Visual detection of classical swine fever virus and identification of hog cholera lapinized virus by reverse transcription loop-mediated isothermal amplification assay

ObjectiveA rapid method for visual detection of classical swine fever virus (CSFV) and identification of hog cholera lapinized virus ( HCLV ) vaccine strain by reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was established to provide technical support for clinical test of classical swine fever virus (CSFV) and identification of hog cholera lapinized virus (HCLV) vaccine strain. MethodTwo sets of specific primers were de-signed to target CSFV and HCLV based on the conserved sequences of non-structural protein NS5B gene of CSFV from GenBank. The reaction conditions LAMP assay were optimized as well as real-time measurement of turbidity by the turbidity meter LA320. ResultThe LAMP assay reaction was conducted in a 63°C water bath condition for 50 min. This method could be directly judged by the naked eyes through calcein color change results. Detection of CSFV was positive (emerald green). Detection of other common pathogens of pig was negative (orange). Specific discriminating HCLV was performed, in which the results were consistent with real-time measurement of turbidity. The detection limits of the LAMP assay to CSFV and HCLV were 100 and 101 copies, respectively. This indicated that the sensitivities of the LAMP assay to CSFV and HCLV were 100-fold and 10-fold higher than that of conventional PCR, respectively. Con-clusionRT-LAMP method is simple , sensitive , specific and can be used for rapid detection of CSFV and specific iden-tification of HCLV. It is of great significance for effective control of CSF.