Table 3.
Distribution of virulence genes among phylogenetic groups of E. coli.
| Phylogenetic groups | |||||||
|---|---|---|---|---|---|---|---|
| General positivity | Intestinal | Extraintestinal | Sig. (Kruskal-Wallis) | ||||
| N = 258 | NT*N = 42 | A N = 16 | B1 N = 16 | B2 N = 96 | D N = 88 | ||
| Count (%) | Count (%) | Count (%) | Count (%) | Count (%) | Count (%) | ||
| GENES | |||||||
| chuA a | 219 (85) | 35 (83) | 0 | 0 | 96 (100) | 88 (100) | –a |
| csgA | 213 (83) | 27 (64) | 10 (63) | 10 (63) | 84 (88) | 82 (93) | 0.000 |
| fyuA b | 200 (78) | 31 (74) | 4 (25) | 0 | 93 (97) | 72 (82) | 0.000 |
| pap b | 120 (47) | 22 (52) | 3 (19) | 2 (13) | 46 (48) | 47 (53) | 0.003 |
| yfcV b | 106 (41) | 14 (33) | 0 | 0 | 73 (76) | 19 (22) | 0.000 |
| vat | 102 (40) | 12 (29) | 10 (63) | 3 (19) | 62 (65) | 15 (17) | 0.000 |
| cnf c | 60 (23) | 8 (19) | 0 | 0 | 52 (54) | 0 | 0.000 |
| focA | 45 (17) | 6 (14) | 12 (75) | 6 (38) | 10 (10) | 11 (13) | 0.000 |
| sfa c | 39 (15) | 5 (12) | 0 | 0 | 34 (35) | 0 | 0.000 |
| ag43 | 21 (8) | 1 (2) | 3 (19) | 0 | 9 (9) | 8 (9) | 0.343 |
| aapA | 12 (5) | 3 (7) | 3 (19) | 0 | 0 | 6 (7) | 0.002 |
| pic c | 11 (4) | 0 | 0 | 0 | 11 (11) | 0 | 0.002 |
| aatA | 9 (3) | 0 | 3 (19) | 0 | 0 | 6 (7) | 0.001 |
| aggR | 9 (3) | 0 | 3 (19) | 0 | 0 | 6 (7) | 0.001 |
| pilS | 9 (3) | 2 (5) | 0 | 0 | 3 (3) | 4 (5) | 0.672 |
| aggA | 3 (1) | 0 | 3 (19) | 0 | 0 | 0 | 0.000 |
| pet | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
| aafA | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
| agg3A | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
| hdaA | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
*
Not tested for phylogenetic groups.
“a”
– the presence of gene chuA is mandatory for the classification into phylogroups B2 or D.
“b”
indicates virulence genes more statistically detected in extraintestinal strains (B2+D) in comparison with intestinal ones (A+B1) (p < 0.001).
“c”
indicates virulence genes exclusively detected in the phylogroup B2.