Rapid diagnosis of pyrazinamide‐resistant multidrug‐resistant tuberculosis using a molecular‐based diagnostic algorithm. (16th July 2014)

• Record Type: Journal Article
• Authors: Simons, S. O.; van der Laan, T.; Mulder, A.; van Ingen, J.; Rigouts, L.; Dekhuijzen, P. N. R.; Boeree, M. J.; van Soolingen, D.; Allerberger, F.
• Is Part Of: Clinical microbiology and infection. Volume 20:Number 10(2014:Oct.)
• Page Start: 1015
• Page End: 1020
• Publication Date: 2014-07-16
• Subjects: Medical microbiology -- Periodicals; Diagnostic microbiology -- Periodicals; Communicable diseases -- Periodicals; Infection -- Periodicals; 616.01
• DOI: 10.1111/1469-0691.12696
• Languages: English
• ISSNs: 1198-743X

Abstract

<abstract abstract-type="main" id="clm12696-abs-0001"> <title>Abstract</title> <p>There is an urgent need for rapid and accurate diagnosis of pyrazinamide‐resistant multidrug‐resistant tuberculosis (MDR‐TB). No diagnostic algorithm has been validated in this population. We hypothesized that <italic>pncA</italic> sequencing added to <italic>rpoB</italic> mutation analysis can accurately identify patients with pyrazinamide‐resistant MDR‐TB. We identified from the Dutch national database (2007–11) patients with a positive <italic>Mycobacterium tuberculosis</italic> culture containing a mutation in the <italic>rpoB</italic> gene. In these cases, we prospectively sequenced the <italic>pncA</italic> gene. Results from the <italic>rpoB</italic> and <italic>pncA</italic> mutation analysis (<italic>pncA</italic> added to <italic>rpoB</italic>) were compared with phenotypic susceptibility testing results to rifampicin, isoniazid and pyrazinamide (reference standard) using the Mycobacterial Growth Indicator Tube 960 system. We included 83 clinical <italic>M. tuberculosis</italic> isolates containing <italic>rpoB</italic> mutations in the primary analysis. Rifampicin resistance was seen in 72 isolates (87%), isoniazid resistance in 73 isolates (88%) and MDR‐TB in 65 isolates (78%). Phenotypic reference testing identified pyrazinamide‐resistant MDR‐TB in 31 isolates (48%). Sensitivity of <italic>pncA</italic> sequencing added to <italic>rpoB</italic> mutation analysis for detecting pyrazinamide‐resistant MDR‐TB was 96.8%, the specificity was 94.2%, the positive predictive value was 90.9%, the negative predictive value was 98.0%, the positive likelihood was 16.8 and the negative likelihood was 0.03. In conclusion, pyrazinamide‐resistant MDR‐TB can be accurately detected using <italic>pncA</italic> sequencing added to <italic>rpoB</italic> mutation analysis. We propose to include <italic>pncA</italic> sequencing in every isolate with an <italic>rpoB</italic> mutation, allowing for stratification of MDR‐TB treatment according to pyrazinamide susceptibility.</p> </abstract>