Characterization of rabies virus isolated from bovines in Parana (Brazil) by using monoclonal antibodies

RESUMO

The identification of two antigenic variants of rabies virus in Brazil, carried out by T.J. Wiktor in 1981 from strains considered to be atypical (Hayashi et al.), as well as the isolation of vaccine virus from one rabies case in a vaccinated coati (Ohi et al.), demonstrate the importance of the studies on antigenic characterization as an indispensable tool for epidemiological surveillance. Thus, a virus strain isolated from a bovine said to be vaccinated with the ERA vaccine and that died 21 days later, as well as a virus isolate from a bovine registered as not vaccinated, were studied with a panel of 36 anti-nucleocapsid monoclonal antibodies and another of 40 anti-glycoprotein monoclonal antibodies, granted by the Wistar Institute (Philadelphia). Ons for the monoclonal antibodies, 502-3, identifies these strains as Lyssavirus, while 103-7 and 422-5 confirm them as true rabies viruses and not rabies - related viruses. The other monoclonal antibodies show minor differences in the antigenic sites III-B and V in the glycoprotein of the rabies virus isolated from the vaccinated bovine as compared with the pattern described for the ERA vaccine strain and that of the isolate from the not-vaccinated animal. It is not yet possible to assign to these differences, wich exclude the hypothesis of vaccine-induced rabies, the major role in the failure of vaccine prophylaxis. It was also showed that the ERA strain and a field strain from bovines have the same antigenic pattern. It is still necessry to characterize more strains isolated from not-vaccinated bovines and vampire bats in order to have a better basis for the comparative study with other virus strains