Genetic analysis and antigenic characterization of human respiratory syncytial virus group A viruses isolated in Germany 1996-2008.

The genetic and antigenic variability of 18 human respiratory syncytial virus group A viruses isolated in Germany from 1996 to 2008 was evaluated by nucleotide sequencing of the complete G and F genes and enzyme-linked immunosorbent assay analysis with anti-G and anti-F monoclonal antibodies. Phylogenetic analyses showed that the G-proteins clustered into the two genotypes GA2 and GA5. The antigenic analysis of G-gene was carried out with a panel of anti-G and anti-F monoclonal antibodies that recognized strain-specific or variable epitopes which were originally derived against long strain (subtype GA1) and MON-3-88 strain (GA2). An amino acid substitution was found in a potential O-glycosylation site leading to a loss of reactivity with a strain-specific MAb. A score was calculated for quantifying the overall reactivity of the antibodies. If reactivity of all MAbs was totalized, a net sum loss of reactivity was seen over the time suggesting that antigenic drift due to immune selection may be occurring.