Abstract
Continuous studies on genetic diversity of Mycobacterium tuberculosis could enhance the awareness on transmission, control and prevention of tuberculosis (TB). In this study, we investigated current genetic diversity of TB and rifampicin resistant TB by, Restriction Fragment Length Polymorphism (RFLP) based on fingerprinting of the IS6110 insertion sequence, in the Western province of Sri Lanka, the famous touristic destination with the highest TB burden in the country. Genomic DNA extracted from susceptible and rifampicin resistant TB strains (confirmed for rpoB gene point mutations) were digested with PvuII restriction enzyme, electrophoresed and subjected to Southern transfer. The blots were hybridised with IS6110 probe and visualized using a chemiluminescence detection. The number of copies of IS6110 per isolate varied from 1 to 14. The dendrogram revealed a total of 68 distinct strains among 77 TB isolates and they belonged to nine clusters. Both rifampicin resistant and susceptible strains were distributed in all clusters. This evaluation revealed the absence of genetically identical or strong relatedness between susceptible and resistant isolates. However, clonal expansion was detected in transmission of both TB and rifampicin resistant TB. In addition, the resistant isolates having the novel mutation had no clonal relatedness. This is the first observational study regarding clonal expansion of TB in Sri Lanka. Thus, further investigation on genotypes, clonal expansion and transmission of drug resistance using additional markers would be useful for controlling TB.
Highlights
Continuous studies on genetic diversity of Mycobacterium tuberculosis could enhance the awareness on transmission, control and prevention of tuberculosis (TB)
The present study utilized the IS6110 fingerprinting to determine the genetic diversity of M. tuberculosis and rifampicinresistant M. tuberculosis isolates retrieved from primary and secondary pulmonary TB patients in Western province of Sri Lanka
The present study showed particular difference compared to previous studies as the copy numbers 3 and 4 were absent in rifampicinsensitive isolates while copy number ranging from 2-5 were absent in rifampicin-resistant isolates indicating the emergence of new isolates
Summary
Continuous studies on genetic diversity of Mycobacterium tuberculosis could enhance the awareness on transmission, control and prevention of tuberculosis (TB). We investigated current genetic diversity of TB and rifampicin resistant TB by, Restriction Fragment Length Polymorphism (RFLP) based on fingerprinting of the IS6110 insertion sequence, in the Western province of Sri Lanka, the famous touristic destination with the highest TB burden in the country. Further investigation on genotypes, clonal expansion and transmission of drug resistance using additional markers would be useful for controlling TB. Better knowledge of epidemiological situation of TB caused by different M. tuberculosis genotypes could help in revealing the source of infection and in tracking transmission routes of various strains [2]. Restriction fragment length polymorphism (RFLP), based on the variable number of IS6110 copies, is used as the genetic marker for molecular epidemiology of TB and especially M. tuberculosis strains, that may contain 025 IS6110 copies [6]. RFLP analysis of IS6110 is Adikaram et al – Clusters of M. tuberculosis strains in Sri Lanka
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
