title: Intranasal immunization with Yersinia enterocolitica O:8 cellular extract protects against local challenge infection.
abstract: Yersinia enterocolitica is enteropathogenic for humans and rodents. Immune protection from oral and respiratory pathogens may be most effectively elicited following intranasal (i.n.) vaccination. An experimental murine intranasal challenge model was used to evaluate the immunogenicity of a Y. enterocolitica O:8 cellular extract (CE) in mucosa. This antigenic preparation has demonstrated to induce protection by subcutaneous immunization. Mice were immunized intranasally with two doses of CE. Immunized and nonimmunized animals were challenged with 5 x 10(6) colony-forming units (CFU) by nasal infection. Antibodies in serum and bronchoalveolar lavage (b.a.l.) fluid were assessed before and 48 hr after challenge. The CFU were determined by analysis of lung homogenate samples. The CE immunization induced significant b.a.l.-specific IgA and IgG, and serum-specific IgG, IgA and IgM. Histopathological studies 24 and 48 hr postchallenge demonstrated that immunization protected against progressive lesions resulting from Y. enterocolitica invasion of the pulmonary mucosa. The CFU in the lungs showed that CE immunization led to significant clearance as compared to the bacterial level in nonimmunized controls. From the results obtained, it can be concluded that CE can induce local and systemic immunity and protect against nasal infection.
authors.affiliation: Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Argentina.
authors.forename: M S
authors.initials: MS
authors.lastname: Di Genaro
authors.forename: M E
authors.initials: ME
authors.lastname: Escudero
authors.forename: E
authors.initials: E
authors.lastname: Muñoz
authors.forename: C
authors.initials: C
authors.lastname: Aguilera
authors.forename: L
authors.initials: L
authors.lastname: Scardapane
authors.forename: A M
authors.initials: AM
authors.lastname: de Guzmán
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology*; D002772:Cholera Toxin / Q000276:immunology; D005260:Female; D018928:Immunity, Mucosal; D007114:Immunization; D008168:Lung / Q000382:microbiology*; D008297:Male; D051379:Mice; D015009:Yersinia Infections / Q000517:prevention & control*; D015008:Yersinia enterocolitica / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D002772:Cholera Toxin