Detection of antibodies specific for sheeppox and goatpox viruses using recombinant capripoxvirus antigens in an indirect enzyme-linked immunosorbent assay.
Viruses in the genus Capripoxvirus, family Poxviridae, cause sheeppox, goatpox and lumpy skin disease, which are the most serious poxvirus diseases of production animals. Despite the considerable threat that these viruses pose to livestock production and global trade in sheep, goats, cattle and their products, convenient and effective serodiagnostic tools are not readily available. To develop a more effective antibody detection capability, selected open reading frames from capripoxvirus DNA were amplified and expressed in Escherichia coli as His-tagged fusion proteins. By screening 42 candidate antigens, two sheeppox virus virion core proteins that were expressed efficiently, purified readily using affinity chromatography and reactive against capripoxvirus immune sera in an indirect enzyme-linked immunosorbent assay (ELISA) were identified. The ELISA performed favourably when sera from sheep and goats infected experimentally with virulent capripoxvirus isolates were tested, with sensitivity and diagnostic specificity ranging between 95 and 97%, but it was unable to detect antibodies reliably in vaccinated sheep or goats. Furthermore, no cross-reactivity with antibodies against orf virus was detected. This assay offers the prospect of a convenient and standardised ELISA-based serodiagnostic test, with no requirement for infectious reagents, that is well suited to high-throughput capripoxvirus surveillance on a flock or herd basis.
Bowden
Timothy R
TR
CSIRO Livestock Industries, Australian Animal Health Laboratory, Geelong, Victoria 3220, Australia. timothy.bowden@csiro.au
Coupar
Barbara E
BE
Babiuk
Shawn L
SL
White
John R
JR
Boyd
Victoria
V
Duch
Christine J
CJ
Shiell
Brian J
BJ
Ueda
Norihito
N
Parkyn
Geoff R
GR
Copps
John S
JS
Boyle
David B
DB
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000235:genetics; D018151:Capripoxvirus / Q000235:genetics / Q000276:immunology*; D003001:Cloning, Molecular; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D004926:Escherichia coli / Q000235:genetics; D015511:Goat Diseases / Q000175:diagnosis* / Q000276:immunology; D006041:Goats; D011213:Poxviridae Infections / Q000175:diagnosis / Q000662:veterinary*; D011994:Recombinant Proteins / Q000235:genetics; D012680:Sensitivity and Specificity; D012756:Sheep; D012757:Sheep Diseases / Q000175:diagnosis* / Q000276:immunology
D000914:Antibodies, Viral; D000956:Antigens, Viral; D011994:Recombinant Proteins