RAPID DETECTION OF VESICULAR STOMATITIS-VIRUS NEW-JERSEY SEROTYPE IN CLINICAL-SAMPLES BY USING POLYMERASE CHAIN-REACTION

Vesicular stomatitis virus of the New Jersey serotype (VSV-NJ) causes vesicular disease in cattle, pigs, and horses throughout the Americas. Vesicular disease is clinically indistinguishable from foot-and-mouth disease (FMD). Therefore, outbreaks of vesicular disease in FMD-free areas must be rapidly diagnosed by laboratory methods and affected far ms must be quarantined until laboratory results confirm the absence of FMD. Diagnosis is currently performed in high-containment (biosafety level 3) laboratories by using complement fixation and virus isolation in tissue culture. We describe here an alternative method for the det ection of VSV-NJ RNA in clinical samples. This method includes a rapid acid guanidine-phenol RNA extraction procedure coupled with a one-tub e polymerase chain reaction (PCR) using reverse transcriptase. By usin g this test, we were able to detect the largest number of positive sam ples (53 of 58), followed by complement (48 of 58) and isolation in ti ssue culture (43 of 58). The primers chosen for this assay amplify a 6 42-nucleotide region of the phosphoprotein gene of VSV-NJ but not of V SV-IN. Sequencing of the PCR product enables genetic typing of virus i solates and epidemiological studies. Since no infectious materials are necessary to perform this test and any infectious virus in clinical s amples is destroyed by acid guanidine-phenol treatment, diagnosis can be safely performed in regular diagnostic laboratories.