Sow Vaccination with a Protein Fragment against Virulent Glaesserella (Haemophilus) parasuis Modulates Immunity Traits in Their Offspring.

Sergi López-Serrano,Virginia Aragon,Marina Sibila,Ayub Darji,Jorge Martínez-Martínez,Mar Costa-Hurtado,Iván José Galindo-Cardiel,Yasser Mahmmod,Fernando Rodríguez,Carlos Neila-Ibáñez

doi:10.3390/vaccines9050534

Abstract

Glaesserella (Haemophilus) parasuis, an early colonizer of the nasal cavity in piglets, is a highly heterogeneous species, comprising both commensal and virulent strains. Virulent G. parasuis strains can cause fibrinous polyserositis called Glässer’s disease. Colostrum is a source of passive immunity for young piglets. When vaccinating sows, protective antibodies are transferred to their offspring through the colostrum. Here, sow vaccination was performed with a protein fragment, F4, from the outer membrane trimeric autotransporters VtaAs exclusively found in virulent G. parasuis. Piglets were allowed to suckle for 3 weeks, following which a challenge with two virulent strains of G. parasuis was performed. A group of nonvaccinated sows and their piglets were included as a control. Antibodies against F4 were confirmed using ELISA in the vaccinated sows and their offspring before the G. parasuis challenge. Compared to the control group, F4-vaccination also resulted in an increased level of serum TGF-β both in vaccinated sows and in their offspring at early time points of life. After the challenge, a lower body temperature and a higher weight were observed in the group of piglets from vaccinated sows. One piglet from the non-vaccinated group succumbed to the infection, but no other significant differences in clinical signs were noticed. At necropsy, performed 2 weeks after the virulent challenge, the level of surfactant protein D (SP-D) in bronchoalveolar lavage was higher in the piglets from vaccinated sows. Vaccination did not inhibit the nasal colonization of the piglets by the challenge strains.

Highlights

Licensee MDPI, Basel, Switzerland.Glaesserella parasuis, formerly known as Haemophilus parasuis, is a rod shaped, Gramnegative proteobacteria from the Pasteurellaceae family that is commonly found in the nasal microbiota of pigs
Sera from piglets reflected the vaccination of the sows, with higher level of antibodies against F4 in piglets nursed by vaccinated sows than in piglets from unvaccinated sows
These outcomes are in line with those reported in human [22], where an upregulation of TGF-β in the mucosa of the upper airways was detected in neonates from mothers vaccinated with Influenza pdm09 H1N1 adjuvanted vaccine during the pregnancy

Summary

Introduction

Glaesserella parasuis, formerly known as Haemophilus parasuis, is a rod shaped, Gramnegative proteobacteria from the Pasteurellaceae family that is commonly found in the nasal microbiota of pigs. G. parasuis is a highly heterogeneous species, comprising commensal and virulent strains. Virulent strains can cause polyserositis, polyarthritis and meningitis, a pathological disorder called Glässer’s disease that is more prevalent in young piglets, especially in the nursery period. The most commonly used treatment for Glässer’s disease and other bacterial diseases affecting piglets are antimicrobials. Increasing concern about antimicrobial resistance arising from the livestock industry is promoting the research of alternative control tools, where vaccines have a relevant role [1]

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