Proteomics analysis of important molecules in serum from meningitic piglets caused by Streptococcus suis serotype 2

Streptococcus suis serotype 2 (SS2) is an important zoonotic pathogen that causes meningitis in China. This study's aim was comparative analysis of serum proteomics from meningitis and non-meningitis piglets.

SS2 meningitis and non-meningitis piglet models were established. The serum samples were collected and analyzed by label-free LC-MS/MS proteomics technology. Differentially expressed proteins (DEPs) from serum were screened out by comparing the meningitis group and non-meningitis group to the healthy group (M/C; N/C), respectively. And then, globally and comparative analysis of DEPs in "M/C" and "N/C" in serum were performed using bioinformatics method. Finally, we comparatively analyzed the serum and cerebrospinal fluid proteomics in piglets that lived with meningitis.

We obtained 316 and 191 DEPs from "M/C" and "N/C" which classification visualizations were established. 157 DEPs were common in both groups and 159 DEPs were unique to the "M/C". These DEPs and the signaling pathways which they participated in were visualized. Moreover, some DEPs which participated in multiple pathways were discovered and the interaction between 159 DEPs was also mapped. 39 common DEPs were also screened out in serum and cerebrospinal fluid during meningitis, and signaling pathways associated with these DEPs were further visualized.

DEPs in "M/C" and "N/C" were comparatively analyzed and the similarities and differences of these DEPS which were involved in signal pathways were summarized. Moreover, several important molecules were screened out.