Family of Escherichia coli Dr Adhesins: Decay‐Accelerating Factor Receptor Recognition and Invasiveness (original) (raw)
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Infection and Immunity
Earlier studies on the binding of Escherichia coli adhesins to the human urinary tract have indicated that the ability to recognize binding sites on the urinary tract epithelial cells is not a characteristic for P fimbriae only, but is also shared by some other adhesins that are not associated with pyelonephritis, especially S fimbriae. In the present study we have investigated whether human urine contains inhibitors of the binding of E. coli adhesins. Normal human urine was found to inhibit hemagglutination by S and type 1 fimbriae but not P fimbriae. The major inhibitor of S fimbriae in normal urine was identified as Tamm-Horsfall glycoprotein, and the interaction with S fimbriae is probably mediated by its sialyloligosaccharide chains. No significant variation was observed in the inhibitory effect of T-H glycoprotein preparations originating from different individuals. In contrast to S fimbriae, the major inhibitors of type 1 fimbriae in urine were identified as low-molecularweight compounds. Gel filtration and ion-exchange chromatography and ax-mannosidase treatment indicated that they were neutral a-mannosides, probably manno-oligosaccharides with three to five saccharides. Studies of urine samples collected from several individuals indicated the common occurrence of these inhibitory a-mannosides. Type 1 fimbriae bound to immobilized T-H glycoprotein, but, unlike S fimbriae, their binding was poorly inhibited by soluble T-H glycoprotein. Some urine samples were also found to contain lowmolecular-weight inhibitors for the 075X adhesin of E. coli. These results emphasize that to function as a virulence factor in human urinary tract infections, an adhesin must evidently recognize such receptor structures at the infection sites that are not excreted in soluble form in urine. This prerequisite is filled by P fimbriae but not by type 1 or S fimbriae.
FEMS Microbiology Letters, 1994
We have recently demonstrated that cultured human intestinal HT-29 and Caco-2 cell lines express receptors for the F1845 fimbrial adhesin harbored by the diarrheagenic C1845 Escherichia coli (Kernéis et al., Infect. Immun. 59 (1991) 4013-4018). This adhesin belongs to a family of adhesins including the Dr hemagglutinin and the afimbrial adhesin AFA-I harbored by uropathogenic E. coli. Here we investigated the cell association of laboratory E. coli strains expressing the Dr hemagglutinin and the afimbrial adhesin AFA-I with human cultured enterocyte-like or mucosecreting cells. We observed that the E. coli strains bearing these adhesins adhere both to human intestinal undifferentiated and differentiated fluid-transporting cells, and to mucus-secreting cells. This result strongly suggests a high capacity of intestinal colonization for the uropathogenic E. coli harboring adhesive factors belonging to the Dr adhesin family. These results further corroborate the intestinal colonization by uropathogenic E. coli of the Dr family related to the fecal-perineal-urethral hypothesis of urinary tract infection pathogenesis.
Infection and immunity, 1997
Bacterial adhesins play an important role in the colonization of the human urogenital tract. Escherichia coli Dr family adhesins have been found to be frequently expressed in strains associated with pyelonephritis in pregnant females. The tissue receptor for known Dr adhesins has been localized to the short consensus repeat-3 (SCR-3) domain of decay accelerating factor (DAF), a complement regulatory protein. In this report, we identified and cloned draE2, a gene encoding a novel 17-kDa DAF-binding adhesin, Dr-II, from a strain of E. coli associated with acute gestational pyelonephritis. Despite the significant sequence diversity between Dr-II and Dr family adhesins, the receptor of Dr-II was found to be the SCR-3 domain of DAF. Sequence analysis of the 186-amino-acid Dr-II open reading frame revealed significant diversity from other members of the Dr adhesin family, including Dr, AFA-I, AFA-III, and F1845, but only an 8-amino-acid difference in sequence from that of the 17-kDa nonfi...
Infection and immunity, 1997
The Dr family of related adherence structures, some fimbriated and others afimbriated, bind to decay-accelerating factor molecules on human cells. Dr is associated with recurring urinary tract infection (UTI), but the distribution of Dr subtypes among uropathogenic Escherichia coli causing UTI among otherwise healthy women has yet to be described. A total of 787 UTI and fecal E. coli isolates from college women were screened for the presence of Dr sequences (drb). Fifteen percent of UTI strains were drb positive, compared to 5% of fecal strains. The adhesin (E gene) subtype of each drb-positive strain was determined by type-specific PCR followed by restriction enzyme analysis. Among 78 drb-positive strains, we found 14 (18%) afaE1, 1 (1.3%) afaE2, 1 (1.3%) afaE3, 9 (12%) draE, 9 (12%) draE-afaE3 hybrid, 1 (1.3%) daaE, 32 (41%) afaE5, 4 (5.1%) F131 E gene-like, and 7 untypeable strains. All untypeable E genes were cloned and sequenced, revealing four additional new classes of E genes...
International Journal of Advanced Research (IJAR), 2019
Background: UropathogenicEscherichia coli (UPEC), possess different adhesin factors for binding the cells of urinary tract, afimbrialadhesin coded by the gene afa is one among the adhesin factors belonging to Dradhesin family. afa facilitates the colonization by binding to the receptor on the Dr blood group antigen, it stimulates the cytopathic effect and various signal cascade reactions. This adhesin accounts for chronic and recurrence in UTI. Aim & Objective: The aim of the study is to determine the prevalence of afa gene by using molecular method PCR. Materials & Methods: Bacteria isolated from urine samples were processed and confirmed for E. coli using standard bacteriological methods. DNA extraction done followed by PCR amplication were processed for detection of afa genes using specific primer and the specific base pair bands were noted using gel documentation. Results:The afa gene was found in 49 isolates (23.1%) of UPEC out of 212 isolates, which were distributed among male patients 19(38.8%) and 30 (61.2%) in female patients with more prevalence among less than 20 years of age group. Conclusion:afa, though a low frequency gene in UPEC showed high percentage in this study comparing the other geographical areas out of its low frequency.
Binding characteristics of Escherichia coli adhesins in human urinary bladder
Infection and Immunity
We studied domains in the human bladder that acted as receptors for Escherichia coli P, S, type 1, type 1C, and O75X fimbriae or adhesin and domains in the human kidneys that were receptors for E. coli type 1C fimbriae. Binding sites in frozen tissue sections were localized by direct staining with fluorochrome-labeled recombinant strains and by indirect immunofluorescence with the purified adhesins. In the bladder, the P and S fimbriae showed closely similar binding to the epithelial and muscular layers, and the S fimbriae also bound to the connective tissue elements. Type 1 fimbriae bound to vascular walls and to muscle cells, whereas the O75X adhesin bound avidly to connective tissue elements and to some extent to epithelial and muscle cells of the bladder. The type 1C fimbriae bound to distal tubules and collecting ducts of the kidney and to vascular endothelial cells in both the kidney and bladder. The binding of all adhesin types was inhibited by specific receptor analogs or Fa...
Cell, 2001
is mediated by adhesins on the surface of the microbe and Molecular Biophysics interacting with receptors displayed on the surface of Washington University School of Medicine the host cell. In pyelonephritic E. coli, the adhesin PapG Saint Louis, Missouri 63110 binds to a Gal␣1-4Gal containing glycolipid on the sur-3 Lund University face of human kidney epithelial cells (Leffler and Svan-Sweden borg-Eden, 1980; Lund et al., 1987). This interaction allows the bacteria to gain a foothold on the tissue and resist being displaced by the mechanical and physical Summary forces in the kidney. The PapG adhesin is assembled into adhesive hair-PapG is the adhesin at the tip of the P pilus that medilike fibers called P pili via the chaperone/usher pathway ates attachment of uropathogenic Escherichia coli to (Sauer et al., 2000; Soto and Hultgren, 1999; Thanassi the uroepithelium of the human kidney. The human and Hultgren, 2000). This pathway is used by diverse specific allele of PapG binds to globoside (GbO4), pathogenic gram-negative bacteria for the assembly of which consists of the tetrasaccharide GalNAc1over 30 different adhesins that are associated with host 3Gal␣1-4Gal1-4Glc linked to ceramide. Here, we and tissue tropism (or selectivity) in a wide variety of present the crystal structures of a binary complex of diseases. P pili are composite fibers consisting of a thin the PapG receptor binding domain bound to GbO4 as tip structure called a tip fibrillum that is joined to the well as the unbound form of the adhesin. The biological distal end of a thicker structure called the pilus rod importance of each of the residues involved in binding (Kuehn et al., 1992). P pilus rods are 68 Å in diameter was investigated by site-directed mutagenesis. These and are comprised of repeating PapA subunits arranged studies provide a molecular snapshot of a host-pathoin a right-handed helical cylinder consisting of 3.28 subgen interaction that determines the tropism of urounits per turn (Bullitt and Makowski, 1995). The tip fibrilpathogenic E. coli for the human kidney and is critical lum of the P pilus is 02ف Å in diameter and is comprised to the pathogenesis of pyelonephritis. mostly of repeating PapE subunits arranged in an open helical configuration. The PapG adhesin is joined to the Introduction distal end of the fibrillum via the PapF adaptor and the fibrillum is joined to the rod by the PapK adaptor (Jacob-Urinary tract infections (UTI) are one of the most preva-Dubuisson et al., 1993). All of the pilin subunits share a lent infectious diseases, second only to infections of the great deal of homology. The recent crystal structures of respiratory tract, with 8 million physician visits per year chaperone-subunit complexes revealed that pilin doand 1.5