Methods:Paraffin-blocked specimens were collected which had been diagnosed as Mycobacterium tuberculosis osteitis at five hospitals. Tests for molecular differentiation were done twice for every specimen. Real-time PCR of the IS6110 gene and SenX3-RegX3 gene was conducted in order to distinguish Mycobacterium bovis BCG from non-BCG Mycobacterium tuberculosis Complex. Real-time PCR of the 16S rRNA gene, hsp65 gene, 16S rRNA hypervariable sequence was conducted in order to distinguish MTBC from non-tuberculosis Myobacteria. Multiplex real-time PCR of the region of difference 1, 8, 14 was used for the differentiation of the Mycobacterium bovis BCG strain. Base sequencing of the Exact Tandem Repeat D between SenX3 and RegX3 was used for the identification of MTBC including the Mycobacterium bovisBCG strain. In addition, medical records of the confirmed BCG osteitis from participating hospitals were reviewed.
Results:A total of 104 specimens were collected from 49 patients. Of the 49 patients, 15 patients (30.6%) showed positive gene amplification for mycobacteria: confirmed Mycobacterium tuberculosis infection in 6 patients; probable Mycobacterium tuberculosis infection in 3 patients; probable Mycobacterium bovisBCG infection in 6 patients. Mean age at the diagnosis of the 12 patients was 20.25 months. Ten out of 12 cases received Tokyo strain BCG percutaneously. Most commonly affected site was knee joint in 6 (50.0%) of 12 patients.
Conclusion:Molecular tests that can distinguish Mycobacterium bovis BCG from Mycobacterium tuberculosis demonstrated that 40% (6/15) of the formerly diagnosed Mycobacterium tuberculosis osteitis might be BCG osteitis. The present findings suggest that BCG osteitis may be underrecognized in the countries where BCG is routinely vaccinated and molecular distinction is warranted for the cases when mycobacterial infection is suggested.
K. S. Bae,
J. H. Choi, None
E. H. Choi, None
H. J. Lee, None
J. H. Kim, None