Table 1.

Characteristics of E. coli isolates containing new variants of papG allele I (i.e., I′) versus comparator strains

Serogroup and strain(s)aThis studyHostbSerotypecPresence ofd:
papsfa/focsfaSfocGihafimhlycnf1cdtfyuAiroNiutAkpsMTrfctraTmalX
F typeACEFalleleIIIII
Serogroup O4
 J96HO4:K-:H513+++I, III+++++++++++
 CP9HO4:54:H5e13, 14+++I, III++++++++++
 C367-82+HO4:H57–2, 10+++I, II, III+++++++++++
 7U and 7R+DO4:H510+++I′, II, III+++++++++
 IA2HO4:K12:H−11, 16+++II+++++++++
 COR149HO4:H510, 15+++II+++++++++
Serogroup O6
 536HO6:K15:H31“536”+++III++++++++
 BOS050HO6:HU48+++III++++++++++
 L31+DO612, 15+++I′++++++++++
 R61HO6:H3112+++III++++++++
  • a Strains C367-82, 7U and 7R, and L31 (“This study”) contained variants of papG allele I that were not detected by published primers based on papG allele I from J96. Reference strains J96 and CP9, which are archetypal members of the J96-like clonal group of serogroup O4, and strain IA2, which is an archetypal non-J96-like O4 strain, were included for comparison with O4 isolates C367-82 and 7U-7R. Reference strain COR149 was included for comparison with strain L31 because of its F15 papA allele content and O4 antigen status (unpublished data). Reference strains 536, BOS050, and R61 were included since they resembled strain L31 with respect to virulence gene profile and O6 antigen expression.

  • b H, human; D, dog.

  • c Serotypes shown include only antigens for which the particular strains were tested. Hu, H untypeable.

  • d F type, papA allele (as determined by PCR). Allele, papG allele. (All strains also were positive for papG per se with flanking primers.)sfa/foc, central consensus regions of S fimbrial and F1C fimbrial operons; sfaS, S fimbrial adhesin; focG, F1C fimbrial adhesin; iha, novel putative adhesin-siderophore gene; fim, type 1 fimbriae;hly, hemolysin; cnf1, cytotoxic necrotizing factor; fyuA, yersiniabactin (siderophore); iroN, novel putative siderophore; iutA, aerobactin receptor;kpsMT, capsule synthesis (group II or III); rfc, O4 lipopolysaccharide synthesis; traT, serum resistance-associated gene; malX, marker for pathogenicity-associated island from strain CFT073 (28, 30). All strains were negative for afa/dra(Dr-binding adhesins), bmaE (M adhesins), gafD (G fimbriae), nfaE (nonfimbrial adhesins), cdtB(cytolethal distending toxin), the K1 variant of kpsMT II, and ibeA (invasion of brain endothelium) (30).

  • e Strain CP9 is serologically positive for K10, K54, and K96 antigens.