Development of an injectable vaccine to control Mycoplasma hyopneumoniae in pigs using SBA-15 nanostructured silica as an adjuvant

• Grant number: 21/14515-9
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: November 01, 2022
• End date: April 02, 2026
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Clinics and Surgery
• Principal Investigator: Luís Guilherme de Oliveira
• Grantee: Fernando Antônio Moreira Petri
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Associated scholarship(s): 23/15067-5 - Communication between the microbial diversity in the respiratory tract of pigs and the response to experimental and commercial vaccines against Mycoplasma hyopneumoniae, BE.EP.DD

Abstract

Mycoplasma hyopneumoniae, the main etiological agent of Porcine Enzootic Pneumonia (PEP), is a microorganism that is widely used in intensive swine farming and whose prevention is of great interest to the Brazilian production system, as its colonization in lung tissue leads to intense production losses. Available commercial vaccines minimize lung damage and clinical signs but do not prevent the colonization of the respiratory tract and excretion of the pathogen. The development of new technologies is an important ally to animal health and intensive production, as is the case of mesoporous silica SBA-15, used as an adjuvant carrier, serving as a replacement for existing technologies, such as aluminum hydroxide. Therefore, this project aims to develop a parenteral vaccine, for intramuscular administration, composed of cellular proteins from M. hyopneumoniae (strain 232) incorporated into SBA-15 silica, serving as an adjuvant and carrier. For the execution of this study, forty-five 21-days-old piglets will be divided into 3 experimental groups with different immunization protocols, where G1: piglets vaccinated with a single dose commercial vaccine at 24 days of age (D0) by intramuscular route; G2: piglets vaccinated with the prepared injectable vaccine (SBA-15), at 24 days of age (D0) by the intramuscular route; G3: control group, will receive sterile saline solution on D0. Twenty-one days after the administration of the vaccine dose, the animals will be challenged with 106 CCU/ml of M. hyopneumoniae (232) through the orotracheal route (D21). The weighing and physical examination of the animals, collection of blood samples, and nasal and laryngeal swabs will be done in D-2, before the animals' vaccination. After vaccination, a physical examination and evaluation of the vaccine application site will be performed in all animals in D1, D2, and D3. Every 7 days, between D0 and D56, a physical examination will be performed, weighing to calculate the daily weight gain (gpd) and temperature measurement. Still, blood serum and nasal swab will be collected from all animals, for detection of IgG and IgA, respectively. Blood samples will be collected at D2, D7, D14, D35, and D56 used to assess the expression of certain inflammatory cytokines (IL-8, IL-17, TGF-², and TNF-±) by qPCR. After the animals are challenged on D21, every 7 days until D49, a physical examination will be performed with observation for the beginning and end of clinical signs of coughing and sneezing, and the collection of nasal and laryngeal swabs to monitor the level of IgA and excretion of M.hyopneumoniae, respectively, in all animals. The evaluation by the Pneumonia Index (IPP) and the collection of lung fragments and tracheobronchial lavage (LTB) will be performed during the animals' necropsy, which will take place at 80 days of life of the animals (D56). BALF samples will be used for pathogen detection by qPCR. Lung fragments will be submitted to histopathological analysis. The normality of the variables will be verified by the Shapiro-Wilk and Bartllett test. If there is normality, analysis of variance (ANOVA) and Tukey's test for multiple comparisons will be applied. If there is no normality, non-parametric tests (Kruskal-Wallis) will be used. To assess the correlation between lesions suggestive of M. hyopneumoniae infection and the investigated variables, Pearson's or Spearman's correlation tests, and linear regression analysis will be performed. Finally, it is expected that the results obtained with the use of silica (SBA-15) in a parenteral vaccine will enable an immune response capable of helping to control the disease in pigs, and consequently, reduce the occurrence of lesions in carcasses during the period of slaughter. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

PETRI, FERNANDO ANTONIO MOREIRA; MALCHER, CLARISSE SENA; MECHLER-DREIBI, MARINA LOPES; PANNEITZ, ANA KAROLINA; BRAGA, EDUARDA RIBEIRO; DE AGUIAR, GABRIEL ALEXANDRE; TOLEDO, LEONARDO TEOFILO; MARTINS, TEREZA SILVA; CIDES-DA-SILVA, LUIS CARLOS; FANTINI, MARCIA C. A.; et al. Shedding reduction and immunity modulation in piglets with an inactivated Mycoplasma hyopneumoniae vaccine encapsulated in nanostructured SBA-15 silica. Vaccine, v. 42, n. 24, p. 12-pg., 2024-08-28. (21/11914-0, 21/14515-9, 19/08582-5, 23/15067-5, 19/07007-7, 17/17844-8)