title: Isolation and characterization of a native avirulent strain of Streptococcus suis serotype 2: a perspective for vaccine development.
abstract: Streptococcus suis, an emerging infectious pathogen, is the cause of two large-scale outbreaks of human streptococcal toxic shock syndrome in China, and has attracted much attention from the scientific community. The genetic basis of its pathogenesis remains enigmatic, and no effective prevention measures have been established. To better understand the virulence differentiation of S. suis and develop a promising vaccine, we isolated and sequenced a native avirulent S. suis strain (05HAS68). Animal experiments revealed that 05HAS68 is an avirulent strain and could protect piglets from the attack of virulent strains. Comparative genomics analyses demonstrated the genetic basis for the lack of virulence in 05HAS68, which is characterized by the absence of some important virulence-associated factors and the intact 89K pathogenicity island. Lack of virulence was also illustrated by reduced survival of 05HAS68 compared to a virulent strain in pig whole blood. Further investigations revealed a large-scale genomic rearrangement in 05HAS68, which was proposed to be mediated by transposase genes and/or prophages. This genomic rearrangement may have caused the genomic diversity of S. suis, and resulted in biological discrepancies between 05HAS68 and highly virulent S. suis strains.
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, 400038, China.
authors.forename: Xinyue
authors.initials: X
authors.lastname: Yao
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, 400038, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing 210002, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing 210002, China.
authors.forename: Changjun
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing 210002, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Hu
authors.affiliation: Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing 210002, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Zheng
authors.affiliation: Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing 210002, China.
authors.forename: Xiuzhen
authors.initials: X
authors.lastname: Pan
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, 400038, China.
authors.forename: Yinling
authors.initials: Y
authors.lastname: Tan
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, 400038, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, 400038, China.
authors.forename: Liwen
authors.initials: L
authors.lastname: Hu
authors.affiliation: PLA Research Institute of Clinical Laboratory Medicine, Nanjing general hospital of Nanjing Military Command, Nanjing 210002, China.
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Tang
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, 400038, China.
authors.forename: Fuquan
authors.initials: F
authors.lastname: Hu
mesh_terms: D000818:Animals; D001428:Bacterial Vaccines / Q000276:immunology; D064112:Clustered Regularly Interspaced Short Palindromic Repeats / Q000235:genetics; D055028:Comparative Genomic Hybridization; D004269:DNA, Bacterial / Q000032:analysis; D004195:Disease Models, Animal; D005814:Genes, Viral; D016680:Genome, Bacterial; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D005810:Multigene Family; D010802:Phylogeny; D039002:Prophages / Q000235:genetics; D011446:Prospective Studies; D017422:Sequence Analysis, DNA; D065288:Serogroup; D013290:Streptococcal Infections / Q000276:immunology / Q000382:microbiology; D017011:Streptococcus suis / Q000145:classification / Q000235:genetics* / Q000276:immunology; D013552:Swine; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001428:Bacterial Vaccines; D004269:DNA, Bacterial; D037521:Virulence Factors