Chauhan D S, Sharma V D, Parashar Deepti, Chauhan Aradhana, Singh D, Singh H B, Das R, Aggarwal B M, Malhotra B, Jain Amita, Sharma Meera, Kataria V K, Aggarwal J K, Hanif Mohamad, Shahani Aruna, Katoch V M
National JALMA Institute for Leprosy & Other Mycobacterial Diseases, Agra, India.
Indian J Med Res. 2007 Apr;125(4):577-81.
BACKGROUND & OBJECTIVE: IS 6110 based typing remains the internationally accepted standard and continues to provide new insights into the epidemiology of Mycobacterium tuberculosis. The aim of the study was to characterize M. tuberculosis isolates obtained from different parts of India based on IS6110 element polymorphism using restriction fragment length polymorphism (RFLP) analysis.
RFLP was analyzed among 308 isolates of M. tuberculosis deposited in the Mycobacterial Repository Centre, Agra, from different parts of India. DNAs isolated from these strains were restricted with Pvu II, transferred on to nylon membrane and hybridized with a PCR amplified DIG-labeled 245 bp IS6110 probe.
Based on the copy number, M. tuberculosis isolates were classified into four groups, (i) lacking IS6110 element; (ii) low copy number (1-2); (iii) intermediate copy number (3-5); and (iv) high copy number (6-19). Copy number higher than 19 however was not observed in any of the isolates studied. At the national level, 56 per cent of the isolates showed high copy number of IS6110, 13 per cent showed intermediate copy number, 20 per cent showed low copy number, whereas 11 per cent isolates lacked IS6110 element. At the regional level, there was not much difference in the RFLP profiles of isolates (IS6110 copy numbers/patterns) from different parts of the country.
INTERPRETATION & CONCLUSION: IS6110 DNA based fingerprinting could be a potentially useful tool for investigating the epidemiology of tuberculosis in India.
基于IS6110的分型仍然是国际公认的标准，并继续为结核分枝杆菌的流行病学提供新的见解。本研究的目的是利用限制性片段长度多态性（RFLP）分析，根据IS6110元件多态性对从印度不同地区获得的结核分枝杆菌分离株进行特征分析。
对保存在阿格拉分枝杆菌储存中心的308株来自印度不同地区的结核分枝杆菌分离株进行RFLP分析。从这些菌株中分离的DNA用Pvu II进行酶切，转移到尼龙膜上，并用PCR扩增的地高辛标记的245 bp IS6110探针进行杂交。
根据拷贝数，结核分枝杆菌分离株分为四组，（i）缺乏IS6110元件；（ii）低拷贝数（1 - 2）；（iii）中等拷贝数（3 - 5）；（iv）高拷贝数（6 - 19）。然而，在所研究的任何分离株中均未观察到拷贝数高于19的情况。在国家层面，56%的分离株显示IS6110高拷贝数，13%显示中等拷贝数，20%显示低拷贝数，而11%的分离株缺乏IS6110元件。在地区层面，来自该国不同地区的分离株（IS6110拷贝数/模式）的RFLP图谱没有太大差异。
基于IS6110 DNA的指纹图谱可能是调查印度结核病流行病学的一个潜在有用工具。
