Evaluation of Two Real-Time, TaqMan Reverse Transcrip-tion-PCR Assays for Detection of Rabies Virus in Circulating Variants from Argentina: Influence of Sequence Variation

CARABALLO, D. A.; LOMBARDO, M. A.; BECKER, P.; SABIO, M. S.; LEMA, C.; MARTINEZ, L. M.; BELTRÁN, F. J.; LI, Y.; CISTERNA, D. M.

Viruses

MDPI

Lugar: Basel; Año: 2020 vol. 13 p. 1 - 23

In rabies diagnosis, it is essential to count on a rapid test to give a quick response. The combined sensitivity and robustness of the TaqMan RT-PCR assays (qRT-PCR) have made these methods a valuable alternative for rabies virus (RABV) detection. We conducted a study to compare the ap-plicability of two widely used qRT-PCR assays targeting the nucleoprotein gene (LysGT1 assay) and leader sequences (LN34 qRT-PCR assay) of RABV genomes, in all variants circulating in Ar-gentina. A total of 44 samples obtained from bats, dogs, cattle, and horses, that were previously tested for rabies by FAT and conventional RT-PCR, were used in the study. All variants were successfully detected by the pan-lyssavirus LN34 qRT-PCR assay. The LysGT1 assay failed to de-tect three bat-related variants. We further sequenced the region targeted by LysGT1 and demon-strated that the presence of three or more mismatches with respect to the primers and probe se-quences precludes viral detection. We conclude that the LysGT1 assay is prone to yield vari-ant-dependent false-negative test results, and in consequence, the LN34 assay would ensure more effective detection of RABV in Argentina.