Previous Article | Next Article ![]()
Infect. Immun., 07 1997, 2812-2820, Vol 65, No. 7
JS Kao, DM Stucker, JW Warren and HL Mobley
Urinary tract infection is the most frequently diagnosed kidney and
urologic disease, and Escherichia coli is by far the most common etiologic
agent. Defined blocks of DNA termed pathogenicity islands have been found
in uropathogenic strains to carry genes not generally found in fecal
strains. We have identified one of these regions of DNA within the
chromosome of the highly virulent E. coli CFT073, isolated from the blood
and urine of a woman with acute pyelonephritis. This strain, which is
cytotoxic for cultured renal cells and causes acute pyelonephritis in
transurethrally infected CBA mice, contains two distinct copies of the pap
operon and is hemolytic. One pap operon was localized on a cosmid clone
which was used to identify three overlapping cosmid clones. By using
restriction mapping, DNA hybridization, sequencing, and PCR amplification,
a region of approximately 50 kb was found to be present in this
uropathogenic strain and to have no corresponding sequences in E. coli
K-12. This gene block also carries hemolysin genes hlyCABD. The
pathogenicity island begins 7 bp downstream of dadX (catabolic alanine
racemase; 26.55 min) and ends at a position in the K-12 genome 75 bp
downstream of the metV tRNA gene (62.74 min); this suggests that a
chromosomal rearrangement has occurred relative to the K-12 linkage map.
The junctions of the pathogenicity island were verified by PCR
amplification directly from the genomic DNA of strain CFT073. DNA
sequencing within the boundaries of the junctions revealed genes not
previously identified in E. coli or in some cases bearing no known
homologs. When used as probes for DNA hybridization, these sequences were
found significantly more often in strains associated with the clinical
syndromes of cystitis (82%) and acute pyelonephritis (79%) than in fecal
strains (19%; P < 0.001).
Copyright © 1997, American Society for Microbiology
Pathogenicity island sequences of pyelonephritogenic Escherichia coli CFT073 are associated with virulent uropathogenic strains
Division of Infectious Diseases, University of Maryland School of Medicine, Baltimore 21201, USA.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|