Grif Katharina, Heller Ingrid, Wagner Martin, Dierich Manfred, Würzner Reinhard
Austrian Reference Laboratory for Listeria, Department for Hygiene, Microbiology, and Social Medicine, Innsbruck Medical University, Innsbruck, Austria.
Foodborne Pathog Dis. 2006 Spring;3(1):138-41. doi: 10.1089/fpd.2006.3.138.
In this study, two typing methods, automated ribotyping and pulsed-field gel electrophoresis (PFGE), were evaluated for the subtyping of Listeria monocytogenes serotype 4b. The strains originated from patients and food samples collected in Austria during 2001-2005 and from Europe and North America in the World Health Organization collaborative study on the subtyping of this species. The largest group of Austrian clinical isolates was of the same PFGE subtype as those isolated from foodborne outbreaks in Switzerland and in the United States. Another subtype of clinical isolates from Austria was indistinguishable to that obtained from isolates responsible for a foodborne outbreak in the United States in 1985. Although the discriminatory power of PFGE was higher than that of automated ribotyping, some PFGE types were differentiated by ribotyping. Thus, combining data obtained by both automated ribotyping and PFGE increases the strain discrimination. Still, many of the Austrian strains remain indistinguishable from strains of foodborne outbreaks in other countries although there is no known epidemiological relation. This complies to previous studies which show the highly clonal nature of L. monocytogenes 4b strains which are responsible for both large outbreaks and sporadic cases.
在本研究中，对两种分型方法，即自动化核糖体分型和脉冲场凝胶电泳（PFGE），进行了评估，以用于单核细胞增生李斯特菌4b血清型的亚型分析。这些菌株来源于2001年至2005年期间在奥地利收集的患者和食品样本，以及世界卫生组织关于该菌种亚型分析的协作研究中来自欧洲和北美的样本。奥地利临床分离株中最大的一组与从瑞士和美国食源性暴发中分离出的菌株具有相同的PFGE亚型。奥地利临床分离株的另一个亚型与1985年在美国引起食源性暴发的分离株所获得的亚型无法区分。虽然PFGE的鉴别能力高于自动化核糖体分型，但一些PFGE型可通过核糖体分型来区分。因此，将自动化核糖体分型和PFGE所获得的数据相结合可提高菌株鉴别能力。尽管没有已知的流行病学关联，但许多奥地利菌株仍与其他国家食源性暴发的菌株无法区分。这与之前的研究结果一致，这些研究表明，导致大规模暴发和散发病例的单核细胞增生李斯特菌4b菌株具有高度的克隆性。
