Two different betaherpesviruses, the English and Maastricht species of rat cytomegalovirus (CMV), have previously been isolated from Rattus norvegicus. CMVs were isolated from both the brown rat, R. norvegicus, and the black rat, R. rattus, within Australia. The viruses isolated from R. norvegicus appeared to be genetically related to the English species of rat CMV by PCR, RFLP, and sequencing, but the viruses isolated from R. rattus were distinct from both prototype virus species, although more closely genetically related to the Maastricht virus. This is the first genetic characterization of cytomegaloviruses from R. rattus, and the first isolation of CMVs from Australian rats.
Smith, L., Tonkin, J., Lawson, M., & Shellam, G. (2004). Isolates of cytomegalovirus (CMV) from the black rat Rattus rattus form a distinct group of rat CMV. Journal of General Virology, 85(5), 1313-1317. https://doi.org/10.1099/vir.0.79839-0