Mannose-resistant adhesins of uropathogenic Escherichia coli (MR adhesins)

Mannose-resistant (MR) adhesins are a diverse class of surface-exposed proteins and fimbrial structures employed by uropathogenic Escherichia coli (UPEC) to colonize the human urinary tract (Wullt, 2003). Unlike mannose-sensitive adhesins, such as Type 1 fimbriae, MR adhesins bind to host cell receptors in a manner that is not inhibited by D-mannose. Key members of this group include P fimbriae, which bind to galabiose-containing glycolipids, and S fimbriae, which recognize sialic acid residues (Spaulding & Hultgren, 2016). The Dr family of adhesins is another significant group that targets decay-accelerating factor (DAF) on host cells. These molecules are essential for the pathogenesis of urinary tract infections (UTIs), particularly pyelonephritis, as they allow bacteria to resist the shearing forces of urine flow (Nielubowicz & Mobley, 2010). They also play a role in triggering host inflammatory responses and facilitating bacterial invasion into deeper tissues. Therapeutic strategies targeting MR adhesins include the development of pilicides, which are small molecules that inhibit the chaperone-usher pathway required for fimbriae assembly (Pinkner et al., 2006). Additionally, carbohydrate-based anti-adhesives are being developed to competitively block the binding sites of these adhesins. By neutralizing these virulence factors, researchers aim to provide alternatives to traditional antibiotics that reduce the risk of developing multi-drug resistance. These targets are particularly valuable for preventing recurrent UTIs and severe kidney infections.

Other names

Other mannose-resistant adhesinsP fimbriaeS fimbriaeDr adhesinsAfa/Dr adhesinsF1C fimbriaeNon-fimbrial adhesins (NFA)X-binding adhesinsPapGSfaSDraE

Inhibition of bacterial attachment to host uroepithelial cells and disruption of the chaperone-usher assembly pathway for fimbriae.