Table 2.
Exposure to NHS drives selection for LPS phase variants in H. influenzae.
| Strain | Serial passage | Gene | No. repeats (reading frame)a | Times observed |
|---|---|---|---|---|
| Rd | ||||
| lpsA– | NHS | lic1A | 17 (OFF) → 18 (ON) | 3/3 |
| lgtF– | NHS | lic2A | 23 (OFF) → 22 (ON) | 3/3 |
| lic1D– | NHS | lgtC | 21 (OFF) → 22 (ON) | 3/3 |
| lic1D– | Neu5Ac + NHS | lgtC | 21 (OFF) → 22 (ON) | 4/4 |
| lic1A-ONb | NHS | lic2A | 21 (OFF) → 22 (ON) | 3/3 |
| R2846 | ||||
| lpsA– | NHS | lic2A | 24 (OFF) → 25 (ON) | 3/3 |
| lic1D– | NHS | lic2A | 24 (OFF) → 25 (ON) | 6/7 |
| lex2A | 16 (OFF) → 14 (ON) | 1/7 | ||
| lic1D– | mAb 6E4 + BRS | lic2A | 24 (OFF) → 25 (ON) | 3/4 |
| lex2A | 16 (OFF) → 14 (ON) | 1/4 | ||
| lic1A-ONb | NHS | lic2A | 24 (OFF) → 25 (ON) | 1/2 |
| lex2A | 16 (OFF) → 14 (ON) | 1/2 | ||
| 2019 | ||||
| lic1D– | NHS | lic2A | 17 (OFF) → 16 (ON) | 3/3 |
| Eagan (cap–) | ||||
| lic1D– | NHS | lic2A | 17 (OFF) → 16 (ON) | 4/4 |
| lgtC | 23 (OFF) → 24 (ON) | 4/4 | ||
a
Refers to the reading frame of the indicated gene as in frame (ON) or out of frame (OFF) based on the number of tetranucleotide repeats.
b
Bactericidal assays with lic1A-ON variants were conducted with CRP-deleted NHS.
NHS, normal human serum; BRS, baby rabbit serum.