ORCID
- Michael A. Jarvis: 0000-0002-0124-4061
- Mathew Upton: 0000-0003-4287-6396
Abstract
Background: Streptococcus suis (S. suis) is a Gram-positive bacterium that causes substantial disease in pigs. S. suis is also an emerging zoonoses in humans, primarily in Asia, through the consumption of undercooked pork and the handling of infected pig meat as well as carcasses. The complexity of S. suis epidemiology, characterized by the presence of multiple bacterial serotypes and strains with diverse sequence types, identifies a critical need for a universal vaccine with the ability to confer cross-protective immunity. Highly conserved immunogenic proteins are generally considered good candidate antigens for subunit universal vaccines. Methods: In this study, the cross-protection of the sugar ABC transporter substrate-binding protein (S-ABC), a surface-associated immunogenic protein of S. suis, was examined in mice for evaluation as a universal vaccine candidate. Results: S-ABC was shown to be highly conserved, with 97% amino acid sequence identity across 31 S. suis strains deposited in GenBank. Recombinantly expressed S-ABC (rS-ABC) was recognized via rabbit sera specific to S. suis serotype 2. The immunization of mice with rS-ABC induced antigen-specific antibody responses, as well as IFN-γ and IL-4, in multiple organs, including the lungs. rS-ABC immunization conferred high (87.5% and 100%) protection against challenges with S. suis serotypes 2 and 9, demonstrating high cross-protection against these serotypes. Protection, albeit lower (50%), was also observed in mice challenged with S. suis serotype 7. Conclusions: These data identify S-ABC as a promising antigenic target within a universal subunit vaccine against S. suis.
DOI
10.3390/vaccines12050544
Publication Date
2024-05-15
Publication Title
Vaccines
Volume
12
Issue
5
ISSN
2076-393X
Keywords
serotypes, Streptococcus suis, subunit vaccine, sugar ABC transporter substrate-binding protein, universal vaccine
Recommended Citation
Liu, J., Li, B., Yan, Z., Pan, R., Zhang, J., Sun, J., Ma, X., Dong, N., Yao, X., Wei, J., Liu, K., Qiu, Y., Sealey, K., Nichols, H., Jarvis, M., Upton, M., Li, X., & Ma, Z. (2024) 'Immunogenicity and Protective Capacity of Sugar ABC Transporter Substrate-Binding Protein against Streptococcus suis Serotype 2, 7 and 9 Infection in Mice', Vaccines, 12(5). Available at: https://doi.org/10.3390/vaccines12050544