CASE REPORTS
JOURNAL ARTICLE
Add like
Add dislike
Add to saved papers

Ruptured aortic aneurysm due to Mycobacterium bovis BCG with a delayed bacteriological diagnosis due to false negative result of the MPB 64 immunochromatographic assay.

BMC Research Notes 2017 January 27
BACKGROUND: Adjuvant therapy with bacillus Calmette-Guerin (BCG), a live attenuated strain of Mycobacterium bovis, has become the treatment of choice for low-risk superficial bladder carcinoma following transurethral resection of the bladder. Complications following vesical BCG instillations are uncommon but, in some cases, severe side-effects can occur such as sepsis or mycotic aneurysm. Besides usual laboratory techniques used for the diagnosis of Mycobacterium tuberculosis complex (MTBC) infections (smear microscopy and cultures), commercial immunochromatographic assays detecting MBP64, a 24 kDa M. tuberculosis complex-specific secretory protein, can rapidly distinguish MTBC and non-tuberculosis mycobacteria (NTM). MPB64 is found in M. tuberculosis, M. bovis and some but not all substrains of M.bovis BCG. Therefore, these immunochromatographic tests can lead to false negative results and delayed bacteriological diagnosis depending on the presence or absence of MPB64 protein in BCG substrains used for intravesical therapy.

CASE PRESENTATION: We report the case of a 78-year-old male patient who was admitted to the hospital because of a 1-month history of unexplained fever, thrill, weight-loss and general malaise. His past medical history was marked by a non-muscle-invasive bladder carcinoma treated by transurethral resection followed by BCG instillations (Oncotice, Merck, USA). The patient was initially treated for a urinary tract infection but as fever persists after 72 h of antibiotherapy, urinary tract ultrasound was performed and revealed a large abdominal aortic aneurysm confirmed by computed tomography. Surgery was performed after multidisciplinary discussion. Direct smear of perioperative samples revealed acid-fast bacilli and both solid and liquid cultures were massively positive. Rapid identification of the positive mycobacterial culture was performed using an immunochromatographic assay based on the detection of the Mycobacterium tuberculosis MPB 64 antigen. The result was negative for Mycobacterium tuberculosis complex. After review of the medical record, a polymerase chain reaction (PCR) was performed and gave a positive result for M. tuberculosis complex. Anti-tuberculosis therapy was started immediately and the patient evolved favorably.

CONCLUSIONS: Through this case, we showed how the utilisation of MPB64 immunochromatographic assays can provide misleading information due to the variable presence of this protein among the different BCG strains. This case further illustrates the utility of rapid TB complex-specific PCR assays which provide a more reliable identification of all MTBC species.

Full text links

We have located links that may give you full text access.
Can't access the paper?
Try logging in through your university/institutional subscription. For a smoother one-click institutional access experience, please use our mobile app.

For the best experience, use the Read mobile app

Mobile app image

Get seemless 1-tap access through your institution/university

For the best experience, use the Read mobile app

All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.

By using this service, you agree to our terms of use and privacy policy.

Your Privacy Choices Toggle icon

You can now claim free CME credits for this literature searchClaim now

Get seemless 1-tap access through your institution/university

For the best experience, use the Read mobile app