Rare group a rotavirus P[9]G3 isolated in Nara Prefecture, Japan.

*Corresponding author: Mailing address: Virology and Bacteriology Division, Nara Prefectural Institute for Hygiene and Environment, Ohmori-cho 57-6, Nara 630-8131, Japan. Tel: +81742-20-2887, Fax: +81-742-27-0634, E-mail: [email protected]. nara.jp The serotypes of rotavirus are determined by neutralization epitopes in their outer capsid proteins, VP4 and VP7. In the past 5 years, we have conducted P (VP4) and G (VP7) serotype determinations and have reported in previous works the patterns of rotavirus epidemics in Nara Prefecture (1,2). The present report describes the case of a rare P[9]G3 type A rotavirus strain showing the sequence in the VP7 region. It was isolated in Nara Prefecture and was named Nara/2003/12. The patient, a male infant aged 1 year and 11 months living in Nara City, developed severe vomiting, diarrhea and a fever of 39°C on March 1, 2003. No other family members showed similar symptoms. Determination of the Pand Gtypes of rotavirus isolated from a fecal specimen was conducted by reverse transcriptase-polymerase chain reaction (RT-PCR) using type-specific primers reported previously (1,2), and a P[9]G3 type rotavirus was identified. To determine the nucleotide and amino acid sequences, the VP7 gene segment (1,062 bp) was amplified by RT-PCR and cloned in a TA cloning vector (Novagen pSTBlue-1 AccepTor Vector Kit; Merck Biosciences, Darmstadt, Germany). DNA sequencing was conducted with a sequencing kit (Thermo Sequenase Cy5.5 Dye Terminator Cycle Sequencing Kit; Amersham Biosciences Corp., Piscataway, N. J., USA). Sequence homology was searched using the Basic Local Alignment Search Tool (BLAST). The determined nucleotide and amino acid sequences are shown in Figs. 1 and 2. The standard strain AU1 (accession no. D86271) was used as a reference strain. AU-1 was first isolated and identified as P[9]G3 type human rotavirus in Akita, Japan in 1982 (3). Nucleotide and amino acid sequences between AU-1 and Nara/2003/12 were well conserved; 904 of 976 bases (93%) and 311 of 321 amino acids (97%) were identical. The high relevance of the AU-1 strain to feline rotavirus has been previously demonstrated (3), however, we interviewed the parents of the patient and confirmed that the patient had no obvious contact with cats. AU-1-like rotaviruses have