First comparison of French and Australian OsHV-1 mu vars by bath exposure
|Author(s)||Burge Colleen A.1, Reecez Kimberly S.2, Dhar Arun K.3, Kirkland Peter4, Morga Benjamin5, Degremont Lionel5, Faury Nicole5, Wippel Bryanda J. T.6, Macintyre Alanna2, Friedman Carolyn S.6|
|Affiliation(s)||1 : Univ Maryland Baltimore Cty, Inst Marine & Environm Technol, 701 E Pratt St, Baltimore, MD 21202 USA.
2 : William & Mary, Virginia Inst Marine Sci, POB 1346, Gloucester Point, VA 23062 USA.
3 : Univ Arizona, Sch Anim & Comparat Biomed Sci, Aquaculture Pathol Lab, 1117 E Lowell Rd, Tucson, AZ 85721 USA.
4 : NSW Dept Primary Ind, Elizabeth Macarthur Agr Inst, Menangle, NSW 2568, Australia.
5 : IFREMER, RBE SG2M LGPMM, Stn La Tremblade, La Tremblade 17390, France.
6 : Univ Washington, Sch Aquat & Fishery Sci, Box 355020, Seattle, WA 98195 USA.
|Source||Diseases Of Aquatic Organisms (0177-5103) (Inter-research), 2020 , Vol. 138 , P. 137-144|
|WOS© Times Cited||2|
|Keyword(s)||Ostreid herpesvirus 1, Microvariant, OsHV-1 mu vars, POMS, Pacific oyster, Crassostrea gigas, Viral disease, qPCR, Alkalinity, Emerging infectious diseases|
Economically devastating mortality events of farmed and wild shellfish due to infectious disease have been reported globally. Currently, one of the most significant disease threats to Pacific oyster Crassostrea gigas culture is the ostreid herpesvirus 1 (OsHV-1), in particular the emerging OsHV-1 microvariant genotypes. OsHV-1 microvariants (OsHV-1 mu vars) are spreading globally, and concern is high among growers in areas unaffected by OsHV-1. No study to date has compared the relative virulence among variants. We provide the first challenge study comparing survival of naive juvenile Pacific oysters exposed to OsHV-1 mu vars from Australia (AUS mu var) and France (FRA mu var). Oysters challenged with OsHV-1 mu vars had low survival (2.5%a exposed to AUS mu var and 10% to FRA mu var), and high viral copy number as compared to control oysters (100% survival and no virus detected). As our study was conducted in a quarantine facility located similar to 320 km from the ocean, we also compared the virulence of OsHV-1 mu vars using artificial seawater made from either facility tap water (3782 mu mol kg(-1) seawater total alkalinity) or purchased distilled water (2003 mu mol kg(-1)). Although no differences in survival or viral copy number were detected in oysters exposed to seawater made using tap or distilled water, more OsHV-1 was detected in tanks containing the lower-alkalinity seawater, indicating that water quality may be important for virus transmission, as it may influence the duration of viral viability outside of the host.