From: Pilus distribution among lineages of group b streptococcus: an evolutionary and clinical perspective
 | Human-derived ( n = 244) | Bovine-derived ( n = 51) |  |  | ||
Pilus island profile | n | (%) | n | (%) |  | Fisher’s exact P-value |
PI-1 and PI-2a (n = 143) | 137 | (56%) | 6 | (12%) |  | <0.00001 |
PI-1 and PI-2b (n = 81) | 81 | (33%) | 0 | (0%) |  | <0.00001 |
PI-2a only (n = 27) | 26 | (11%) | 1 | (2%) |  | 0.06 |
PI-2b only (n = 44) | 0 | (0%) | 44 | (86%) |  | <0.00001 |
 | Maternal colonizing ( n = 99) | Neonatal invasive ( n = 120) |  |  | ||
Pilus island profile | n | (%) | n | (%) | Chi square | P-value |
PI-1 and PI-2a (n = 143) | 66 | (53%) | 59 | (47%) | 6.8 | 0.009 |
PI-1 and PI-2b (n = 81) | 20 | (27%) | 54 | (73%) | 14.8 | 0.0001 |
PI-2a only (n = 27) | 13 | (65%) | 7 | (35%) | 3.5 | 0.06 |
PI-2b only (n = 44) | 0 | (0%) | 0 | (0%) | -- | -- |