Presence of porcine cytomegalovirus, a porcine roseolovirus, in wild boars in Italy and Germany

Abstract

Porcine cytomegalovirus (PCMV), a porcine roseolovirus (PRV) that is closely related to human herpesviruses 6 and 7, is commonly found in commercial pigs. PCMV/PRV is important in xenotransplantation, because in preclinical trials in which pig organs were transplanted into non-human primates, transmission of PCMV/PRV was shown to be associated with significantly reduced survival of the xenotransplants. PCMV/PRV was also transmitted in the first transplantation of a pig heart into a human patient worldwide and apparently contributed to the death of the patient. The prevalence of PCMV/PRV in wild boars is largely unknown. In this study, we screened wild boars from several areas of northern Italy and Germany to test for the presence of PCMV/PRV using PCR-based and Western blot assays. By Western blot analysis, 54% and 82% of Italian and German wild boars, respectively, were found to be PCMV/PRV positive, while 36% and 60%, respectively, tested positive by real-time polymerase chain reaction (PCR). These data indicate that the virus is common in German and Italian wild boars and that the Western blot assay detected a PCMV/PRV infection more often than did real-time PCR. The data also indicate that pigs raised for xenotransplantation should be protected from contact with materials from wild boars and commercial pigs.

Fig. 1

(A) Results of Western blot analysis of sera from German and Italian (Euganean Hills) wild boars using the recombinant fragment R2 of the gB of PCMV/PRV as an antigen. P, positive control. German pigs 4, 5, and 8 and Italian pig 2 were negative, and all other animals were positive. (B) Titration of the serum from a wild boar from the Euganean Hills against the recombinant fragment R2 of the gB of PCMV/PRV. P, positive control. (C) Repetition of the testing of the German sera 1, 2, 3, 6, and 7 using a higher concentration of polyacrylamide in the gel (17% instead of 12%) and a higher concentration of serum (a 1:150 dilution instead of 1:300).