Evaluation of the draft Australian and New Zealand standard diagnostic procedure (ANZSDP) for PCR-detection of betanodaviruses

Abstract

Several Australian betanodaviruses (NNVs) and other, exotic NNVs were used in a study of the performance of a nested PCR test in common use in Australia and New Zealand. This test for the detection of NNVs, designated the ANZSDP VNN Nested PCR, was compared with a currently available commercial PCR kit for NNV detection. With respect to the endemic viruses, the ANZSDP was pan-specific for the NNVs tested, while the commercial PCR kit failed to detect the South Australian strain of barramundi Lates calcarifer NNV. With respect to the relative sensitivities of the two tests, in general, the ANZSDP appeared more sensitive than the commercial test. The exception was the Australian bass Macquaria novemaculeata NNV isolate, which was detected at lower levels by the commercial test. Among the exotic NNVs, both tests detected red-spotted grouper nervous necrosis virus and barfin flounder nervous necrosis virus, but neither test detected striped jack nervous necrosis virus (SJNNV). Further investigation revealed mismatches between SJNNV sequences and the nested primers used in the ANZSDP.