Multilocus Sequence-Based Analysis Delineates a Clonal Population of Agrobacterium (Rhizobium) radiobacter (Agrobacterium tumefaciens) of Human Origin
Multilocus Sequence-Based Analysis Delineates a Clonal Population of Agrobacterium (Rhizobium) radiobacter (Agrobacterium tumefaciens) of Human Origin
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DOI：
10.1128/jb.00107-11
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发表时间：
2011-05-01
影响因子：
3.2
通讯作者：
Teyssier, Corinne
中科院分区：
文献类型：
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作者：
Aujoulat, Fabien;Jumas-Bilak, Estelle;Teyssier, Corinne
农杆菌属包括与植物相关的细菌和条件人类病原体。该属内的分类学和命名法仍然存在争议。特别是，人类来源的菌株都隶属于农杆菌(根瘤菌)放射状杆菌，而植物致病菌株则被指定为同名农杆菌。为了研究不同来源的农杆菌菌株的相对分布，我们对来自不同来源的89株临床和环境菌株进行了基于多位点序列的分析(MLSA)。根据根癌农杆菌C58环染色体上存在的7个看家基因(atpD、zwf、trpE、GroEL、dna K、glnA和rpoB)的部分序列，我们提出了一种MLSA方案。多位点系统发育分析表明，88%的临床分离株属于A7基因，形成了一个连锁不平衡的同源群体，表明重组率较低。通过脉冲场凝胶电泳(PFGE)获得的基因组指纹图谱的比较表明，A7基因组株在流行病学上没有亲缘关系。我们提出的遗传证据表明，A7基因可能构成了一个与环境种群不同的人类相关种群。此外，表型特征，如42摄氏度的培养，也与这一说法一致。这种与人类相关的种群可能代表着农杆菌属的一个潜在的新物种。
The genus Agrobacterium includes plant-associated bacteria and opportunistic human pathogens. Taxonomy and nomenclature within the genus remain controversial. In particular, isolates of human origin were all affiliated with the species Agrobacterium (Rhizobium) radiobacter, while phytopathogenic strains were designated under the synonym denomination Agrobacterium tumefaciens. In order to study the relative distribution of Agrobacterium strains according to their origins, we performed a multilocus sequence-based analysis (MLSA) on a large collection of 89 clinical and environmental strains from various origins. We proposed an MLSA scheme based on the partial sequence of 7 housekeeping genes (atpD, zwf, trpE, groEL, dnaK, glnA, and rpoB) present on the circular chromosome of A. tumefaciens C58. Multilocus phylogeny revealed that 88% of the clinical strains belong to genovar A7, which formed a homogeneous population with linkage disequilibrium, suggesting a low rate of recombination. Comparison of genomic fingerprints obtained by pulsed-field gel electrophoresis (PFGE) showed that the strains of genovar A7 were epidemiologically unrelated. We present genetic evidence that genovar A7 may constitute a human-associated population distinct from the environmental population. Also, phenotypic characteristics, such as culture at 42 degrees C, agree with this statement. This human-associated population might represent a potential novel species in the genus Agrobacterium.