Charlton K M, Garcia M M
Vet Pathol. 1977 Jul;14(4):297-313. doi: 10.1177/030098587701400401.
Sixteen of 17 sheep with spontaneous listeric encephalitis had neuritis characterized by diffuse and focal intrafascicular and perineural accumulations of lymphocytes, plasma cells, macrophages and neutrophils in one or more cranial nerves. Nine sheep had extensive trigeminal neuritis which was usually unilateral. Brain lesions were mainly in the stem and were foci of macrophages or neutrophils or both, malacia, neutrophilic neuronophagia, vascular cuffing, and meningitis. Lesions in the brain and trigeminal ganglia were most severe on the same side as the affected trigeminal nerve. Gram-positive bacilli were in proximal parts of cranial nerves in foci of inflammatory cells and occasionally in morphologically intact nerve fibers. Organisms in the brain were in phagocytes in areas of inflammation and in scattered neurons and axons. The results were consistent with centripetal migration of the infectious agent along one or more branches of the trigeminal nerve to the brain and dissemination in the brain stem occurring, at least partly, along fiber tracts. Intraaxonal movement of bacteria probably is a mechanism involved in the pathogenesis of this disease.
17只患自发性李斯特菌性脑炎的绵羊中，有16只出现神经炎，其特征为一条或多条颅神经内弥漫性和局灶性束内及神经周淋巴细胞、浆细胞、巨噬细胞和中性粒细胞聚集。9只绵羊出现广泛性三叉神经炎，通常为单侧性。脑部病变主要位于脑干，表现为巨噬细胞或中性粒细胞或两者的病灶、软化、嗜中性神经元吞噬、血管套袖形成和脑膜炎。脑部和三叉神经节的病变在患侧三叉神经同侧最为严重。革兰氏阳性杆菌存在于炎性细胞灶内的颅神经近端部分，偶尔也存在于形态完整的神经纤维中。脑内的病原体存在于炎症区域的吞噬细胞以及散在的神经元和轴突中。结果表明，感染因子沿三叉神经的一个或多个分支向心性迁移至脑部，并至少部分地沿纤维束在脑干中播散。细菌的轴突内移动可能是该疾病发病机制中的一种机制。
