TABLE 1.

Distribution of virulence factors according to antimicrobial resistance phenotype among 85 E. coli urine isolates from phylogenetic group B2

Drug (no. susceptible, no. resistant)aVirulence factorbNo. (%) of isolates that were:cP valued
SusceptibleResistant
Nalidixic acid (64, 21) sfa/focDE 46 (72)7 (33)(0.0015)
bmaE 3 (5)5 (24)0.009
gafD 3 (5)5 (24)0.009
hlyD 42 (66)7 (33)(0.009)
cnf1 39 (61)7 (33)(0.02)
iutA 21 (33)15 (71)0.006
ireA 15 (23)11 (52)0.012
cvaC 10 (16)9 (43)0.009
iss 9 (14)14 (66)<0.001
Ampicillin (30, 55)K1 kpsM13 (43)7 (13)(0.001)
Cotrimoxazole (59, 26) bmaE 3 (5)5 (19)0.03
gafD 3 (5)5 (19)0.03
iroN 46 (78)10 (38)(<0.001)
malX 53 (89)19 (73)(0.047)
Gentamicin (81, 4) fimH 78 (96)3 (75)(0.04)
iutA 32 (39)4 (100)0.01
  • a Susceptibility and resistance are as defined by E-test.

  • b Only those virulence factors that yielded a P value of <0.05 are shown. sfa/focDE, S and F1C fimbriae; bmaE, M fimbriae; gafD, G fimbriae; fimH, type 1 fimbriae; hlyD, hemolysin; cnf1, cytotoxic necrotizing factor 1; iutA, aerobactin receptor; iroN and ireA, novel siderophore receptors; cvaC, colicin (microcin) V; iss, increased serum survival; K1 kpsM, group 2 capsule (variant K1); and malX, pathogenicity island marker. No statistically significant association with resistance was noted for the following virulence factors: papA, P fimbriae structural subunit; papC, P fimbriae assembly; papEF, P fimbriae tip pilis; papG, P fimbriae adhesin (and alleles II and III); sfaS, S fimbriae; focG, F1C fimbriae; afa/draBC, Dr-binding adhesins; iha, putative adhesin-siderophore; cdtB, cytolethal distending toxin; sat, secreted autotransporter toxin; fyuA, yersiniabactin receptor; kpsM II, group 2 capsule (variant K2); kpsMT III, group 3 capsule; rfc, O4 lipopolysaccharide; ibeA, invasion of brain endothelium; ompT, outer membrane protease T; and fliC, flagellin.

  • c Numbers of isolates that were susceptible or resistant to drugs in column 1 are shown. Comparison groups varied by drug.

  • d P values (by Fisher's exact test or χ2 test) are for comparisons of isolates susceptible and resistant to the indicated drug. Parentheses indicate negative associations of virulence factor with resistance.