Table 2.
C3 deposition on S. pneumoniae strains expressing PspA proteins of clades 1 through 5 and capsular types 2, 3, and 11
| % C3 positive bacteria
|
||||||
|---|---|---|---|---|---|---|
| Strain | Capsule type | PspA family | PspA Clade | Antiserum | 1% anti-PspA + baby rabbit C′ | baby rabbit C′ alone |
| JY1119 | 3 | None | None | Anti-clade 2 | 14.1 | 10.5 |
| 3JY4182-95 | 3 | 1 | 1 | Anti-clade 2 | 85.2 | 0.6 |
| WU2 | 3 | 1 | 2 | Anti-clade 2 | 95.7 | 5.7 |
| BR93.1 | 3 | 2 | 3 | Anti-clade 3 | 96.4 | 8.6 |
| 3JYP2670 | 3 | 2 | 4 | Anti-clade 4 | 54.2 | 2.3 |
| ATCC6303 | 3 | 2 | 5 | Anti-clade 4 | 88.9 | 3.7 |
| D39 | 2 | 1 | 2 | Anti-clade 2 | 61.6 | 3.2 |
| BG7941 | 11 | 2 | 5 | Anti-clade 4 | 59.5 | 1.9 |
Note: S. pneumoniae strains were incubated with 1% heat-inactivated rabbit anti-PspA sera followed by baby rabbit complement (C′). The proportion of C3-positive bacteria was determined by flow cytometric analysis. Anti-PspA sera were generated in rabbits after immunization with the PspA proteins Rx1, EF3296 and EF5668 representing clades 2, 3 and 4 in the presence of Freund’s adjuvant.