Insight into genetic diversity of Mycobacterium tuberculosis in Kandy, Sri Lanka reveals predominance of the Euro-American lineage

Abstract

is a country where the molecular epidemiology of Mycobacterium tuberculosis (MTB) is poorly explored. Therefore, this study was performed to identify circulating lineages/sub-lineages of MTB and their transmission patterns. Methods: DNA was extracted from 89 isolates of MTB collected during 2012 and 2013 from new pulmonary tuberculosis patients in Kandy, Sri Lanka and analyzed by spoligotyping, large sequence polymorphism (LSP), mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) typing, and drug resistance-associated gene sequencing. Results: The predominant lineage was lineage 4 (Euro-American, 45.9%), followed by lineage 1 (Indo-Oceanic, 29.4%), lineage 2 (East-Asian, 23.5%), and lineage 3 (Central-Asian, 1.2%). Among 26 spoligotype patterns, eight were undesignated or new types and seven of these belonged to lineage 4. Undesignated lineage 4/SIT124 (n = 2/8) and SIT3234 (n = 8/8) clustered together based on 24-locus MIRU-VNTR typing. The dominant sub-lineage was Beijing/SIT1 (n = 19), with the isoniazid resistance katG G944C mutation (Ser315Thr) detected in two of them. Conclusions: The population structure of MTB in Kandy, Sri Lanka was different from that in the South Asian region. The clonal expansion of locally evolved lineage 4/SIT3234 and detection of the premultidrug resistant Beijing isolates from new tuberculosis patients is alarming and will require continuous monitoring.

Molecular epidemiology and drug susceptibility profiles of Mycobacterium tuberculosis complex isolates from Northern Ghana

“…Even though only one (1/15, 6.7%) out of the 15 L2 isolates was drug resistant (INH mono resistant) in our study, the proportion (6.7%) is indeed high compared to the likelihood of a Ghanaian MTBC isolate to be resistant to at least one anti-TB drug (Almeida Da Silva andPalomino, 2011, Yeboah-Manu et al, 2016). Our findings affirms the widespread reports of L2 and its association with outbreaks of multidrugresistant tuberculosis (MDR-TB) in various parts of the world (Mendis et al, 2019, Merker et al, 2015, San et al, 2018. Furthermore, the proportion of Maf L5 in the north (4.7%) was significantly lower compared to the south but compares to the proportion of L5 in Burkina Faso (De Jong et al, 2010).…”

“…However, pathogenic factors cannot be over emphasized. Molecular epidemiology of MTBC allows for better understanding of specific strain distribution in the communities and development of new interventions, including vaccines, drugs and novel diagnostic tools (Gagneux et al, 2006, Hirsh et al, 2004, Malik and Godfrey-Faussett, 2005, Mendis et al, 2019. Through this cross-sectional study, we observed that pulmonary TB in the Northern regions of Ghana was predominantly caused by Mtbss (241, 82.0%).…”

Is International Travel an Emerging Issue on Transmission of Beijing Lineage Mycobacterium tuberculosis?

“…However, this study was conducted among a group of Sri Lankans who travelled abroad and may not be a good representative. During 2005–2006, 14.3% BL prevalence was reported from Colombo, Sri Lanka, and in Kandy, Sri Lanka, it was 22.4% in 2012 [ 10 , 11 ]. After the end of the 30-year civil war in 2009 and attaining politicoeconomic stability, the country experienced an increase in the number of travellers/workers to and from high TB-burden countries for tourism and construction workforce.…”

“…However, there are concerns that highly virulent BL strains may get imported from the neighboring countries as was seen in Canaria Islands [ 5 ]. Therefore, there is a need to assess the current BL prevalence and monitor its trends in various geographic settings of the country [ 11 ]. In this context, we undertook a study in Kandy (a popular tourist destination) with the aim of understanding the prevalence, patient characteristics, and treatment outcomes associated with BL strains among tuberculosis patients in Kandy, Sri Lanka.…”

A pilot study on the genetic diversity of Mycobacterium tuberculosis complex strains from tuberculosis patients in the Littoral region of Cameroon

“…Although a hypothesis suggesting that lineages not previously described in a defined population earlier could be introduced by immigrants, paucity of information and data on various drug resistant genotypes especially in Africa makes this assumption difficult to prove. The introduction of new MTB strains that more transmissible and virulent and more prone to develop drug resistance has been associated with migration, (especially movement of population to bigger cosmopolitan cities in search of better health care facilities as well as employment opportunities) and can drive the current changing TB situation [67] . In the current context of globalization and population movement, this is a particular challenge in the control of drug resistant TB strains dissemination.…”