First detection of white spot syndrome virus (WSSV) and infectious hypodermal and hematopoietic necrosis virus (IHHNV) from wild-caught giant tiger prawn, Penaeus monodon Fabricius, 1798 (Penaeoidea: Penaeidae) from the Gulf of Mexico and Northwestern Atlantic Ocean

Abstract

We screened the gill and somatic muscle of 152 wild-caught invasive giant tiger prawns (GTPs), Penaeus monodon Fabricius, 1798 (Penaeoidea: Penaeidae) for infection by white spot syndrome virus (WSSV), infectious hypodermal and hematopoietic necrosis virus (IHHNV), and Taura syndrome virus (TSV) using molecular methods (PCR and qPCR) and transmission electron microscopy (TEM). The sampled GTPs comprised 1 freshly-collected specimen from Mississippi Sound (Northern Gulf of Mexico) during 2020; 54 frozen specimens originally captured from the Northern Gulf of Mexico off Mississippi, Alabama, and Florida during 2014-2016; 76 frozen specimens originally captured from the Northwestern Atlantic Ocean off North Carolina, South Carolina, Georgia, and Florida during 2014-2020; and 21 museum-accessioned specimens (19 initially ethanol-preserved; 2 initially formalin-fixed) captured from the Gulf of Mexico and Northwestern Atlantic Ocean off Florida during 1988, 2011-2013, and 2016. Molecular viral detection relied upon qPCR with TaqMan chemistry for WSSV, conventional PCR for IHHNV, and rt-PCR for Taura virus. TEM was performed on WSSV qPCR+ positive GTP gill to confirm viral infection. A total of 18 GTPs were positive for WSSV by qPCR, 1 was positive for IHHNV by conventional PCR, and none were positive for Taura virus. This is the first report of a WSSV or IHHNV infection in a wild-caught GTP from the Gulf of Mexico or Northwestern Atlantic Ocean and first detection of an IHHNV infection in a wild-caught host in the Northwestern Atlantic Ocean. The phylogenetic analyses indicated that, broadly, sympatric WSSV isolates (unless identical) do not share a recent common ancestor (they are paraphyletic), suggesting that the virus has been repeatedly translocated and introduced into the Gulf of Mexico and Northwestern Atlantic Ocean and that it originated from different localities