Meningoencephalitis and septicemia in a 4-week-old piglet due to dual streptococcal infections

A 4-week-old male crossbred piglet was presented for necropsy examination with history of neurological signs progressing to death. Grossly, the meninges covering the brain were thickened, opaque containing purulent exudates. Besides, the other visceral organs like lungs, heart, spleen, lymph nodes, kidneys and intestine were severely congested. Histologically, suppurative meningoencephalitis was observed in addition to suppurative bronchopneumonia, hepatitis, nephritis and splenitis indicating the septicemia in pig. Immunolabelling of S. suis antigen was observed in meninges, brain, lungs, spleen, tonsil and lymph nodes. Both S. suis and S. dysgalactiae subspecies equisimilis were isolated from the brain, lungs and spleen. The biochemical characterization by API 20 strep kit and genomic detection test by PCR further confirmed both the isolates. This is the first report of dual infection of S. suis and S. dysgalactiae subspecies equisimilis infection in a pig with severe disseminated suppurative meningoencephalomyelitis.