Increased sensitivity of the updated FluoroType MTBDR V2 with addition of IS6110 analysis

Tuberculosis (TB) remains a major global health challenge, requiring rapid, reliable molecular tests to detect the Mycobacterium tuberculosis complex (MTBC) and resistance to the drugs that cause multidrug resistance, i.e., rifampicin and isoniazid. Although many moderate-complexity automated nucleic acid amplification tests use multiple targets to improve sensitivity, previous versions of FluoroType MTBDR (FTv2old; Bruker-Hain) relied on a single MTBC DNA target, often necessitating the use of an initial multilocus MTBC assay in the workflow to achieve comparable sensitivity. This prospective head-to-head study compared FTv2old with an updated version (FTv2new) that includes the multi-copy IS6110 insertion sequence to improve MTBC detection. Using 1,483 clinical specimens from pulmonary and extrapulmonary sources, with culture and whole-genome sequencing (WGS) as reference standards, FTv2new showed a significant 17-percentage-point increase in overall sensitivity, reaching 87% compared with 70% for FTv2old (P = 0.008). The improvement was particularly notable in microscopy-negative, culture-positive samples, where the sensitivity increased from 50% to 78% (P = 0.008). Specificity remained high and comparable between versions at 99%. Because the assay's resistance-conferring targets remained unchanged, the capability for resistance profiling did not improve significantly. These findings indicate that inclusion of the IS6110 target closes the performance gap of the FluoroType platform, eliminating the need for reflex testing and streamlining laboratory workflows for high-throughput tuberculosis screening.IMPORTANCETuberculosis remains a major global health threat, and rapid, accurate diagnosis is essential for disease control. This study evaluates an updated molecular assay for detecting the Mycobacterium tuberculosis complex (MTBC). Earlier versions of this assay relied on a single genetic target and were less sensitive than competing methods. The inclusion of a multi-copy target significantly improves MTBC detection, particularly in specimens with low bacterial loads that are frequently microscopy-negative. This improvement is clinically relevant, enabling faster, more reliable diagnosis while eliminating the need for additional, time-consuming reflex testing, thereby streamlining laboratory workflows and supporting timely initiation of appropriate treatment, thereby supporting global efforts to eliminate TB.