Duplex lateral flow assay for the simultaneous detection of Yersinia pestis and Francisella tularensis

High-risk pathogens such as Francisella tularensis and Yersinia pestis are categorised as highly hazardous organisms that can be used as biological weapons. Given the extreme infectivity of these potential biowarfare agents, a rapid, sensitive, cost-effective and specific method for their detection is required. Here, we report the multiplexed amplification detection of genomic DNA from Francisella tularensis and Yersinia pestis. Amplification was achieved using isothermal recombinase polymerase amplification, exploiting tailed primers, followed by detection using a nucleic-acid lateral flow assay. Excess primers were removed using a novel fishing strategy, avoiding the use of post-amplification purification that requires centrifugation and infers additional assay cost. The entire assay is completed in less than 1 hour, achieving limits of detection of 243 fg and 4 fg for Francisella tularensis and Yersinia pestis, respectively.