination of a higher frequency of non-O157 STEC infections in infants and a lower sensitivity of the method to detect LPS of non-O157 STEC. Indeed, various studies show that non-O157 serogroups, particularly the O26 serogroup, are predominant in the younger population.…”

Lipopolysaccharide Renders Transgenic Mice Expressing Human Serum Amyloid P Component Sensitive to Shiga Toxin 2

“…Circulating antibodies specific to O157 LPS are also common in HUS patients and serum LPS binding protein (LBP) concentrations are increased [43], [44], [45]. The simple presence of antibodies to LPS in circulation does not predict progression to HUS in EHEC-infected patients [46], but these studies all suggest that at least some LPS has entered the circulation in these subjects. In some of the more severe cases of HUS preceded by EHEC infection, subjects were observed to exhibit many of the clinical signs associated with septic shock, suggesting severe endotoxemia [47].…”