Hypervariable loci that enhance the discriminatory ability of newly proposed 15-loci and 24-loci variable-number tandem repeat typing method on Mycobacterium tuberculosis strains predominated by the Beijing family.
The newly proposed 15- and 24-loci mycobacterial interspersed repetitive unit (MIRU)-variable-number tandem repeat (VNTR) typing method was evaluated for its ability to differentiate 181 Mycobacterium tuberculosis Beijing family strains. Compared with the original 12-loci MIRU-VNTR typing method, the 15-loci system dramatically improved the discriminatory power for Beijing strains; however, large clusters that could be further differentiated by IS6110 restriction fragment length polymorphism (RFLP) were still obtained. The clonal stability and allelic diversity of a total of 31 VNTR loci were evaluated. VNTRs 3232, 3820, and 4120 were identified as the effective hypervariable VNTR set for the second-line typing of clustered strains following the 15-loci based scheme. Consequently, the discriminatory power of the new scheme (18 loci) equaled that of IS6110 RFLP.
Iwamoto
Tomotada
T
Department of Microbiology, Kobe Institute of Health, Kobe, Japan. kx2t-iwmt@asahi-net.or.jp
Yoshida
Shiomi
S
Suzuki
Katsuhiro
K
Tomita
Motohisa
M
Fujiyama
Riyo
R
Tanaka
Noriko
N
Kawakami
Yasuto
Y
Ito
Masahiro
M
D015373:Bacterial Typing Techniques; D002681:China; D005192:Family Health; D006801:Humans; D020071:Interspersed Repetitive Sequences / Q000235:genetics*; D018598:Minisatellite Repeats / Q000235:genetics*; D009169:Mycobacterium tuberculosis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D014376:Tuberculosis / Q000382:microbiology