Requirement of MrpH for mannose-resistant Proteus-like fimbria-mediated hemagglutination by Proteus mirabilis.
Requirement of MrpH for mannose-resistant Proteus-like fimbria-mediated hemagglutination by Proteus mirabilis.
复制标题
奇异变形杆菌对甘露糖抗性变形杆菌样菌毛介导的血凝作用需要 MrpH。
DOI：
10.1128/iai.67.6.2822-2833.1999
复制
发表时间：
1999
影响因子：
3.1
通讯作者：
Mobley,HL
中科院分区：
文献类型：
--
作者：
Li,X;Johnson,DE;Mobley,HL
Two new genes,mrpHandmrpJ, were identified downstream ofmrpGin themrpgene cluster encoding mannose-resistantProteus-like (MR/P) fimbriae of uropathogenicProteus mirabilis. Since the predicted MrpH has 30% amino acid sequence identity to PapG, the Galα(1-4)Gal-binding adhesin ofEscherichia coliP fimbriae, we hypothesized thatmrpHencodes the functional MR/P hemagglutinin. MR/P fimbriae, expressed inE. coliDH5α, conferred on bacteria both the ability to cause mannose-resistant hemagglutination and the ability to aggregate to form pellicles on the broth surface. Both a ΔmrpHmutant expressed inE. coliDH5α and an isogenicmrpH::aphAmutant ofP. mirabiliswere unable to produce normal MR/P fimbriae efficiently, suggesting that MrpH was involved in fimbrial assembly. Amino acid residue substitution of the N-terminal cysteine residues (C66S and C128S) of MrpH abolished the receptor-binding activity (hemagglutinating ability) of MrpH but allowed normal fimbrial assembly, supporting the notion that MrpH was the functional MR/P hemagglutinin. Immunogold electron microscopy ofP. mirabilisHI4320 revealed that MrpH was located at the tip of MR/P fimbriae, also consistent with its role in receptor binding. The isogenicmrpH::aphAmutant of HI4320 was less able to colonize the urine, bladder, and kidneys in a mouse model of ascending urinary tract infection (P< 0.01), and therefore MR/P fimbriae contribute significantly to bacterial colonization in mice. While there are similarities betweenP. mirabilisMR/P andE. coliP fimbriae, there are more notable differences: (i) synthesis of the MrpH adhesin is required to initiate fimbrial assembly, (ii) MR/P fimbriae confer an aggregation phenotype, (iii) site-directed mutation of specific residues can abolish receptor binding but allows fimbrial assembly, and (iv) mutation of the adhesin gene abolishes virulence in a mouse model of ascending urinary tract infection.
