State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China.
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China; College of Animal Science & Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China.
Vaccine. 2019 Apr 10;37(16):2194-2199. doi: 10.1016/j.vaccine.2019.03.028. Epub 2019 Mar 20.
Streptococcus suis serotype 2 (S. suis 2) is a major pathogen causing streptococcosis in swine, resulting in significant losses in swine breeding worldwide. We previously reported that the non-antibiotic-resistant double-mutant strain ΔSspepO/ΔSspspC can be used as a live vaccine, providing effective protection against S. suis 2 infections in mice. This study aimed to understand the characteristics of streptococcosis and develop vaccine candidates for immunization. Intramuscular injection of live S. suis ΔSspepO/ΔSspspC in pigs induced discernable antibody production and provided cross-protection against challenges by a type 2 strain (100% protection) and a type 7 strain (60% protection). Protection was evaluated via clinical, bacteriological, serological, and post-mortem examinations. Furthermore, vaccination induced the production of opsonizing antibodies against serotypes 2 and 7. Analysis of IgG subclasses (IgG1 and IgG2a) revealed that both Th1 and Th2 responses were induced by S. suis ΔSspepO/ΔSspspC, although the IgG2a (Th1) response predominated over the IgG1 (Th2) response. This study is the first, to our knowledge, to establish a live vaccine candidate to protect against two major S. suis serotypes. Further studies are required to assess these candidate vaccines and examine their feasibility in providing cross-protection against S. suis.
猪链球菌 2 型（S. suis 2）是一种主要的病原体，可导致猪链球菌病，给全球的养猪业造成了巨大的损失。我们之前曾报道过，非耐药性的双突变株 ΔSspepO/ΔSspspC 可以作为活疫苗，为小鼠提供针对 S. suis 2 感染的有效保护。本研究旨在了解链球菌病的特点，并开发免疫接种的疫苗候选物。在猪中肌肉内注射活的 S. suis ΔSspepO/ΔSspspC 可诱导明显的抗体产生，并提供针对 2 型菌株（100%保护）和 7 型菌株（60%保护）的交叉保护。通过临床、细菌学、血清学和剖检检查来评估保护作用。此外，疫苗接种可诱导针对 2 型和 7 型的调理抗体产生。对 IgG 亚类（IgG1 和 IgG2a）的分析表明，S. suis ΔSspepO/ΔSspspC 可诱导 Th1 和 Th2 反应，尽管 IgG2a（Th1）反应优于 IgG1（Th2）反应。据我们所知，本研究首次建立了一种活疫苗候选物，可预防两种主要的 S. suis 血清型。需要进一步研究来评估这些候选疫苗，并研究它们在提供针对 S. suis 的交叉保护方面的可行性。
