Acquired rifampicin resistance during first TB treatment: magnitude, relative importance, risk factors and keys to control in low-income settings.

Background: The incidence of acquired rifampicin resistance (RIF-ADR; RR) during first-line treatment varies.

Objectives: Compare clinically significant RIF-ADR versus primary and reinfection RR, between regimens (daily versus no rifampicin in the continuation phase; daily versus intermittent rifampicin in the continuation phase) and between rural Bangladesh and Kinshasa, Democratic Republic of Congo.

Methods: From patients with treatment failure, relapse, or lost to follow-up, both the outcome and baseline sputum sample were prospectively collected for sequencing to determine whether RR was present in both samples (primary RR) or only at outcome (RIF-ADR or reinfection RR).

Pseudo-outbreak of pre-extensively drug-resistant (Pre-XDR) tuberculosis in Kinshasa: collateral damage caused by false detection of fluoroquinolone resistance by GenoType MTBDRsl.

Fluoroquinolones are the core drugs for the management of multidrug-resistant tuberculosis (MDR-TB). Molecular drug susceptibility testing methods provide considerable advantages for scaling up programmatic management and surveillance of drug-resistant TB. We describe here the misidentification of fluoroquinolone resistance by the GenoType MTBDRsl (MTBDRsl) (Hain Lifescience GmbH, Nehren, Germany) line probe assay (LPA) encountered during a feasibility and validation study for the introduction of this rapid drug susceptibility test in Kinshasa, Democratic Republic of Congo.

Rifampin drug resistance tests for tuberculosis: challenging the gold standard.

The rapid diagnosis of rifampin resistance is hampered by a reported insufficient specificity of molecular techniques for detection of rpoB mutations. Our objective for this study was to document the prevalence and prognostic value of rpoB mutations with unclear phenotypic resistance. The study design entailed sequencing directly from sputum of first failure or relapse patients without phenotypic selection and comparison of the standard retreatment regimen outcome, according to the mutation present.