LIVE BACTERIAL VACCINES AGAINST <i>ESCHERICHIA COLI</i> O157:H7

摘要

Disclosed are novel live bacterial vaccines against E. coli O157:H7, to treat or prevent colonization of the gastrointestinal tract of a vertebrate by the pathogen. The vaccines comprise an effective amount of non-pathogenic bacteria naturally expressing the O157 antigen or a structural mimic thereof as a part of their lipopolysaccharide. In a preferred embodiment, the non-pathogenic bacteria are selected from bacterial strains of the genus Salmonella or Citrobacter. The vaccines of the invention are particularly useful in maintaining cattle herds free of E. coli O157:H7 and in reducing carriage and fecal shedding of E. coli O157:H7 prior to slaughter, thus potentially reducing the clin ical incidence of E. coli O157:H7infections in humans.