High genetic diversity revealed by variable-number tandem repeat genotyping and analysis of hsp65 gene polymorphism in a large collection of "Mycobacterium canettii" strains indicates that the M-tuberculosis complex is a recently emerged clone of "M-canettii"
High genetic diversity revealed by variable-number tandem repeat genotyping and analysis of hsp65 gene polymorphism in a large collection of "Mycobacterium canettii" strains indicates that the M-tuberculosis complex is a recently emerged clone of "M-canettii"
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DOI：
10.1128/jcm.42.7.3248-3255.2004
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发表时间：
2004-07-01
影响因子：
9.4
通讯作者：
Pourcel, C
中科院分区：
文献类型：
--
作者：
Fabre, M;Koeck, JL;Pourcel, C
我们已经分析了，使用互补的分子方法，43株“卡氏分枝杆菌”的多样性，从1998年至2003年，来自吉布提共和国，在非洲之角。多位点可变数目串联重复序列分析的基因分型表明，所有菌株属于一个单一的，但非常遥远的组相比，结核分枝杆菌复合体（MTBC）的菌株。31个菌株聚成一个大群，变异性很小，5个菌株形成另一个群，而其他7个菌株则更加分歧。总共观察到14种基因型。DR基因座分析揭示了额外的变异性，一些菌株缺乏直接重复基因座，而另一些菌株具有独特的间隔区。采用限制性内切酶分析和PCR扩增产物测序的方法检测hsp65基因多态性。发现了4个新的单核苷酸多态性。一个菌株的特点是在441 bp的三个核苷酸的变化，创造新的限制性内切酶多态性。由于在整个MTBC中没有发现hsp65的序列变异性，并且由于单个点突变将M.结核病从最近的“M。canettii”菌株内的这种多样性。canettii”亚种强烈表明它是MTBC的最可能的来源种，而不仅仅是MTBC的另一个分支。
We have analyzed, using complementary molecular methods, the diversity of 43 strains of "Mycobacterium canettii" originating from the Republic of Djibouti, on the Horn of Africa, from 1998 to 2003. Genotyping by multiple-locus variable-number tandem repeat analysis shows that all the strains belong to a single but very distant group when compared to strains of the Mycobacterium tuberculosis complex (MTBC). Thirty-one strains cluster into one large group with little variability and five strains form another group, whereas the other seven are more diverged. In total, 14 genotypes are observed. The DR locus analysis reveals additional variability, some strains being devoid of a direct repeat locus and others having unique spacers. The hsp65 gene polymorphism was investigated by restriction enzyme analysis and sequencing of PCR amplicons. Four new single nucleotide polymorphisms were discovered. One strain was characterized by three nucleotide changes in 441 bp, creating new restriction enzyme polymorphisms. As no sequence variability was found for hsp65 in the whole MTBC, and as a single point mutation separates M. tuberculosis from the closest "M. canettii" strains, this diversity within "M. canettii" subspecies strongly suggests that it is the most probable source species of the MTBC rather than just another branch of the MTBC.