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).

EPR spectra at 94.5 GHz (3 mm) and 249.9 GHz (1 mm) have been measured for the dichloro-, dibromo-, and diiodobis(triphenylphosphine oxide)manganese(II) complexes. These compounds have a distorted tetrahedral geometry, and the highest possible symmetry obtainable is C 2 v . Because the spectra are taken in the high-field limit, they are simple and much easier to interpret than at lower magnetic fields. Accurate values of the zero-field splitting parameters, D and η (E/D), are determined by least-squares fitting and homotopy using matrix diagonalization. The compounds have g-values near 2 and large values of D and η. Across the series, D increases from 0.165 to 0.906 cm-1, while η decreases slightly from 0.273 to 0.246.