Isolation of avian pneumovirus from an outbreak of respiratory illness in Minnesota turkeys

Antibodies to avian pneumovirus (APV) were first detected in Minnesota turk eys in 1997. Virus isolation was attempted on 32 samples (28 tracheal swabs , 4 pools of trachea and turbinates) that were positive for APV by reverse transcriptase polymerase chain reaction (RT-PCR). The cell cultures used we re chicken embryo fibroblast (CEF), Vero cells, and QT-35 cells. Five virus isolates were obtained from these samples, and the identity of the isolate s was confirmed by RT-PCR. Four isolates were obtained by inoculation of CE F cells, and 1 isolate was obtained in QT-35 cells after 3-7 blind passages in cell cultures. Vero cells did not yield any isolate on primary isolatio n; however, all 5 isolates could be adapted to grow in Vero cells following primary isolation in CEF or QT-35 cells. This is the first report of isola tion of APV in Minnesota and also the first report of primary isolation of APV in QT-35 cells.