TABLE 3.
Distribution of taxonomic traits among H. influenzae and H. haemolyticus isolates
| Trait | No. (%) of isolatesa
|
PRb | Result of χ2 analysis (P valued) | |
|---|---|---|---|---|
| H. influenzae (n = 88) | H. haemolyticus (n = 109) | |||
| Molecular-based traits | ||||
| iga gene probe hybridization | 88 (100) | 0 (0.0) | Referent | |
| MAb 7F3 reactivity | 85 (96.6) | 13 (11.9) | 8.10 | <0.0001 |
| Classical traits | ||||
| H2S production | 11 (12.5) | 75 (68.8) | 0.18 | <0.0001 |
| Gas production | 5 (5.7) | 96 (88.1) | 0.06 | <0.0001 |
| Indole production | 73 (83.0) | 68 (62.4) | 1.33 | 0.0015 |
| Urease activity | 74 (84.1) | 77 (70.6) | 1.19 | 0.0265 |
| ODC activity | 24 (27.3) | 8 (7.3) | 3.72 | 0.0002 |
| Biotype I | 18 (20.5) | 4 (3.7) | 5.57 | 0.0002 |
| Biotype II | 44 (50.0) | 43 (39.4) | 1.27 | 0.1382 |
| Biotype III | 12 (13.6) | 28 (25.7) | 0.53 | 0.0366 |
| Biotype IV | 0 (0)c | 2 (1.8) | 0.31 | 0.2015 |
| Biotype V | 5 (5.7) | 2 (1.8) | 3.10 | 0.1470 |
| Biotype VI | 1 (1.1) | 0 (0)c | 2.48 | 0.2645 |
| Biotype VII | 6 (6.8) | 19 (17.4) | 0.39 | 0.0261 |
| Biotype VIII | 2 (2.3) | 11 (10.1) | 0.23 | 0.0280 |
| LOS gene virulence traits | ||||
| licA | 84 (95.5) | 46 (42.2) | 2.26 | <0.0001 |
| lic2A | 80 (90.0) | 17 (15.6) | 5.83 | <0.0001 |
| lgtC | 88 (100.0) | 2 (1.8) | 54.50 | <0.0001 |
a
The species designation is based on the stratification of strains in the MLSA dendrogram of Fig. 1 and on the presence or absence of hybridization with an iga gene probe.
b
PR, prevalence ratio. The prevalence ratios were calculated for H. influenzae by using H. haemolyticus as the referent group.
c
Logit, 0.5 was used in place of 0 for prevalence ratio and statistical calculations.
d
A P value of <0.05 is considered statistically significant.