TABLE 1.

Bacterial traits significantly associated with blood source among 131 fecal or blood isolates of Escherichia coli from veteransa

Category and traitbPrevalence of trait (no. [%]) in isolates:P value (fecal vs blood isolates)Odds ratio (fecal vs blood isolates)95% Confidence intervalNegelkerke r2d
Total (n = 131)Fecal (n = 69)Blood (n = 62)
Adhesins
    papA, papC, papEF, or papG64 (49)21 (30)43 (69)<0.0015.172.46-10.890.19
    F10 papA allele26 (20)6 (9)20 (32)0.0015.01.85-13.490.12
    papG allele II42 (32)12 (17)30 (48)<0.0014.452.01-9.880.14
    sfa or focDE35 (27)11 (16)24 (39)0.0053.331.46-7.480.09
    focG17 (13)4 (6)13 (21)0.0174.311.32-14.040.07
    iha35 (27)10 (14)25 (40)0.0013.991.72-9.240.11
    hra42 (32)14 (20)28 (45)0.0053.121.44-6.750.09
Toxins
    hlyD39 (30)11 (16)28 (45)<0.0014.341.92-9.820.13
    cnf132 (24)9 (13)23 (37)0.0023.931.65-9.380.10
    sat37 (28)13 (19)24 (39)0.0192.671.21-5.900.06
    clbB and clbN58 (44)22 (32)36 (58)0.0032.961.45-6.050.09
    vat78 (60)34 (49)44 (71)0.0132.521.22-5.190.06
Siderophores
    iroN46 (35)18 (26)28 (45)0.0282.331.12-4.860.05
    fyuA91 (69)40 (56)51 (82)0.0043.361.50-7.540.09
    ireA25 (25)5 (7)20 (32)<0.0016.102.12-17.500.13
    iutA48 (37)14 (20)34 (55)<0.0014.772.21-10.310.16
Capsule kpsM II84 (64)34 (49)50 (81)<0.0014.291.95-9.420.14
Miscellaneous
    traT70 (53)30 (43)40 (65)0.022.361.17-4.780.06
    ompT66 (50)15 (22)51 (82)<0.00116.697.71-39.720.43
    malX80 (61)36 (52)44 (71)0.022.241.09-4.620.05
ExPEC (combination of above)c82 (63)31 (45)51 (82)<0.0015.682.54-12.720.19
Phylogenetic group B115 (11)13 (19)2 (3)0.0050.140.03-0.670.09
  • a A total of 36 genes or traits were detected in at least one isolate each but not yielding P < 0.05 (in comparisons of the percentage of positive isolates; newly detected traits shown in bold type): papA alleles F7-1 (5%), F7-2 (1.5%), F8 (<1%), F9 (<1%), F11 (14%), F12 (2%), F13 (5%), F14 (7%), F16 (3%); papG allele III, P-adhesin variant (15%); sfaS, S fimbriae (10%); afa and/or draBC, Dr-binding adhesins (5%); afaE8, afimbrial adhesin variant (1.5%); bmaE, M fimbriae (1.5%); F17 fimbriae, mannose-resistant adhesin (1.5%); clpG, mannose-resistant adhesin (<1%); tsh, temperature-sensitive hemagglutinin (4%); fimH, type 1 fimbriae (97%); hlyF, variant hemolysin (7%); cdtB, cytolethal distending toxin (5%); astA, enteroaggregative E. coli toxin (3%); pic, autotransporter protease (9%); K1, group 2 capsule variant (26%); K2, group 2 capsule variant (6%); kfiC, K5 group 2 capsule variant (11%); kpsM III, group 3 capsule (1.5%); rfc, O4 lipopolysaccharide (4%); cvaC, microcin V (6%); usp, uropathogen-specific protein (62%); ibeA, invasion of brain endothelium (14%); iss, increased serum survival (8%); H7 fliC, flagellin variant (18%); and phylogenetic group A (11%), phylogenetic group B2 (61%), and phylogenetic group D (16%). Five traits were sought but not detected (newly sought traits shown in bold type): F15 and F536 papA allele, papG allele I, gafD (G fimbriae), and K15 (group 2 capsule variant).

  • b The 25 individual traits shown are those that yielded P < 0.05 when the P values for fecal versus blood isolates were compared. Newly detected traits are shown in bold type. Definitions: papA, papC, papEF, and papG, P-fimbria structural subunit, assembly, tip pilins, and adhesin, respectively (all gave highly similar results; values shown are for papA); sfa and/or focDE, S and/or F1C fimbriae; focG, F1C fimbriae; iha, adhesin siderophore; hra, heat-resistant agglutinin; hlyD, alpha-hemolysin; cnf1, cytotoxic necrotizing factor 1; sat, secreted autotransporter toxin; clbB, colibactin (clbN gave identical results); vat, vacuolating toxin; iroN, salmochelin receptor; fyuA, yersiniabactin receptor; ireA, siderophore receptor; iutA, aerobactin receptor; kpsM II, group 2 capsule; traT, serum resistance associated; ompT, outer membrane protease; malX, pathogenicity island marker.

  • c ExPEC, extraintestinal pathogenic E. coli, which was operationally defined as the presence of at least two of the following genes: papA and/or papC, sfa and/or focDE, afa and/or draBC, iutA, and kpsM II.

  • d Negelkerke r2, fraction of variance (blood versus fecal) accounted for by the indicated trait.