Identification and characterization of a uroepithelial cell adhesin from a uropathogenic isolate of Proteus mirabilis

Abstract

Proteus mirabilis is a frequent cause of urinary tract infections in rehabilitation hospitals and among persons with structural abnormalities of the urinary tract. Adherence to uroepithelial tissues may be an important virulence determinant in these infections because most Proteus strains adhere to desquamated uroepithelial cells. To identify the adherence factor responsible for this phenomenon, we sheared outer membrane material from 35S04-radiolabeled bacteria and allowed it to bind to uroepithelial cells. Following sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the major adherence element was a protein with an apparent molecular weight of 17,500 and was provisionally designated as the uroepithelial cell adhesin. This adhesin was purified by heat shock and gel filtration on Sepharose CL-4B. After purification, the adhesin was seen assembled as long, flexible rods by electron microscopy. The N-terminal amino acid sequence of the subunit had limited homology with that of the K99 fimbriae of Escherichia coli.

Fimbriae of uropathogenicProteus mirabilis

“…Fimbriae and adhesins of P. mirabilis UCA/NAF Wray et al (1986) isolated and identified UCA from an isolate of uropathogenic P. mirabilis. This fimbria was found to be organized as long and flexible rods, with a thin filament of 4 nm predominating.…”

Repression of motility during fimbrial expression: identification of 14 mrpJ gene paralogues in Proteus mirabilis

“…These swarmer cells also exhibit reduced expression of fimbriae (Mobley et al, 1996;Jansen et al, 2003), suggesting possible co-ordinate expression between flagella and fimbriae. Prior to the sequencing of the P. mirabilis genome, expression of five different fimbriae had been documented in P. mirabilis: MR/P fimbriae (Adegbola et al, 1983;Bahrani et al, 1994), uroepithelial cell adhesin (UCA, also known as non-agglutinating fimbriae or NAF) (Wray et al, 1986;Cook et al, 1995), P. mirabilis fimbriae (PMF) (Adegbola et al, 1983;Massad et al, 1994a), ambient temperature fimbriae (ATF) (Massad et al, 1994b) and P. mirabilis P-like pili (PMP) (Bijlsma et al, 1995). The MR/P fimbria is encoded by an operon containing nine genes (Bahrani et al, 1994).…”

Proteus mirabilisuroepithelial cell adhesin (UCA) fimbria plays a role in the colonization of the urinary tract

“…Uroepithelial cell adhesin was the first fimbriae identified in P. mirabilis (Wray et al, 1986). In this pioneer study, the authors proved the adhesive properties of the isolated fimbrial material.…”

“…Adherence to human uroepithelial cells was assessed according to the procedure described by Wray et al (1986). Pellets containing 2 9 10 5 uroepithelial cells, recovered after centrifugation of urine form three healthy female donors, were suspended in 1 mL of BSG containing 5 9 10 7 Pr 2921 and UM1 bacteria and incubated for 1 h at 37°C.…”