Diagnostic Reliability of Different RT-PCR Protocols for the Detection of Bluetongue Virus Serotype 14 (BTV-14)

INTRODUCTION: The reverse transcription polymerase chain reaction (RT-PCR) is one of the most extensively used methods for identification of animals infected with bluetongue virus (BTV). There are several RT-PCR protocols published and several real-time RT-PCR (rtRT-PCR) commercial kits available on the market. Because Poland faced BTV-14 infection in 2012, different protocols were implemented in the country to confirm the RT-PCR results positive for this virus. The article presents a comparative study of several RT-PCR protocols and discusses their diagnostic reliability and applicability. MATERIAL AND METHODS: Six rtRT-PCR/RT-PCR protocols were compared for the laboratory diagnostic of fourteen BTV-14 isolates circulating in Poland in 2012–2014. RESULTS: All 14 isolates were positive in the protocols of Shaw et al. (18), a commercial LSI NS3 kit, and Eschbaumer et al. (5). Four out of fourteen BTV-14 isolates gave positive results in Hoffmann’s 2 and 6 protocols and none of the 14 isolates yielded positive results in Maan et al. (8) method. Phylogenetic study of a short fragment of 450 nt of BTV segment 2 (258–696 positions) revealed 100% identity within Polish variants and with Russian and Spanish isolates. CONCLUSION: The paper points to the possible false negative results in the diagnosis of BTV infections depending on the protocol used.