German Federal Institute for Risk Assessment, Department of Biological Safety, Berlin, Germany.
German Federal Institute for Risk Assessment, Department of Biological Safety, Berlin, Germany
Appl Environ Microbiol. 2018 Aug 31;84(18). doi: 10.1128/AEM.00675-18. Print 2018 Sep 15.
In this study, the prevalence of in wild boars in northeast Germany was determined. For that purpose, the tonsils of 503 wild boars were sampled. The presence of was studied by diagnostic PCR. Positive samples were analyzed by cultural detection using a modified cold enrichment protocol. Ten isolates were obtained, which were characterized by biotyping, molecular serotyping, and multilocus sequence typing (MLST). In addition, whole-genome sequences and the antimicrobial susceptibility of the isolates were analyzed. was isolated from male and female animals, most of which were younger than 1 year. A prevalence of 2% (10/503) was determined by cultural detection, while 6.4% (32/503) of the animals were positive by PCR. The isolates belonged to the biotypes 1 and 2 and serotypes O:1a ( = 7), O:1b ( = 2), and O:4a ( = 1). MLST analysis revealed three sequence types, ST9, ST23, and ST42. Except one isolate, all isolates revealed a strong resistance to colistin. The relationship of the isolates was studied by whole-genome sequencing demonstrating that they belonged to four clades, exhibiting five different pulsed-field gel electrophoresis (PFGE) restriction patterns and a diverse composition of virulence genes. Six isolates harbored the virulence plasmid pYV. Besides two isolates, all isolates contained and genes and a complete or incomplete high-pathogenicity island (HPI). None of them possessed a gene for the superantigen YPM. The study shows that various strains exist in wild boars in northeast Germany, which may pose a risk to humans. is a foodborne pathogen whose occurrence is poorly understood. One reason for this situation is the difficulty in isolating the species. The methods developed for the isolation of are not well suited for We therefore designed a protocol which enabled the isolation of from a relatively high proportion of PCR-positive wild boar tonsils. The study indicates that wild boars in northeast Germany may carry a variety of strains, which differ in terms of their pathogenic potential and other properties. Since wild boars are widely distributed in German forests and even populate cities such as Berlin, they may transmit yersiniae to other animals and crop plants and may thus cause human infections through the consumption of contaminated food. Therefore, the prevalence of should be determined also in other animals and regions to learn more about the natural reservoir of this species.
本研究旨在确定德国东北部野猪中 的流行情况。为此，采集了 503 头野猪的扁桃体样本。通过诊断 PCR 研究 的存在。使用改良的冷富集方案进行培养检测分析阳性样本。获得了 10 株 分离株，通过生物分型、分子血清分型和多位点序列分型（MLST）进行了特征分析。此外，还分析了全基因组序列和分离株的抗菌敏感性。从雄性和雌性动物中分离出 ，其中大多数动物年龄小于 1 岁。通过培养检测确定 2%（10/503）的流行率，而 6.4%（32/503）的动物通过 PCR 呈阳性。分离株属于生物型 1 和 2 以及血清型 O:1a（ = 7）、O:1b（ = 2）和 O:4a（ = 1）。MLST 分析显示三种序列类型，ST9、ST23 和 ST42。除 1 株外，所有分离株对粘菌素均表现出强烈耐药性。通过全基因组测序研究分离株的关系表明，它们属于四个分支，表现出五种不同的脉冲场凝胶电泳（PFGE）限制图谱和不同的毒力基因组成。6 株分离株携带毒力质粒 pYV。除两株分离株外，所有分离株均含有 和 基因以及完整或不完整的高致病性岛（HPI）。它们均不含有超级抗原 YPM 基因。本研究表明，德国东北部野猪中存在多种 菌株，可能对人类构成威胁。 是一种食源性病原体，其发生情况尚不清楚。造成这种情况的一个原因是该物种的分离困难。为此，我们设计了一种从相对较高比例的 PCR 阳性野猪扁桃体中分离 的方案。该研究表明，德国东北部野猪可能携带多种 菌株，其在致病潜力和其他特性方面存在差异。由于野猪广泛分布于德国森林中，甚至在柏林等城市也有野猪出没，它们可能会将耶尔森氏菌传播给其他动物和作物植物，并可能通过食用受污染的食物导致人类感染。因此，还应在其他动物和地区确定 的流行情况，以更多地了解该物种的自然宿主。
