TbpBY167A-Based Vaccine Can Protect Pigs against Glässer’s Disease Triggered by Glaesserella parasuis SV7 Expressing TbpB Cluster I

Abstract

Glaesserella parasuis is the etiological agent of Glässer’s disease (GD), one of the most important diseases afflicting pigs in the nursery phase. We analyzed the genetic and immunological properties of the TbpB protein naturally expressed by 27 different clinical isolates of G. parasuis that were typed as serovar 7 and isolated from pigs suffering from GD. All the strains were classified as virulent by LS-PCR. The phylogenetic analyses demonstrated high similarity within the amino acid sequence of TbpB from 24 clinical strains all belonging to cluster III of TbpB, as does the protective antigen TbpBY167A. Three G. parasuis isolates expressed cluster I TbpBs, indicating antigenic diversity within the SV7 group of G. parasuis. The antigenic analysis demonstrated the presence of common epitopes on all variants of the TbpB protein, which could be recognized by an in vitro analysis using pig IgG induced by a TbpBY167A-based vaccine. The proof of concept of the complete cross-protection between clusters I and III was performed in SPF pigs immunized with the TbpBY167A-based vaccine (cluster III) and challenged with G. parasuis SV7, strains LM 360.18 (cluster I). Additionally, pigs immunized with a whole-cell inactivated vaccine based on G. parasuis SV5 (Nagasaki strain) did not survive the challenge performed with SV7 (strain 360.18), demonstrating the absence of cross-protection between these two serovars. Based on these results, we propose that a properly formulated TbpBY167A-based vaccine may elicit a protective antibody response against all strains of G. parasuis SV7, despite TbpB antigenic diversity, and this might be extrapolated to other serovars. This result highlights the promising use of the TbpBY167A antigen in a future commercial vaccine for GD prevention.

TbpB-based oral mucosal vaccine provides heterologous protection against Glässer’s disease caused by different serovars of Spanish field isolates ofGlaesserella parasuis

“…The TbpB Y167A subunit vaccine, derived from TbpB cluster III (11), has established a precedent for TbpB-based vaccines conferring protection across various capsular types within the homologous TbpB cluster III, including strains belonging to SV5 (11) and SV7 (12). Moreover, it has demonstrated cross-protection across TbpB clusters, effectively against G. parasuis SV7 from TbpB cluster I (23). Here, we have extended these findings by corroborating the efficacy of the vaccine against a broader selection of four field clinical isolates from Spanish pig farms, spanning different SVs and TbpB clusters.…”

Development and validation of a flow cytometry antibody test for Lawsonia intracellularis

“…Sera from pigs with 63 – 120 days old; C) Study conducted by Ramos et al. ( 21 ). *) Sera previously titrated by IPMA.…”

“…The analysis was performed as recommended by Selliah, Eck ( 22 ). Briefly, a panel of 48 sera ( Table 1 , Specificity) from SPF pigs immunized with Glaesserella parasuis (bacterin prepared with SV7 ( 21 ), n=8), Mycoplasma hyopneumoniae (Safesui Mycoplasma, Ourofino, n=8), Pasteurella multocida A (Bacterin formulated with a Brazilian clinical strain of P. multocida A, pfhA + , Vaxxinova, n=8), Salmonella enterica , serovar Choleraesuis (Enterisol ® SC-54 vaccine, Boehringer Ingelheim, n=8), Clostridium perfringes type C and Escherichia coli (Porcilis ® Coliclos, MSD, n=8) and Porcine circovirus type 2 (Porcilis ® PCV ID, MSD, n=8) were assessed using the protocol described in subsection 2.8.…”