Li Siyan, Wang Dan, Guo Chenyao, Tian Motong, Liu Qi, Pan Zihao
College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; OIE Reference Laboratory for Swine Streptococcosis, Nanjing, 210095, China.
College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; MOE Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agricultural University, Nanjing, 210095, China; OIE Reference Laboratory for Swine Streptococcosis, Nanjing, 210095, China.
Microb Pathog. 2021 May;154:104865. doi: 10.1016/j.micpath.2021.104865. Epub 2021 Mar 24.
Streptococcus suis (S.suis)is an important zoonotic pathogen in pigs and human. Bacterial ghosts (BGs) which are empty envelopes were used recently as efficient delivery system in vaccine development. In this study, S.suis ghosts were prepared and protective efficacy was evaluated in mice. Sodium hydroxide was used to prepare S.suis ghosts which were visualized under scanning electron microscopy. The optimum concentration of is Sodium hydroxide 6 mg/mL for ghosts formed. To investigate the S.suis ghosts as a candidate vaccine, the 50 BALB/c mice were randomly divided into three groups: Group A (control group), group B (subcutaneous injection of inactivated S.suis 2), group C (subcutaneous injection of inactivated S.suis 9), group D (subcutaneous injection of S.suis 2 ghosts), group E (subcutaneous injection of S.suis 9 ghosts). Serum were collected from five groups on the day of 7, 14, 21 and 28 after the first immunization for potency assay. Indirect ELISA results showed that antibody titer of blood serum of mice from group S.suis2 ghosts and group S.suis9 ghosts were significantly higher than blank group(P < 0.01), but were approximate to the conventional inactivated vaccine group SS2. In comparison with the conventional inactivated vaccine, S.suis ghosts as candidate vaccine strategy showed the excellent immunogenicity and provided protection against S.suis challenge in mice model.
猪链球菌是猪和人类中一种重要的人畜共患病原体。细菌幽灵（BGs）即空的包膜，最近被用作疫苗开发中的有效递送系统。在本研究中，制备了猪链球菌幽灵并在小鼠中评估了其保护效力。使用氢氧化钠制备猪链球菌幽灵，并在扫描电子显微镜下观察。形成幽灵的氢氧化钠最佳浓度为6mg/mL。为了研究猪链球菌幽灵作为候选疫苗，将50只BALB/c小鼠随机分为三组：A组（对照组）、B组（皮下注射灭活猪链球菌2型）、C组（皮下注射灭活猪链球菌9型）、D组（皮下注射猪链球菌2型幽灵）、E组（皮下注射猪链球菌9型幽灵）。首次免疫后第7、14、21和28天从五组收集血清进行效力测定。间接ELISA结果显示，猪链球菌2型幽灵组和猪链球菌9型幽灵组小鼠血清抗体滴度显著高于空白组（P<0.01），但与传统灭活疫苗组SS2相近。与传统灭活疫苗相比，猪链球菌幽灵作为候选疫苗策略显示出优异的免疫原性，并在小鼠模型中提供了针对猪链球菌攻击的保护。
