A novel real-time PCR approach for detection of infectious hypodermal and haematopoietic necrosis virus (IHHNV) in the freshwater crayfish Procambarus clarkii

[Display omitted] •A novel SYBR Green-based RT PCR method specifically amplifies IHHNV.•This method showed no cross reaction with the other five pathogens.•The assay can detect one single copy of IHHNV plasmid DNA.•80% of IHHNV-fed Procambarus clarkii samples were IHHNV positive.•IHHNV can heavily infect the gill of P. clarkii. Infectious hypodermal and haematopoietic necrosis virus (IHHNV) infects many crustacean hosts, including cultured penaeid shrimp. In the present study, we aimed to develop a novel sensitive SYBR Green-based real-time PCR method to specifically amplify DNA fragments of IHHNV. Our newly developed real-time PCR method with a 195-bp amplicon specifically detected IHHNV and showed no cross reaction with white spot syndrome virus (WSSV), hepatopancreatic parvovirus (HPV), Enterocytozoon hepatopenaei (EHP), infectious myonecrosis virus (IMNV) and yellow-head virus (YHV). This method could detect as low as one single copy of IHHNV plasmid DNA, more sensitive than other SYBR Green-based real-time PCR methods and less expensive and more convenient than the TaqMan probe-based real-time PCR. Moreover, our data using the newly designed method showed that 80% of IHHNV-fed Procambarus clarkii samples were IHHNV positive. Our findings further confirmed that P. clarkii can be infected by IHHNV.