Demonstration of homology between IS6110 of Mycobacterium tuberculosis and DNAs of other Mycobacterium spp.?

Abstract

The insertion sequence IS6110 has an important role in diagnostic PCR and typing of Mycobacterium tuberculosis. We have evaluated a one-tube nested PCR which detects IS6110. Positive results were obtained with DNAs from four of four M. tuberculosis isolates, seven of eight M. fortuitum isolates, four of seven M. avium-M. intracellulare complex isolates, four of five M. kansasii isolates, five of five M. xenopi isolates, two of four M. malmoense isolates, and two of two M. chelonei isolates. These results were confirmed by hybridization of genomic DNA from bp 505 to 685 of the IS6110 from M. tuberculosis H37Rv. Dot blot hybridization of genomic DNAs from these isolates with the same probe confirmed the presence of a homologous sequence in these mycobacterial species. These data suggest that false-positive results may be obtained for clinical samples when some methods based on IS6110 are used.

Amplification of IS6110 sequence for detection of Mycobacterium tuberculosis complex in HIV‐negative patients with fever of unknown origin (FUO) and evidence of extrapulmonary disease

“…These findings confirmed the absence of false-positive results by our PCR protocol. False-positive results have been reported for specimens containing mycobacteria other than TB (MOTT) [22,23]. The lack of HIV-positive patients in this study, who are more often infected by mycobacteria of other species, may explain the absence of false-positive results.…”

False positive diagnosis of meningococcal infection by the IS1106 PCR ELISA

“…Cimolai and Trombley [8] were able to use IS primers, originally intended for the rapid diagnosis of Bordetella pertussis respiratory infection, to di¡erentiate strains of Burkholderia (Pseudomonas) cepacia. False positives were also demonstrated by a nested IS6110 based PCR for the detection of Mycobacterium tuberculosis when applied to mycobacteria that did not belong to the M. tuberculosis complex [9]. More recently, ampli¢ed DNA from Aspergillus spp., Streptococcus pneumoniae and S. pyogenes was found to hybridise to a probe derived from a 181-bp fragment of M. tuberculosis IS6110 [10].…”

The application of molecular techniques to the diagnosis and epidemiology of mycobacterial diseases

“…This may account for the results obtained by Kent et al (1995) who used a one tube nested PCR for IS6110 and primers in the 505-685 bp region (Wilson et a/. 1993).…”