title: Oral immunization against porcine pleuropneumonia using the cubic phase of monoolein and purified toxins of Actinobacillus pleuropneumoniae.
abstract: The main goal of this work was to obtain an orally administered immunogen that would protect against infections by Actinobacillus pleuropneumoniae. The Apx I, II and III toxins were obtained from the supernatants of cultures of serotypes 1 and 3 of A. pleuropneumoniae. The capacity of monoolein gel to trap and protect the Apx toxins, and the effect of their incorporation on the stability of the cubic phase were evaluated. The gel was capable of trapping a 400-μg/ml concentration of the antigen with no effects on its structure. Approximately 60% of the protein molecules were released from the gel within 4h. Four experimental groups were formed, each one with four pigs. All challenges were conducted in a nebulization chamber. Group A: Control (-) not vaccinated and not challenged; Group B: Control (+) not vaccinated but challenged; Group C: vaccinated twice intramuscularly with ToxCom (a commercial toxoid) at an interval of 15 days and then challenged; and Group D: vaccinated orally twice a week for 4 weeks with ToxOral (an oral toxoid) and challenged on day 28 of the experiment with a same dose of 2.0 × 10(4) UFC of A. pleuropneumoniae serotypes 1 and 3. The lesions found in group B covered 27.7-43.1% of the lungs; the pigs in group C had lesions over 12.3-28%; and those in group D over 15.4-32.3%. No lesions were found in the Group A pigs. A. pleuropneumoniae induced macroscopic lesions characteristic of infection by and lesions microscopic detected by histopathology. The etiologic agent was recovered from the infected lungs, tonsils and spleen. The serotypes identified were 1 and 3. An indirect ELISA test identified the antibodies against the Apx toxins in the serum of the animals immunized orally.
authors.affiliation: Laboratorio de Virología-FES-Cuautitlán, UNAM, Mexico.
authors.forename: Jorge
authors.initials: J
authors.lastname: Lopez-Bermudez
authors.affiliation: Laboratorio en Tecnología Farmacéutica FES-Cuautitlán, UNAM, Mexico.
authors.forename: David
authors.initials: D
authors.lastname: Quintanar-Guerrero
authors.affiliation: Laboratorios Avi-Mex, S.A. de C.V., Mexico.
authors.forename: Horacio
authors.initials: H
authors.lastname: Lara Puente
authors.affiliation: Laboratorio de Patología-FES-Cuautitlán, UNAM, Mexico.
authors.forename: Jorge
authors.initials: J
authors.lastname: Tórtora Perez
authors.affiliation: Facultad de Medicina Veterinaria y Zootecnia, UNAM, Mexico.
authors.forename: Francisco
authors.initials: F
authors.lastname: Suárez Güemez
authors.affiliation: Laboratorio de Virología-FES-Cuautitlán, UNAM, Mexico.
authors.forename: Abel
authors.initials: A
authors.lastname: Ciprián Carrasco
authors.affiliation: Laboratorio de Virología-FES-Cuautitlán, UNAM, Mexico. Electronic address: seme@unam.mx.
authors.forename: Susana
authors.initials: S
authors.lastname: Mendoza Elvira
mesh_terms: D000189:Actinobacillus Infections / Q000517:prevention & control / Q000662:veterinary*; D016977:Actinobacillus pleuropneumoniae / Q000276:immunology*; D000284:Administration, Oral; D000818:Animals; D001427:Bacterial Toxins / Q000008:administration & dosage / Q000276:immunology* / Q000302:isolation & purification; D004337:Drug Carriers / Q000008:administration & dosage*; D005989:Glycerides / Q000008:administration & dosage*; D006651:Histocytochemistry; D007114:Immunization / Q000379:methods; D008168:Lung / Q000382:microbiology / Q000473:pathology; D014066:Palatine Tonsil / Q000382:microbiology; D011001:Pleuropneumonia / Q000517:prevention & control / Q000662:veterinary*; D013154:Spleen / Q000382:microbiology; D013552:Swine; D013553:Swine Diseases / Q000517:prevention & control*
chemical_list: D001427:Bacterial Toxins; D004337:Drug Carriers; D005989:Glycerides; C005953:monoolein
keywords: Apx I; Apx II; Apx III; Immunity; Oral vaccine; Porcine pleuropneumonia