Persistence of naturally occurring and genetically modified Choristoneura fumiferana nucleopolyhedroviruses in outdoor aquatic microcosms.
BACKGROUND
To assess the persistence of genetically modified and naturally occurring baculoviruses in an aquatic environment, replicate (three) outdoor, aquatic microcosms were spiked with spruce budworm viruses [Ireland strain of Choristoneura fumiferana multiple nucleopolyhedrovirus (CfMNPV) and the recombinant CfMNPVegt(-)/lacZ(+)] at a rate of 1.86 x 10(10) occlusion bodies (OBs) m(-2) of surface area. The presence of virus in water samples collected at various times after inoculation was determined by PCR amplification of baculoviral DNA extracted from OBs.


RESULTS
Although UV radiation rapidly degrades baculoviruses under natural conditions, both viruses persisted above the level of detection (>100 OBs 450 microL(-1) of natural pond water) for at least 1 year post-inoculation, with little difference between the viruses in their patterns of persistence.


CONCLUSIONS
The present microcosm study suggests that occlusion bodies of baculoviruses can persist in the flocculent layer of natural ponds. On disturbance, OBs could re-enter the main water column and thus be available for transport to new locations. Implications for environmental risk assessment are discussed.
Holmes
Stephen B
SB
Natural Resources Canada, Canadian Forest Service, Sault Ste. Marie, ON P6A 2E5, Canada. steve.holmes@nrcan.gc.ca
Fick
William E
WE
Kreutzweiser
David P
DP
Ebling
Peter M
PM
England
Laura S
LS
Trevors
Jack T
JT
D000818:Animals; D004279:DNA, Viral / Q000235:genetics; D005618:Fresh Water / Q000821:virology*; D050296:Microbial Viability; D009036:Moths / Q000821:virology*; D017924:Nucleopolyhedroviruses / Q000235:genetics* / Q000302:isolation & purification* / Q000502:physiology; D010572:Pest Control, Biological / Q000379:methods*
D004279:DNA, Viral