Diagnostics and new treatment regimens for TB: can the Xpert MTB/XDR assay fill the gap for fluoroquinolone testing?

Rapid diagnosis of resistance-conferring mutations to antibiotics used for the treatment of tuberculosis (TB) is critical for patient care and public health control efforts. Prior guidelines included the use of fluoroquinolones (FQs) for the treatment of drug-resistant TB, including multidrug-resistant TB, pre-extensively drug-resistant TB, and extensively drug-resistant TB. More recently, a short-course regimen for antibiotic-susceptible TB was introduced, which includes the use of a FQ, a drug class that diagnostic algorithms in the United States (US) typically do not test for if all first-line agents are susceptible.

Diagnostic Accuracy of the Abbott SD Bioline MPT64 antigen test for identification of MTB Complex in a U.S. Clinical Mycobacteriology Laboratory.

Identification of the complex (MTBC) from culture and differentiation from other non-tuberculous mycobacterial species is required for rapid diagnosis and accurate treatment. However, gaps exist in culture-based identification of acid-fast bacilli (AFB) positive cultures for rapid rule-out of MTBC in the United States. The SD Bioline™ MPT64 (Abbott Inc, South Korea) lateral flow assay (LFA) has high sensitivity and specificity for the detection of MTBC in liquid culture but has not been evaluated in a clinical mycobacteriology laboratory in the United States.