Abstract
To assess whether anticolonization factor antigen I (CFA/I) fimbriae antibodies (Abs) from enterotoxigenic Escherichia coli (ETEC) can protect against various routes of challenge, BALB/c mice were immunized with a live attenuated Salmonella vaccine vector expressing CFA/I fimbriae. Vaccinated mice elicited elevated systemic IgG and mucosal IgA Abs, unlike mice immunized with the empty Salmonella vector. Mice were challenged with wild-type ETEC by the oral, intranasal (i.n.), and intraperitoneal (i.p.) routes. Naïve mice did not succumb to oral challenge, but did to i.n. challenge, as did immunized mice; however, vaccinated mice were protected against i.p. ETEC challenge. Two intramuscular (i.m.) immunizations with CFA/I fimbriae without adjuvant conferred 100% protection against i.p. ETEC challenge, while a single 30 μg dose conferred 88% protection. Bactericidal assays showed that ETEC is highly sensitive to anti-CFA/I sera. These results suggest that parenteral immunization with purified CFA/I fimbriae can induce protective Abs and may represent an alternative method to elicit protective Abs for passive immunity to ETEC.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, Non-P.H.S.
MeSH terms
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Administration, Intranasal
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Administration, Oral
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Animals
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Antibodies / immunology
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Antibodies / metabolism*
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Blood Bactericidal Activity / drug effects
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Blood Bactericidal Activity / immunology*
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Enterotoxigenic Escherichia coli / immunology*
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Enterotoxigenic Escherichia coli / metabolism
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Escherichia coli Infections / immunology
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Escherichia coli Infections / prevention & control
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Escherichia coli Proteins / administration & dosage
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Escherichia coli Proteins / immunology
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Female
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Fimbriae Proteins / administration & dosage*
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Fimbriae Proteins / immunology*
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Fimbriae Proteins / isolation & purification
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Immunity, Mucosal / immunology
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Immunization / methods*
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Immunoglobulin A / blood
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Immunoglobulin A / immunology
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Immunoglobulin G / blood
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Immunoglobulin G / immunology
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Injections, Intraperitoneal*
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Mice
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Mice, Inbred BALB C
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Salmonella Vaccines / administration & dosage
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Salmonella Vaccines / immunology
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Serum Bactericidal Antibody Assay
Substances
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Antibodies
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Escherichia coli Proteins
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Immunoglobulin A
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Immunoglobulin G
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Salmonella Vaccines
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colonization factor antigens
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Fimbriae Proteins