title: Characterization of extensively drug-resistant Mycobacterium tuberculosis in Nepal.
abstract: The emergence of extensively drug-resistant tuberculosis (XDR-TB) has raised public health concern for global control of TB. Although molecular characterization of drug resistance-associated mutations in multidrug-resistant isolates in Nepal has been made, mutations in XDR isolates and their genotypes have not been reported previously. In this study, we identified and characterized 13 XDR Mycobacterium tuberculosis isolates from clinical isolates in Nepal. The most prevalent mutations involved in rifampicin, isoniazid, ofloxacin, and kanamycin/capreomycin resistance were Ser531Leu in rpoB gene (92.3%), Ser315Thr in katG gene (92.3%), Asp94Gly in gyrA gene (53.9%) and A1400G in rrs gene (61.5%), respectively. Spoligotyping and multilocus sequence typing revealed that 69% belonged to Beijing family, especially modern types. Further typing with 26-loci variable number of tandem repeats suggested the current spread of XDR M. tuberculosis. Our result highlights the need to reinforce the TB policy in Nepal with regard to control and detection strategies.
authors.affiliation: Hokkaido University Research Center for Zoonosis Control, Sapporo, Japan.
authors.forename: Ajay
authors.initials: A
authors.lastname: Poudel
authors.forename: Bhagwan
authors.initials: B
authors.lastname: Maharjan
authors.forename: Chie
authors.initials: C
authors.lastname: Nakajima
authors.forename: Yukari
authors.initials: Y
authors.lastname: Fukushima
authors.forename: Basu D
authors.initials: BD
authors.lastname: Pandey
authors.forename: Antje
authors.initials: A
authors.lastname: Beneke
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Suzuki
mesh_terms: D000293:Adolescent; D000328:Adult; D015373:Bacterial Typing Techniques / Q000379:methods; D016000:Cluster Analysis; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D054908:Extensively Drug-Resistant Tuberculosis / Q000453:epidemiology / Q000382:microbiology*; D005798:Genes, Bacterial / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D008875:Middle Aged; D018598:Minisatellite Repeats / Q000235:genetics; D058885:Multilocus Sequence Typing / Q000379:methods; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000145:classification / Q000187:drug effects / Q000235:genetics*; D009390:Nepal / Q000453:epidemiology; D010802:Phylogeny; D055815:Young Adult