Use of Nanostructured Silica SBA-15 as an Oral Vaccine Adjuvant to Control Mycoplasma hyopneumoniae in Swine Production

Author(s)

Gabriel Yuri Storino

• Document type: Doctoral Thesis
• Press: Jaboticabal. 2023-06-05.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal
• Defense date: 2023-12-10
• Advisor: Luís Guilherme de Oliveira

Abstract

Mycoplasma hyopneumoniae is a difficult-to-control bacterium since commercial vaccines do not prevent colonization and excretion. The present study aimed to evaluate the performance of an orally administered vaccine, composed of antigens extracted from Mycoplasma hyopneumoniae and incorporated into mesoporous silica (SBA-15), which has an adjuvant-carrier function, aiming to potentiate the action of the commercial intramuscular vaccine. The oral vaccine was administered to piglets born to nulliparous females challenged with M. hyopneumoniae, to promote an increase in the immune response against the pathogen from the stimulation of the mucosa-associated lymphoid tissue (MALT), starting in the intestinal mucosa. A total of 60 piglets were divided into four groups (n=15) submitted to different vaccination protocols as follows, Group 1: oral SBA15 + commercial vaccine at 24 days after weaning, G2: oral vaccine on the third day of life + vaccine commercial vaccine at 24 days, G3: commercial vaccine at 24 days and G4: commercial vaccine + oral vaccine at 24 days. On the first day, the piglets were weighed and, from the 3rd day onwards, submitted to blood collections for the detection and quantification of anti-Mycoplasma hyopneumoniae IgG. Nasal swabs were collected for monitoring IgA by ELISA, and oropharyngeal swabs were for assessing the bacterial load by qPCR. Biological samples were collected periodically from the third day of life until the 73rd day. At 41 days of life, 15 individuals of the same age, experimentally challenged with an inoculum containing M. hyopneumoniae, were inserted into the pen with the animals from groups (1 to 4) to increase the infection pressure during the nursery period. At the end of the study, at 73 days, all piglets were euthanized and necropsied for evaluation of the lungs and collection of lung samples for estimation of bacterial load by qPCR and histopathological evaluation. Tracheobronchial lavage samples were also collected and submitted to the qPCR test. Quantitative data obtained from physical parameters and laboratory investigation were analyzed regarding assumptions of normality and homoscedasticity using the Shapiro-Wilk and Bartlett tests, before performing parametric or non-parametric statistical tests. (AU)

• FAPESP's process: 20/05198-7 - Nanostructured silica SBA-15 usage as an oral vaccine adjuvant to control Mycoplasma hyopmeunoniae in pig production
• Grantee: Gabriel Yuri Storino
• Support Opportunities: Scholarships in Brazil - Doctorate