Porcine spleen_Streptococcus suis serotype 2 infected_3 days

Streptococcus suis serotype 2 (SS2), a major swine pathogen and an emerging zoonotic agent, has greatly challenged global public health. Systematical information about host immune response to the infection is important for understanding the molecular mechanism of diseases. Here, we investigated the global expression changes in spleen following SS2 infection using the Affymetrix Porcine Genechip. Our findings indicate previously unrecognized gene transcription changes in case of SS infection in vivo. Our data should provide new clues for immune response in mammals and identification of candidate genes related to SS resistance. All animal tissue collection procedures were performed according to protocols approved by The Hubei Province, PR China for Biological Studies Animal Care and Use Committee. Piglets at 35 days old were determined to be S.suis 2-free by antibody-based ELISA before artificial bacterial challenges. Each piglet was intranasally challenged with 2×106 colony-forming units (CFU) per millilitre of SS2 strain 05ZY or ΔHP0197. A total of 4 piglets were challenged with 05ZY, 4 were challenged with ΔHP0197, and 4 pigs were used as controls. These three groups were raised in isolated facilities. Nine microarrays were used in the experiment, corresponding to the RNAs from spleen tissues of piglets with arthritis after SS2 infection and spleen tissues of piglets with no clinical signs and three controls.