Linde Jörg, Homeier-Bachmann Timo, Dangel Alexandra, Riehm Julia M, Sundell David, Öhrman Caroline, Forsman Mats, Tomaso Herbert
Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, 07743 Jena, Germany.
Institute of Epidemiology, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany.
Microorganisms. 2020 Dec 5;8(12):1932. doi: 10.3390/microorganisms8121932.
is the causative agent of the zoonotic disease tularemia. In Germany, most human infections are caused by contact with infected hares. The aim of this study was to characterize subsp. strains isolated from hares in Germany and to develop bioinformatics tools to analyze their genetic relatedness. In total, 257 German isolates-obtained mainly from hares ( = 233), other vertebrate animals, and ticks, but also from humans ( = 3)-were analyzed within this study. Publically available sequence data from 49 isolates were used to put our isolates into an epidemiological context and to compare isolates from natural foci and humans. Whole-genome sequences were analyzed using core-genome Multi-Locus-Sequence-Typing, canonical Single Nucleotide Polymorphism (SNP) typing and whole-genome SNP typing. An overall conformity of genotype clustering between the typing methods was found, albeit with a lower resolution for canonical single SNP typing. The subclade distribution, both on local and national levels, among strains from humans and hares was similar, suggesting circulation of the same genotypes both in animals and humans. Whilst close to identical isolates of the same subclade were found distributed over large areas, small geographical foci often harbored members of different subclades. In conclusion, although genomic high-resolution typing was shown to be robust, reproducible and allowed the identification of highly closely related strains, genetic profiling alone is not always conclusive for epidemiological linkage of strains.
是动物源性疾病兔热病的病原体。在德国,大多数人类感染是由接触受感染的野兔引起的。本研究的目的是对从德国野兔中分离出的亚种菌株进行特征描述,并开发生物信息学工具来分析它们的遗传相关性。在本研究中,总共分析了257株德国分离株,这些分离株主要从野兔(n = 233)、其他脊椎动物和蜱中获得,但也有来自人类的(n = 3)。利用来自49株分离株的公开可用序列数据,将我们的分离株置于流行病学背景中,并比较来自自然疫源地和人类的分离株。使用核心基因组多位点序列分型、标准单核苷酸多态性(SNP)分型和全基因组SNP分型对全基因组序列进行分析。尽管标准单SNP分型的分辨率较低,但发现分型方法之间的基因型聚类总体一致。在人类和野兔菌株中,亚分支分布在地方和国家层面上相似,这表明相同基因型在动物和人类中都有传播。虽然在大片区域发现了同一亚分支的几乎相同的分离株,但小地理疫源地往往含有不同亚分支的成员。总之,虽然基因组高分辨率分型被证明是可靠的、可重复的,并且能够识别高度密切相关的菌株,但仅靠基因分型对于菌株的流行病学关联并不总是具有决定性意义。