Antibody Responses to Escherichia coli O157 and Other Lipopolysaccharides in Healthy Children and Adults

Abstract

In Mexico, diarrheal disease due to different serotypes of Escherichia coli is highly prevalent, with only sporadic isolation of O157 non-H7 strains. This could be due to exposure to the O157 or related E. coli lipopolysaccharide (LPS), such as O7 or O116, at an early age. By using enzyme-linked immunosorbent assay (ELISA) and Western blotting, the present study analyzed 605 serum samples from Mexican adults and infants without clinical symptoms of disease for the presence of antibodies to these three E. coli LPSs. The bactericidal activities of homologous and heterologous rabbit and human serum samples against O7, O116, and O157 E. coli LPSs were also determined. By using a cutoff point of 0.7, it was found by the ELISAs that 28 of 562 (5%) of the serum samples from adolescents and adults and 2 of 43 (5%) of the serum samples from infants less than 1 year of age reacted with the O157 LPS. By using cutoff points between 0.4 and 0.699, the proportion of serum samples from both age groups that reacted with the O157 LPS increased to 20%. Western blotting analysis of selected serum samples that showed an intermediate response against the O157 LPS by the ELISAs showed that 61 of 88 (69%) reacted with the same LPS. A similar result was observed for maternal milk samples. The bactericidal activities of rabbit serum samples against the O7, O116, and O157 LPSs showed that they were positive for both homologous and heterologous antigens. Similar results were observed with the human serum samples. O157 non-H7 strains were identified in only 10% of the E. coli strains isolated from 263 Mexican children with and without diarrhea over the past 15 years. This absence of O157:H7 strains in Mexico may be associated with the presence of antibodies against O157 or related E. coli LPSs.Enterohemorrhagic Escherichia coli O157:H7 is of great clinical and epidemiological importance as a cause of hemorrhagic colitis (HC) and hemolytic-uremic syndrome (HUS) in developed countries (2, 21, 35). The incidence of these bacteria in Mexico and other developing countries is low, although it has been reported that these bacteria are present in Chile, Brazil, Argentina, and Colombia (12,17,19,20).The presence of antibodies in sera from patients with HUS against the lipopolysaccharide (LPS) of E. coli O157 was reported initially by Notenboom et al. (23). Subsequent studies designed to characterize the immune responses of patients infected with E. coli O157 have reported the presence of immunoglobulin M (IgM) (8), IgG (16), and both IgM and IgG (1) antibodies to O157 LPS in patients with HUS. IgA antibodies have also been reported in the serum and feces of patients with HUS (6, 30). A study carried out by Reymond et al. (28) showed the presence of antibodies to O157 LPS in 12% of the population living in rural areas where O157 strains are endemic, whereas they were found in only 4.7% of the population living in urban areas. Similar results were observed by Belongia et al. (3) in a rural Wisconsin population.Cross-reactivities between the LPS of...

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

“…Antibodies to LPS O157 in healthy adults and children may be acquired by contact with O157 non-H7 E. coli and other serogroups such as O7 or O116 E. coli or strains with cross-reacting LPS and by placental transfer or breastfeeding in infants. 8 Cross-reactions among antibodies reactive with common epitopes of different LPS were also confirmed in bovine serum samples. 19 Our results suggest that there is a gradual acquisition of anti-LPS antibodies with increasing age, with the increase in antibody values occurring earlier for IgM antibodies than for IgG antibodies, probably simultaneously with the development of total serum immunoglobulin concentrations.…”

Serological Evidence of Asymptomatic Infections during Escherichia coli O104:H4 Outbreak in Germany in 2011

“…Therefore measurement of antibodies against LPS by serological assays such as ELISA and Western Blot (WB) has been widely used for diagnosis of a number of illnesses caused by gram-negative organisms including E. coli O157:H7 [7]–[9]. However, at the time of the outbreak an assay able to give evidence of the antibody status after an infection with the outbreak strain was not available.…”

Common epitopes in LPS of different Enterobacteriaceae are associated with an immune response against Escherichia coli O157 in bovine serum samples

“…Isolation rates have been widely reported (Naylor et al, 2005), with levels of 1.8 % in Japan (Miyao et al, 1998), 1.9 % in Australia (Cobbold & Desmarchelier, 2000) and from 0 to 7.4 % in the USA (Faith et al, 1996). In Mexico, serotyping data of approximately 16 000 E. coli isolates collected over the past 20 years have shown an isolation frequency of 1 % for E. coli O157 strains (Navarro et al, 2003). In another study in Mexico, Callaway et al (2004) showed an isolation frequency of 1.25 % for E. coli O157 in cattle and 2.1 % in swine.…”