Utility of mycobacterial interspersed repetitive unit typing for differentiating multidrug-resistant Mycobacterium tuberculosis isolates of the Beijing family.
Mycobacterial interspersed repetitive unit (MIRU) typing has been found to allow rapid, reliable, high-throughput genotyping of Mycobacterium tuberculosis and may represent a feasible approach to study global M. tuberculosis molecular epidemiology. To evaluate the use of MIRU typing in discriminating drug-resistant M. tuberculosis strains of the Beijing genotype family, 102 multidrug-resistant (MDR) clinical isolates and 253 randomly selected non-MDR isolates collected from 2000 to 2003 in Hong Kong were subjected to 12-locus MIRU typing, spoligotyping, and IS6110 restriction fragment length polymorphism (RFLP) typing. Spoligotyping showed that 243 (68.5%) of 355 isolates belonged to Beijing family genotype. MIRU typing showed lower discrimination in differentiating between the Beijing family strains (Hunter-Gaston discriminative index [HGI] of 0.8827) compared with the IS6110 RFLP method (HGI = 0.9979). For non-Beijing strains, MIRU typing provided discrimination (HGI = 0.9929) comparable to that of the RFLP method (HGI = 0.9961). There was no remarkable difference in discrimination power between the two methods in differentiating both within and between MDR and non-MDR strains of M. tuberculosis. Dendrograms constructed with the MIRU typing data showed a clear segregation between the Beijing and non-Beijing genotype. Addition of RFLP to MIRU typing offered a higher discrimination ability (92.6%) than did addition of MIRU typing to RFLP (40.0%). This supported the potential use of this method to analyze the global genetic diversity of MDR M. tuberculosis strains that may be at different levels of evolutionary divergence.
Kam
Kai Man
KM
Tuberculosis Reference Laboratory, Public Health Laboratory Service Branch, Centre for Health Protection, Department of Health, Hong Kong Special Administrative Region, Kowloon, Hong Kong. kmkam@dh.gov.hk
Yip
Chi Wai
CW
Tse
Lai Wa
LW
Wong
Kin Lai
KL
Lam
Tak Kam
TK
Kremer
Kristin
K
Au
Betty Kam Yan
BK
van Soolingen
Dick
D
D015373:Bacterial Typing Techniques; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000032:analysis; D005838:Genotype; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D020071:Interspersed Repetitive Sequences / Q000235:genetics*; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000235:genetics; D009841:Oligonucleotides / Q000032:analysis; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D018088:Tuberculosis, Multidrug-Resistant / Q000453:epidemiology / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000382:microbiology
D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D009841:Oligonucleotides