Differentiation of Mycobacterium tuberculosis isolates by spoligotyping and IS6110 restriction fragment length polymorphism

Abstract

Mycobacterium tuberculosis isolates from 167 patients attending three London hospitals were analyzed by two techniques for strain differentiation. A significant number of isolates that appeared identical with the recently developed spoligotyping system could be distinguished from each other by IS6110 restriction fragment length polymorphism analysis, with the latter technique demonstrating a generally higher level of discrimination. Spoligotyping, on the other hand, was particularly useful for analysis of isolates with low IS6110 copy numbers, and use of the two techniques in tandem provided an optimal approach to the identification of clusters with epidemiological evidence consistent with recent transmission. Spoligotyping can be applied directly to clinical samples by PCR and provides an important tool for the rapid detection of nosocomial transmission of individual strains.

Follow up of Mycobacterium tuberculosis transmission in the French West Indies by IS6110-DNA fingerprinting and DR-based spoligotyping

“…This investigation con¢rms that strain typing by two methods has a greater discriminatory ability for epidemiological purposes than by either test used alone [21]. Consequently, it is a logical follow up of a preliminary investigation in Guadeloupe [9] which described 51 patient isolates by IS6110-RFLP instead of 115 isolates from 80 patients in the present study that were typed by three methods in parallel (IS6110 and DR-RFLP, spoligotyping).…”

Comparison ofMycobacterium tuberculosisGenomes Reveals Frequent Deletions in a 20 kb Variable Region in Clinical Isolates

“…Cultures were grown in Middlebrook 7H9 medium, supplemented with albumin, dextrose and catalase (Difco). Genomic DNA was extracted from cultures in the exponential phase of growth by standard phenol–chloroform extraction, as described previously (Goyal et al ., 1997), and made up in HPLC grade water at a concentration of approximately 50 µg/ml.…”

Molecular epidemiology of tuberculosis and other mycobacterial infections: main methodologies and achievements

“…Unfortunately, a proportion of M. tuberculosis isolates contain no, or only a few, copies of IS 6110 , and this proportion differs significantly by geographical area [99, 108–110, 114–116]. Strain typing based on a low copy number of IS 6110 is not sufficiently discriminatory [46, 99, 109, 117–124], so it has been decided to apply an additional genetic typing method when M. tuberculosis isolates contain fewer than five copies of IS 6110. There are several genetic markers that can be used in addition to IS 6110 RFLP typing.…”

“…Some PCR‐based methods, such as the mixed‐linker PCR [141, 148], reveal a level of discrimination and reproducibility almost comparable with IS 6110 RFLP typing [18]. However, because of its simplicity, spoligotyping is currently a frequently used PCR typing method for M. tuberculosis complex [120, 122, 152–154]. Spoligotyping is also used as an additional typing method for strains with fewer than five copies of IS 6110 [120, 122, 154].…”