Simonson Tatum S, Okinaka Richard T, Wang Bingxiang, Easterday W Ryan, Huynh Lynn, U'Ren Jana M, Dukerich Meghan, Zanecki Shaylan R, Kenefic Leo J, Beaudry Jodi, Schupp James M, Pearson Talima, Wagner David M, Hoffmaster Alex, Ravel Jacques, Keim Paul
Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011-5640, USA.
BMC Microbiol. 2009 Apr 15;9:71. doi: 10.1186/1471-2180-9-71.
The global pattern of distribution of 1033 B. anthracis isolates has previously been defined by a set of 12 conserved canonical single nucleotide polymorphisms (canSNP). These studies reinforced the presence of three major lineages and 12 sub-lineages and sub-groups of this anthrax-causing pathogen. Isolates that form the A lineage (unlike the B and C lineages) have become widely dispersed throughout the world and form the basis for the geographical disposition of "modern" anthrax. An archival collection of 191 different B. anthracis isolates from China provides a glimpse into the possible role of Chinese trade and commerce in the spread of certain sub-lineages of this pathogen. Canonical single nucleotide polymorphism (canSNP) and multiple locus VNTR analysis (MLVA) typing has been used to examine this archival collection of isolates.
The canSNP study indicates that there are 5 different sub-lineages/sub-groups in China out of 12 previously described world-wide canSNP genotypes. Three of these canSNP genotypes were only found in the western-most province of China, Xinjiang. These genotypes were A.Br.008/009, a sub-group that is spread across most of Europe and Asia; A.Br.Aust 94, a sub-lineage that is present in Europe and India, and A.Br.Vollum, a lineage that is also present in Europe. The remaining two canSNP genotypes are spread across the whole of China and belong to sub-group A.Br.001/002 and the A.Br.Ames sub-lineage, two closely related genotypes. MLVA typing adds resolution to the isolates in each canSNP genotype and diversity indices for the A.Br.008/009 and A.Br.001/002 sub-groups suggest that these represent older and established clades in China.
B. anthracis isolates were recovered from three canSNP sub-groups (A.Br.008/009, A.Br.Aust94, and A.Br.Vollum) in the western most portion of the large Chinese province of Xinjiang. The city of Kashi in this province appears to have served as a crossroads for not only trade but the movement of diseases such as anthrax along the ancient "silk road". Phylogenetic inference also suggests that the A.Br.Ames sub-lineage, first identified in the original Ames strain isolated from Jim Hogg County, TX, is descended from the A.Br.001/002 sub-group that has a major presence in most of China. These results suggest a genetic discontinuity between the younger Ames sub-lineage in Texas and the large Western North American sub-lineage spread across central Canada and the Dakotas.
此前，1033株炭疽杆菌分离株的全球分布模式已通过一组12个保守的标准单核苷酸多态性（canSNP）得以确定。这些研究强化了这种炭疽致病病原体存在三个主要谱系以及12个亚谱系和亚组的观点。形成A谱系的分离株（与B和C谱系不同）已广泛散布于世界各地，并构成了“现代”炭疽地理分布的基础。来自中国的191株不同炭疽杆菌分离株的档案资料，让人得以一窥中国的贸易和商业活动在该病原体某些亚谱系传播中可能发挥的作用。已运用标准单核苷酸多态性（canSNP）和多位点可变数目串联重复序列分析（MLVA）分型方法来检测这组分离株档案。
canSNP研究表明，在先前描述的全球12种canSNP基因型中，中国存在5种不同的亚谱系/亚组。其中三种canSNP基因型仅在中国最西部的省份新疆被发现。这些基因型分别是A.Br.008/009，这是一个分布于欧洲和亚洲大部分地区的亚组；A.Br.Aust 94，这是一个存在于欧洲和印度的亚谱系；以及A.Br.Vollum，这也是一个存在于欧洲的谱系。其余两种canSNP基因型分布于中国全境，属于A.Br.001/002亚组和A.Br.Ames亚谱系，这是两个密切相关的基因型。MLVA分型为每个canSNP基因型中的分离株增加了分辨率，A.Br.008/009和A.Br.001/002亚组的多样性指数表明，这些在中国代表着更古老且已确立的进化枝。
在中国最大省份新疆最西部的地区，从三个canSNP亚组（A.Br.008/009、A.Br.Aust94和A.Br.Vollum）中分离出了炭疽杆菌。该省的喀什市似乎不仅是贸易的十字路口，也是炭疽等疾病沿着古老“丝绸之路”传播的通道。系统发育推断还表明，最初在从德克萨斯州吉姆·霍格县分离出的原始埃姆斯菌株中鉴定出的A.Br.Ames亚谱系，源自在中国大部分地区占主要地位的A.Br.001/002亚组。这些结果表明，德克萨斯州较年轻 的埃姆斯亚谱系与分布于加拿大中部和达科他州的北美西部大型亚谱系之间存在遗传间断。
