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Safety and Immunogenicity of Escherichia coli O157 O-Specific Polysaccharide Conjugate Vaccine in 2–5-Year-Old Children

  1. Amina Ahmed1,
  2. Jianpin Li2,
  3. Yossi Shiloach3,
  4. John B. Robbins2 and
  5. Shousun C. Szu2⇓
  1. 1Carolinas Medical Center, Charlotte, North Carolina
  2. 2National Institute of Child Health and Human Development, Bethesda, Maryland
  3. 3National Institute of Digestive, Diabetes, and Kidney Diseases, National Institutes of Health,, Boston, Massachusetts
  1. ↵Reprints or correspondence: Dr. Shousun C. Szu, National Institute of Child Health and Human Development, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892 (szus{at}mail.nih.gov).
 
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Abstract

Background. Escherichia coli O157:H7 causes severe enteritis and hemolytic-uremic syndrome, mostly in young children and older adults. Similar to the case with Shigella, serum IgG against the O-specific polysaccharide of E. coli O157:H7 may confer immunity by lysing the inoculum in the intestine. A phase 1 trial in adults showed that a vaccine of E. coli O157:H7 O-specific polysaccharide conjugated to recombinant exotoxin A of Pseudomonas aeruginosa (O157-rEPA) was safe and immunogenic.

Methods. A phase 2 trial of the O157-rEPA vaccine was conducted in 49, children 2–5 years old who were divided randomly into groups receiving 1 or 2 doses of vaccine. Adverse reactions were monitored. Serum IgG lipopolysaccharide (LPS) antibodies were determined.

Results. No significant adverse reactions were observed. At 1 week after the first dose was administered, most children (81%) responded with a >4-fold increase in serum IgG LPS antibodies. At 6 weeks after the first dose was administered, all children responded with a >8-fold increase; a second dose did not elicit a booster response. At 26 weeks after the first dose was administered, the geometric mean titer of serum IgG LPS antibodies was ∼20- fold higher than was the prevaccination titer. These serum samples had high titers of bactericidal activity that were correlated roughly with serum IgG LPS antibody titers (r = .78).

Conclusions. The O157-rEPA vaccine was safe and immunogenic in young children. A phase 3 trial of the administration of this conjugate vaccine concurrently with routine immunization in infants is planned.

Escherichia coli O157:H7, which was first recognized as a pathogen in the early 1980s, has been linked to outbreaks of illness worldwide [1–6]. The attack rate of E. coli O157:H7 is age related, with young children and the elderly being most susceptible. Approximately 10% of patients with E. coli O157:H7 infection develop hemolytic-uremic syndrome, which is a life-threatening complication that is characterized by hemolytic anemia, thrombocytopenia, and renal failure [2, 4, 7, 8]. It is presently the most common cause of acute renal failure in children in the United States [3, 8]. Mortality occurs in 5% of patients, and long-term renal impairment occurs in 10%–30% of survivors [8–13]. Treatment for E. coli O157:H7 infection remains controversial. Antimicrobial agents have not been proven to affect the severity of disease, duration of shedding, or development of hemolytic-uremic syndrome [7, 14–16].

The infectious dose of E. coli O157:H7. is low; in most cases, <100 cfu can cause disease [17–19]. Cattle are the most common animal reservoir for this organism and also account for the major source of E. coli O157:H7 infection [17, 18, 20]. Because of the wide range of food contaminated by E. coli O157:H7—including beef, vegetables, and fruits—as well as other vehicles of transmission—such as recreational water sources and petting zoo animals—prevention efforts aimed at eliminating E. coli O157:H7 from the source of infection have been difficult [20–24]. Attempts to eliminate E. coli O157:H7 from the cattle intestine by dietary change or vaccination also have been largely unsuccessful [25, 26].

Immunity to E. coli O157:H7 is poorly understood. High serum titers of antibodies to the lipopolysaccharide (LPS) of E. coli O157:H7 are detectable after symptomatic infection [9, 27]. The protective role that these antibodies play is suggested in populations with frequent contact with cattle, such as dairy farm workers, who have higher serum titers of antibodies to E. coli O157:H7 and a lower risk of symptomatic infection than does the general population [28, 29]. That children <5 years old have the highest risk of acquiring E. coli O157:H7 infection suggests that natural immunity is acquired with age [28]. Adults probably have low serum IgG LPS antibody titers induced by either E. coli O157:H7 or cross-reactive organisms in the environment, including Citrobacter species (authors' unpublished data and [30]).

E. coli and Shigella can be considered a single genus, because their genomic sequences show extensive similarities and share a phylogenetic tree [31, 32]. Both E. coli Ol57:H7 and Shigella dysenteriae produce Shigella toxin and cause bloody diarrhea [32–34]. On the basis of our study of Shigella and Salmonella species, we propose that to protect young children against E. coli O157:H7 infection, a polysaccharide conjugate vaccine eliciting IgG antibodies to the LPS could lyse the inoculum on contact and confer immunity [28, 29, 34–40].

In a phase 1 trial, we showed that such conjugate vaccines administered to healthy adults were safe and elicited high serum IgG LPS antibody titers with bactericidal activity [41]. In the present study, we report the safety and immunogenicity of an E. coli O157:H7 investigational conjugate vaccine in 2–5-year old children.

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SUBJECTS, MATERIALS, AND METHODS

Investigational vaccine. E. coli O157:H7 O-specific polysaccharide conjugated to recombinant exotoxin A of Pseudomonas aeruginosa (O157-rEPA; lot 011094) was produced at the National Institute of Child Health and Human Development, National Institutes of Health (NIH), and bottled by the Pharmaceutical Development Section, Pharmacy Department, Clinical Center, NIH. The investigational vaccine was approved by the US Food and Drug Administration (investigational new drug no. 5528). Of the 3 conjugates studied in our phase 1 trial, the conjugate using acid-detoxified LPS (O-specific polysaccharide) as the polysaccharide antigen elicited the highest serum IgG LPS antibody titers, although the differences between the titers were not statistically significantly different, and it was used in the present phase 2 trial [41]. Briefly, LPS was purified from E. coli O157:H7 that was fermented in a medium containing no bovine components [41]. LPS was detoxified in 1 N acetic acid and covalently linked to the recombinant exoprotein A from P. aeruginosa, which was purified at the NIH [41, 42]. The endotoxin levels of O-specific polysaccharide in the final vaccine were <20 endotoxin units/dose. The vaccine met the safety requirements of US Code of Federal Regulations 610. Each 0.5-mL dose contained 26 µg of polysaccharide and 77 µg of protein.

Study design. The human experimentation guidelines of the US Department of Health and Human Services and those of the Carolinas Medical Center were followed in the conduct of the clinical research. The clinical protocol was approved by the institutional review boards of the National Institute of Child Health and Human Development and of Carolinas Medical Centers and by the Office for Human Research Protection. Healthy children, 2–5 years old, were recruited from April 2002 to July 2003. Children who had a chronic disease warranting daily systemic medications, were immunocompromised, or had a history of vaccine-associated reactions were excluded. Informed consent was obtained from parents or guardians, and baseline laboratory measurements (serum transaminase levels, HIV status, and prevaccination serum E. coli O157:H7 LPS antibody titers) were obtained.

Children returned 7–14 days after the enrollment visit for vaccination. Children were randomized using computer-generated numbers to receive 1 or 2 doses of vaccine. They were examined by a physician, and their axillary temperature was measured. Children with a temperature ⩽37.5°C received an intramuscular injection of 0.5 mL of vaccine in the deltoid muscle and then were monitored for local and systemic reactions for 30 min by the vaccination team. Parents/guardians were provided with diaries, thermometers, and measuring tapes to record temperatures and reactions at 6, 24, 48, and 72 h after each dose was administered. Redness or swelling at the injection site was recorded in millimeters. Signs and symptoms (pain at injection site, myalgias or arthralgias, headache, nausea, vomiting, diarrhea, abdominal pain, and appetite or activity changes) were categorized as mild, moderate, or severe. Other signs that were elicited included rash and increased somnolence. To review observations by parents/guardians, the study coordinator conducted telephone interviews at 6, 24, and 48 h after each dose was administered. Serum transaminase levels were measured in all children at 1 and 10 weeks after vaccination. Rectal swab samples for culture of E. coli O157:H7 were collected at 6, 10, and 26 weeks after vaccination.

Serum E. coli O157 LPS antibodies. Serum antibodies to E. coli O157:H7 LPS were measured by ELISA [41, 42]. A serum sample (from subject no. ECO 161) from our phase 1 trial was used as a reference for IgG antibody titers and was arbitrarily assigned a value of 100.00 ELISA units (EU) of IgG antibodies. A second serum sample (from subject no. ECO 110) from our phase 1 trial was selected as a reference for IgM antibody titers and was arbitrarily assigned a value of 100.00 EU of IgM antibodies [41]. Serum antibody titers were expressed as geometric means, with 25th–75th percentiles. Comparisons of geometric means were made with the unpaired or paired t test. The χ2 test or, when appropriate, Fisher's exact test for paired or unpaired t test was used for comparison of categorical variables.

Bactericidal activity was measured in representative serum samples before and 26 weeks after the first dose was administered [41, 43]. An isolate of E. coli O157:H7 from a patient was used as the test strain. Guinea pig serum (MP Biomedicals) was used as the source of complement [41, 44]. Serum samples were analyzed before and after treatment with 2-mercaptoethanol (50 mmol/L at 37°C for 30 min).

Cross-reaction with Vibrio cholerae 01 LPS antibodies. Perosamine, a 3,6-di-deoxy-a-mannosamine, is present on the O-specific polysaccharide of E. coli O157:H7 and V. cholerae 01 [45, 46]. Serum samples from children who received 1 or 2 doses of the O157-rEPA vaccine were assayed by ELISA for antibodies to LPS from V. cholerae O1 serotypes Inaba and Ogawa. A serum sample (from subject no. CHO 24) from our cholera vaccine clinical trial was used as a reference for IgG antibody titers and was arbitrarily assigned a value of 100.00 EU of IgG antibodies [44]. The correlation between IgG antibodies to E. coli O157:H7 LPS and IgG antibodies to V. cholerae 01 LPS was evaluated.

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RESULTS

Subjects. Fifty-five children were enrolled. Six children completed ⩽3 visits and were excluded from the analysis. Of the remaining 49 children, 25 received 1 dose of vaccine, and 24 received 2 doses of vaccine. The mean age for each group was 3.5 years.

Safety. No serious adverse reactions were reported after either dose was administered. There were no hospitalizations that were considered to be vaccine related. For the group receiving 1 dose, 24 (96%) of 25 diaries were completed. For the group receiving 2 doses, all diaries were completed after the first dose was administered, and 19 (79%) of24 were completed after the second dose was administered. Compliance was >95% for all visits. One child had a fever (temperature, 38.2°C) at 72 h after the second dose was administered; otherwise, no fevers (temperature, >38.0°C) were reported within 72 h of the administration of either dose. Mild erythema (3–17 mm), with spontaneous resolution, was reported by 5 subjects at 6 hand by 2 subjects at 24 h after the first dose was administered. There were no reports of erythema after the second dose was administered. One subject reported mild pain at 6 h after the second dose was administered, and 1 subject reported swelling of >3 cm at 24 h and resolution by 48 h after the second dose was administered. Rashes were reported by 2 children in the 2-dose group. One child developed palmar erythema 24–48 h after the first dose was administered, and it resolved spontaneously. The same child developed a maculopapular rash 72 h after the second dose was administered. This rash was attributed by her primary care physician to an antibiotic she received to treat otitis media, and it resolved with discontinuation of the antibiotic. There were no significant differences between prevaccination and postvaccination serum transaminase levels for any of the children. E. coli O157:H7 was not isolated from any of the rectal swab samples.

Serum antibody response to E. coli O157 LPS. All children had low serum IgG LPS antibody titers before vaccination, and there was no statistically significant difference between the groups (table 1). At 1 week after the first dose was administered, there was a significant increase in serum IgG LPS antibody titers (for all children, 3.32 vs. 0.27 EU; P< .0001): 81% of the children had a >4-fold increase, compared with prevaccination titers. There was an additional increase at 6 weeks after the first dose was administered (for all children, 11.36 vs. 3.32 EU; P< .001); only 1 of 49 children had a <10-fold increase (this child had a 6.45-fold increase).

Table 1
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Table 1

Serum IgG and IgM lipopolysaccharide antibodies in 2–5-year-old children, as assayed by ELISA.

Children who received a second dose of vaccine (given at 6 weeks after the first dose was administered) had an increase in serum IgG LPS antibody titers 4 weeks later, at week 10 of the study (13.75 vs. 10.28 EU; P = .01). Children who received a second dose had higher serum IgG LPS antibody titers at 10 weeks and at 26 weeks after the first dose was administered than did children who received only 1 dose, but the differences were not statistically significant. At 26 weeks after the first dose was administered, the geometric mean titer of serum IgG LPS antibodies in all children remained ⩾4-fold higher than was the prevaccination titer (5.84 vs. 0.27 ED; P< .0001), except that 1 child had a 3.7-fold increase.

To a lesser degree than it induced increases in serum IgG LPS antibody titers, the O157-rEPA vaccine induced increases in serum IgM LPS antibody titers (table 1). An increase was observed as early as 1 week after the first dose was administered (in all children, 7.09 vs. 2.28 ED; P< .005). However, unlike serum IgG LPS antibody titers, serum IgM LPS antibody titers declined at 6 weeks after the first dose was administered. Four weeks after the second dose was administered (at week 10 of the study), there was a small increase in geometric mean titers of serum IgM LPS antibodies in this group of children (6.97 vs. 5.29 ED), but the increase was not statistically significant. At 26 weeks after the first dose was administered, the geometric mean titers of serum IgM LPS antibodies in both groups remained higher than were the prevaccination titers, and the differences were statistically significant (in the 1-dose group, 3.66 vs. 2.48 ED [P = .02]; in the 2-dose group, 4.61 vs. 2.07 ED [P< .001]). There was no correlation between the serum IgG and IgM LPS antibody titers.

Age-related serum IgG LPS antibody responses elicited by the O157-rEPA vaccine. The antibody response to the O157-rEPA vaccine was age related (table 2). Compared with those in adults in our phase 1 trial, children had lower prevaccination and postvaccination titers (prevaccination titers, 0.27 vs. 0.47 ED; postvaccination titers, 5.63 vs. 32.82 ED). At 26 weeks after the first dose was administered, the increase in serum IgG LPS antibody titers was ∼20-fold in children and 70-fold in adults.

Table 2
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Table 2

Age-related serum IgG lipopolysaccharide antibodies in adults and children.

Bactericidal assay. Neither the prevaccination serum samples nor the samples treated with complement showed bactericidal activity (table 3). Serum samples from children receiving 1 or 2 doses of vaccine showed high bactericidal titers against E. coli O157:H7 LPS, and these were similar to those observed in our phase 1 trial. The bactericidal titers were approximately correlated with the serum IgG LPS antibody titers (before 2-mercaptoethanol treatment, r = .75; after 2-mercaptoethanol treatment, r = .78). There was no correlation between bactericidal titers and IgM LPS antibody titers (r< .10).

Table 3
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Table 3

Reciprocal bactericidal activity of serum lipopolysaccharide (LPS) antibodies elicited in 2–5-year-old children.

Cross-reaction with V. cholerae 01. Fourteen postvaccination serum samples were chosen randomly for analysis of serum IgG antibodies to LPS of V. cholerae O1 serotypes lnaba and Ogawa. None showed significant increases in geometric mean titers of serum IgG antibodies to serotype Ogawa LPS (table 4). There was, however, an ∼3-fold increase in the geometric mean titers of serum IgG antibodies to serotype Inaba LPS (21.38 vs. 7.22 ED; P< .001). There was no correlation between the titers of serum IgG antibodies to LPS of E. coli O157 :H7 LPS and those to LPS of V. cholerae 01 serotype Inaba (r< .1).

Table 4
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Table 4

IgG antibodies to Vibrio cholerae 01 serotype Inaba lipopolysaccharide (LPS) or Escherichia coli O157:H7 LPS.

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DISCUSSION

The investigational E. coli O157:H7 conjugate vaccine was safe and immunogenic in 2–5-year-old children. None of the children had a fever or a significant skin reaction. Nearly all of the children had a >10-fold increase in serum IgG LPS antibody titers at 6 weeks after the first dose was administered. At 26 weeks after the first dose was administered, the serum IgG LPS antibody titers remained significantly higher than were the prevaccination titers (an ∼20-fold increase). A second dose of the vaccine did not induce a booster response, as has been observed in this age group in response to most conjugate vaccines [40, 47–49]. The vaccine also elicited high bactericidal activity that was correlated with serum IgG LPS antibody titers. The antibody response was age related; adults responded with ∼4-fold higher serum IgG LPS antibody titers than did children. The postvaccination serum IgG LPS antibody titers in 2–5-year-old children were higher than were the prevaccination titers in adults (6.08 vs. 0.47 EU; P< .001), implying that the children had immunity to E. coli O157:H7 after vaccination.

In the past 2 decades, E. coli O157:H7 infection has evolved from a clinical novelty to a major public health concern. Hundreds of outbreaks have been reported worldwide, with hospitalization required in up to 47% of symptomatic patients [7–9, 11, 50]. Extrarenal complications also occur in substantial numbers [11, 50, 51]. Complications following hemolytic-uremic syndrome include stroke, seizures, and myocardial dysfunctions [51, 52].

Because there is no effective treatment for E. coli O157:H7 infection, efforts have been directed toward prevention. Our findings demonstrate that vaccination elicits high bactericidal activity that is correlated with serum IgG LPS antibody titers. Because of the low infectious dose of the organism, lysis of the inoculum through vaccination should prevent the establishment of infection. The findings of the present study suggest that vaccination of humans may prevent the establishment of infection.

Most E. coli O157:H7 infections occur either sporadically or in outbreaks [1–6,9, 12–13, 18–24, 52]. Although E. coli O157: H7 infection is generally considered to be a foodborne disease, animal-to-person or person-to-person spread is described in petting zoos, households, day care centers, and chronic care facilities [53–56]. In day care centers, where shedding among children may last 2–4 weeks, a high potential for secondary transmission is combined with a population at risk for severe outcomes. Because the O157-rEPA vaccine elicited high serum LPS antibody titers as early as 7 days after the first dose was administered, and on the basis of our experience with a Shigella sonnei-rEPA conjugate vaccine trial during an outbreak, this vaccine may be used to prevent primary or secondary transmission of E. coli O157:H7 during outbreaks [37, 41]. Alternatively, E. coli O157:H7 conjugates could be used to prepare high-titer IgG LPS antibody globulin for prophylaxis and treatment of case contacts during an outbreak.

The O-specific polysaccharide of E. coli O157 LPS is a linear copolymer composed of the tetrasaccharide repeating unit (-3 )-α-D-GalpNAc-( 1-2)-α-D-PerpNAc-( 1-3 )-α-L-Fucp-(1-4)β-D-Glcp-(1-) [45]. Although perosamine is found in the 0- specific polysaccharide of both the Inaba and Ogawa serotypes of V. cholerae O1, only a weak cross-reaction with serotype Inaba was found in children who received the E. coli O157:H7 conjugate vaccine. This cross-reaction, however, was not observed in our phase 1 trial [41]. In a previous study, antibody cross-reactions with LPS from E. coli O157:H7 were found after cholera vaccinations [57]. Numerous other E. coli serotypes—as well as other gram-negative organisms containing LPS, such as Citrobacter species, Yersinia enterocolitica, Salmonella urbana, Pseudomonas maltophilia, and Brucella melitensi—cross-react with E. coli O157:H7 [30, 58–62]. Prolonged exposure to these antigens in the environment probably contributes to the high serum IgG LPS antibody titers found in US adults and, thus, may explain the age-related attack rate of E. coli O157:H7.

Shigella toxin (Stx) 1 and Stx2 are important virulence factors for causing hemolytic-uremic syndrome [2, 7, 10, 33]. We have prepared a conjugate of O-specific polysaccharide with the B-subunit of Stx1, and this conjugate elicited high serum titers of neutralizing antitoxin in mice [63]. Because Stx2 is the most common Stx found in patients with hemolytic-uremic syndrome, we plan to prepare an O-specific polysaccharide conjugate with the B-subunit of Stx2 [64].

It is apparent that E. coli O157:H7 infections impose a substantial clinical and public health burden. Given the seriousness of the disease, the lack of therapeutic options, and the vastness of transmission sources, prevention of infection should focus on immunization. Efforts should be directed toward those most at risk, especially those in community settings. Although outbreaks of infection have gained the most attention, sporadic disease accounts for the majority of the disease burden, and this situation underscores the importance of universal immunization to prevent disease. Because hemolytic-uremic syndrome occurs most often in children <5 years old, we plan to evaluate the efficacy of the E. coli O157:H7 conjugate vaccine in infants, with the objective of administering it as part of routine vaccination [65, 66].

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Acknowledgments

We thank Nancy Tremblay and Jennifer West, for assistance in the development of the protocol and coordination of the study; David Rupar and J. c. Parke, Jr., for assistance with the conduct of the study; and Rachael Schneerson, for he!pful discussions.

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Footnotes

  • Financial support: National Institutes of Health Icontract no. HD-2-3337).

  • Potential conflicts of interest: none reported.

  • Received April 21, 2005.
  • Accepted September 7, 2005.
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References

  1. 1.↵
    1. Riley LW,
    2. Remis RS,
    3. Helgerson SD,
    4. et al
    . Hemorrhagic colitis associated with a rare Escherichia coli serotype. N Engl J Med 1983;308:681-5.
    MedlineWeb of Science
  2. 2.↵
    1. Karmali MA,
    2. Petrie M,
    3. Lim C,
    4. Fleming PC,
    5. Arbus GS,
    6. Lior H
    . The association between idiopathic hemolytic uremic syndrome and infection by verotoxin-producing Escherichia coli. J Infect Dis 1985;151:775-82.
    Abstract/FREE Full Text
  3. 3.↵
    1. Griffin PM,
    2. Tauxe RY
    . The epidemiology of infections caused by E. coli O157:H7, other enterohemorrhagic E. coli, and the associated hemolytic uremic syndrome. Epidemiol Rev 1991;13:60-98.
    FREE Full Text
  4. 4.↵
    1. Bitzan M,
    2. Ludwig K,
    3. Klemt M,
    4. Konig H,
    5. Buren J,
    6. Muller-Wiefel DE
    . The role of Escherichia coli O 157 infections in the classical (enteropathic) haemolytic uraemic syndrome: results of a central European, multicentre study. Epidemiol Infect 1993;110:183-96.
    Medline
  5. 5.
    1. Michino H,
    2. Araki K,
    3. Minami S
    . Massive outbreak of Escherichia coli O157:H7 infection in schoolchildren in Sakai City, Japan, associated with consumption of white radish sprouts. Am J Epidemiol 1999;150:797-803.
    FREE Full Text
  6. 6.↵
    Waterborne outbreak of gastroenteritis associated with a contaminated municipal water supply, Walkerton, Ontario, May-June 2000. Can Commun Dis Rep 2000;26:170-3.
    Medline
  7. 7.↵
    1. Tarr PI
    . Escherichia coli O157:H7: clinical, diagnostic, and epidemiological aspects of human infection. Clin Infect Dis 1995;20:1-8.
    FREE Full Text
  8. 8.↵
    1. Pavia AT,
    2. Nichols CR,
    3. Green DP,
    4. et al
    . Hemolytic-uremic syndrome during an outbreak of Escherichia coli O157:H7 infections in institutions for mentally retarded persons: clinical and epidemiologic observations. J Pediatr 1990;116:544-51.
    CrossRefMedlineWeb of Science
  9. 9.↵
    1. Bell BP,
    2. Griffin PM,
    3. Lozano P,
    4. Christie DL,
    5. Kobayashi JM,
    6. Tarr PI
    . Predictors of hemolytic uremic syndrome in children during a large outbreak of Escherichia coli O157:H7 infections. Pediatrics 1997;100:E12.
    CrossRefMedline
  10. 10.↵
    1. Karmali MA
    . Infection by Shiga toxin-producing Escherichia coli: an overview. Mol Biotechnol 2004;26:117-22.
    CrossRefMedlineWeb of Science
  11. 11.↵
    1. Garg AX,
    2. Suri RS,
    3. Barrowman N
    . Long-term renal prognosis of diarrhea-associated hemolytic uremic syndrome: a systematic review, meta-analysis, and meta-regression. JAMA 2003;290:1379-81.
    FREE Full Text
  12. 12.↵
    1. Slutsker L,
    2. Ries AA,
    3. Maloney K,
    4. Wells JG,
    5. Greene KD,
    6. Griffin PM
    . A nationwide case-control study of Escherichia coli O157:H7 infection in the United States. J Infect Dis 1998;177:962-6.
    Abstract/FREE Full Text
  13. 13.↵
    1. Rangel JM,
    2. Sparling PH,
    3. Crowe C,
    4. Griffin PM,
    5. Swerdlow DL
    . Epidemiology of Escherichia coli O157:H7 outbreaks, United States, 1982-2002. Emerg Infect Dis 2005;11:603-9.
    MedlineWeb of Science
  14. 14.↵
    1. Wong CS,
    2. Jelacic S,
    3. Habeeb RL,
    4. Watkins SL,
    5. Tarr PI
    . The risk of the hemolytic-uremic syndrome after antibiotic treatment of Escherichia coli O157:H7 infections. N Engl J Med 2000;342:1930-6.
    CrossRefMedlineWeb of Science
  15. 15.
    1. Safdar N,
    2. Said A,
    3. Gangnon RE,
    4. Maki DG
    . Risk of hemolytic uremic syndrome after antibiotic treatment of Escherichia coli O157:H7 enteritis: a meta-analysis. JAMA 2002;288:996-1001.
    Abstract/FREE Full Text
  16. 16.↵
    1. Molbak K,
    2. Mead PS,
    3. Griffin PM
    . Antimicrobial therapy in patients with Escherichia coli O157:H7 infection. JAMA 2002;288:1014-6.
    FREE Full Text
  17. 17.↵
    1. Cassin MH,
    2. Lammerding AM,
    3. Todd EC,
    4. Ross W,
    5. McColl RS
    . Quantitative risk assessment for Escherichia coli O157:H7 in ground beef hamburgers. Int J Food Microbiol 1998;41:21-44.
    CrossRefMedlineWeb of Science
  18. 18.↵
    1. Tuttle J,
    2. Gomez T,
    3. Doyle MP,
    4. et al
    . Lessons from a large outbreak of Escherichia coli O157:H7 infections: insights into the infectious dose and method of widespread contamination of hamburger patties. Epidemiol Infect 1999;122:185-92.
    CrossRefMedline
  19. 19.↵
    1. Teunis P,
    2. Takumi K,
    3. Shinagawa K
    . Dose response for infection by Escherichia coli O157:H7 from outbreak data. Risk Anal 2004;24:401-7.
    CrossRefMedlineWeb of Science
  20. 20.↵
    1. Crump JA,
    2. Braden CR,
    3. Dey ME,
    4. et al
    . Outbreaks of Escherichia coli O157 infections at multiple county agricultural fairs: a hazard of mixing cattle, concession stands, and children. Epidemiol Infect 2003;131:1055-62.
    CrossRefMedline
  21. 21.
    1. Howie H,
    2. Mukerjee A,
    3. Cowden J,
    4. Leith J,
    5. Reid T
    . Investigation of an outbreak of Escherichia coli O157 infection caused by environmental exposure at a scout camp. Epidemiol Infect 2003;131:1063-9.
    Medline
  22. 22.
    1. Harrison S,
    2. Kinra S
    . Outbreak of Escherichia coli O157 associated with a busy bathing beach. Commun Dis Public Health 2004;7:47-50.
    Medline
  23. 23.
    1. Varma JK,
    2. Greene KD,
    3. Reller ME,
    4. et al
    . An outbreak of Escherichia coli O157 infection following exposure to a contaminated building. JAMA 2003;290:2709-12.
    Abstract/FREE Full Text
  24. 24.↵
    1. Breuer T,
    2. Benkel DH,
    3. Shapiro RL,
    4. et al
    . A multistate outbreak of Escherichia coli O157:H7 infections linked to alfalfa sprouts grown from contaminated seeds. Emerg Infect Dis 2001;7:977-82.
    MedlineWeb of Science
  25. 25.↵
    1. Moon H,
    2. Bunn T
    . Vaccines for preventing enterotoxigenic Escherichia coli infections in farm animals. Vaccine 1993;11:213-20.
    CrossRefMedlineWeb of Science
  26. 26.↵
    1. Hancock DD,
    2. Besser TE,
    3. Gill C,
    4. Bohach CH
    . Cattle, hay, and E. coli. Science 1999;284:51-3.
    MedlineWeb of Science
  27. 27.↵
    1. Chart H,
    2. Smith HR,
    3. Scotland SM,
    4. Rowe B,
    5. Milford DV,
    6. Taylor CM
    . Serological identification of Escherichia coli O157:H7 infection in haemolytic uraemic syndrome. Lancet 1991;337:138-40.
    CrossRefMedlineWeb of Science
  28. 28.↵
    1. Reymond D,
    2. Johnson RD,
    3. Karmali MA,
    4. et al
    . Neutralizing antibodies to Escherichia coli Vero cytotoxin 1 and antibodies to O157 lipopolysaccharide in healthy farm family members and urban residents. J Clin Microbiol 1996;34:2053-7.
    Abstract/FREE Full Text
  29. 29.↵
    1. Haack JP,
    2. Jelacic S,
    3. Besser TE,
    4. et al
    . Escherichia coli O157 exposure in Wyoming and Seattle: serologic evidence of rural risk. Emerg Infect Dis 2003;9:1226-31.
    MedlineWeb of Science
  30. 30.↵
    1. Nichiuchi Y,
    2. Doe M,
    3. Hotta H,
    4. Kobayashi K
    . Structure and serologic properties of O-specific polysaccharide from Citrobacter freundii possessing cross-reactivity with Escherichia coli O157:H7. FEMS Immunol Med Microbiol 2000;28:163-71.
    CrossRefMedlineWeb of Science
  31. 31.↵
    1. Hayashi T,
    2. Makino K,
    3. Ohnishi M,
    4. et al
    . Complete genome sequence of enterohemorrhagic Escherichia coli O157:H7 and genomic comparison with a laboratory strain K-12. DNA Res 2001;8:11-22.
    Abstract
  32. 32.↵
    1. Fukiya S,
    2. Mizoguchi H,
    3. Tobe T,
    4. Mori H
    . Extensive genomic diversity in pathogenic Escherichia coli and Shigella strains revealed by comparative genomic hybridization microarray. J Bacteriol 2004;186:3911-21.
    Abstract/FREE Full Text
  33. 33.↵
    1. O'Brien AO,
    2. Lively TA,
    3. Chen ME,
    4. Rothman SW,
    5. Formal SB
    . Escherichia coli O157:H7 strains associated with haemorrhagic colitis in the United States produce a Shigella dysenteriae 1 (SHIGA) like cytotoxin [letter]. Lancet 1983;1:702.
    Medline
  34. 34.↵
    1. Robbins JB,
    2. Chu C,
    3. Schneerson R
    . Hypothesis for vaccine development: protective immunity to enteric diseases caused by nontyphoidal salmonellae and shigellae may be conferred by serum IgG antibodies to the O-specific polysaccharide of their lipopolysaccharides. Clin Infect Dis 1992;15:346-61.
    Abstract/FREE Full Text
  35. 35.
    1. Iglewski BH,
    2. Clark VL
    1. Jimenez-Lucho VE,
    2. Leive LL,
    3. Joiner KA
    . Role of the O-antigen of lipopolysaccharide in Salmonella in protection against complement action. In: Iglewski BH, Clark VL, editors. Molecular basis of bacterial pathogenesis. Vol. 11. New York: Academic Press; 1990. p. 339-54.
  36. 36.
    1. Bilge SS,
    2. Vary JC Jr.,
    3. Dowell SF,
    4. Tarr PI
    . Role of the Escherichia coli O157:H7 0 side chain in adherence and analysis of an rfb locus. Infect Immun 1996;64:4795-801.
    Abstract/FREE Full Text
  37. 37.↵
    1. Cohen D,
    2. Ashkenazi S,
    3. Green MS,
    4. et al
    . Double-blind vaccine-controlled randomized efficacy trial of an investigational Shigella sonnei conjugate vaccine in young adults. Lancet 1997;349:155-9.
    CrossRefMedlineWeb of Science
  38. 38.
    1. Bull DM,
    2. Bienenstock J,
    3. Tomasi TB Jr..
    Studies on human intestinal immunoglobulin A. Gastroenterology 1971;60:370-80.
    MedlineWeb of Science
  39. 39.
    1. Ahrenstedt O,
    2. Knutson L,
    3. Nilsson B,
    4. Nilsson-Ekdahl K,
    5. Odlind B,
    6. Hallgren R
    . Enhanced local production of complement components in the small intestines of patients with Crohn's disease. N Engl J Med 1990;322:1345-9.
    MedlineWeb of Science
  40. 40.↵
    1. Lin FY,
    2. Ho VA,
    3. Khiem HB,
    4. et al
    . The efficacy of a Salmonella typhi Vi conjugate vaccine in two-to-five-year-old children. N Engl J Med 2001;344:1263-9.
    CrossRefMedlineWeb of Science
  41. 41.↵
    1. Konadu EY,
    2. Parke JC Jr..,
    3. Tran HT,
    4. Bryla DA,
    5. Robbins JB,
    6. Szu Sc
    . Investigational vaccine for Escherichia coli O157: phase 1 study of O157 O-specific polysaccharide-Pseudomonas aeruginosa recombinant exoprotein A conjugates in adults. J Infect Dis 1998;177:383-7.
    Abstract/FREE Full Text
  42. 42.↵
    1. Konadu E,
    2. Robbins JB,
    3. Schiloach J,
    4. Bryla DA,
    5. Szu Sc
    . Preparation, characterization, and immunological properties in mice of Escherichia coli O157 O-specific polysaccharide-protein conjugate vaccine. Infect Immun 1994;62:5048-54.
    Abstract/FREE Full Text
  43. 43.↵
    1. Kossaczka Z,
    2. Shiloach J,
    3. Johnson V,
    4. et al
    . Vibrio cholerae O139 conjugate vaccines: synthesis and immunogenicity of V. cholerae O139 capsular polysaccharide conjugates with recombinant diphtheria toxin mutant in mice. Infect Immun 2000;68:5037-43.
    Abstract/FREE Full Text
  44. 44.↵
    1. Gupta RK,
    2. Taylor DN,
    3. Bryla DA,
    4. Robbins JB,
    5. Szu SC
    . Phase 1 evaluation of Vibrio cholerae O1, serotype Inaba, polysaccharide-cholera toxin conjugates in adult volunteers. Infect Immun 1998;66:3095-9.
    Abstract/FREE Full Text
  45. 45.↵
    1. Perry MB,
    2. Bundle DR
    . Antigenic relationships of the lipopolysaccharides of Escherichia, Brucella melitensis, and Brucella abortus. Infect Immun 1990;58:1391-5.
    Abstract/FREE Full Text
  46. 46.↵
    1. Bystricky S,
    2. Szu SC,
    3. Gotoh M,
    4. Kovac P
    . Circular dichroism of the O-specific polysaccharide of Vibrio cholerae O1 and some related derivatives. Carbohydr Res 1995;270:115-22.
    CrossRefMedlineWeb of Science
  47. 47.↵
    1. Claesson BA,
    2. Schneerson R,
    3. Trollfors B,
    4. Lagergard T,
    5. Taranger J,
    6. Robbins JB
    . Duration of serum antibodies elicited by Haemophilus influenzae type b capsular polysaccharide alone or conjugated to tetanus toxoid in 18-to 23-month-old children. J Pediatr 1990;116:929-31.
    CrossRefMedlineWeb of Science
  48. 48.
    1. Konadu E,
    2. Lin FY,
    3. Ho V,
    4. et al
    . Phase 1 and phase 2 studies of Salmonella enterica serovar paratyphi A O-specific polysaccharide-tetanus toxoid conjugates in adults, teenagers, and 2- to 4-year old children in Vietnam. Infect Immun 2000;68:1529-34.
    Abstract/FREE Full Text
  49. 49.↵
    1. Ashkenazi S,
    2. Passwell JH,
    3. Harlev E,
    4. et al
    . Safety and immunogenicity of Shigella sonnei-CRM9 and Shigella flexneri type 2a-rEPAsucc conjugate vaccines in one-to four-year-old children. Pediatr Infect Dis J 2003;22:701-6.
    MedlineWeb of Science
  50. 50.↵
    1. Siegler RL
    . Hemolytic uremic syndrome in children. Curr Opin Pediatr 1995;7:159-63.
    Medline
  51. 51.↵
    1. Brandt JR,
    2. Fouser LS,
    3. Watkins SL,
    4. et al
    . Escherichia coli O157:H7-associated hemolytic-uremic syndrome after ingestion of contaminated hamburgers. J Pediatr 1994;125:519-26.
    CrossRefMedlineWeb of Science
  52. 52.↵
    1. Lynn RM,
    2. O'Brien SJ,
    3. Taylor CM,
    4. et al
    . Childhood hemolytic uremic syndrome, United Kingdom and Ireland. Emerg Infect Dis 2005;11:590-6.
    MedlineWeb of Science
  53. 53.↵
    1. Galanis E,
    2. Longmore K,
    3. Hasselback P,
    4. Swann D,
    5. Ellis A,
    6. Panaro L
    . Investigation of an E. coli O157:H7 outbreak in Brooks, Alberta, June-July 2002: the role of occult cases in the spread of infection within a daycare setting. Can Commun Dis Rep 2003;29:21-8.
    Medline
  54. 54.
    1. O'Donnell JM,
    2. Thornton L,
    3. McNamara EB,
    4. Prendergast T,
    5. Igoe D,
    6. Cosgrove C
    . Outbreak ofVero cytotoxin-producing Escherichia coli O157 in a child day care facility. Commun Dis Public Health 2002;5:54-8.
    Medline
  55. 55.
    1. Ryan CA,
    2. Tauxe RV,
    3. Hosek GW,
    4. et al
    . Escherichia coli Ol57:H7 diarrhea in a nursing home: clinical, epidemiological, and pathological findings. J Infect Dis 1986;154:631-8.
    Abstract/FREE Full Text
  56. 56.↵
    1. Honish A
    . Summary of E. coli O157:H7 at an Edmonton extended care facility. Alberta Soc Serv Commun Health 1966;10:363-8.
  57. 57.↵
    1. Chart H,
    2. Rowe B
    . Antibody cross-reactions with lipopolysaccharide from E. coli O157 after cholera vaccination. Lancet 1993;341:1282.
    MedlineWeb of Science
  58. 58.↵
    1. Chart H,
    2. Cheasty T,
    3. Cope D,
    4. Gross RJ,
    5. Rowe B
    . The serological relationship between Yersinia enterocolitica O9 and Escherichia coli O157 using sera from patients with yershiniosis and haemolytic uraemic syndrome. Epidemiol Infect 1991;107:349-56.
    Medline
  59. 59.
    1. DiFabio JL,
    2. Perry MB,
    3. Bundle DR
    . Analysis of the lipopolysaccharide of Salmonella 555. Biochem Cell Biol 1987;65:968-77.
    MedlineWeb of Science
  60. 60.
    1. Samuel G,
    2. Hogbin JP,
    3. Wang L,
    4. Reeves PR
    . Relationships of the Escherichia coli O157, 0111, and 055 O-antigen gene clusters with those of Salmonella enterica and Citrobacter freundii, which express identical O antigens. J Bacteriol 2004;186:6536-43.
    Abstract/FREE Full Text
  61. 61.
    1. Vinogradov E,
    2. Conlan JW,
    3. Perry MB
    . Serological cross-reaction between the lipopolysaccharide O-polysaccharide antigens of Escherichia coli O 157:H7 and strains of Citrobacter freundii and Citrobacter sedlakii. FEMS Microbiol Lett 2000;190:157-61.
    CrossRefMedlineWeb of Science
  62. 62.↵
    1. Bettelheim KA,
    2. Evangelidis H,
    3. Pearce JL,
    4. Sowers E,
    5. Strockbine NA
    . Isolation of a Citrobacter freundii strain which carries the Escherichia coli O157 antigen. J Clin Microbiol 1993;31:760-1.
    Abstract/FREE Full Text
  63. 63.↵
    1. Konadu E,
    2. Donohue-Rolfe A,
    3. Calderwood SB,
    4. Shiloach J,
    5. Robbins JB,
    6. Szu SC
    . Syntheses and immunologic properties of Escherichia coli O157 O-specific polysaccharide and Shiga toxin 1 B subunit conjugates in mice. Infect Immun 1999;67:6191-3.
    Abstract/FREE Full Text
  64. 64.↵
    1. Marcato P,
    2. Mulvey G,
    3. Read RJ,
    4. Vander Helm K,
    5. Nation PN,
    6. Armstrong GD
    . Immunoprophylactic potential of cloned Shiga toxin 2 B subunit. J Infect Dis 2001;183:435-43.
    Abstract/FREE Full Text
  65. 65.↵
    Progress toward elimination of Haemophilus influenzae type b invasive disease among infants and children—United States, 1998–2000. MMWR Morb Mortal Wkly Rep 2002;51:234-7.
    Medline
  66. 66.↵
    An Advisory Committee Statement (ACS). National Advisory Committee on Immunization (NACI). Statement on recommended use of pneumococcal conjugate vaccine. Can Commun Dis Rep 2002;28((ACS-2)):1-32.
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