Specific differentiation between Mycobacterium bovis BCG and virulent strains of the Mycobacterium tuberculosis complex.
A PCR procedure based on the intergenic region (IR) separating two genes encoding a recently identified mycobacterial two-component system, named SenX3-RegX3, was developed and was shown to be suitable for identifying Mycobacterium bovis BCG. The senX3-regX3 IR contains a novel type of repetitive sequence, called mycobacterial interspersed repetitive units (MIRUs). All tested BCG strains exclusively contained 77-bp MIRUs within the senX3-regX3 IR, whereas all non-BCG M. tuberculosis complex strains contained a 53-bp MIRU, in addition to the 77-bp MIRUs. All 148 strains analyzed so far could be divided into eight different groups according to the copy numbers of the 77-bp MIRU and to the presence or absence of the 53-bp MIRU. BCG strains contained either one, two, or three 77-bp MIRUs. The other strains contained one to five 77-bp MIRUs invariably followed by a 53-bp MIRU. The consistent absence of the 53-bp MIRU in BCG strains and its presence in virulent strains allowed us to develop an enzyme-linked immunosorbent assay using specific capture oligonucleotide probes to distinguish between BCG and other M. tuberculosis complex strains.
Laboratoire de Microbiologie Génétique et Moléculaire, INSERM U447, Institut Pasteur de Lille, F-59019 Lille Cedex, France.
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J
Magdalena
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P
Supply
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C
Locht
D000595:Amino Acid Sequence; D000818:Animals; D001500:BCG Vaccine; D001483:Base Sequence; D002417:Cattle; D017931:DNA Primers; D004797:Enzyme-Linked Immunosorbent Assay; D006041:Goats; D008969:Molecular Sequence Data; D009163:Mycobacterium bovis / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D009693:Nucleic Acid Hybridization; D009876:Operon; D016133:Polymerase Chain Reaction / Q000379:methods*; D012091:Repetitive Sequences, Nucleic Acid; D014774:Virulence
D001500:BCG Vaccine; D017931:DNA Primers