PMID- 15472293
OWN - NLM
STAT- MEDLINE
DCOM- 20041223
LR  - 20191210
IS  - 0095-1137 (Print)
IS  - 1098-660X (Electronic)
IS  - 0095-1137 (Linking)
VI  - 42
IP  - 10
DP  - 2004 Oct
TI  - Detection of U.S., Lelystad, and European-like porcine reproductive and 
      respiratory syndrome viruses and relative quantitation in boar semen and serum 
      samples by real-time PCR.
PG  - 4453-61
AB  - Transmission of porcine reproductive and respiratory syndrome virus (PRRSV) via 
      boar semen has been documented. Since semen is widely disseminated for artificial 
      insemination and the virus can cause significant health and economic 
      consequences, it is essential to have well-validated, rapid diagnostic techniques 
      to detect and quantitate the virus for diagnostic and research purposes. 
      Previously, boar semen was tested by a nested PCR (nPCR) assay which was compared 
      to the "gold standard" swine bioassay. A correlation of 94% was observed, 
      indicating that, most of the time, PCR detected infectious virus. Subsequently, a 
      real-time PCR targeting the 3' untranslated region of the PRRSV genome was 
      compared with nPCR by testing 413 serum and semen samples from PRRSV-inoculated 
      and control boars. There was 95% agreement between the results of the two tests, 
      with the majority of samples with discordant results containing virus at the 
      lower range of detection by the assays. The virus in all samples was quantitated 
      by using a standard curve obtained by serial dilution of an in vitro transcript. 
      By using the in vitro transcript, the lower limit of sensitivity was observed to 
      be approximately 33 copies/ml. Reactivity with a panel of more than 100 PRRSV 
      isolates from various geographical regions in the United States was also 
      documented. No reactivity with nine nonrelated swine viruses was noted. A 
      real-time PCR was also developed for the detection of the European Lelystad virus 
      and the European-like PRRSV now found in the United States. In six of six 
      PRRSV-inoculated boars, peak levels of viremia occurred at 5 days postinoculation 
      (DPI) and were most consistently detectable throughout 22 DPI. In five of six 
      boars, PRRSV was shed in semen for 0 to 2 days during the first 10 DPI; however, 
      one of six boars shed the virus in semen through 32 DPI. Therefore, in general, 
      the concentration and duration of PRRSV shedding in semen did not correlate with 
      the quantity or duration of virus in serum. These differences warrant further 
      studies into the factors that prevent viral replication in the reproductive 
      tract.
FAU - Wasilk, A
AU  - Wasilk A
AD  - Department of Veterinary Science, South Dakota State University, Brookings, South 
      Dakota 57007-1396, USA.
FAU - Callahan, J D
AU  - Callahan JD
FAU - Christopher-Hennings, J
AU  - Christopher-Hennings J
FAU - Gay, T A
AU  - Gay TA
FAU - Fang, Y
AU  - Fang Y
FAU - Dammen, M
AU  - Dammen M
FAU - Reos, M E
AU  - Reos ME
FAU - Torremorell, M
AU  - Torremorell M
FAU - Polson, D
AU  - Polson D
FAU - Mellencamp, M
AU  - Mellencamp M
FAU - Nelson, E
AU  - Nelson E
FAU - Nelson, W M
AU  - Nelson WM
LA  - eng
PT  - Evaluation Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Clin Microbiol
JT  - Journal of clinical microbiology
JID - 7505564
RN  - 0 (RNA, Viral)
SB  - IM
MH  - Animals
MH  - Male
MH  - Polymerase Chain Reaction/*methods
MH  - Porcine Reproductive and Respiratory Syndrome/*virology
MH  - Porcine respiratory and reproductive syndrome virus/genetics/*isolation & 
      purification
MH  - RNA, Viral/*blood/isolation & purification
MH  - Reproducibility of Results
MH  - Semen/*virology
MH  - Sensitivity and Specificity
MH  - Sus scrofa/*virology
MH  - Swine Diseases/virology
MH  - Viral Load
PMC - PMC522289
EDAT- 2004/10/09 09:00
MHDA- 2004/12/24 09:00
PMCR- 2004/10/01
CRDT- 2004/10/09 09:00
PHST- 2004/10/09 09:00 [pubmed]
PHST- 2004/12/24 09:00 [medline]
PHST- 2004/10/09 09:00 [entrez]
PHST- 2004/10/01 00:00 [pmc-release]
AID - 42/10/4453 [pii]
AID - 0144-04 [pii]
AID - 10.1128/JCM.42.10.4453-4461.2004 [doi]
PST - ppublish
SO  - J Clin Microbiol. 2004 Oct;42(10):4453-61. doi: 10.1128/JCM.42.10.4453-4461.2004.