G2 rotavirus infections in an infantile population of the South of Italy: Variability of viral strains over time
✍ Scribed by Serenella Arista; Giovanni M. Giammanco; Simona De Grazia; Claudia Colomba; Vito Martella; Antonio Cascio; Miren Iturriza-Gòmara
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 150 KB
- Volume
- 77
- Category
- Article
- ISSN
- 0146-6615
No coin nor oath required. For personal study only.
✦ Synopsis
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.