Distinguishing baboon cytomegalovirus from human cytomegalovirus: Importance for xenotransplantation

The severe shortage of human organs for transplantation is the driving force behind xenotransplant research. Nonhuman primates, particularly baboons, are potential sources of organs and tissues. Human cytomegalovirus (HCMV) is the most common donor-associated infection after allotransplantation. Baboon cytomegalovirus (BCMV) is endemic in baboon populations and therefore is a potential cause of donor-associated disease after xenotransplantation. Accordingly, the ability for BCMV to grow in human cells was determined and a sensitive method to distinguish BCMV from HCMV was developed. Human fibroblasts were permissive for BCMV, isolates exhibited cytopathology characteristic of HCMV, and herpesvirus-like virions were observed by electron microscopy. BCMV and HCMV could be distinguished by restriction fragment length polymorphism patterns and by polymerase chain reaction with primers targeting the BCMV major immediate-early gene promoter. These methods can be used to evaluate BCMV pathogenicity in laboratory and clinical xenotransplant trials.