Genomic characterisation of Felis catus papillomavirus type 5 with proposed classification within a new papillomavirus genus.

Four Felis catus papillomavirus (FcaPV) types have been fully sequenced from domestic cats. Of these, FcaPV-2 and -3 are thought to cause feline viral plaques and Bowenoid in situ carcinomas. Two short sequences of DNA from a previously unreported PV type were amplified from a feline viral plaque using consensus PCR primers. DNA was then extracted from a swab of the lesion and two sets of 'outward facing' primers were designed using the short sequences to amplify the entire 7600bp genome of the novel PV. The PV was designated FcaPV-5 and contained putative coding regions that were predicted to produce five early proteins and two late ones. The ORF L1 showed over 65% similarity to that of FcaPV-3 and -4. Assignment to a genus was difficult as the PV was over 60% similar to PV types from 4 different genera. However, due to the ORF L1 similarity of FcaPV-3, -4, and -5, the shared host species of all three PVs, and the similar lesions associated with FcaPV-3 and -5, it is proposed all three PVs are classified within a new genus. FcaPV-5 is the third PV type to be associated with feline viral plaques. The plaque that contained FcaPV-5 showed unusual histological features including hyperplasia and PV-induced cell changes in sebaceous glands and deep within hair follicles. While additional study of further lesions of this type is required, it is possible that FcaPV-5 may be able to infect a broader range of cells than other PV types.