Table 2. Signature codon changes in circulating global RSV group A genotype ON1 viruses*.
| Signature change† | First detected | No. viruses with mutation | No. viruses compared‡ | Detection location(s) | Comment(s) |
|---|---|---|---|---|---|
| P88S | 2012 Nov | 3 | 7 | China | Occur within the mucin-like first hypervariable region; potentially O-glycosylated (4) |
| L115P | 2012 Aug | 10 | 84 | China, Kenya | Defines Kenyan RSV lineage 3; occurs within the mucin-like first hypervariable region; potentially O-glycosylated (4) |
| S128F | 2012 May | 5 | 84 | Kenya | Defines Kenya RSV lineage 2 |
| T136I | 2012 Feb | 54 | 111 | Kenya | Defines Kenyan RSV lineage 1 |
| P172A | 2012 Dec | 9 | 150 | Italy | |
| P206Q | 2011 | 5 | 162 | India, Italy, Japan | |
| T249N | 2012 Jan | 5 | 195 | Italy | |
| L274P | 2011 | 131 | 195 | India, Italy, Germany, Japan, Kenya | Predicted to be positively selected; exhibits reversible amino acid substitutions (i.e., flip-flop pattern) (25); position N-glycosylated in some strains |
| H290Y | 2012 Feb | 5 | 195 | Italy | Predicted to be positively selected; exhibits flip-flop pattern(25) |
| G296S | 2012 Dec | 11 | 195 | Italy | Adjacent codon (i.e., 295) predicted to be positively selected (26) |
| L298P | 2011 | 133 | 195 | India, Italy, Germany, Japan, Kenya | Duplicated epitope; concurrent substitution with L274P in many sequences |
| Y304H | 2011 | 129 | 195 | India, Italy, Germany, Japan, Kenya | |
| E308K | 2012 Feb | 13 | 195 | Italy, South Africa, China | |
| L310P | 2011 | 96 | 195 | Italy, Kenya, Japan, India | Equivalent to L286P in non-ON1 genotypes; change previously observed in certain monoclonal antibody escape mutants (27) |
*RSV, respiratory syncytial virus. †Only substitutions observed in >3 viruses are shown. ‡Numbers in this column indicate the number of sequences that span the given amino acid position; the number 195 implies that all the datasets we collated, including the sequences for viruses from Kilifi, Kenya. The numbers differ because the nucleotide sequences found in GenBank for these viruses were of variable lengths.