title: Virulence genotyping and population analysis of Streptococcus suis serotype 2 isolates from China.
abstract: Streptococcus suis is one of the most important swine pathogens worldwide. In this study, a total of 22 virulence-related genes in 101 strains of S. suis serotype 2 (SS2) were detected by PCR, namely, mrp, epf, sly, fbps, rgg, ofs, srtA, pgdA, gapdh, iga, endoD, ciaRH, salKR, manN, purD, rgg, DppIV, neuB, dltA, SMU_61-like, SpyM3_0908 (Permease) and the SspA gene. The distribution of virulence-related genes among isolates was visualized using BioNumerics software to study similarities among the isolates. Two clusters of SS2 were apparent on the phylogenetic tree, namely, Clusters A and B. Both mouse and zebrafish infection models revealed that strains in Cluster B were more virulent than those in Cluster A. Statistical comparison between the two clusters was performed, and structure analysis demonstrated that epf, sly, rgg, endoD, SMU_61-like and SpyM3_0908 were possible predictive markers for SS2 virulence. The transcription levels of highly prevalent genes in both clusters were detected by qRT-PCR in representative strains. For Cluster A isolates, the transcription levels of neuB, dltA, fbps and pgdA were significantly lower, but the transcription level of iga was significantly higher than that in Cluster B isolates. Although encoded in the genomes of the selected Cluster A isolates, DppIV and mrp genes were not expressed. These results revealed the genetic differences between virulent and low-virulence SS2 isolates from China and provide a better understanding of the SS2 pathogenic mechanism.
authors: OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Wenyang
authors: W
authors: Dong
authors: OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Jiale
authors: J
authors: Ma
authors: OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Yinchu
authors: Y
authors: Zhu
authors: OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Jielian
authors: J
authors: Zhu
authors: OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Lvfeng
authors: L
authors: Yuan
authors: OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Yanan
authors: Y
authors: Wang
authors: OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Jueqiong
authors: J
authors: Xu
authors: OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Zihao
authors: Z
authors: Pan
authors: OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Zongfu
authors: Z
authors: Wu
authors: OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Wei
authors: W
authors: Zhang
authors: OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors: Chengping
authors: C
authors: Lu
authors: OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: yaohch@njau.edu.cn.
authors: Huochun
authors: H
authors: Yao
mesh_terms: D000818:Animals; D002681:China; D016000:Cluster Analysis; D020869:Gene Expression Profiling; D005798:Genes, Bacterial; D005838:Genotype; D008297:Male; D051379:Mice; D010802:Phylogeny; D065288:Serogroup; D013290:Streptococcal Infections / Q000662:veterinary; D017011:Streptococcus suis / Q000145:classification* / Q000235:genetics* / Q000472:pathogenicity; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000382:microbiology; D014158:Transcription, Genetic; D014774:Virulence / Q000235:genetics*; D015027:Zebrafish
keywords: Genotype; S. suis; Virulence; Virulence-associated gene