Immunogenicity evaluation of a vaccine against Mycoplasma hyopneumoniae using nanostructured silica SBA-15 as an adjuvant

• Grant number: 23/04557-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2023
• End date: June 30, 2024
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Pathology
• Principal Investigator: Luís Guilherme de Oliveira
• Grantee: Gabriel Alexandre de Aguiar
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

Mycoplasma hyopneumoniae (M. hyopneumoniae) is the etiologic agent of Swine Enzootic Pneumonia (PES) that causes changes in the respiratory epithelium and in the ciliary structures of the animal's airways, causing great economic losses to the global swine industry due to its high prevalence and continuous loss of animal performance, mainly weight. To control the pathogen, the producing farms have high costs with the purchase of inputs, such as antibiotics and vaccines to administer to their animals. Such vaccines, even though they provide reinforcement and stimulate the immune system against the disease, often provide partial protection to the animals, and an increase in the number of cases of pigs infected with the bacteria can be detected. Therefore, the aim of this study is to evaluate the immunogenicity of a new vaccine against M. hyopneumoniae, developed with mesoporated silica (SBA-15) as an adjuvant, by analyzing the concentration of IgG and IgA immunoglobulins and acute phase proteins ( PFAs), obtained by electrophoresis in polyacrylamide gel containing sodium dodecyl sulfate (SDS-PAGE). For this, 36 weaned piglets (20 days old) will be evaluated and allocated into three experimental groups, as follows: Group 1 (VC; n = 12): piglets immunized with a single dose commercial vaccine at 24 days of age (D0) via the intramuscular route; Group 2 (VP; n = 12): piglets immunized with the prepared vaccine (SBA-15), at 24 days of age (D0) via the intramuscular route; and Group 3 (CONTROL; n = 12): group that will receive SBA-15 without antigen incorporation in PBS solution (pH 7.4) at 24 days of age (D0) via the intramuscular route. At moment D0, immediately before immunization of the animals, samples of venous blood will be collected to obtain serum, which will be used to determine the serum proteinogram (basal value). New samples of venous blood will be collected two days after the immunization of the animals (D2). Twenty-one days after vaccination (D21), all animals will be challenged with 5 mL of culture medium containing 10 6 CCU/mL of M. hyopneumoniae (strain 232) at 45 days of age. New venous blood samples will be collected 14 days after the animals challenge (D35). At the same time of blood collection (D0, D2 and D35) the physical examination (measurement of rectal temperature and evaluation of the presence of signs of respiratory alteration) and weighing of the animals will be performed. If the normality of the variables studied is verified using the Shapiro Wilkins test, analysis of variance (ANOVA) and Tukey's test will be performed for comparison between groups at different times (p<0.05).