MOLECULAR CHARACTERIZATION OF CAMBERWELL VIRUS AND SEQUENCE VACATION IN ORF3 OF SMALL ROUND-STRUCTURED (NORWALK-LIKE) VIRUSES

Five small round-structured viruses (SRSVs) associated with gastroente ritis in Victoria, Australia, from January to November 1994 were exami ned by sequencing cDNA prepared from faecal samples using RT-PCR. The sequence of the 3' half (3.8 kb) of the genome of one of these viruses , Camberwell, was determined. Camberwell virus was related most closel y to Bristol and Lordsdale viruses, and belonged to the genetic group of SRSVs containing Bristol, Lordsdale, Toronto, OTH-25, Mexico, and H awaii viruses. The amino acid identities between Camberwell and Bristo l viruses for proteins encoded by ORF1 (partial), ORF2, and ORF3 were 99%, 98%, and 90%, respectively. A highly variable region in ORF3 corr esponding to amino acid residues 123 to 169 (Bristol and Camberwell nu mbering) were identified. Short segments of ORF1 (polymerase region) a nd the highly variable ORF3 region was analysed for the other four vir uses. The results obtained indicated the potential usefulness of the v ariable region in distinguishing between closely related viruses. (C) 1996 Wiley-Liss, Inc.