Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
Ruralia Institute, Faculty of Agriculture and Forestry, University of Helsinki, Seinäjoki, Finland.
Appl Environ Microbiol. 2019 Feb 6;85(4). doi: 10.1128/AEM.02365-18. Print 2019 Feb 15.
Poultry are considered a major reservoir and source of human campylobacteriosis, but the roles of environmental reservoirs, including wild birds, have not been assessed in depth. In this study, we isolated and characterized from western jackdaws ( = 91, 43%), mallard ducks ( = 82, 76%), and pheasants ( = 9, 9%). Most of the western jackdaw and mallard duck isolates represented multilocus sequence typing (MLST) sequence types (STs) that diverged from those previously isolated from human patients and various animal species, whereas all pheasant isolates represented ST-19, a common ST among human patients and other hosts worldwide. Whole-genome MLST revealed that mallard duck ST-2314 and pheasant ST-19 isolates represented bacterial clones that were genetically highly similar to human isolates detected previously. Further analyses revealed that in addition to a divergent ClonalFrame genealogy, certain genomic characteristics of the western jackdaw isolates, e.g., a novel gene cluster and the type VI secretion system (T6SS), may affect their host specificity and virulence. Game birds may thus pose a risk for acquiring campylobacteriosis; therefore, hygienic measures during slaughter and meat handling warrant special attention. The roles of environmental reservoirs, including wild birds, in the molecular epidemiology of have not been assessed in depth. Our results showed that game birds may pose a risk for acquiring campylobacteriosis, because they had genomotypes highly similar to human isolates detected previously. Therefore, hygienic measures during slaughter and meat handling warrant special attention. On the contrary, a unique phylogeny was revealed for the western jackdaw isolates, and certain genomic characteristics identified among these isolates are hypothesized to affect their host specificity and virulence. Comparative genomics within sequence types (STs), using whole-genome multilocus sequence typing (wgMLST), and phylogenomics are efficient methods to analyze the genomic relationships of isolates.
家禽被认为是人类弯曲菌病的主要储主和来源，但环境储主（包括野生鸟类）的作用尚未得到深入评估。在本研究中，我们从西部寒鸦（=91，43%）、绿头鸭（=82，76%）和雉鸡（=9，9%）中分离并鉴定了 。大多数西部寒鸦和绿头鸭 的分离株代表了与先前从人类患者和各种动物物种中分离的多基因座序列分型（MLST）序列型（ST）不同的 ST，而所有雉鸡分离株均代表了在全球范围内人类患者和其他宿主中常见的 ST-19。全基因组 MLST 显示，绿头鸭 ST-2314 和雉鸡 ST-19 分离株代表了与先前检测到的人类分离株遗传上高度相似的细菌克隆。进一步分析表明，除了具有不同的克隆框架系统发育外，西部寒鸦 分离株的某些基因组特征，例如新型 基因簇和 VI 型分泌系统（T6SS），可能影响其宿主特异性和毒力。野生鸟类可能因此成为获得弯曲菌病的风险因素；因此，在屠宰和肉类处理过程中采取卫生措施需要特别注意。环境储主（包括野生鸟类）在 分子流行病学中的作用尚未得到深入评估。我们的结果表明，野生鸟类可能成为获得弯曲菌病的风险因素，因为它们的基因组基因型与先前检测到的人类分离株非常相似。因此，在屠宰和肉类处理过程中采取卫生措施需要特别注意。相比之下，西部寒鸦分离株显示出独特的系统发育，并且假设这些分离株中鉴定出的某些基因组特征会影响其宿主特异性和毒力。使用全基因组多位点序列分型（wgMLST）和系统发育基因组学对序列型（ST）内进行比较基因组学分析是分析 分离株基因组关系的有效方法。
