Development of a Loop-Mediated Isothermal Amplification Assay for the Detection of Dickeya spp

Dickeya and Pectobacterium spp. are responsible for soft-rotting diseases of several plant species, some with overlapping host range. On potato, symptoms caused by these pathogens cannot be clearly differentiated. Disease results in the downgrading and rejection of potato seed, thus requiring additional phytosanitary restrictions across Northern Europe and other parts of the world. In an effort to provide a more timely and accurate diagnostic to distinguish these two groups of pathogens, a method for detecting Dickeya spp. using loop-mediated isothermal amplification (LAMP) was developed. The LAMP assay can be used to test crude extracts prepared directly from symptomatic lesions. The entire test can be completed in less than 30 min, making it faster than the current diagnostic standard, the pelADE conventional polymerase chain reaction. Additionally, the LAMP assay was able to detect Dickeya DNA in samples spiked with varying amounts of Pectobacterium DNA, thus demonstrating the highly specific and sensitive nature of the assay, which can be applied on survey samples with mixed soft-rotting bacterial populations.