Detection of smallpox virus DNA by LightCycler PCR.
A 300-bp plasmid fragment of the hemagglutinin gene was used as target DNA to develop a rapid real-time LightCycler (Roche Applied Science, Indianapolis, Ind.) PCR assay for laboratory detection of smallpox virus. PCR primers and probes were designed specifically for detection of smallpox virus DNA, but all viruses of the genus Orthopoxvirus tested could be detected by use of the hemagglutinin gene target sequence. Base pair mismatches in the 204-bp amplicon allowed discrimination of cowpox virus (melting temperature [T(m)], 56.40 degrees C), monkeypox virus (T(m), 56.24 degrees C), and vaccinia virus (T(m), 56.72 degrees C), including the Dryvax vaccine strain, from smallpox virus (T(m), 62.45 degrees C) by melting curve analysis. The analytical sensitivity was 5 to 10 copies of target DNA per sample. The assay was specific for members of the genus Orthopoxvirus; the DNAs of herpes simplex virus and varicella-zoster virus were not detected by the smallpox virus LightCycler PCR.
Espy
Mark J
MJ
Division of Clinical Microbiology, Mayo Clinic and Foundation, Rochester, MN 55905, USA.
Cockerill III
Franklin R
FR
Meyer
Richard F
RF
Bowen
Michael D
MD
Poland
Gregory A
GA
Hadfield
Ted L
TL
Smith
Thomas F
TF
D000818:Animals; D002417:Cattle; D004279:DNA, Viral / Q000032:analysis*; D006389:Hemagglutinins, Viral / Q000235:genetics; D006801:Humans; D018155:Orthopoxvirus / Q000145:classification / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013997:Time Factors; D012901:Variola virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*
D004279:DNA, Viral; D006389:Hemagglutinins, Viral