Lindstedt Bjørn-Arne, Tham Wilhelm, Danielsson-Tham Marie-Louise, Vardund Traute, Helmersson Seved, Kapperud Georg
Division of Infectious Diseases control, Norwegian Institute of Public Health, Geitmyrsveien 75, Nydalen, Oslo, Norway.
J Microbiol Methods. 2008 Feb;72(2):141-8. doi: 10.1016/j.mimet.2007.11.012. Epub 2007 Nov 22.
The multiple-locus variable-number tandem-repeats analysis (MLVA) method for genotyping has proven to be a fast and reliable typing tool in several bacterial species. MLVA is in our laboratory the routine typing method for Salmonella enterica subsp. enterica serovar Typhimurium and Escherichia coli O157. The gram-positive bacteria Listeria monocytogenes, while not isolated as frequent as S. Typhimurium and E. coli, causes severe illness with an overall mortality rate of 30%. Thus, it is important that any outbreak of this pathogen is detected early and a fast trace to the source can be performed. In view of this, we have used the information provided by two fully sequenced L. monocytogenes strains to develop a MLVA assay coupled with high-resolution capillary electrophoresis and compared it to pulsed-field gel electrophoresis (PFGE) in two sets of isolates, one Norwegian (79 isolates) and one Swedish (61 isolates) set. The MLVA assay could resolve all of the L. monocytogenes serotypes tested, and was slightly more discriminatory than PFGE for the Norwegian isolates (28 MLVA profiles and 24 PFGE profiles) and opposite for the Swedish isolates (42 MLVA profiles and 43 PFGE profiles).
多位点可变数目串联重复序列分析（MLVA）基因分型方法已被证明是几种细菌的快速可靠分型工具。在我们实验室，MLVA是肠炎沙门氏菌肠炎亚种鼠伤寒血清型和大肠杆菌O157的常规分型方法。革兰氏阳性菌单核细胞增生李斯特菌虽然不像鼠伤寒沙门氏菌和大肠杆菌那样频繁分离，但会导致严重疾病，总体死亡率为30%。因此，尽早检测到这种病原体的任何疫情爆发并能快速溯源至关重要。有鉴于此，我们利用两个全基因组测序的单核细胞增生李斯特菌菌株提供的信息，开发了一种结合高分辨率毛细管电泳的MLVA检测方法，并在两组分离株中与脉冲场凝胶电泳（PFGE）进行比较，一组是挪威的（79株分离株），另一组是瑞典的（61株分离株）。MLVA检测方法能够分辨所有测试的单核细胞增生李斯特菌血清型，对于挪威分离株，MLVA的鉴别力略高于PFGE（28个MLVA图谱和24个PFGE图谱），而对于瑞典分离株则相反（42个MLVA图谱和43个PFGE图谱）。
