title: Deletion of ssnA Attenuates the Pathogenicity of Streptococcus suis and Confers Protection against Serovar 2 Strain Challenge.
abstract: Streptococcus suis serotype 2 (SS2) is a major porcine and human pathogen which causes arthritis, meningitis, and septicemia. Streptococcus suis nuclease A (SsnA) is a recently discovered deoxyribonuclease (DNase), which has been demonstrated to contribute to escape killing in neutrophil extracellular traps (NETs). To further determine the effects of ssnA on virulence, the ssnA deletion mutant (ΔssnA) and its complemented strain (C-ΔssnA) were constructed. The ability of ΔssnA mutant to interact with human laryngeal epithelial cell (Hep-2) was evaluated and it exhibited dramatically decreased ability to adhere to and invade Hep-2 cells. This mutation was found to exhibit significant attenuation of virulence when evaluated in CD1 mice, suggesting ssnA plays a critical role in the pathogenesis of SS2. Finally, we found that immunization with the ΔssnA mutant triggered both antibody responses and cell-mediated immunity, and conferred 80% protection against virulent SS2 challenge in mice. Taken together, our results suggest that ΔssnA represents an attractive candidate for designing an attenuated live vaccine against SS2.
authors.affiliation: Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou, China.|Guangdong Open Laboratory of Veterinary Public Health, Guangzhou, China.|Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Guangzhou, China.
authors.forename: Miao
authors.initials: M
authors.lastname: Li
authors.affiliation: Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou, China.|Guangdong Open Laboratory of Veterinary Public Health, Guangzhou, China.|Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Guangzhou, China.
authors.forename: Ru-Jian
authors.initials: RJ
authors.lastname: Cai
authors.affiliation: Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou, China.|Guangdong Open Laboratory of Veterinary Public Health, Guangzhou, China.|Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Guangzhou, China.
authors.forename: Chun-Ling
authors.initials: CL
authors.lastname: Li
authors.affiliation: Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou, China.|Guangdong Open Laboratory of Veterinary Public Health, Guangzhou, China.|Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Guangzhou, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Song
authors.affiliation: Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou, China.|Guangdong Open Laboratory of Veterinary Public Health, Guangzhou, China.|Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Guangzhou, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou, China.|Guangdong Open Laboratory of Veterinary Public Health, Guangzhou, China.|Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Guangzhou, China.
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Jiang
authors.affiliation: Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou, China.|Guangdong Open Laboratory of Veterinary Public Health, Guangzhou, China.|Guangdong Provincial Key Laboratory of Livestock Disease Prevention, Guangzhou, China.
authors.forename: Dong-Xia
authors.initials: DX
authors.lastname: Yang
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D001422:Bacterial Adhesion / Q000235:genetics / Q000276:immunology; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology; D002460:Cell Line; D003851:Deoxyribonucleases / Q000235:genetics / Q000276:immunology; D004847:Epithelial Cells / Q000276:immunology / Q000382:microbiology; D017353:Gene Deletion; D006801:Humans; D007111:Immunity, Cellular; D051379:Mice; D013290:Streptococcal Infections / Q000235:genetics / Q000276:immunology / Q000517:prevention & control; D022541:Streptococcal Vaccines / Q000235:genetics / Q000276:immunology; D017011:Streptococcus suis / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity; D014613:Vaccines, Attenuated / Q000235:genetics / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D022541:Streptococcal Vaccines; D014613:Vaccines, Attenuated; D003851:Deoxyribonucleases