The expression of CD14 antigen in experimental encephalitic listeriosis in rabbits

The present study examined the distribution of Listeria monocytogenes 1/2a (L.m. 1/2a) and the antigen CD14 by using immunohistochemical methods in the brain of healthy and experimentally infected rabbits with L.m. 1/2a. The ten New Zealand White rabbits were inoculated by intracerebral route, and 4 rabbits were used for control. Only the brains of the animals were removed during necropsy, and they were analysed by conventional histological techniques. By Haematoxylin and Eosin staining all L.m. 1/2a inoculated rabbits presented meningitis or meningoencephalitis. In healthy rabbits, the immunohistochemical staining of brains for CD14 was very slight and seen only in the lumen of the vessels, whereas, in infected rabbits the CD14 immunoreactivity was more prominent especially in inflammation areas of parenchyma and meninges. Moreover, the CD14 positive immunostainings were seen massively in L.m. positive inflamed areas. The present study provides the immunohistochemical expression of CD14 and L.monocytogenes antigen in the brain and a positive correlation was obtained between CD14 and this infectious agent.