RABIES VARIANTS CIRCULATING IN ARGENTINA ISOLATED IN NEUROBLASTOMA CELLS

LA ROSA, I.; PRESTERA, N. E.; DÍAZ PÉREZ, P. M.; PANOZO, R.; CARABALLO, D. A.; TEALDO, M. S.; BELTRÁN, F. J.; GURY DOHMEN, F. E.

Buenos Aires

Congreso; XXIX Rabies in the Americas; 2018

Rabies is a major public health problem in our country. It is a fatal encephalitis, caused by a highly neurotropic RNA virus, genus Lyssavirus, family Rhabdoviridae. Detection of rabies antigen in brain tissue by the Fluorescent antibody test (FAT) technique remains the gold standard for diagnosis.Also, a confirmatory test in which amplification of the virus is performed in a biological system is needed for a definitive rabies diagnosis. Traditionally, mouse inoculation test (MIT) has been used with high concordance. A disadvantage is that this technique involves the use of laboratory animals.Cell culture isolation test (RCIT) is an alternative that avoids this issue. The World Organization for Animal Health (OIE) recommends to test cell sensitivity for the virus variants circulating in the area.In this sense, our objective was to analyze the cell culture isolation of different variants found in Argentina from different species. Neuroblastoma cells were cultured in MEM 10 at 37°C in 5% CO2 humidified atmosphere. Brain tissue homogenates were centrifuged. Supernatants were coincubated with cell suspension (2 x 105 cell/ml) and seeded in a 96 well plate and incubated for 96 hours. Cells were fixed and stained with FITC-antinucleocapsid antibody. Rabies variants were determined by monoclonal antibody panel and sequencing. During 2015-2018 a total of 95 FAT positive samples were isolated by RCIT from dogs (V1 and V2), cats (V1 and V4), cows (V3a), and insectivorous bats (V4, V6, Eptesicus, Histiotus and Myotis). These results indicate that the variants circulating more frequently in Argentine could be detected by the isolation test in neuroblastoma cells. This is of major importance to establish RCIT as confirmatory test and to encourage other laboratories in our country. It is notable that cell isolation is a useful tool not only for diagnosis but also for research.