| Title |
Shedding of Viral Hemorrhagic Septicemia Virus (Genotype IVb) by Experimentally Infected Muskellunge (Esox masquinongy) |
| Author |
Robert K. Kim1 and Mohamed Faisal1,2,3* |
| Address |
1Comparative Medicine and Integrative Biology Program, College of Veterinary Medicine, Michigan State University, MI, USA, 2Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, MI, USA, 3Department of Fisheries and Wildlife, College of Agriculture and Natural Resources, Michigan State University, MI, USA |
| Bibliography |
Journal of Microbiology, 50(2),278-284, 2012,
|
| DOI |
|
| Key Words |
viral hemorrhagic septicemia virus, genotype IVb, shedding, muskellunge, rhabdovirus |
| Abstract |
Previous experimental infection demonstrated that juvenile
muskellunge (Esox masquinongy) can survive experimental
infection of viral hemorrhagic septicemia virus, Genotype
IVb (VHSV IVb) at a low concentration of exposure. Herein
we report that survivors of experimental infection with
VHSV IVb shed the virus into the surrounding environment
for an extended period of time. When muskellunge were
exposed to VHSV IVb by immersion at a concentration of
1,400 plaque forming units (PFU)/ml, VHSV IVb was detected
in the water of surviving fish for up to 15 weeks postexposure
(p.e.) with the highest levels of shedding occurring
between weeks 1 and 5 p.e. We estimated that each juvenile
muskellunge can shed upwards of 1.36×105 PFU/fish/h after
initial exposure signifying the uptake and amplification of
VHSV to several orders of magnitude above the original
exposure concentration. Muskellunge surviving low concentration
exposure were re-infected with VHSV IVb by immersion
at week 22 p.e. at concentrations ranging from 0 to
106 PFU/ml. Viral shedding was detected in all re-exposed
fish, including mock rechallenged controls up to 15 consecutive
weeks. Rates of viral shedding were substantially higher
following rechallenge in the first 5 weeks. The highest rate
of viral shedding was approximately 4.6×106 PFU/fish/h and
shedding did not necessarily correspond to the re-exposure
VHSV concentration. The results of this study shed new
light into the dynamics of VHSV IVb shedding in a highly
susceptible host and provide useful insights to fishery managers
to design effective control strategies to this deadly
virus. |
