3'-TERMINAL SEQUENCE OF A SMALL ROUND STRUCTURED VIRUS (SRSV) IN JAPAN

We determined the nucleotide sequence of about 1 000 bases from the 3' -terminus of a small round structured virus (SRSV), which caused a gas troenteritis outbreak in Chiba Prefecture, Japan, in 1987. The sequenc e was compared with the corresponding sequence region of Norwalk virus ; it consisted of a part of the open reading frame 2 (ORF2), whole ORF 3, and 3'-noncoding region (NCR). The 624-base-long ORF3 had sequence homology of 68% with the corresponding region of Norwalk virus. (The a mino acid sequence homology was 74%.) The 94-base-long NCR had 65% hom ology with Norwalk virus. We then selected two consensus-sequence port ions in the above sequence between Chiba and Norwalk viruses for prime rs in the reverse transcriptase-polymerase chain reaction (RT-PCR). Us ing this primer set, we detected 669-bp bands in agarose gel electroph oresis of RT-PCR products from feces containing Chiba or Norwalk virus es. Furthermore, in Southern hybridization with Chiba probes which wer e labeled with digoxigenin-dUTP in PCR, the bands of the two viruses w ere clearly stained under a low stringency condition. Since both Chiba and Norwalk viruses were detected by the above primer set although th ey are geographically and chronologically different viruses, our prime r-pair may be useful for detection of a broad range of SRSVs which cau se gastroenteritis in different areas.