Characterization of nontypeable rotavirus strains from the United States: identification of a new rotavirus reassortant (P2A[6],G12) and rare P3[9] strains related to bovine rotaviruses

Virology. 2002 Mar 15;294(2):256-69. doi: 10.1006/viro.2001.1333.


Among 1316 rotavirus specimens collected during strain surveillance in the United States from 1996 to 1999, most strains (95%) belonged to the common types (G1 to G4 and G9), while 5% were mixed infections of common serotypes, rare strains, or not completely typeable. In this report, 2 rare (P[9],G3) and 2 partially typeable (P[6],G?; P[9],G?) strains from that study were further characterized. The P[6] strain was virtually indistinguishable by hybridization analysis in 10 of its 11 gene segments with recently isolated P2A[6],G9 strains (e.g., U.S.1205) from the United States, but had a distinct VP7 gene homologous (94.7% a.a. and 90.2% nt) to the cognate gene from P1B[4],G12 reference strain L26. Thus, this serotype P2A[6],G12 strain represents a previously unrecognized reassortant. Three P3[9] strains were homologous (97.8-98.2% aa) in the VP8 region of VP4 to the P3[9],G3 feline-like reference strain AU-1, but had a high level of genome homology to Italian bovine-like, P3[9],G3 and P3[9],G6 rotavirus strains. Two of the U.S. P3[9] strains were confirmed to be type G3 (97.2-98.2% VP7 aa homology with reference G3 strain AU-1), while the other was most similar to Italian bovine-like strain PA151 (P3[9],G6), sharing 99.0% a.a. homology in VP7. Cross-neutralization studies confirmed all serotype assignments and represented the first detection of these rotavirus serotypes in the United States. The NSP4 genes of all U.S. P3[9] strains and rotavirus PA151 were most closely related to the bovine and equine branch within the DS-1 lineage, consistent with an animal origin. These results demonstrate that rare strains with P and G serotypes distinct from those of experimental rotavirus vaccines circulate in the United States, making it important to understand whether current vaccine candidates protect against these strains.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigens, Viral / immunology
  • Capsid / genetics
  • Capsid Proteins*
  • Cattle
  • Genotype
  • Glycoproteins / genetics
  • Humans
  • Phylogeny
  • RNA-Binding Proteins / immunology
  • Reassortant Viruses / classification
  • Reassortant Viruses / genetics*
  • Reassortant Viruses / immunology
  • Reassortant Viruses / isolation & purification
  • Rotavirus / classification
  • Rotavirus / genetics*
  • Rotavirus / immunology
  • Rotavirus / isolation & purification
  • Rotavirus Infections / immunology
  • Rotavirus Infections / virology
  • Sequence Analysis, RNA
  • Toxins, Biological
  • United States
  • Viral Nonstructural Proteins / genetics
  • Viral Nonstructural Proteins / immunology


  • Antigens, Viral
  • Capsid Proteins
  • Glycoproteins
  • NS28 protein, rotavirus
  • RNA-Binding Proteins
  • Toxins, Biological
  • VP4 protein, Rotavirus
  • VP7 protein, Rotavirus
  • Viral Nonstructural Proteins
  • NS35 protein, rotavirus