title: Impact of Infection Dose and Previous Serum Antibodies against the Locus of Enterocyte Effacement Proteins on Escherichia coli O157:H7 Shedding in Calves following Experimental Infection.
abstract: Escherichia coli O157:H7 is the main causative agent of haemolytic uremic syndrome. Cattle are the main reservoir of these bacteria, and have been shown to develop immune response to colonization. Our aim was to investigate the faecal shedding pattern of E. coli O157:H7 in calves challenged intragastrically with either 10(8) or 10(10) CFU, as well as the ability of specific preexisting antibodies to reduce shedding of the pathogen. Shedding was analysed by direct counting as well as enrichment of rectoanal mucosal swabs. Statistical analysis was performed using a linear model for repeated measures with and without the inclusion of preexisting antibodies against the carboxy-terminal fraction of intimin-γ (γ-intimin C280) as a covariable. Results suggest that there is a statistical difference in the area under the shedding curves between both doses for 14 as well as 28 days after challenge (p = 0.0069 and 0.0209, resp.). This difference is increased when the prechallenge antibodies are taken into account (p = 0.0056 and 0.0185). We concluded that the bacterial dose influences shedding on calves experimentally challenged and that preexisting antibodies against E. coli O157:H7 γ-intimin C280 could partially reduce faecal excretion.
authors.affiliation: Instituto de Patobiología, CICVyA, INTA, 1686 Hurlingham, Argentina.
authors.forename: L
authors.initials: L
authors.lastname: Martorelli
authors.affiliation: School of Food Science, University of Idaho, Moscow, ID 83844-3025, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Hovde
authors.affiliation: Instituto de Patobiología, CICVyA, INTA, 1686 Hurlingham, Argentina.
authors.forename: D A
authors.initials: DA
authors.lastname: Vilte
authors.affiliation: Laboratorio de Fisiopatogenia, Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, 1121 Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: A
authors.initials: A
authors.lastname: Albanese
authors.affiliation: Laboratorio de Fisiopatogenia, Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, 1121 Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: E
authors.initials: E
authors.lastname: Zotta
authors.affiliation: Laboratorio de Fisiopatogenia, Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, 1121 Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: C
authors.initials: C
authors.lastname: Ibarra
authors.affiliation: Facultad de Agronomía, Universidad de Buenos Aires-CONICET, 1417 Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: R J C
authors.initials: RJ
authors.lastname: Cantet
authors.affiliation: Instituto de Patobiología, CICVyA, INTA, 1686 Hurlingham, Argentina.
authors.forename: E C
authors.initials: EC
authors.lastname: Mercado
authors.affiliation: Instituto de Biotecnología, CICVyA, INTA, 1686 Hurlingham, Argentina.
authors.forename: A
authors.initials: A
authors.lastname: Cataldi
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D057138:Bacterial Shedding / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000382:microbiology; D004195:Disease Models, Animal; D004927:Escherichia coli Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary; D019453:Escherichia coli O157 / Q000737:chemistry / Q000276:immunology / Q000472:pathogenicity; D029968:Escherichia coli Proteins / Q000276:immunology*; D054884:Host-Pathogen Interactions / Q000276:immunology*; D008297:Male; D010750:Phosphoproteins / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D029968:Escherichia coli Proteins; C457340:LEE protein, E coli; D010750:Phosphoproteins