Affiliation:
1. Mucosal and Vaccine Research Center
2. Medicine
3. Geriatric Research, Education, and Clinical Center, VA Medical Center, Minneapolis, Minnesota, and Departments of
4. Psychiatry, University of Minnesota, Minneapolis, Minnesota
Abstract
ABSTRACT
Characteristics differentiating
Escherichia coli
strains that cause cystitis or pyelonephritis from fecal
E. coli
remain incompletely defined, particularly among adult women in the United States. Accordingly, phylogenetic group, O antigens, and virulence factors (VFs) were analyzed among 329
E. coli
isolates from the mid-to-late 1990s from women in the United States with acute pyelonephritis (
n
= 170), cystitis (
n
= 83), or no infection (fecal;
n
= 76). Compared with fecal and cystitis isolates, pyelonephritis isolates exhibited a greater prevalence of phylogenetic group B2, most virulence-associated O antigens, and most VFs and had higher VF scores. In contrast, cystitis and fecal isolates differed minimally. By stepwise multivariable logistic regression, significant (
P
≤ 0.015) predictors of cystitis and/or pyelonephritis (versus fecal) included
afa/dra
(Dr-binding adhesins),
ibeA
(invasion of brain endothelium),
iha
(putative adhesin-siderophore),
malX
(pathogenicity island marker), the O75 antigen,
papEF
(P fimbriae),
papG
allele II (P adhesin variant), group B2, and
sfa
/
foc
(S and F1C fimbriae). However, virulence profiles overlapped considerably among source groups and varied greatly within each group.
E. coli
“clonal group A” (CGA) and the O2:K5/K7:H1 and O75:K+ clonal groups were significantly associated with cystitis and/or pyelonephritis. These findings identify potential vaccine targets, suggest that urovirulence is multiply determined, and confirm the urovirulence of specific
E. coli
clonal groups, including recently recognized CGA.
Publisher
American Society for Microbiology