Mycobaterial interspersed repetitive units-variable number of tandem repeats analysis and pattern of drug resistance in extended drug resistant (XDR) TB isolates from pulmonary tuberculosis patients in Bangladesh
DOI:
https://doi.org/10.3329/bmrcb.v46i1.47465Keywords:
MTB strains, XDR-TB, MIRU-VNTR Typing, Line probe assayAbstract
Background: To investigate the spread of specific genotypes in a defined geographical area and to determine any relationship of these genotypes with drug resistance the most essential method is molecular typing. It allows a rapid and precise species differentiation.
Objective: This study was intended to observe the genotypes of XDR mycobacterium tuberculosis by determining 24 loci MIRU-VNTR analysis.
Methods: To gain an insight about molecular typing of MTB and drug resistance-associated mutations in XDR-TB isolates a total of 98 multi drug resistant tuberculosis (MDR-TB) isolates collected through Xpert MTB/RIF assay. They were subjected to 2nd line (Fluoroquinolones, kanamycin, capreomycin and amikacin) drug susceptibility testing through line probe assay (LPA) in a view to detect extensively drug resistant tuberculosis (XDR-TB). Genotyping was done for XDR-TB isolates using 24 loci Mycobacterial Interspersed Repetitive Units-Variable Number of Tandem Repeats (MIRU-VNTR) using the online tool at http://www.MIRU-VNTRplus.org.. Out of 98 MDR-TB isolates 11(11.23%) XDR-TB isolates were typed and analysed.
Results: Twenty four loci MIRU-VNTR genotyping involving similarity searching and phylogenetic tree analysis revealed that six (54.60%) XDR-TB isolates belonged to Beijing strain, Other MTB strain also detected were Delhi/CAS two(18.20%), Haarlem two(18.20%) and New-1, one (9.10%) in number. Minimum spanning tree analysis showed two strain of Beijing family form a clonal complex. Beijing strains were more common among younger age group and within urban population. Beijing strains were also predominant in treatment failure patient. Only one new case of XDR-TB belongs to Delhi/CAS family. Second line mycobacterial drug resistance (MTBDRsl) detected by LPA showed the most prevalent mutations involved in Fluoroquinolones drug resistance (FQ) was Asp94Gly in gyrA gene (54.55%) in quinolone resistance determining region (QRDR) and for Injectable 2nd line Drug resistance (ISL) was A1401G, C1402T in 16S rrs gene (100%).. All XDR-TB isolates showed resistance to Levofloxacin in 2nd line LPA but Moxifloxacin showed low level resistance to some cases.
Conclusion: Molecular typing of XDR- TB isolates and pattern of drug resistance associated mutations in XDR-TB isolates in Bangladesh have not been reported previously. The result of this study highlights the need to reinforce the TB policy in Bangladesh with regard to control the spread and transmission as well as detection and treatment strategies regarding XDR-TB.
Bangladesh Med Res Counc Bull 2020; 46(1): 22-28
Downloads
28
31 Online View
0
Downloads
Published
How to Cite
Issue
Section
License
Authors who publish with this journal agree to the following terms.
Authors retain copyright and grant the journal right of first publication.
Articles in the Bangladesh Medical Research Council Bulletin are licensed under a Creative Commons Attribution 4.0 International License (CC-BY) that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).
