Use of a portable real-time reverse transcriptase-polymerase chain reaction assay for rapid detection of foot-and-mouth disease virus.
OBJECTIVE
To evaluate a portable real-time reverse transcriptase-polymerase chain reaction (RT-PCR) assay designed to detect all 7 viral serotypes of foot-and-mouth disease virus (FMDV).


METHODS
Laboratory and animal studies.


METHODS
Viruses grown in tissue culture and animals experimentally infected with FMDV.


METHODS
1 steer, pig, and sheep were infected with serotype O FMDV. Twenty-four hours later, animals were placed in separate rooms that contained 4 FMDV-free, healthy animals of the same species. Oral and nasal swab specimens, oropharyngeal specimens obtained with a probang, and blood samples were obtained at frequent intervals, and animals were observed for fever and clinical signs of foot-and-mouth disease (FMD). Samples from animals and tissue cultures were assayed for infectious virus and viral RNA.


RESULTS
The assay detected viral RNA representing all 7 FMDV serotypes grown in tissue culture but did not amplify a panel of selected viruses that included those that cause vesicular diseases similar to FMD; thus, the assay had a specificity of 100%, depending on the panel selected. The assay also met or exceeded sensitivity of viral culture on samples from experimentally infected animals. In many instances, the assay detected viral RNA in the mouth and nose 24 to 96 hours before the onset of clinical disease.


CONCLUSIONS
The assay reagents are produced in a vitrified form, which permits storage and transportation at ambient temperatures. The test can be performed in 2 hours or less on a portable instrument, thus providing a rapid, portable, sensitive, and specific method for detection of FMDV.
Callahan
Johnny D
JD
Tetracore Inc, Gaithersburg, MD 20878, USA.
Brown
Fred
F
Osorio
Fernando A
FA
Sur
Jung H
JH
Kramer
Ed
E
Long
Gary W
GW
Lubroth
Juan
J
Ellis
Stefanie J
SJ
Shoulars
Katina S
KS
Gaffney
Kristin L
KL
Rock
Daniel L
DL
Nelson
William M
WM
D000818:Animals; D002417:Cattle; D005536:Foot-and-Mouth Disease / Q000097:blood / Q000175:diagnosis* / Q000821:virology; D029544:Foot-and-Mouth Disease Virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D008297:Male; D012367:RNA, Viral / Q000032:analysis* / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000295:instrumentation / Q000662:veterinary*; D012463:Saliva / Q000821:virology; D012680:Sensitivity and Specificity; D012703:Serotyping / Q000662:veterinary; D012756:Sheep; D013552:Swine; D013997:Time Factors
D012367:RNA, Viral