A Polyphasic and Taxogenomic Evaluation Uncovers Arcobacter cryaerophilus as a Species Complex That Embraces Four Genomovars
A Polyphasic and Taxogenomic Evaluation Uncovers Arcobacter cryaerophilus as a Species Complex That Embraces Four Genomovars
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多相和分类基因组学评估揭示了嗜冷弓形杆菌是一个包含四个基因变种的物种复合体
DOI：
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发表时间：
2018
影响因子：
5.2
通讯作者：
M. Figueras
中科院分区：
文献类型：
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作者：
A. Pérez;L. Collado;Oscar Salgado;Violeta Lefiñanco;M. Figueras
嗜冷弧菌存在于许多动物源性食品中，是废水中的主要菌种。此外，它还与农场动物和人类传染病病例有关。该物种包括两个亚群，即1A （LMG 24291T = LMG 9904T）和1B (LMG 10829)，可通过其16S rRNA-RFLP模式进行区分。然而，一些作者，基于共享的DNA-DNA杂交的中间水平，建议放弃亚群分类。这一矛盾表明该物种的分类学尚未解决。本研究的目的是对嗜冷芽孢杆菌的多样性进行分类评价。利用基因组信息、多位点系统发育分析（MLPA）和表型表征对来自9个国家不同类型样本和宿主的52个时间和地理分散的菌株进行分析。MLPA分析表明，这些菌株形成了4个聚类（I-IV）。在代表4个簇的菌株的13个基因组之间获得的平均核苷酸同一性（ANI）和硅DNA-DNA杂交（isDDH）值分别低于建议的截断值96%和70%，证实每个簇代表不同的基因组物种。然而，没有评估表型测试使他们明确分化成物种。因此，基因组划分的集群应该被认为是嗜冷芽孢杆菌的基因组变体。这些基因组变体可能具有不同的临床重要性，因为只有集群1包括从人类标本中分离出来的菌株。至少需要发现一个稳定的独特表型特征，才能将每个簇或基因组型定义为不同的物种。在那之前，我们建议将它们命名为A。cryaerophilus问。伪嗜冷菌（Cluster I = LMG 10229T）；cryaerophilus问。（Cluster II = LMG 9065T）；cryaerophilus问。冻干杆菌”（类群III = lmg24291t）和“A。cryaerophilus问。（群集IV = LMG 29976T）。
The species Arcobacter cryaerophilus is found in many food products of animal origin and is the dominating species in wastewater. In addition, it is associated with cases of farm animal and human infectious diseases,. The species embraces two subgroups i.e., 1A (LMG 24291T = LMG 9904T) and 1B (LMG 10829) that can be differentiated by their 16S rRNA-RFLP pattern. However, some authors, on the basis of the shared intermediate levels of DNA-DNA hybridization, have suggested abandoning the subgroup classification. This contradiction indicates that the taxonomy of this species is not yet resolved. The objective of the present study was to perform a taxonomic evaluation of the diversity of A. cryaerophilus. Genomic information was used along with a Multilocus Phylogenetic Analysis (MLPA) and phenotypic characterization on a group of 52 temporally and geographically dispersed strains, coming from different types of samples and hosts from nine countries. The MLPA analysis showed that those strains formed four clusters (I–IV). Values of Average Nucleotide Identity (ANI) and in silico DNA-DNA Hybridization (isDDH) obtained between 13 genomes representing strains of the four clusters were below the proposed cut-offs of 96 and 70%, respectively, confirming that each of the clusters represented a different genomic species. However, none of the evaluated phenotypic tests enabled their unequivocal differentiation into species. Therefore, the genomic delimited clusters should be considered genomovars of the species A. cryaerophilus. These genomovars could have different clinical importance, since only the cluster I included strains isolated from human specimens. The discovery of at least one stable distinctive phenotypic character would be needed to define each cluster or genomovar as a different species. Until then, we propose naming them “A. cryaerophilus gv. pseudocryaerophilus” (Cluster I = LMG 10229T), “A. cryaerophilus gv. crypticus” (Cluster II = LMG 9065T), “A. cryaerophilus gv. cryaerophilus” (Cluster III = LMG 24291T) and “A. cryaerophilus gv. occultus” (Cluster IV = LMG 29976T).
DOI：
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发表时间：
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作者：
Systems Biology
通讯作者：
Systems Biology