Table 2.
Comparison of evolutionary relevant amino acid (aa) residues of putative VP2 proteins of canine parvovirus (CPV) strains detected on the island of St. Kitts (KNA), Caribbean region, with those of CPV-2, CPV-2a, CPV-2b, CPV-2c, new CPV-2a, new CPV-2b, and vaccine strains. The KNA CPV strains are underlined. A dot ‘.’ indicates an identical amino acid residue at cognate position of deduced VP2 aa sequence of the concerned CPV strain with that of reference strain CPV-b/USA/1978. Alignment of complete deduced aa sequences of putative VP2 proteins of the CPV strains is shown in supplementary Fig. S2.
| Amino acid positiona |
80 |
87 |
93 |
101 |
103 |
232 |
267 |
297b |
300 |
305 |
321 |
323 |
324 |
375 |
426c |
440 |
555 |
560 |
564 |
568 |
570 |
Variant |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Strain | ||||||||||||||||||||||
| CPV-b/USA/1978 | R | M | N | I | A | I | F | S | A | D | N | N | Y | N | N | T | V | N | S | G | K | CPV-2 |
| CPV-15/USA/1984 | . | L | . | T | . | . | . | . | G | Y | . | . | . | D | N | . | I | . | . | . | . | CPV-2a |
| CPV-39/USA/1984 | . | L | . | T | . | . | . | . | G | Y | . | . | . | D | D | . | . | . | . | . | . | CPV-2b |
| 219/08-13/ITA/2008 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | E | . | . | . | . | . | . | CPV−2c |
| CPV-435/USA/2003 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| Pome/KOR/2005 | . | L | . | T | . | . | . | A | Dd | Y | . | . | . | D | . | A | . | . | . | . | . | New CPV−2ad |
| Uy-243/URY/2010 | . | L | . | T | . | . | Y | A | G | Y | . | . | I | D | . | A | . | . | . | . | . | New CPV−2a |
| CPV-436/USA/2003 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | D | . | . | . | . | . | . | New CPV−2b |
| PVC6/KNA/2015 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| PVC8/KNA/2015 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| PVC11a/KNA/2015 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| PVC12/KNA/2015 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| PVC13/KNA/2015 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| RVC6/KNA/2015 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| RVC11/KNA/2015 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| RVC17/KNA/2015 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| RVC20/KNA/2015 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| RVC21/KNA/2015 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| RVC23/KNA/2015 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| RVC26/KNA/2015 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| RVC43/KNA/2016 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| RVC44/KNA/2016 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| RVC49/KNA/2016 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| RVC50/KNA/2016 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| RVC53/KNA/2016 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| RVC54/KNA/2016 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV−2a |
| RVC55/KNA/2016 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV-2a |
| RVC57/KNA/2016 | . | L | . | T | . | . | . | A | G | Y | . | . | . | D | . | . | . | . | . | . | . | New CPV-2a |
| – | ||||||||||||||||||||||
| Vaccine VANGUARD | . | . | . | . | . | . | . | . | . | . | . | . | . | E | . | . | . | . | . | . | . | CPV-2 |
| Vaccine (Duramune) strain SAH | . | L | . | T | . | . | . | A | G | Y | K | . | . | D | D | . | . | . | . | . | E | New CPV−2b |
Positions of amino acid residues are based on those of CPV strain CPV-b/USA/1978.
The S297A mutation has been found to be fixed in VP2 of recent CPV-2a and CPV-2b strains, and these variants are sometimes designated as new CPV-2a and new CPV-2b strains (Decaro and Buonavoglia, 2012, Miranda and Thompson, 2016). In a recent study, new CPV-2a and new CPV-2b strains have also been designated as CPV-2a-297A and CPV-2b-297A, respectively (Zhou et al., 2017).
Amino Acid residue 426 of VP2 constitutes the sole basis of differentiating the new CPV-2a (426-N), new CPV-2b (426-D), and CPV-2c (426-E) strains (Decaro and Buonavoglia, 2012, Miranda and Thompson, 2016).
New CPV-2a strains exhibiting G300D are also referred to as CPV-2a-297A300D (Zhou et al., 2017).