The Isolation and Cell Culture Adaptation of a Hantaan-related Virus from a Rattus norvegicus captured in Houston, Texas

Abstract

Recent aerological surveys conducted in Philadelphia, PA and Houston, TX presented evidence that a Hantaan (HTN)-related agent was present among wild Rattus populations of the United States. A virus isolated from a Rattus norvegicus live trapped in Philadelphia, PA was shown to be closely related to but distinct from HTN virus by immunofluorescent antibody tests (IFAT) and plaque reduction neutralization tests (PRNT). The current study was undertaken to determine whether the agent circulating among wild Rattus populations of Houston, TX was similarly related to HTN virus. Serum and organs of six Rattus norvegicus collected during earlier studies in Houston were examined by IFAT for evidence of recent infection by a HTN-like agent. A HTN-like virus was isolated from antibody and antigen positive wild-caught rats by intramuscular inoculation of infected lung sus-suspension into Wistar rats. The agent was adapted to growth in vitro by co-cultivation of infected lung suspension with Vero E-6 cells. The virus recovered from these animals was found to be closely related to HTN virus by IFAT but clearly distinct by PRNT. Monoclonal antibodies confirmed these findings and indicated that the virus isolated from Houston TX was antigenically distinct from the Girard Point virus strain isolated from Philadelphia, PA.