Skip to Main content Skip to Navigation
Journal articles

Molecular epidemiology and evolutionary genetics of Mycobacterium tuberculosis isolated from different parts of India

Abstract : Background: The evolutionary changes in mycobacterium tuberculosis (MTB) have been phenotypic as well as genotypic by diversifying into various lines of descent or lineages. Methodology and findings: A total of 538 MTB isolates obtained from different parts of India were included in the study. Spoligotyping and drug susceptibility testing was performed on all the MTB isolates. Major cities and parts of India from where these isolations were made include: Delhi, Assam, Punjab, Maharashtra (Nagpur, Mumbai), Tamilnadu (Chennai), Uttar Pradesh (Agra), and West Bengal (Kolkata). Spoligotyping analysis detected 93 distinct spoligo-patterns. A total of 440 (81.7%) isolates could be grouped into 77 SITs which matched the pre-existing database, whereas 16 SITs were newly created for 51 (9.7%) isolates and for 47 (8.7%) isolates no SIT number could be assigned and these were grouped as ‘orphans’. Overall, CAS family was predominant, comprised of 37.9% isolates, followed by EAI 23.6%, Beijing in 13.9%, Manu in 6.8% and T in 4.6% isolates. Other families were rare. Drug susceptibility testing (DST) identified 361 (67.1%) isolates as pan-sensitive to all 4 first-line drugs, 83 (15.4%) were resistant to any one or more drugs, and 94 (17.4%) were identified as multidrug-resistant (MDR). Out of the 94 MDR isolates, the majority of isolates (32; 34%) were Beijing, 31 (32%) CAS, 11 (11.7%) unknown, and 6 (6.3%) each of EAI and T lineages. Among the Beijing lineage, SIT621 was more associated with MDR-TB compared with SIT1. Conclusions: The study provides important baseline data to understand and monitor the molecular epidemiology of MTB in India. The CAS lineage was the most common and widely prevalent across India, while EAI lineage was more common in south and eastern India. The Beijing lineage was significantly (p-value <0.0001) associated with MDR-TB.
Document type :
Journal articles
Complete list of metadata
Contributor : Nalin Rastogi <>
Submitted on : Tuesday, May 19, 2015 - 11:32:16 PM
Last modification on : Monday, October 8, 2018 - 5:44:05 PM

Links full text




Sarman Singh, Jitendra Singh, Manimuthu Mani Sankar, David Couvin, Nalin Rastogi. Molecular epidemiology and evolutionary genetics of Mycobacterium tuberculosis isolated from different parts of India. International Journal of Mycobacteriology, 2015, 4 (Supplement 1), pp.26. ⟨10.1016/j.ijmyco.2014.11.021⟩. ⟨pasteur-01153539⟩



Record views