Phylogenetic Trees of Six Representative Isolates Based on Comparison of 16S rDNA and Five Putative Virulence-Associated-Factor Genes with Known Sequences

<p>Swine isolates from Sichuan ( S. suis ZYS3 and S. suis ZYS8) labeled in green, human isolates ( S. suis ZYH13 and S. suis ZYH14) from Sichuan labeled in red, Jiangsu isolates from 1998 ( S. suis 9801 and S. suis Habb) labeled in blue, and the standard highly virulent strain S. suis P1/7 labeled in pink. All representative strains from other streptococcus species or isolates of S. suis 2 are as indicated in the tree. </p

RFLP Analysis of Different S. suis 2 Isolates

<p> S. suis S10: a highly virulent strain from China; <i>S</i>. <i>suis</i> 9801: swine isolate from Jiangsu Province in 1998; S. suis Habb: human isolate from Jiangsu Province in 1998; S. suis ZYS3: swine isolate from Sichuan Province in 2005; S. suis ZYH13: human isolate from Sichuan Province in 2005; M: 1 kb DNA Ladder (MBI Ferments, Gdansk, Poland). </p

Microscopic Characterization of Sectioned Liver Tissue from Patients Who Had Died

<div><p>(A) Light image of a liver tissue section (×100). The central vein is indicated with an arrow.</p> <p>(B) Light image of a liver tissue section (×200).</p> <p>(C) The convergent zone is indicated with an arrow (×100).</p> <p>(D) TEM image of a liver tissue section (×20,000). A bacterium found in the tissue is highlighted with an arrow.</p></div

Immunohistochemical Analysis of Liver Tissue Sections from Dead Patients Incubated with Normal and S. suis 2-Infected Swine Serum

<div><p>(A) Staining with normal swine serum detected no S. suis 2 antigen. </p> <p>(B) Staining with the serum from the infected swine indicated the presence of S. suis 2 antigen. </p></div

Detection of the Pathogenic SS2 and Identification of Its Specific Genes

<div><p>(A) Light microscopy image of the isolates cultured from autopsy specimens.</p> <p>GP⁺ cocci (pointed to with black arrows) are arranged in various short chains (×100). </p> <p>(B) Qualitative PCR detection of isolates from the liver of fatal human cases with a set of primers specific for <i>S</i>. <i>suis</i> 2. M: 100bp DNA marker (Fermentas, Vilnius, Lithuania). CK: 16S rDNA PCR product from the R 735 standard strain of S. suis 2. Multi-PCR: performed with a set of unique primers specific for <i>mrp, epf, suilysin,</i> and <i>cps-2J,</i> respectively. </p></div