Table 3.
Molecular Characteristics in Relation to Resistance Category Among 425 Fecal Escherichia coli Strains
| Strain Characteristic | No. of Strains (Column %) | P Value | |||
|---|---|---|---|---|---|
| Categorya,b,c | Trait | Total (n = 425f) | FQR (n = 77) | FQS (n = 348) | |
| Adhesin genes | papAH | 85 (20) | 5 (7) | 80 (23) | <.001 |
| sfa/focDE | 69 (16) | 0 (0) | 69 (20) | <.001 | |
| sfaS | 21 (5) | 0 (0) | 21 (6) | .01 | |
| focG | 31 (7) | 0 (0) | 31 (9) | .002 | |
| iha | 109 (26) | 53 (69) | 56 (16) | <.001 | |
| fimH | 411 (97) | 71 (92) | 340 (98) | .01 | |
| hra | 92 (22) | 9 (12) | 83 (24) | .01 | |
| yfcV | 207 (49) | 54 (70) | 153 (44) | <.001 | |
| Toxin genes | hlyD | 65 (15) | 0 (0) | 65 (19) | <.001 |
| hlyF | 30 (7) | 0 (0) | 30 (9) | .002 | |
| cnf1 | 51 (12) | 0 (0) | 51 (15) | <.001 | |
| cdtB | 27 (6) | 0 (0) | 27 (8) | .004 | |
| sat | 106 (25) | 57 (74) | 49 (14) | <.001 | |
| pic | 30 (7) | 0 (0) | 30 (9) | .002 | |
| vat | 129 (31) | 7 (9) | 122 (35) | <.001 | |
| tsh | 22 (5) | 0 (0) | 22 (6) | .01 | |
| Siderophore genes | iroN | 96 (23) | 0 (0) | 96 (28) | <.001 |
| fyuA | 267 (63) | 68 (88) | 199 (58) | <.001 | |
| ireA | 41 (10) | 2 (3) | 39 (11) | .01 | |
| iutA | 134 (32) | 59 (77) | 75 (22) | <.001 | |
| chuA | 304 (72) | 66 (86) | 238 (67) | .001 | |
| Protectin genes | K5 | 42 (10) | 24 (31) | 18 (5) | <.001 |
| iss | 27 (6) | 0 (0) | 27 (8) | .004 | |
| rfc | 23 (5) | 0 (0) | 23 (7) | .009 | |
| cvaC | 17 (4) | 0 (0) | 17 (5) | .03 | |
| traT | 183 (43) | 45 (58) | 138 (40) | .002 | |
| Miscellaneous virulence genes | usp | 203 (48) | 49 (64) | 154 (45) | .002 |
| ibeA | 65 (15) | 2 (3) | 63 (18) | <.001 | |
| ompT | 279 (66) | 58 (75) | 221 (64) | .04 | |
| H7 fliC | 38 (9) | 0 (0) | 38 (11) | <.001 | |
| malX | 201 (48) | 57 (74) | 144 (42) | <.001 | |
| clbB/N | 81 (19) | 1 (1) | 80 (23) | <.001 | |
| Pathotype (gene combination) | ExPEC | 178 (42) | 45 (58) | 133 (38) | .001 |
| Phylogroupd | B1 | 60 (14) | 5 (7) | 55 (16) | .03 |
| B2 | 201 (48) | 48 (62) | 153 (44) | .004 | |
| Clonal groupe | STc12 | 21 (5) | 0 (0) | 21 (6) | .02 |
| ST131 | 61 (15) | 39 (51) | 22 (6) | <.001 | |
| ST131-non-H30 | 20 (5) | 1 (1) | 19 (5) | <.001 | |
| ST131-H30 | 41 (7) | 38 (49) | 3 (1) | .001 | |
| ST131-H30Rx | 8 (2) | 8 (10) | 0 (0) | .001 | |
| ST648 | 5 (1) | 3 (4) | 0 (0) | .006 | |
| ST73 | 28 (7) | 0 (0) | 28 (8) | .004 | |
| STc95 | 18 (4) | 0 (0) | 18 (5) | .048 |
Abbreviations: ExPEC, extraintestinal pathogenic Escherichia coli; FQR, fluoroquinolone resistant; FQS, fluoroquinolone susceptible; ST, sequence type; STc, ST complex (group of closely related STs).
aGenes shown are those that yielded P < .05 (by Fisher’s Exact Test) for the 2-group comparison. Boldface, higher prevalence group. Gene definitions: papAH/C/EF/G, P fimbriae; sfa/focDE, S and F1C fimbriae; sfaS, S fimbriae adhesin; focG, F1C fimbriae adhesin; afa/draBC, Dr-binding adhesins; iha, adhesin-siderophore receptor; fimH, type-1 fimbriae adhesin; hra, heat-resistant agglutinin; yfcV, putative chaperone-usher fimbria; 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; tsh, temperature-sensitive hemagglutinin; iroN, salmochelin receptor; fyuA, yersiniabactin receptor; ireA, catecholate siderophore receptor; iutA, aerobactin receptor; chuA, heme-binding outer membrane; K5, group 2 capsule variants; iss, increased serum survival; rfc, O4 lipopolysaccharide; cvaC, microcin V; usp, uropathogenic-specific protein; traT, serum resistance-associated; ibeA, invasion of brain endothelium A; ompT, outer membrane protease; H7 fliC, flagellar variant; malX, pathogenicity island marker; clbB/N, colibactin (polyketide) synthesis.
bGenes detected in ≥1 isolate but not yielding P < .05 (% of 425): afa/draBC (Dr-binding adhesins, 3%), gafD (G fimbriae, 1%), astA (enteroaggregative E. coli toxin, 6%), kpsM II (group 2 capsules, 54%), kpsMT III (group 3 capsules, 3%), K2/K100 (group 2 capsule variants, 4%)
cGenes sought but not detected: afaE8, F17, clpG, bmaE (variant mannose-resistant adhesin).
dPhylogroups detected in ≥1 isolate but not yielding P < .05 (% of 425): A (13%): C (.2%), D (18%), E (2%), F (4%). Phylogroup was indeterminate for 1% of isolates.
eClonal groups detected in ≥1 isolate but not yielding P < .05 (% of 425): ST127 (3%), ST141 (3%), ST144 (1%), ST372 (2%), STc405 (2%), STc69/CGA (5%). Each of the 12 clonal groups sought was detected at least in one isolate.
fThe 425 strains were selected to include all strains of interest, all other unique strains from strain-of-interest households, and all strains from the first 62 non-strain-of-interest households.