Persistence and Retention of Porcine Reproductive and Respiratory Syndrome Virus in Stable Flies (Diptera: Muscidae).
We investigated the acquisition of porcine reproductive and respiratory syndrome (PRRS) virus by the stable fly (Diptera: Muscidae; Stomoxys calcitrans (L.)) through a bloodmeal, and virus persistence in the digestive organs of the fly using virus isolation and quantitative reverse-transcription PCR (qRT-PCR). Stable flies were fed blood containing live virus, modified live vaccine virus, chemically inactivated virus, or no virus. Stable flies acquired PRRSV from the bloodmeal and the amount of virus in the flies declined with time, indicating virus did not replicate in fly digestive tissues. Virus RNA was recovered from the flies fed live virus up to 24 h postfeeding using virus isolation techniques and 96 h using qRT-PCR. We further examined the fate of PRRSV in the hemolymph of the flies following intrathoracic injection to bypass the midgut barrier. PRRSV was detected in intrathoracically inoculated adult stable flies for 10 d using qRT-PCR. In contrast to what we observed in the digestive tract, detectable virus quantities in the intrathoracically inoculated stable flies followed an exponential decay curve. The amount of virus decreased fourfold in the first 3 d and remained stable thereafter, up to 10 d.
University of Manitoba, 214 Entomology Bldg., Winnipeg, Manitoba, Canada, R3T 2N2. kateryn.rochon@umanitoba.ca.
K
K
Rochon
Iowa State University, College of Veterinary Medicine, PO Box 3020, Ames, IA 50010.
R B
RB
Baker
North Carolina State University, College of Veterinary Medicine, 4700 Hillsborough St., Raleigh, NC 27606.
G W
GW
Almond
North Carolina State University, College of Veterinary Medicine, 4700 Hillsborough St., Raleigh, NC 27606.
I M
IM
Gimeno
Knipling-Bushland US Livestock Insects Research Laboratory, 2700 Fredericksburg Rd., Kerrville, TX 78028-1984.
A A
AA
Pérez de León
North Carolina State University, College of Agriculture and Life Sciences, 1111 Grinnells Laboratory, Campus Box 7626, Raleigh, NC 27695-7626.
D W
DW
Watson
D000818:Animals; D007303:Insect Vectors / Q000821:virology*; D009117:Muscidae / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000502:physiology*; D012367:RNA, Viral / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014779:Virus Replication
D012367:RNA, Viral
Stomoxys calcitrans; intrathoracic inoculation; midgut barrier; virus persistence