Nodaviruses in Wild Fish Population Collected Around Aquaculture Cage Sites from Coastal Areas of Tunisia

摘要

This report describes the viral epidemiology of wild fish adjacent to cage farms within the Tunisian coasts and isfocused on viral nervous necrosis virus (VNNV). A total of 92 apparently healthy wild marine fish were collected nearaquaculture facilities in five different coastal areas of Tunisia. The brains and eyes of fish were examined byquantitative real time reverse transcriptase-polymerase chain reaction (qRT-PCR) to detect the nodavirus coatprotein gene of. A total of 57 out of 92 (61.9%) samples were positive for nodavirus by qRT-PCR. This findingindicates that carrier fish occur at a considerable level in populations of wild marine fish. Samples from 13 fishspecies were found to be positive to the virus genome: Sarpa salpa, Trachurs trachurus, Boobs boops, Sardinellaaurita, Diplodus vulgaris, Diplodus puntazzo Liza aurata, Diplodue sargus, Sparus aurata, Sardina pilchardus,Spicara maena, Spondyliosoma cantharus, and Diplodus annularis. The partial sequences of the RNA2 coat proteingene of these strains were identical with RGNNV type previously identified within farmed sea bass and sea breamspecies in Tunisia, with a homology >97%. With respect to the proximity of the sampling sites to the coast and torearing facilities, results analysis can suggest that these viruses may be indigenous to Tunisian coastal waters.