Molecular Analysis of the VP7, VP4, VP6, NSP4, and NSP5/6 Genes of a Buffalo Rotavirus Strain: Identification of the Rare P[3] Rhesus Rotavirus-Like VP4 Gene Allele

Abstract

We report the detection and molecular characterization of a rotavirus strain, 10733, isolated from the feces of a buffalo calf affected with diarrhea in Italy. Strain 10733 was classified as a P[3] rotavirus, as the VP8* trypsin cleavage product of the VP4 protein revealed a high amino acid identity (96.2%) with that of rhesus rotavirus strain RRV (P5B[3]), used as the recipient virus in the human-simian reassortant vaccine. Analysis of the VP7 gene product revealed that strain 10733 possessed G6 serotype specificity, a type common in ruminants, with an amino acid identity to G6 rotavirus strains ranging from 88 to 98%, to Venezuelan bovine strain BRV033, and Hungarian human strain Hun4. Phylogenetic analysis based on the VP7 gene of G6 rotaviruses identified at least four lineages and an apparent linkage between each lineage and the VP4 specificity, suggesting the occurrence of repeated interspecies transmissions and genetic reassortment events between ruminant and human rotaviruses. Moreover, strain 10733 displayed a bovine-like NSP4 and NSP5/6 and a subgroup I VP6 specificity, as well as a long electropherotype pattern. The detection of the rare P[3] genotype in ruminants provides additional evidence for the wide genetic and antigenic diversity of group A rotaviruses.

Genomic characterization of a novel group A lamb rotavirus isolated in Zaragoza, Spain

“…OVR strains have been isolated in the United Kingdom, Japan, and China, but only those isolated from the United Kingdom and China have been characterized [3,13,[16][17][18][19][20]. Indeed, the most well- [25] P [8] P [4] P [19] P [6] P [27] P [5] P [12] P [10] P [21] P[15] P [24] P [7] P [13] P [20] P [16] P [3] P [2] P [18] P [1] P [17] P [11] P [26] P [14] 0.05 nucleotide substitutions per bp A Fig. 4 The present study constitutes the first report of an OVR strain, 762, with P [14] and G8 specificities.…”

“…3). The deduced aa sequence of the NSP4 of OVR762 exhibited 93-99% aa identity with ovine, bovine, simian, equine, and human rotavirus strains in the NSP4 genotype E2, previously knows as genotype A (Table 1, and data not shown) [5,7,10]. The NSP4 of OVR762 exhibited the greatest aa identity (99%) with the genotype E2 HRV strain PA589, isolated in Italy, while the range of aa identities to other HRV strain belonging to the same genotype E2 was 94-97%.…”

“…The deduced aa sequence contained two potential N-linked glycosylation sites located at aa 8 and 18, two cysteine residues at aa 63 and 71, and histidine-131 (a key residue for enterotoxigenic activity) which are conserved in NSP4 proteins [7,10,21] (Fig. 3).…”

“…The predicted NSP5 and NSP6 proteins of OVR762 were 198 and 92 aa in length, respectively (data not shown). The serine residues (153, 155, 163, and 165) involved with phosphorylation [10], the cysteine residues at position 171 and 174, and the highly conserved COOH terminus in the NSP5 protein were maintained. The deduced aa sequence of the NSP5/NSP6 of OVR762 was compared with NSP5 sequences of representative rotavirus strains (Table 1), and the aa identity Si, simian; Ov, ovine; Gu, guanaco; Pi, Pigeon; Av, avian (turkey or chicken) b P genotype is designated in brackets while serotype (when known) preceeds P genotype [1] c VP6 and VP7 genotypes, I and G, respectively, as recently described by Matthijnssens et al [5] d…”

“…Genome segment 11 encodes NSP5, a phosphoprotein with kinase activity, and, via an out-of-phase open reading frame (ORF), a smaller, likely dispensable protein, NSP6 [1]. The NSP5/ NSP6 gene has been shown to be suitable to trace species of origin [10] and can be genetically classified into six genotypes (H1 to H6) [5].…”