Table 2.
Pathogen-associated factors related to early mortality in patients with E. col BSI.
| Characteristics | Totala |
Survival |
Early deathb |
Pc |
|---|---|---|---|---|
| (n = 1492) | 1351 (90·5%) | 141 (9·5%) | ||
| Strain type | ||||
| Phylogenetic group A | 289 (19·4%) | 275 (20·4%) | 14 (9·9%) | 0·002 |
| B2 | 833 (55·8%) | 741 (54·8%) | 92 (65·2%) | 0·020 |
| D | 368 (24·7%) | 333 (24·6%) | 35 (24·8%) | 0·999 |
| ST131 | 359 (24·1%) | 310 (22·9%) | 49 (34·8%) | 0·003 |
| Non-H30 | 19 (1·3%) | 17 (1·3%) | 2 (1·4%) | 0·699 |
| H30 | 40 (2·7%) | 34 (2·5%) | 6 (4·3%) | 0·264 |
| H30R | 121 (8·1%) | 108 (8·0%) | 13 (9·2%) | 0·626 |
| H30Rx | 179 (12·0%) | 151 (11·2%) | 28 (19·9%) | 0·004 |
| ST95 | 143 (9·6%) | 135 (10%) | 8 (5·7%) | 0·131 |
| ST69 | 128 (8·6%) | 117 (8·7%) | 11 (7·8%) | 0·874 |
| ST1193 | 96 (6·4%) | 83 (6·1%) | 13 (9·2%) | 0·151 |
| ST73 | 69 (4·6%) | 63 (4·7%) | 6 (4·3%) | >0·999 |
| ST38 | 56 (3·8%) | 53 (3·9%) | 3 (2·1%) | 0·359 |
| Antimicrobial resistance categoryd | ||||
| DS | 330 (22·1%) | 306 (22·6%) | 24 (17·0%) | 0·136 |
| DR | 297 (19·9%) | 277 (20·5%) | 20 (14·2%) | 0·077 |
| MDR | 865 (58·0%) | 768 (56·8%) | 97 (68·8%) | 0·007 |
| Non-susceptible toe | ||||
| Penicillins | 1024 (68·6%) | 918 (67·9%) | 106 (75·2%) | 0·086 |
| Penicillins/beta-lactamase inhibitors | 546 (36·6%) | 476 (35·2%) | 70 (49·6%) | 0·001 |
| 1st-generation cephalosporins | 987 (66·2%) | 885 (65·5%) | 102 (72·3%) | 0·112 |
| 3rd/4th-generation cephalosporins | 524 (35·1%) | 457 (33·8%) | 67 (47·5%) | 0·002 |
| Monobactams | 402 (26·9%) | 349 (25·8%) | 53 (37·6%) | 0·004 |
| Cephamycins | 77 (5·2%) | 69 (5·1%) | 8 (5·7%) | 0·692 |
| Carbapenems | 3 (0·2%) | 3 (0·2%) | 0 (0%) | 0·999 |
| Aminoglycosides | 463 (31·0%) | 409 (30·3%) | 54 (38·3%) | 0·056 |
| Fluoroquinolones | 590 (39·5%) | 521 (38·6%) | 69 (48·9%) | 0·019 |
| Sulfonamides | 494 (33·1%) | 445 (32·9%) | 49 (34·8%) | 0·707 |
| Glycylcyclines | 3 (0·2%) | 3 (0·2%) | 0 (0%) | >0·999 |
| Polymyxins | 3 (0·2%) | 3 (0·2%) | 0 (0%) | >0·999 |
| Resistance determinant | ||||
| CTX-M ESBL | 463 (31·0%) | 403 (29·8%) | 60 (42·6%) | 0·003 |
| Group 1 | 254 (17·0%) | 216 (16·0%) | 38 (27·0%) | 0·002 |
| Group 9 | 225 (15·1%) | 202 (15·0%) | 23 (16·3%) | 0·710 |
| Plasmid-mediated AmpC | 37 (2·5%) | 32 (2·4%) | 5 (3·5%) | 0·388 |
| Carbapenemase | 1 (0·1%) | 0 (0%) | 1 (0·7%) | 0·095 |
| Virulence determinants | ||||
| No· of virulence determinantsf (mean ± SD) | 3·3 ± 2·4 | 3·3 ± 2·4 | 3·9 ± 2·5 | 0·004 |
| Haemolysis | ||||
| hlyA, haemolysin A | 107 (7·2%) | 92 (6·8%) | 15 (1·1%) | 0·120 |
| hlyE, avian E. coli haemolysin | 52 (3·5%) | 45 (3·3%) | 7 (5·0%) | 0·329 |
| Toxins | ||||
| sat, serine protease autotransporter | 332 (22·3%) | 293 (21·7%) | 39 (27·7%) | 0·111 |
| vat, vacuolating autotransporter | 298 (20·0%) | 261 (19·3%) | 37 (26·2%) | 0·059 |
| astA, heat-stable enterotoxin | 34 (2·3%) | 29 (2·1%) | 5 (3·5%) | 0·245 |
| Siderophore | ||||
| ireA, siderophore receptor | 193 (12·9%) | 176 (13·0%) | 17 (12·1%) | 0·895 |
| iro, siderophore esterase | 184 (12·3%) | 165 (12·2%) | 19 (13·5%) | 0·686 |
| fyuA, yersiniabactin | 421 (28·2%) | 366 (27·1%) | 55 (39·0%) | 0·004 |
| iutA, ion uptake system | 120 (8·0%) | 105 (7·8%) | 15 (10·6%) | 0·253 |
| Cytotoxicity | ||||
| ETTT, type III secretion system | 295 (19·8%) | 268 (19·8%) | 27 (19·1%) | 0·912 |
| Colibactin, genotoxic metabolite | 240 (16·1%) | 215 (15·9%) | 25 (17·7%) | 0·549 |
| cnf1, cytotoxic necrotizing factor | 173 (11·6%) | 151 (11·2%) | 22 (15·6%) | 0·128 |
| Bacteriocin | ||||
| cvaC, colicin V | 82 (5·5%) | 78 (5·8%) | 4 (2·8%) | 0·175 |
| Serum resistance | ||||
| traT, outer membrane protein | 870 (58·3%) | 790 (58·5%) | 80 (56·7%) | 0·720 |
| Invasion | ||||
| afa, invasion protein | 80 (5·4%) | 66 (4·9%) | 14 (9·9%) | 0·017 |
| ibeA, brain microvascular endothelial cell invasion | 68 (4·6%) | 61 (4·5%) | 7 (5·0%) | 0·831 |
| ompT, outermembrane protease T | 263 (17·6%) | 238 (17·6%) | 25 (17·7%) | >0·999 |
| Encapsulation | ||||
| kpsMII, capsule synthesis | 142 (9·5%) | 123 (9·1%) | 19 (13·5%) | 0·097 |
| Adhesion | ||||
| papA, P fimbriae | 28 (1·9%) | 25 (1·9%) | 3 (2·1%) | 0·743 |
| sfa/foc, S fimbriae minor subunit | 108 (7·2%) | 92 (6·8%) | 16 (11·3%) | 0·059 |
| Others | ||||
| usp, uropathogenic protein | 681 (45·6%) | 601 (44·5%) | 80 (56·7%) | 0·006 |
| PAI, pathogenic island marker | 83 (5·6%) | 74 (5·5%) | 9 (6·4%) | 0·698 |
| pic, protease involved in intestinal colonization | 103 (6·9%) | 96 (7·1%) | 7 (5·0%) | 0·483 |
SD, standard deviation.
The percentage was calculated out of total number of E. coli blood isolates.
All-cause mortality within 30 days from the initial blood culture.
P value is either from Pearson's chi-square test for categorical data or from t-test for continuous data. Bonferroni corrected significance level was considered as P < 0.0009 and no variable was statistically significant.
Isolates categorized as XDR and PDR were not identified. DS, drug susceptible; DR, drug resistant; MDR, multi-drug resistant; XDR, extensively drug resistant; PDR, pan-drug resistant [21].
Ampicillin and piperacillin for penicillins; amoxicillin-sulbactam for penicillins/beta-lactamase inhibitors; cephazolin for 1st-generation cephalosporins; cefotaxime, ceftazidime, and cefepime for 3rd/4th-generation cephalosporins; cefoxitin for cephamycins; aztreonam for monobactam; imipenem, meropenem, and ertapenem for carbapenems; gentamicin and amikacin for aminoglycosides; ciprofloxacin for fluoroquinolone; trimethoprim-sulfamethoxazole for sulfonamides; tigecycline for glycylcyclines; colistin for polymyxins.
Number of identified virulence determinants among the 23 genes tested.