UropathogenicEscherichia coliAL511 requires flagellum to enter renal collecting duct cells

Abstract

SummaryEscherichia coli is the leading cause of urinary tract infections, but the mechanisms governing renal colonization by this bacterium remain poorly understood. We investigated the ability of 13 E. coli strains isolated from the urine of patients with pyelonephritis and cystitis and normal stools to invade collecting duct cells, which constitute the first epithelium encountered by bacteria ascending from the bladder. The AL511 clinical isolate adhered to mouse collecting duct mpkCCD cl4 cells, used as a model of renal cell invasion, and was able to enter and persist within these cells. Previous studies have shown that bacterial flagella play an important role in host urinary tract colonization, but the role of flagella in the interaction of E. coli with renal epithelial cells remains unclear. An analysis of the ability of E. coli AL511 mutants to invade renal cells showed that flagellin played a key role in bacterial entry. Both flagellum filament assembly and the motor proteins MotA and MotB appeared to be required for E. coli AL511 uptake into collecting duct cells. These findings indicate that pyelonephritis-associated E. coli strains may invade renal collecting duct cells and that flagellin may act as an invasin in this process.

The Flagella of an Atypical Enteropathogenic Escherichia coli Strain Are Required for Efficient Interaction with and Stimulation of Interleukin-8 Production by Enterocytes In Vitro

“…Similarly, the ability of E. coli O83:H1 to adhere to and invade Caco-2BBe or T84 monolayers was shown to be dependent on these structures (8). Flagella have also been involved in the internalization of uropathogenic E. coli into collecting duct cells in vitro (30).…”

“…A ⌬fliC derivative of 1711-4 was constructed by the one-step allelic exchange recombination method as described earlier (5,6,30). Primers containing a 40-bp region homologous to the 5Ј (fliCH40.zeo-5) and 3Ј (fliCH40.zeo-3) extremities of the fliC gene and specific sequences for the Zeo resistance-encoding gene were used to amplify the Zeo cassette ( Table 2).…”

Real-Time Observation ofListeria monocytogenes-Phagocyte Interactions in Living Zebrafish Larvae

“…For standard ultrastructure analyses, dissected tail segments from anesthetized embryos were fixed overnight at 4°C in 2.5% glutaraldehyde in 0.1 M Na cacodylate buffer, postfixed for 1 h in the same buffer containing 1% osmium tetroxide, dehydrated through a graded series of ethanol, and then embedded in an Epon-Araldite resin (33). Thin sections (50 to 70 nm) were cut using a Leica Ultracut-ECT microtome, stained for 4 min with 4% uranyl acetate, and observed under a Jeol (Croissy sur Seine, France) Jem 1010 transmission electron microscope at 80 kV.…”

The fimbriae activator MatA switches off motility in Escherichia coli by repression of the flagellar master operon flhDC

“…Competitive in vivo experiments in mice have demonstrated that flagella contribute to the fitness of UPEC during colonization of the UT (Lane et al, 2005;Wright et al, 2005), and transient expression of flagella enhances bacterial ascent from the bladder to the kidneys (Lane et al, 2007b). In the kidneys, motility as well as the flagellar filament itself are apparently required for bacterial invasion into cells of renal collecting ducts (Pichon et al, 2009), which also are targets for fimbriae-mediated adherence of UPEC (Korhonen et al, 1986). For newborn meningitis-associated E. coli (NMEC), which represents another extraintestinal E. coli pathogroup, the flagellar structure rather than the motility function has been shown to be relevant for bacterial association with and invasion into human brain microvascular endothelial cells (Parthasarathy et al, 2007).…”