G2 rotavirus infections in an infantile population of the South of Italy: variability of viral strains over time

J Med Virol. 2005 Dec;77(4):587-94. doi: 10.1002/jmv.20496.


Rotavirus positive samples collected in Palermo, Italy, during 2002-2004 did not react with the G2 type-specific RV5:3 monoclonal antibodies (MAbs) and could be identified as G2 only by RT-PCR genotyping. The genetic variation of VP7 and VP4 antigenic proteins was studied in 14 G2 samples including a selection of both those successfully characterized by serotyping and those failing to be serotyped. The phylogenetic analysis performed on partial VP7 sequences showed a temporal clustering of these strains, with those isolated in Palermo in 2003 belonging to the same lineage of G2 MAbs-unreactive strains identified in UK in 1996-1997 and in Bari, Italy, in 2003-2004. A single amino acid substitution in VP7 antigenic region A, at position 96 (Asp-->Asn), was consistently associated with the loss of antigenic reactivity. Five of the G2 strains were further characterized by sequencing of VP4-encoding genes as belonging to the P[4] type, and separate lineages clustering the strains according to a temporal distribution could be described. VP7 and VP4 antigenic proteins analysis provided evidence that over the last 11 years, at least two different populations of G2P[4] rotavirus strains have been infecting the infant population in Palermo. Considering the role of anti-VP7 and anti-VP4 neutralizing antibodies in rotavirus immunity, the emergence of new VP7-VP4 gene combinations might influence rotavirus circulation in the infant population and should be taken into consideration when devising vaccination strategies.

MeSH terms

  • Antigens, Viral / chemistry
  • Antigens, Viral / genetics*
  • Capsid Proteins / chemistry
  • Capsid Proteins / genetics*
  • Child, Preschool
  • Feces / virology
  • Humans
  • Infant
  • Infant, Newborn
  • Italy / epidemiology
  • Phylogeny
  • Rotavirus / classification
  • Rotavirus / genetics*
  • Rotavirus / immunology
  • Rotavirus / isolation & purification
  • Rotavirus Infections / epidemiology*
  • Rotavirus Infections / virology
  • Serotyping
  • Time Factors


  • Antigens, Viral
  • Capsid Proteins
  • VP4 protein, Rotavirus
  • VP7 protein, Rotavirus