Table 5: Characterization of the 6 ETEC clonal groups based on MLST, serotype, classical and nonclassical virulence factors, and antibiotic pattern.

IsolateClassical virulence factorsa Non-classical virulence factorsClonal groupeSeqT groupfSerotype Antibiotic resistanceh
EnterotoxinsCSc
STbLT

COCt122+CFA/I, CS21eatA, irp2, fyuA, etpA, etpB 12332O128:H45AM, STX
COCt129+CFA/I, CS21eatA, irp2, fyuA, etpA, etpB 12332O128:H45AM, STX
COCt142+CFA/I, CS21eatA, irp2, fyuA, etpA, etpB 12332O128:H45AM, STX
COCt249+CFA/I, CS21eatA, irp2, fyuA, etpA, etpB 12332O128:H45AM, STX
COCt253+CFA/I, CS21eatA, irp2, fyuA, etpA, etpB 12332O128:H45AM, STX
COCt310+CFA/I, CS21eatA, irp2, fyuA, etpA, etpB 12332O128:H45AM, STX, CZ
COCt140cc+CFA/I, CS21eatA, irp2, fyuA, etpA, etpB 12332O128:H45AM, STX, AMC

COCt124++CS5, CS6eatA, tia 2443gO167:H5ND
COCt201++CS5, CS6eatA, tia 2443gO167:H5AM, STX
COCt235++CS5, CS6eatA, tia, irp2, fyuA 2443gO167:H5AM, STX
1COSc36++CS5, CS6eatA, tia 2443gO167:H5AM, STX

COCt 161+NDdirp2, fyuA 338O153:H18AM, STX, CZ
COCt 285+CFA/I, CS21eatA, irp2, fyuA, etpA, etpB 338O153:H18AM, STX

1COCt40+CS6, CS21eatA, irp2, fyuA 41312O25:H16AM, STX, CZ
1COSc61+CS6, CS21eatA, irp2, fyuA 41312O25:H16AM, STX, CZ

COCt200 + CS21, CFA/I eatA, irp2, fyuA, etpA, etpBirp2, fyuA 5 88 O128:H45 AM, STX
1COCt43 + CS18 5 88 O8:H9 AM, STX, CZ

COCt131 + CS7, CS21 eatA, tibA, irp2, fyuA, etpA, etpB 6 137 O78:H10 AM, STX
COCt337 + CS7 eatA, tibA, irp2, fyuA, etpA, etpB 6 137 O(−):H(−) AM, STX, CZ

ST, heat-stable toxin; heat-labile toxin.
bAll ETEC TS positives were positive for the STh variant.
cCS refers to colonization surface antigens.
dND: not detected.
eBased on phylogenetics (see Section 2).
fAs determined by EcMLST (http://mlst.ucc.ie/mlst/dbs/Ecoli).
gETEC strains with SeqT 443 that contain a single icd locus variant. The icd gene has 517/518 matches (mutation in T-229).
hResistance to AM, ampicillin; STX: sulfamethoxazole; CZ: cefazolin; AMC: amoxicillin /clavulanic acid.