Background: Mycobacterium abscessus is an important pathogen that has been increasingly associated with many clinical and nosocomial infections. A reliable molecular typing scheme is essential for the epidemiological study of this rapidly growing mycobacterium. Pulsed-field gel electrophoresis (PFGE), considered to be the gold standard among molecular typing methods, has failed to provide satisfactory results in the molecular typing of this bacterium. A newly developed molecular typing method, infrequent-restriction-site polymerase chain reaction (IRS-PCR), was examined in this study to determine its suitability for fingerprinting M. abscessus isolates.
Methods: Eight clinical isolates of M. abscessus and two reference strains (M. abscessus ATCC 19977 and M. chelonae ATCC 35749) were studied by DNA macrorestriction analysis with XbaI resolved by PFGE, and IRS-PCR assay with adaptors designed for XbaI and HhaI restriction sites.
Results: By PFGE, different banding patterns were found in two clinical isolates of M. abscessus; the other isolates yielded only broken DNA and could not be assessed. By IRS-PCR, unique patterns were noted for the 10 isolates; the 10 appeared to be genetically different.
Conclusion: IRS-PCR may be an efficient substitute for PFGE in analyzing the DNA polymorphism and epidemiology of M. abscessus.