Table 3.
Prevalence of Virulence Traits in Relation to Resistance Category Among 360 Escherichia coli Clinical Isolates
| Category | Specific Traita,b,c,d | Prevalence of Traite, No. (Column %) | P Valuef | |||
|---|---|---|---|---|---|---|
| Total n = 360 | ESC-RS n = 120 | FQ-R n = 120 | FQ-S n = 120 | |||
| Adhesins | papA/C/EF/G | 80 (22) | 26 (22) | 8 (7) | 46 (38) | < .001 |
| papG allele II | 66 (18) | 22 (18) | 8 (7) | 36 (30) | < .001 | |
| papG allele III | 21 (6) | 7 (6) | 0 (0) | 14 (12) | < .001 | |
| sfa/focDE | 40 (11) | 7 (6) | 0 (0) | 33 (28) | < .001 | |
| sfaS | 7 (2) | 1 (1) | 0 (0) | 6 (5) | .02 | |
| focG | 24 (7) | 3 (3) | 0 (0) | 21 (18) | < .001 | |
| afa/draBC | 25 (7) | 13 (11) | 3 (3) | 9 (8) | .03 | |
| iha | 204 (57) | 67 (56) | 101 (84) | 36 (30) | < .001 | |
| hra | 76 (21) | 35 (29) | 4 (3) | 37 (31) | < .001 | |
| Toxins | hlyD | 57 (16) | 20 (17) | 2 (2) | 35 (29) | .005 |
| hlyF | 20 (6) | 5 (4) | 3 (3) | 12 (10) | .04 | |
| cnf1 | 35 (10) | 14 (12) | 0 (0) | 21 (18) | < .001 | |
| cdtB | 10 (3) | 1 (1) | 0 (0) | 9 (8) | .001 | |
| sat | 199 (55) | 65 (54) | 101 (84) | 33 (28) | < .001 | |
| pic | 17 (5) | 4 (3) | 0 (0) | 13 (11) | < .001 | |
| vat | 99 (28) | 15 (13) | 9 (8) | 75 (63) | < .001 | |
| Siderophores | iroN | 59 (16) | 11 (9) | 3 (3) | 45 (38) | < .001 |
| ireA | 30 (8) | 5 (4) | 1 (1) | 24 (20) | < .001 | |
| iutA | 242 (67) | 87 (73) | 107 (89) | 48 (40) | < .001 | |
| Protectins | K1 capsule | 54 (15) | 7 (6) | 8 (7) | 39 (33) | < .001 |
| K5 capsule | 66 (18) | 18 (15) | 36 (30) | 12 (10) | < .001 | |
| K2/K100 capsule | 48 (13) | 31 (26) | 9 (8) | 8 (7) | < .001 | |
| iss | 20 (6) | 3 (4) | 3 (3) | 13 (11) | .02 | |
| Miscellaneous | usp | 260 (72) | 73 (61) | 102 (85) | 85 (71) | < .001 |
| ibeA | 36 (10) | 3 (3) | 3 (3) | 30 (25) | < .001 | |
| ompT | 280 (78) | 82 (68) | 103 (86) | 95 (79) | .005 | |
| H7 fliC | 20 (6) | 1 (1) | 0 (0) | 19 (16) | < .001 | |
| malX | 265 (74) | 88 (73) | 104 (87) | 73 (61) | < .001 | |
| clbB/N | 66 (18) | 12 (10) | 0 (0) | 54 (45) | < .001 | |
Abbreviations: ESC-RS, extended-spectrum cephalosporin-reduced susceptibility (whether or not fluoroquinolone-resistant); FQ-R, fluoroquinolone-resistant and ESC-susceptible; FQ-S, fluoroquinolone-susceptible and ESC-susceptible.
aTraits shown are those that yielded P < .05 for the 3-group comparison.
bTrait definitions: papA/C/EF/G, P fimbriae major subunit, assembly, minor subunits, and adhesin (which gave similar results); papG alleles II and III, variant P adhesins; sfa/focDE, S and F1C fimbriae; sfaS, S fimbriae adhesin; focG, F1C fimbriae adhesin; afa/draBC, Dr-binding adhesins; iha, adhesin-siderophore receptor; hra, heat-resistant agglutinin; hlyD, alpha hemolysin; hlyF, variant hemolysin; cnf1, cytotoxic necrotizing factor 1; cdtB cytolethal distending toxin; sat, secreted autotransporter toxin; pic, protein associated with intestinal colonization; vat, vacuolating toxin; iroN, salmochelin receptor; ireA, catecholate siderophore receptor; iutA, aerobactin receptor; K2, K5, K2/K100, group 2 capsule variants; iss, increased serum survival; usp, uropathogenic-specific protein; ibeA, invasion of brain endothelium A; ompT, outer membrane protease; H7 fliC, flagellar variant; malX, pathogenicity island marker; clb/N, colibactin (polyketide) synthesis.
cTraits detected in ≥1 isolate but not significantly associated with resistance category (definition, % of 360 with trait): papG allele 1 (variant P adhesin, 1%), gafD (G fimbriae, 1%), fimH (type-1 fimbriae adhesin, 99%), tsh (temperature-sensitive hemagglutinin, 2%), astA (enteroaggregative E. coli toxin, 3%), fyuA (yersiniabactin receptor, 88%), kpsM II (group 2 capsules, 69%), K15 (variant group 2 capsule, 1%), kpsMT III (group 3 capsules, 3%), rfc (O4 lipopolysaccharide, 2%), traT (serum-resistance associated, 74%), cvaC (microcin V, 4%), ExPEC (extraintestinal pathogenic E. coli, 64%).
dTraits sought but not detected in any isolate: afaE8, clpG, F17, bmaE (variant mannose-resistant adhesins).
eBoldface indicates the resistance category with the highest prevalence value.
f P values (by Fisher’s exact test) are for 3-group comparisons: ESC-RS, FQ-R, FQ-S.