Reverse transcription loop-mediated isothermal amplification (RT-LAMP) for rapid detection of viral hemorrhagic septicaemia virus (VHS)

A one step reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for detection of viral hemorrhagic septicaemia virus (VHS). A set of six primers were designed, based on the G-protein sequence of the VHS virus serotypes (He, F1, 23.75, Klapmolle and Rindsholm). The assay was optimised to amplify VHS RNA by incubation at 63 °C for only 1 h, and required only a simple water bath or heating block to provide a constant temperature of 63 °C. RT-LAMP amplification products were detected by visual inspection using SYBR Green I stain and had a ladder-like appearance when electrophoresed on an agarose gel. The detection limit of the RT-LAMP assay was found to be similar to the commonly used RT-PCR method: both methods detected VHS RNA at a dilution of 106. The assay was evaluated using clinical samples and the results indicated the suitability and simplicity of the test as a rapid, field diagnostic tool for VHS virus.