title: Reactivity and protective capacity of a polyclonal antiserum derived from mice immunized with antibiotic exposed Escherichia coli.
abstract: The murine immune response to Escherichia coli O6:K-alone or pre-exposed to 0.1 x MIC of aztreonam was investigated. Relative to mice immunized with untreated bacteria, mice immunized with antibiotic-treated microorganisms presented a significantly enhanced protection towards a challenge of 100 x LD50 of viable E. coli O6:K-. Previous injection of 0.1 mL of serum drawn from mice immunized with treated and untreated bacteria protected non-immunized mice towards a challenge of 10 x LD50 of viable E. coli O6:K--. Serum from mice immunized with treated bacteria also protected non-immunized mice towards a lethal challenge of E. coli O111. The antiserum contained high titre of IgG antibodies that cross-reacted with lipopolysaccharide isolated from smooth and rough Gram-negative bacteria. Immunoblotting showed additional bands of reactivity to the untreated E. coli O6:K-. Immunization with antibiotic-treated bacteria led to the production of type specific and cross reactive antibodies that protected animals against viable homologous and heterologous lethal challenges.
authors.affiliation: II Chair of Microbiology, Faculty of Medicine, La Sapienza University of Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Raponi
authors.forename: M T
authors.initials: MT
authors.lastname: Lun
authors.forename: G
authors.initials: G
authors.lastname: Lorino
authors.forename: C
authors.initials: C
authors.lastname: Nazzari
authors.forename: A
authors.initials: A
authors.lastname: Gaeta
authors.forename: C
authors.initials: C
authors.lastname: Mancini
authors.forename: F
authors.initials: F
authors.lastname: Filadoro
mesh_terms: D000818:Animals; D001398:Aztreonam / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects* / Q000276:immunology; D004927:Escherichia coli Infections / Q000517:prevention & control; D007106:Immune Sera / Q000276:immunology*; D007116:Immunization, Passive; D051379:Mice; D011292:Premedication
chemical_list: D007106:Immune Sera; D001398:Aztreonam