Shinde Vidyagouri, Newton Hema, Sakamuri Rama Murthy, Reddy Venkateshwar, Jain Suman, Joseph Abraham, Gillis Tom, Nath Indira, Norman Gift, Vissa Varalakshmi
Blue Peter Research Centre, LEPRA Society, Cherlapally, Hyderabad 501301, India.
Lepr Rev. 2009 Sep;80(3):290-301.
To study the suitability, stability and diversity of short tandem repeat (STR) genomic markers to elicit strain variation in the Mycobacterium leprae isolates within leprosy patients from Andhra Pradesh and Tamil Nadu states in South India.
Slit skin smear (SSS) samples were collected from lesions and various body sites of newly diagnosed leprosy patients. The SSSs from each patient were pooled, except in the case of five patients. Total DNA was extracted from SSS samples. M. leprae STRs were amplified from the DNA either by multiplex PCR (MP) or single PCR methods. The number of repeats for each STR locus (the STR allele) was obtained either by fragment length analysis (FLA) or by DNA sequencing of the PCR amplicons.
Multiplex PCR minimised the use of DNA and reagents, and together with FLA, was time and cost effective for STR strain typing. After examination of the isolates of South Indian origin at 13 STR loci, it was determined that the alleles for (AC)8b, (GGT)5, 6-3a (rpoT), 21-3, 27-5, and 23-3 were conserved in two study populations. In a family from Andhra Pradesh, the M. leprae STR patterns in two patients were identical in 16 of 18 loci which indicate a common source of infection. Fourteen of 15 STR loci showed no intra-patient variation in the five patients tested in Tamil Nadu. Altogether, these studies indicate the suitability of STR strain typing for assessing short-range transmission chains.
研究短串联重复序列（STR）基因组标记在印度南部安得拉邦和泰米尔纳德邦麻风病患者中麻风分枝杆菌分离株引起菌株变异方面的适用性、稳定性和多样性。
从新诊断的麻风病患者的病变部位和身体各个部位采集皮肤涂片（SSS）样本。除5名患者外，将每位患者的SSS样本合并。从SSS样本中提取总DNA。通过多重PCR（MP）或单重PCR方法从DNA中扩增麻风分枝杆菌STR。通过片段长度分析（FLA）或PCR扩增子的DNA测序获得每个STR位点的重复次数（STR等位基因）。
多重PCR最大限度地减少了DNA和试剂的使用，并且与FLA一起，对于STR菌株分型具有时间和成本效益。在对来自南印度的分离株进行13个STR位点检测后，确定（AC）8b、（GGT）5、6 - 3a（rpoT）、21 - 3、27 - 5和23 - 3的等位基因在两个研究群体中是保守的。在安得拉邦的一个家庭中，两名患者的麻风分枝杆菌STR模式在18个位点中的16个位点相同，这表明存在共同的感染源。在泰米尔纳德邦测试的5名患者中，15个STR位点中的14个位点在患者体内没有变异。总之，这些研究表明STR菌株分型适用于评估短程传播链。
