Detection of Bacillus Galmette-Guerin (Mycobacterium bovis BCG) DNA in Urine and Blood Specimens after Intravesical Immunotherapy for Bladder Carcinoma

A real-time PCR targeting IS6110 was employed for the detection of Mycobacterium tuberculosis DNA in specimens collected from 10 patients treated with intravesical M. bovis bacillus Galmette-Guerin (BCG) immunotherapy for bladder malignancy. BCG DNA was detected in all urine specimens taken 24 h after the instillations, as well as in 24% of the specimens collected 7 days after the instillations; it was also detected in a single specimen taken 6 weeks after the last instillation. BCG DNA was detected in 8.3% of the blood specimens taken 1 day after instillation, and its amplification was associated with cases of self-limiting fever. These findings give indications that this real-time PCR is helpful to recognize BCG bacteremic cases, which may lead to mycobacterial infection.