Rectal single dose immunization of mice with Escherichia coli O157:H7 bacterial ghosts induces efficient humoral and cellular immune responses and protects against the lethal heterologous challenge

Microb Biotechnol. 2012 Mar;5(2):283-94. doi: 10.1111/j.1751-7915.2011.00316.x. Epub 2011 Nov 22.


Bacterial ghosts (BGs) have been applied through oral, aerogenic, intraocular or intranasal routes for mucosal immunization using a wide range of experimental animals. All these applications required a booster after primary immunization to achieve protective immunity against the lethal challenge. Here we report for the first time that a single rectal dose of BGs produced from enterohaemorrhagic Escherichia coli (EHEC) O157:H7 fully protects mice against a 50% lethal challenge with a heterologous EHEC strain given at day 55. BGs from EHEC O157:H7 were prepared by a combination of protein E-mediated cell lysis and expression of staphylococcal nuclease A guaranteeing the complete degradation of pathogen residual DNA. The lack of genetic material in the EHEC BGs vaccine abolished any potential hazard for horizontal gene transfer of plasmid encoded antibiotic resistance genes or pathogenic islands to the recipient's gut flora. Single rectal immunization using EHEC O157:H7 BGs without any addition of adjuvant significantly stimulated efficient humoral and cellular immune responses, and was equally protective as two immunizations, which indicates the possibility to develop a novel efficacious single dose mucosal EHEC O157:H7 BGs vaccine using a simplified immunization regimen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Rectal
  • Animals
  • Antibodies, Bacterial / immunology*
  • Disease Models, Animal
  • Escherichia coli Infections / immunology
  • Escherichia coli Infections / microbiology
  • Escherichia coli Infections / prevention & control*
  • Escherichia coli O157 / immunology*
  • Escherichia coli Vaccines / administration & dosage*
  • Escherichia coli Vaccines / immunology*
  • Mice
  • Survival Analysis
  • T-Lymphocytes / immunology*
  • Vaccination / methods*


  • Antibodies, Bacterial
  • Escherichia coli Vaccines