Characterization of a herpesvirus isolated from domestic geese in Australia

A herpesvirus (GHV 552/89) associated with high mortality in a flock of dom estic geese in Australia was compared with duck virus enteritis (DVE) herpe svirus by cross-protection studies in domestic geese, Muscovy ducks and com mercial Pekin ducks. In DVE-vaccinated geese, Muscovy ducks and Pekin ducks , mortality levels of 100, 50 and 0%, respectively, were recorded following challenge with GHV 552/89. Conversely, in geese, Muscovy ducks and Pekin d ucks immunized with inactivated GHV 552/89, 100% mortality was observed in the geese and Muscovy ducks, and 80% in the Pekin ducks following challenge with DVE virus. The isolate was also compared with six other avian herpesv iruses using cross-neutralization tests in cell cultures. No detectable cro ss-neutralization occurred with any of the avian herpesviruses tested. Furt her characterization of GHV 552/89 was undertaken by comparing its genome w ith strains of DVE herpesvirus using restriction endonuclease analysis of t he viral DNA and a polymerase chain reaction (PCR) test. Following digestio n with HindIII, the DNA fragment pattern of GHV 552/89 was found to be comp letely different from the DVE viruses. Similarities were found between the digestion patterns of a UK and a US DVE isolate, but both mere distinguisha ble from a UK vaccine strain. The results of the PCR analysis and compariso n using two DVE-specific primer sets did not produce specific amplification products of expected molecular weights (603 and 446 base pairs) from the G HV 552/89 genome. The PCR products derived from the DVE strains were simila r to those derived from the DVE control DNA. From the results of this study , it is concluded that the goose herpesvirus GHV 552/89 is antigenically an d genomically distinct from DVE herpesvirus.