Understanding Streptococcus suis serotype 2 infection in pigs through a transcriptional approach

Streptococcus suis serotype 2 is an important pathogen of pigs, and the disease it causes is characterized by meningitis, septicaemia and pneumonia with high mortality. The pathogen is also an emerging zoonotic agent and threatens humans that are exposed to pigs or their by-products. We investigated the response of PBMC (Peripheral Blood Mononuclear Cell), brain and lung tissues to infection with S. suis 2 strain SC19 by using the Affymetrix Porcine Genome Array. Six piglets free of S. suis 2 were allocated randomly to the infected group and the uninfected group. Each piglet of the infected group was intravenous injection with Streptococcus suis 2 strain SC19 at a dose of 3×105 colony-forming units (CFU). Each piglet of the noninfected group was treated similarly with an identical volume of PBS as control. At 24 h after challenge, the pigs were slaughtered and their brains, lungs and PBMC were collected with RNase-free equipment for microarray analysis.