Wiedmann M, Czajka J, Bsat N, Bodis M, Smith M C, Divers T J, Batt C A
Department of Food Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York 14853.
J Clin Microbiol. 1994 Apr;32(4):991-6. doi: 10.1128/jcm.32.4.991-996.1994.
Two outbreaks of epizootic listerial encephalitis, one in sheep and one in goats, were investigated through pathology, microbiology, and DNA amplification-based techniques. Efforts were made to survey the diversity of Listeria monocytogenes strains in the silage consumed by affected animals and to verify the causal relationship between silage and disease outbreak. In both outbreaks, L. monocytogenes was isolated from silage and brain tissue samples. Random amplified polymorphic DNA patterns revealed two distinct L. monocytogenes strains, one of which was identical to the sheep brain isolate, in the silage associated with the outbreak in sheep. Three brain isolates and one silage isolate, all of which had different random amplified polymorphic DNA patterns, were found in the outbreak involving goats. All isolates from both outbreaks were indistinguishable in an in vitro assay for cell-to-cell spread and growth in macrophages. All brain isolates from the goat outbreak had identical intracellular ActA patterns, which were different from the pattern for the silage isolate. While the sheep brain isolate had an ActA pattern different from that of the corresponding silage isolate, the patterns for the brain isolates from the two outbreaks were not identical. This survey demonstrates the diversity of L. monocytogenes in silage and suggests the existence of one or more selective processes by which certain strains are more prone to give rise to disease.
通过病理学、微生物学以及基于DNA扩增的技术，对两起动物李斯特菌性脑炎疫情进行了调查，其中一起发生在绵羊身上，另一起发生在山羊身上。研究人员努力调查受感染动物食用的青贮饲料中单核细胞增生李斯特菌菌株的多样性，并验证青贮饲料与疾病爆发之间的因果关系。在这两起疫情中，均从青贮饲料和脑组织样本中分离出了单核细胞增生李斯特菌。随机扩增多态性DNA图谱显示，在与绵羊疫情相关的青贮饲料中存在两种不同的单核细胞增生李斯特菌菌株，其中一种与绵羊脑部分离株相同。在涉及山羊的疫情中，发现了三株脑部分离株和一株青贮饲料分离株，它们的随机扩增多态性DNA图谱均不同。在体外细胞间传播和巨噬细胞生长试验中，两起疫情中的所有分离株均无差异。山羊疫情中的所有脑部分离株具有相同的细胞内肌动蛋白A（ActA）图谱，与青贮饲料分离株的图谱不同。虽然绵羊脑部分离株的ActA图谱与相应青贮饲料分离株的不同，但两起疫情中脑部分离株的图谱并不相同。这项调查证明了青贮饲料中单核细胞增生李斯特菌的多样性，并表明存在一个或多个选择过程，某些菌株更容易引发疾病。
