Development of a serum neutralization assay to detect Pteropine Orthoreovirus Indonesia/2010 neutralizing antibodies

Pteropine Orthoreoviruses (PRVs) are fusogenic bat-borne orthoreoviruses that cause flu-like upper respiratory tract infections in humans. The presence of this group of viruses in bats and humans has been well documented in areas where their biological reservoirs - fruit bats (family Pteropodidae) - live densely. In the present study, a serum neutralization (SN) assay to detect neutralizing antibodies against PRV Indonesia/2010 isolate was set up and used to assess the seroprevalence of this virus in Italian domestic animals. The new developed assay was able of detecting PRV neutralizing antibodies in the hyper-immune polyclonal serum produced in rabbits (titer of 1:160). The negative serum was negative at all tested dilutions. No cross-reactions have been evidenced neither against reference MRVs nor against their respective hyper-immune sera. Eight hundred and fifty-three serum samples collected from 524 bovines, 271 small ruminants, and 58 horses (all used as sentinel animals in the Bluetongue and West Nile disease National surveillance program) were also tested with the new developed SN assay. According to the results of this survey, neither PRV nor PRV cross- reacting viruses antibodies have been demonstrated in Italian domestic animals. However, the new developed SN assay could be a very valuable diagnostic tool to detect infection in animals and humans.