Griekspoor Petra, Hansbro Philip M, Waldenström Jonas, Olsen Björn
Section for Zoonotic Ecology and Epidemiology, Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), School of Natural Sciences, Linnaeus University, Kalmar, Sweden;
Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Newcastle, Australia.
Infect Ecol Epidemiol. 2015 Dec 2;5:28383. doi: 10.3402/iee.v5.28383. eCollection 2015.
The zoonotic bacterium Campylobacter jejuni has a broad host range but is especially associated with birds, both domestic and wild. Earlier studies have indicated thrushes of the genus Turdus in Europe to be frequently colonized with C. jejuni, and predominately with host-associated specific genotypes. The European Blackbird Turdus merula has a large distribution in Europe, including some oceanic islands, and was also introduced to Australia by European immigrants in the 1850s.
The host specificity and temporal stability of European Blackbird C. jejuni was investigated with multilocus sequence typing in a set of isolates collected from Sweden, Australia, and The Azores.
Remarkably, we found that the Swedish, Australian, and Azorean isolates were genetically highly similar, despite extensive spatial and temporal isolation. This indicates adaptation, exquisite specificity, and stability in time for European Blackbirds, which is in sharp contrast with the high levels of recombination and mutation found in poultry-related C. jejuni genotypes.
The maintenance of host-specific signals in spatially and temporally separated C. jejuni populations suggests the existence of strong purifying selection for this bacterium in European Blackbirds.
人畜共患病细菌空肠弯曲菌宿主范围广泛，但特别与家禽和野禽有关。早期研究表明，欧洲的鸫属鸟类常被空肠弯曲菌定植，且主要是与宿主相关的特定基因型。欧洲乌鸫在欧洲分布广泛，包括一些海洋岛屿，19世纪50年代还被欧洲移民引入澳大利亚。
通过多位点序列分型，对从瑞典、澳大利亚和亚速尔群岛收集的一组分离株进行研究，以调查欧洲乌鸫空肠弯曲菌的宿主特异性和时间稳定性。
值得注意的是，我们发现，尽管存在广泛的空间和时间隔离，瑞典、澳大利亚和亚速尔群岛的分离株在基因上高度相似。这表明欧洲乌鸫具有适应性、高度特异性和时间稳定性，这与家禽相关的空肠弯曲菌基因型中发现的高水平重组和突变形成鲜明对比。
在空间和时间上分离的空肠弯曲菌群体中宿主特异性信号的维持表明，欧洲乌鸫体内的这种细菌存在强烈的纯化选择。
