title: Variable colonization of chickens perorally inoculated with Escherichia coli O157:H7 and subsequent contamination of eggs.
abstract: Challenging 1-day-old White Leghorn chicks perorally with 2.6 x 10(1) to 2.6 x 10(5) Escherichia coli O157:H7 bacteria per chick resulted in cecal colonization at all levels. Two of six chicks inoculated with only 2.6 x 10(1) E. coli O157:H7 bacteria carried 10(3) to 10(4) E. coli O157:H7 bacteria per g of cecal tissue when sacrificed 3 months postinoculation. E. coli O157:H7 colonization persisted at least 10 to 11 months when chicks were administered 10(8) E. coli O157:H7 bacteria. Eggs from five hens that were fecal shedders of E. coli O157:H7 until the termination of the study (10 to 11 months) were assayed for E. coli O157:H7. The organism was isolated from the shells of 14 of 101 (13.9%) eggs but not from the yolks and whites. Considering that chicks can be readily colonized by small populations of E. coli O157:H7 and continue to be long-term shedders, it is possible that chickens and hen eggs can serve as vehicles of this human pathogen.
authors.affiliation: Department of Food Microbiology and Toxicology, University of Wisconsin, Madison 53706.
authors.forename: J L
authors.initials: JL
authors.lastname: Schoeni
authors.forename: M P
authors.initials: MP
authors.lastname: Doyle
mesh_terms: D000818:Animals; D002432:Cecum / Q000382:microbiology; D002645:Chickens / Q000382:microbiology*; D004531:Eggs / Q000382:microbiology*; D004926:Escherichia coli / Q000254:growth & development*; D005243:Feces / Q000382:microbiology; D005260:Female; D005516:Food Microbiology; D006801:Humans; D008297:Male