Downloaded from www.microbiologyresearch.org by IP: 54.162.133.179 On: Tue, 23 Feb 2016 00:14:36 Journal of General Virology (1994),75, 1775-1780. Printedin Great Britain 1775 Comparative analysis of VP8* sequences from rotaviruses possessing M37-1ike VP4 recovered from children with and without diarrhoea Norma Santos, 1 Vera Gouvea, 1. Maria do Carmo Timenetsky, 2 H Fred Clark, 3 Marie Riepenhoff-Talty 4 and Antoine Garbarg-Chenon 5 1Division of Molecular Biological Research and Evaluation, Food and Drug Administration, Washington, D.C. 20204, U.S.A., 2Instituto Adolfo Lutz, S~o Paulo, Brazil 01246-900, 3 The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, 4 The Children's Hospital of Buffalo, Buffalo, New York 14222, U.S.A. and 5 H6pital d'Enfants Armand- Trousseau, 75012 Paris, France Rotavirus strains belonging to G types 1 to 4 and having a P3 genotype (M37-1ike VP4) were recovered from children with symptomatic and asymptomatic infections. Partial sequences of their VP4 genes were determined in an attempt to characterize these strains further. The genomic regions encoding VP8*, the connecting and putative fusion peptides and three other regions in VP5* were sequenced. The deduced amino acid sequences were compared with rotavirus strains belonging to different P genotypes that had been previously reported. High degrees of identity were found between the VP8* fragment of all human P3 strains (92"7 to 99-7%) suggesting that they belong to the same genotype, regardless of differences in their virulence. Furthermore, based on comparative sequence analysis, we did not identify any amino acid(s) that differ appreciably between symptomatic and asymptomatic strains and could therefore be associated with virulence. The results suggest that the P3 genotype, although frequently associated with asymptomatic infections, may not be the single determining factor in attenuation of symptoms. Neonatal rotavirus infection in children is rarely associ- ated with symptoms (Chrystie et al., 1978; Rodger et al., 1981 ; Perez-Schael et al., 1984). Nevertheless, it seems to confer protection against subsequent severe rotavirus diarrhoea (Bishop et al., 1983). Strains recovered from neonates with asymptomatic infections differed from the strain of the rotavirus causing symptomatic infection and may be naturally attenuated (Flores et al., 1986; Gorziglia et al., 1988). Thus, they are suitable candidates for vaccines. Attempts to develop a vaccine using the asymptomatic strain M37 are currently underway (Flores et al., 1990; Midthun et al., 1991 ; Vesikari et al., 1991). Cross-hybridization studies and nucleotide sequence analysis of rotavirus strains recovered from neonates with symptomatic and asymptomatic infections have implicated the fourth gene (which encodes the VP4 protein) in virus attenuation (Flores et al., 1986; Gorziglia et al., 1988). A neutralization assay has also been used to show the distinct nature of the asymptomatic The sequencedata reported in this paper have been submitted to GenBank and assigned the following accession numbers: rotavirus strain VE7156, L25265; strain SC2, L25266; strain MtB2, L25267; strain MtA5, 25268. strains (Gorziglia et al., 1990). The VP4 protein is a minor constituent of the rotavirus outer capsid and performs a number of biologically important functions. It is responsible for the haemagglutination activity of certain rotaviruses and for restriction of human rotavirus growth in cell culture. It also plays an important role in the virulence of heterologous rotaviruses for mice, induces neutralizing antibodies and is the site for protease activation of infectivity (Kapikian & Chanock, 1990). VP4 types have been defined on the basis of neutral- ization assays (Gorziglia et al., 1990) or sequence analysis (Gorziglia et al., 1988; Estes & Cohen, 1989). Com- parison of the sequences of the fourth gene identified at least five genotypes (P types) among human rotaviruses: P1, associated with symptomatic rotavirus strains of serotypes G1, G3, G4 and G9; P2, associated with symptomatic infections caused by strains of serotype G2 and G12; P3, associated with strains of serotypes G1 to G4 and obtained from newborns with asymptomatic infections; P4 and P5, found in strains K8 (G1) and 69M (G8) respectively, which were recovered from patients with symptomatic infections (Gorziglia et al., 1988; Taniguchi et al., 1989, 1990; Qian & Green, 1991). Recently a sixth P genotype was described in the strain HCR3 (G3), isolated from an asymptomatic infant in the 0001-2235 © 1994SGM