biostudies-literatureLu XThe fundamental research funds for the Central Universitythe National Key Research and Development Program of ChinaNational Natural Science Foundation of ChinaThe National Natural Science Foundation of ChinaNational Key Research and Development Program of China283https://www.ebi.ac.uk/biostudies/studies/S-EPMC10974582biostudies-literatureUnknown12(3)<i>Streptococcus suis</i> is an important zoonotic pathogen that mainly causes meningitis, septicemia, and arthritis. Due to the limited cross-protection between numerous serotypes, the existing inactive vaccines in clinical use fail to offer sufficient protection. In this study, a gene deletion-attenuated strain Δ<i>cps/ssna</i>-m<i>sly</i> (P353L)-SC-19 was constructed by deleting <i>cps</i> and <i>ssna</i> genes from the epidemic strain SC-19 with a mutation of SLY (P353L). The safety of Δ<i>cps/ssna</i>-m<i>sly</i> (P353L)-SC-19 was confirmed in both in vitro and in vivo experiments. We further demonstrated that immunization with Δ<i>cps/ssna</i>-m<i>sly</i> (P353L)-SC-19 induced significant cellular immunity and humoral immunity in mice and protected against infections caused by type VaccinesA <i>Streptococcus suis</i> Strain Δ<i>cps/ssna</i>-m<i>sly</i> (P353L)-SC19 Provides Cross-Protection against Serotypes 2 and 9 Strain Challenges in a Mouse Model.PMC109745822662018PY044319726492022YFD18009042022YFD0500204Xu LZhou LLu XDai BCui SLin LZhang AfalseA <i>Streptococcus suis</i> Strain Δ<i>cps/ssna</i>-m<i>sly</i> (P353L)-SC19 Provides Cross-Protection against Serotypes 2 and 9 Strain Challenges in a Mouse Model.<i>Streptococcus suis</i> is an important zoonotic pathogen that mainly causes meningitis, septicemia, and arthritis. Due to the limited cross-protection between numerous serotypes, the existing inactive vaccines in clinical use fail to offer sufficient protection. In this study, a gene deletion-attenuated strain Δ<i>cps/ssna</i>-m<i>sly</i> (P353L)-SC-19 was constructed by deleting <i>cps</i> and <i>ssna</i> genes from the epidemic strain SC-19 with a mutation of SLY (P353L). The safety of Δ<i>cps/ssna</i>-m<i>sly</i> (P353L)-SC-19 was confirmed in both in vitro and in vivo experiments. We further demonstrated that immunization with Δ<i>cps/ssna</i>-m<i>sly</i> (P353L)-SC-19 induced significant cellular immunity and humoral immunity in mice and protected against infections caused by type 2024-01-01T00:00:00Z2024 Mar2026-07-09T10:36:53.226Z2026-07-09T10:25:52.356ZS-EPMC109745823854391710.3390/vaccines12030283