Streptococcus parasuis , an Emerging Zoonotic Pathogen, Possesses the Capacity to Induce Cerebral Inflammatory Responses.

To date, three strains, BS26, BS27, and NN1, have been isolated from the blood cultures of patients with peritonitis, pneumonia, and arthritis, indicating that is an emerging threat to susceptible people. There is thus an urgent need to further evaluate the pathogenesis of clinical strains in order to design efficient anti-inflammatory strategies. Our previous study demonstrated the capacity of clinical strains to enter the central nervous system (CNS) of infected mice. However, the characteristics and inflammatory mechanism of CNS infections caused by are still non-available. In the present study, we investigated the proportion and time of two clinical strains NN1 and BS26 infected mice that developed neurological symptoms. The characteristics of histopathological changes and the cerebral immune response in mice with neurological symptoms were analyzed. Furthermore, we evaluated the roles of microglia and astrocytes in the clinical strain-induced cerebral inflammation. Our data indicated that clinical strains possess a high potential to induce cerebral inflammation in susceptible people at the early phase of infection. Our study contributes to increasing the understanding of the pathogenicity of and the inflammatory mechanisms of the brain against infection caused by .