Genetic diversity of Mycobacterium tuberculosis isolates from a tertiary care tuberculosis hospital in South Korea.
Tuberculosis (TB) remains an immense public health problem in the Republic of Korea despite a more than fivefold decrease in the prevalence of the disease over the last 3 decades. The rise in drug-resistant TB has compounded the situation. We analyzed 208 clinical isolates of M. tuberculosis from the National Masan Tuberculosis Hospital by spoligotyping, IS6110 restriction fragment length polymorphism (RFLP), and 24-locus-based mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) typing to assess the diversity and transmission dynamics of the tubercle bacilli in the Republic of Korea. The majority of the isolates (97.1%) belonged to the Beijing genotype. Cluster analysis by MIRU-VNTR yielded a low clustering rate of 22.3%, with most of the clusters comprising isolates with diverse drug resistance patterns. The discriminatory capacity of the typing methods was high for RFLP and MIRU-VNTR (allelic diversity [h] = 0.99) but low for spoligotyping (h = 0.31). Although analysis of 19 MIRU-VNTR loci was needed to achieve maximum discrimination, an informative set of 8 loci (960, 1955, 2163b, 2165, 2996, 3192, 4052, and 4348) (h = 0.98) that was able to differentiate most of the closely related strains was identified. These findings suggest that 24-locus-based MIRU-VNTR typing is a likely suitable alternative to RFLP to differentiate clinical isolates in this setting, which is dominated by M. tuberculosis Beijing strains. Within the study limits, our results also suggest that the problem of drug-resistant TB in the Republic of Korea may be largely due to acquired resistance as opposed to transmission.
Shamputa
Isdore Chola
IC
Tuberculosis Research Section, Laboratory of Clinical Infectious Disease, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
Lee
Jongseok
J
Allix-Béguec
Caroline
C
Cho
Eun-Jin
EJ
Lee
Ji-im
JI
Rajan
Vignesh
V
Lee
Eun Gae
EG
Min
Jin Hong
JH
Carroll
Matthew W
MW
Goldfeder
Lisa C
LC
Kim
Jin Hee
JH
Kang
Hyung Seok
HS
Hwang
Soohee
S
Eum
Seok-Yong
SY
Park
Seung Kyu
SK
Lee
Hyeyoung
H
Supply
Philip
P
Cho
Sang-Nae
SN
Via
Laura E
LE
Barry
Clifton E
CE
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000995:Antitubercular Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques / Q000379:methods; D016000:Cluster Analysis; D016172:DNA Fingerprinting / Q000379:methods; D004269:DNA, Bacterial / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006763:Hospitals, Chronic Disease; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D018598:Minisatellite Repeats; D017720:Molecular Epidemiology; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D012150:Polymorphism, Restriction Fragment Length; D056910:Republic of Korea; D055815:Young Adult
D000995:Antitubercular Agents; D004269:DNA, Bacterial